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Diffstat (limited to 'gcc/ada/gcc-interface/utils.c')
| -rw-r--r-- | gcc/ada/gcc-interface/utils.c | 4895 |
1 files changed, 4895 insertions, 0 deletions
diff --git a/gcc/ada/gcc-interface/utils.c b/gcc/ada/gcc-interface/utils.c new file mode 100644 index 0000000..4188d38 --- /dev/null +++ b/gcc/ada/gcc-interface/utils.c @@ -0,0 +1,4895 @@ +/**************************************************************************** + * * + * GNAT COMPILER COMPONENTS * + * * + * U T I L S * + * * + * C Implementation File * + * * + * Copyright (C) 1992-2008, Free Software Foundation, Inc. * + * * + * GNAT is free software; you can redistribute it and/or modify it under * + * terms of the GNU General Public License as published by the Free Soft- * + * ware Foundation; either version 3, or (at your option) any later ver- * + * sion. GNAT is distributed in the hope that it will be useful, but WITH- * + * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * + * for more details. You should have received a copy of the GNU General * + * Public License along with GCC; see the file COPYING3. If not see * + * <http://www.gnu.org/licenses/>. * + * * + * GNAT was originally developed by the GNAT team at New York University. * + * Extensive contributions were provided by Ada Core Technologies Inc. * + * * + ****************************************************************************/ + +/* We have attribute handlers using C specific format specifiers in warning + messages. Make sure they are properly recognized. */ +#define GCC_DIAG_STYLE __gcc_cdiag__ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "tree.h" +#include "flags.h" +#include "defaults.h" +#include "toplev.h" +#include "output.h" +#include "ggc.h" +#include "debug.h" +#include "convert.h" +#include "target.h" +#include "function.h" +#include "cgraph.h" +#include "tree-inline.h" +#include "tree-iterator.h" +#include "gimple.h" +#include "tree-dump.h" +#include "pointer-set.h" +#include "langhooks.h" + +#include "ada.h" +#include "types.h" +#include "atree.h" +#include "elists.h" +#include "namet.h" +#include "nlists.h" +#include "stringt.h" +#include "uintp.h" +#include "fe.h" +#include "sinfo.h" +#include "einfo.h" +#include "ada-tree.h" +#include "gigi.h" + +#ifndef MAX_FIXED_MODE_SIZE +#define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (DImode) +#endif + +#ifndef MAX_BITS_PER_WORD +#define MAX_BITS_PER_WORD BITS_PER_WORD +#endif + +/* If nonzero, pretend we are allocating at global level. */ +int force_global; + +/* Tree nodes for the various types and decls we create. */ +tree gnat_std_decls[(int) ADT_LAST]; + +/* Functions to call for each of the possible raise reasons. */ +tree gnat_raise_decls[(int) LAST_REASON_CODE + 1]; + +/* Forward declarations for handlers of attributes. */ +static tree handle_const_attribute (tree *, tree, tree, int, bool *); +static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *); +static tree handle_pure_attribute (tree *, tree, tree, int, bool *); +static tree handle_novops_attribute (tree *, tree, tree, int, bool *); +static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *); +static tree handle_sentinel_attribute (tree *, tree, tree, int, bool *); +static tree handle_noreturn_attribute (tree *, tree, tree, int, bool *); +static tree handle_malloc_attribute (tree *, tree, tree, int, bool *); +static tree handle_type_generic_attribute (tree *, tree, tree, int, bool *); + +/* Fake handler for attributes we don't properly support, typically because + they'd require dragging a lot of the common-c front-end circuitry. */ +static tree fake_attribute_handler (tree *, tree, tree, int, bool *); + +/* Table of machine-independent internal attributes for Ada. We support + this minimal set of attributes to accommodate the needs of builtins. */ +const struct attribute_spec gnat_internal_attribute_table[] = +{ + /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */ + { "const", 0, 0, true, false, false, handle_const_attribute }, + { "nothrow", 0, 0, true, false, false, handle_nothrow_attribute }, + { "pure", 0, 0, true, false, false, handle_pure_attribute }, + { "no vops", 0, 0, true, false, false, handle_novops_attribute }, + { "nonnull", 0, -1, false, true, true, handle_nonnull_attribute }, + { "sentinel", 0, 1, false, true, true, handle_sentinel_attribute }, + { "noreturn", 0, 0, true, false, false, handle_noreturn_attribute }, + { "malloc", 0, 0, true, false, false, handle_malloc_attribute }, + { "type generic", 0, 0, false, true, true, handle_type_generic_attribute }, + + /* ??? format and format_arg are heavy and not supported, which actually + prevents support for stdio builtins, which we however declare as part + of the common builtins.def contents. */ + { "format", 3, 3, false, true, true, fake_attribute_handler }, + { "format_arg", 1, 1, false, true, true, fake_attribute_handler }, + + { NULL, 0, 0, false, false, false, NULL } +}; + +/* Associates a GNAT tree node to a GCC tree node. It is used in + `save_gnu_tree', `get_gnu_tree' and `present_gnu_tree'. See documentation + of `save_gnu_tree' for more info. */ +static GTY((length ("max_gnat_nodes"))) tree *associate_gnat_to_gnu; + +#define GET_GNU_TREE(GNAT_ENTITY) \ + associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] + +#define SET_GNU_TREE(GNAT_ENTITY,VAL) \ + associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] = (VAL) + +#define PRESENT_GNU_TREE(GNAT_ENTITY) \ + (associate_gnat_to_gnu[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE) + +/* Associates a GNAT entity to a GCC tree node used as a dummy, if any. */ +static GTY((length ("max_gnat_nodes"))) tree *dummy_node_table; + +#define GET_DUMMY_NODE(GNAT_ENTITY) \ + dummy_node_table[(GNAT_ENTITY) - First_Node_Id] + +#define SET_DUMMY_NODE(GNAT_ENTITY,VAL) \ + dummy_node_table[(GNAT_ENTITY) - First_Node_Id] = (VAL) + +#define PRESENT_DUMMY_NODE(GNAT_ENTITY) \ + (dummy_node_table[(GNAT_ENTITY) - First_Node_Id] != NULL_TREE) + +/* This variable keeps a table for types for each precision so that we only + allocate each of them once. Signed and unsigned types are kept separate. + + Note that these types are only used when fold-const requests something + special. Perhaps we should NOT share these types; we'll see how it + goes later. */ +static GTY(()) tree signed_and_unsigned_types[2 * MAX_BITS_PER_WORD + 1][2]; + +/* Likewise for float types, but record these by mode. */ +static GTY(()) tree float_types[NUM_MACHINE_MODES]; + +/* For each binding contour we allocate a binding_level structure to indicate + the binding depth. */ + +struct gnat_binding_level GTY((chain_next ("%h.chain"))) +{ + /* The binding level containing this one (the enclosing binding level). */ + struct gnat_binding_level *chain; + /* The BLOCK node for this level. */ + tree block; + /* If nonzero, the setjmp buffer that needs to be updated for any + variable-sized definition within this context. */ + tree jmpbuf_decl; +}; + +/* The binding level currently in effect. */ +static GTY(()) struct gnat_binding_level *current_binding_level; + +/* A chain of gnat_binding_level structures awaiting reuse. */ +static GTY((deletable)) struct gnat_binding_level *free_binding_level; + +/* An array of global declarations. */ +static GTY(()) VEC(tree,gc) *global_decls; + +/* An array of builtin function declarations. */ +static GTY(()) VEC(tree,gc) *builtin_decls; + +/* An array of global renaming pointers. */ +static GTY(()) VEC(tree,gc) *global_renaming_pointers; + +/* A chain of unused BLOCK nodes. */ +static GTY((deletable)) tree free_block_chain; + +static void gnat_install_builtins (void); +static tree merge_sizes (tree, tree, tree, bool, bool); +static tree compute_related_constant (tree, tree); +static tree split_plus (tree, tree *); +static void gnat_gimplify_function (tree); +static tree float_type_for_precision (int, enum machine_mode); +static tree convert_to_fat_pointer (tree, tree); +static tree convert_to_thin_pointer (tree, tree); +static tree make_descriptor_field (const char *,tree, tree, tree); +static bool potential_alignment_gap (tree, tree, tree); + +/* Initialize the association of GNAT nodes to GCC trees. */ + +void +init_gnat_to_gnu (void) +{ + associate_gnat_to_gnu + = (tree *) ggc_alloc_cleared (max_gnat_nodes * sizeof (tree)); +} + +/* GNAT_ENTITY is a GNAT tree node for an entity. GNU_DECL is the GCC tree + which is to be associated with GNAT_ENTITY. Such GCC tree node is always + a ..._DECL node. If NO_CHECK is nonzero, the latter check is suppressed. + + If GNU_DECL is zero, a previous association is to be reset. */ + +void +save_gnu_tree (Entity_Id gnat_entity, tree gnu_decl, bool no_check) +{ + /* Check that GNAT_ENTITY is not already defined and that it is being set + to something which is a decl. Raise gigi 401 if not. Usually, this + means GNAT_ENTITY is defined twice, but occasionally is due to some + Gigi problem. */ + gcc_assert (!(gnu_decl + && (PRESENT_GNU_TREE (gnat_entity) + || (!no_check && !DECL_P (gnu_decl))))); + + SET_GNU_TREE (gnat_entity, gnu_decl); +} + +/* GNAT_ENTITY is a GNAT tree node for a defining identifier. + Return the ..._DECL node that was associated with it. If there is no tree + node associated with GNAT_ENTITY, abort. + + In some cases, such as delayed elaboration or expressions that need to + be elaborated only once, GNAT_ENTITY is really not an entity. */ + +tree +get_gnu_tree (Entity_Id gnat_entity) +{ + gcc_assert (PRESENT_GNU_TREE (gnat_entity)); + return GET_GNU_TREE (gnat_entity); +} + +/* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */ + +bool +present_gnu_tree (Entity_Id gnat_entity) +{ + return PRESENT_GNU_TREE (gnat_entity); +} + +/* Initialize the association of GNAT nodes to GCC trees as dummies. */ + +void +init_dummy_type (void) +{ + dummy_node_table + = (tree *) ggc_alloc_cleared (max_gnat_nodes * sizeof (tree)); +} + +/* Make a dummy type corresponding to GNAT_TYPE. */ + +tree +make_dummy_type (Entity_Id gnat_type) +{ + Entity_Id gnat_underlying = Gigi_Equivalent_Type (gnat_type); + tree gnu_type; + + /* If there is an equivalent type, get its underlying type. */ + if (Present (gnat_underlying)) + gnat_underlying = Underlying_Type (gnat_underlying); + + /* If there was no equivalent type (can only happen when just annotating + types) or underlying type, go back to the original type. */ + if (No (gnat_underlying)) + gnat_underlying = gnat_type; + + /* If it there already a dummy type, use that one. Else make one. */ + if (PRESENT_DUMMY_NODE (gnat_underlying)) + return GET_DUMMY_NODE (gnat_underlying); + + /* If this is a record, make a RECORD_TYPE or UNION_TYPE; else make + an ENUMERAL_TYPE. */ + gnu_type = make_node (Is_Record_Type (gnat_underlying) + ? tree_code_for_record_type (gnat_underlying) + : ENUMERAL_TYPE); + TYPE_NAME (gnu_type) = get_entity_name (gnat_type); + TYPE_DUMMY_P (gnu_type) = 1; + if (AGGREGATE_TYPE_P (gnu_type)) + { + TYPE_STUB_DECL (gnu_type) = build_decl (TYPE_DECL, NULL_TREE, gnu_type); + TYPE_BY_REFERENCE_P (gnu_type) = Is_By_Reference_Type (gnat_type); + } + + SET_DUMMY_NODE (gnat_underlying, gnu_type); + + return gnu_type; +} + +/* Return nonzero if we are currently in the global binding level. */ + +int +global_bindings_p (void) +{ + return ((force_global || !current_function_decl) ? -1 : 0); +} + +/* Enter a new binding level. */ + +void +gnat_pushlevel () +{ + struct gnat_binding_level *newlevel = NULL; + + /* Reuse a struct for this binding level, if there is one. */ + if (free_binding_level) + { + newlevel = free_binding_level; + free_binding_level = free_binding_level->chain; + } + else + newlevel + = (struct gnat_binding_level *) + ggc_alloc (sizeof (struct gnat_binding_level)); + + /* Use a free BLOCK, if any; otherwise, allocate one. */ + if (free_block_chain) + { + newlevel->block = free_block_chain; + free_block_chain = BLOCK_CHAIN (free_block_chain); + BLOCK_CHAIN (newlevel->block) = NULL_TREE; + } + else + newlevel->block = make_node (BLOCK); + + /* Point the BLOCK we just made to its parent. */ + if (current_binding_level) + BLOCK_SUPERCONTEXT (newlevel->block) = current_binding_level->block; + + BLOCK_VARS (newlevel->block) = BLOCK_SUBBLOCKS (newlevel->block) = NULL_TREE; + TREE_USED (newlevel->block) = 1; + + /* Add this level to the front of the chain (stack) of levels that are + active. */ + newlevel->chain = current_binding_level; + newlevel->jmpbuf_decl = NULL_TREE; + current_binding_level = newlevel; +} + +/* Set SUPERCONTEXT of the BLOCK for the current binding level to FNDECL + and point FNDECL to this BLOCK. */ + +void +set_current_block_context (tree fndecl) +{ + BLOCK_SUPERCONTEXT (current_binding_level->block) = fndecl; + DECL_INITIAL (fndecl) = current_binding_level->block; +} + +/* Set the jmpbuf_decl for the current binding level to DECL. */ + +void +set_block_jmpbuf_decl (tree decl) +{ + current_binding_level->jmpbuf_decl = decl; +} + +/* Get the jmpbuf_decl, if any, for the current binding level. */ + +tree +get_block_jmpbuf_decl () +{ + return current_binding_level->jmpbuf_decl; +} + +/* Exit a binding level. Set any BLOCK into the current code group. */ + +void +gnat_poplevel () +{ + struct gnat_binding_level *level = current_binding_level; + tree block = level->block; + + BLOCK_VARS (block) = nreverse (BLOCK_VARS (block)); + BLOCK_SUBBLOCKS (block) = nreverse (BLOCK_SUBBLOCKS (block)); + + /* If this is a function-level BLOCK don't do anything. Otherwise, if there + are no variables free the block and merge its subblocks into those of its + parent block. Otherwise, add it to the list of its parent. */ + if (TREE_CODE (BLOCK_SUPERCONTEXT (block)) == FUNCTION_DECL) + ; + else if (BLOCK_VARS (block) == NULL_TREE) + { + BLOCK_SUBBLOCKS (level->chain->block) + = chainon (BLOCK_SUBBLOCKS (block), + BLOCK_SUBBLOCKS (level->chain->block)); + BLOCK_CHAIN (block) = free_block_chain; + free_block_chain = block; + } + else + { + BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (level->chain->block); + BLOCK_SUBBLOCKS (level->chain->block) = block; + TREE_USED (block) = 1; + set_block_for_group (block); + } + + /* Free this binding structure. */ + current_binding_level = level->chain; + level->chain = free_binding_level; + free_binding_level = level; +} + + +/* Records a ..._DECL node DECL as belonging to the current lexical scope + and uses GNAT_NODE for location information and propagating flags. */ + +void +gnat_pushdecl (tree decl, Node_Id gnat_node) +{ + /* If this decl is public external or at toplevel, there is no context. + But PARM_DECLs always go in the level of its function. */ + if (TREE_CODE (decl) != PARM_DECL + && ((DECL_EXTERNAL (decl) && TREE_PUBLIC (decl)) + || global_bindings_p ())) + DECL_CONTEXT (decl) = 0; + else + { + DECL_CONTEXT (decl) = current_function_decl; + + /* Functions imported in another function are not really nested. */ + if (TREE_CODE (decl) == FUNCTION_DECL && TREE_PUBLIC (decl)) + DECL_NO_STATIC_CHAIN (decl) = 1; + } + + TREE_NO_WARNING (decl) = (gnat_node == Empty || Warnings_Off (gnat_node)); + + /* Set the location of DECL and emit a declaration for it. */ + if (Present (gnat_node)) + Sloc_to_locus (Sloc (gnat_node), &DECL_SOURCE_LOCATION (decl)); + add_decl_expr (decl, gnat_node); + + /* Put the declaration on the list. The list of declarations is in reverse + order. The list will be reversed later. Put global variables in the + globals list and builtin functions in a dedicated list to speed up + further lookups. Don't put TYPE_DECLs for UNCONSTRAINED_ARRAY_TYPE into + the list, as they will cause trouble with the debugger and aren't needed + anyway. */ + if (TREE_CODE (decl) != TYPE_DECL + || TREE_CODE (TREE_TYPE (decl)) != UNCONSTRAINED_ARRAY_TYPE) + { + if (global_bindings_p ()) + { + VEC_safe_push (tree, gc, global_decls, decl); + + if (TREE_CODE (decl) == FUNCTION_DECL && DECL_BUILT_IN (decl)) + VEC_safe_push (tree, gc, builtin_decls, decl); + } + else + { + TREE_CHAIN (decl) = BLOCK_VARS (current_binding_level->block); + BLOCK_VARS (current_binding_level->block) = decl; + } + } + + /* For the declaration of a type, set its name if it either is not already + set, was set to an IDENTIFIER_NODE, indicating an internal name, + or if the previous type name was not derived from a source name. + We'd rather have the type named with a real name and all the pointer + types to the same object have the same POINTER_TYPE node. Code in the + equivalent function of c-decl.c makes a copy of the type node here, but + that may cause us trouble with incomplete types. We make an exception + for fat pointer types because the compiler automatically builds them + for unconstrained array types and the debugger uses them to represent + both these and pointers to these. */ + if (TREE_CODE (decl) == TYPE_DECL && DECL_NAME (decl)) + { + tree t = TREE_TYPE (decl); + + if (!TYPE_NAME (t) || TREE_CODE (TYPE_NAME (t)) == IDENTIFIER_NODE) + ; + else if (TYPE_FAT_POINTER_P (t)) + { + tree tt = build_variant_type_copy (t); + TYPE_NAME (tt) = decl; + TREE_USED (tt) = TREE_USED (t); + TREE_TYPE (decl) = tt; + DECL_ORIGINAL_TYPE (decl) = t; + t = NULL_TREE; + } + else if (DECL_ARTIFICIAL (TYPE_NAME (t)) && !DECL_ARTIFICIAL (decl)) + ; + else + t = NULL_TREE; + + /* Propagate the name to all the variants. This is needed for + the type qualifiers machinery to work properly. */ + if (t) + for (t = TYPE_MAIN_VARIANT (t); t; t = TYPE_NEXT_VARIANT (t)) + TYPE_NAME (t) = decl; + } +} + +/* Do little here. Set up the standard declarations later after the + front end has been run. */ + +void +gnat_init_decl_processing (void) +{ + /* Make the binding_level structure for global names. */ + current_function_decl = 0; + current_binding_level = 0; + free_binding_level = 0; + gnat_pushlevel (); + + build_common_tree_nodes (true, true); + + /* In Ada, we use a signed type for SIZETYPE. Use the signed type + corresponding to the size of Pmode. In most cases when ptr_mode and + Pmode differ, C will use the width of ptr_mode as sizetype. But we get + far better code using the width of Pmode. Make this here since we need + this before we can expand the GNAT types. */ + size_type_node = gnat_type_for_size (GET_MODE_BITSIZE (Pmode), 0); + set_sizetype (size_type_node); + build_common_tree_nodes_2 (0); + + ptr_void_type_node = build_pointer_type (void_type_node); +} + +/* Create the predefined scalar types such as `integer_type_node' needed + in the gcc back-end and initialize the global binding level. */ + +void +init_gigi_decls (tree long_long_float_type, tree exception_type) +{ + tree endlink, decl; + unsigned int i; + + /* Set the types that GCC and Gigi use from the front end. We would like + to do this for char_type_node, but it needs to correspond to the C + char type. */ + if (TREE_CODE (TREE_TYPE (long_long_float_type)) == INTEGER_TYPE) + { + /* In this case, the builtin floating point types are VAX float, + so make up a type for use. */ + longest_float_type_node = make_node (REAL_TYPE); + TYPE_PRECISION (longest_float_type_node) = LONG_DOUBLE_TYPE_SIZE; + layout_type (longest_float_type_node); + create_type_decl (get_identifier ("longest float type"), + longest_float_type_node, NULL, false, true, Empty); + } + else + longest_float_type_node = TREE_TYPE (long_long_float_type); + + except_type_node = TREE_TYPE (exception_type); + + unsigned_type_node = gnat_type_for_size (INT_TYPE_SIZE, 1); + create_type_decl (get_identifier ("unsigned int"), unsigned_type_node, + NULL, false, true, Empty); + + void_type_decl_node = create_type_decl (get_identifier ("void"), + void_type_node, NULL, false, true, + Empty); + + void_ftype = build_function_type (void_type_node, NULL_TREE); + ptr_void_ftype = build_pointer_type (void_ftype); + + /* Build the special descriptor type and its null node if needed. */ + if (TARGET_VTABLE_USES_DESCRIPTORS) + { + tree field_list = NULL_TREE, null_list = NULL_TREE; + int j; + + fdesc_type_node = make_node (RECORD_TYPE); + + for (j = 0; j < TARGET_VTABLE_USES_DESCRIPTORS; j++) + { + tree field = create_field_decl (NULL_TREE, ptr_void_ftype, + fdesc_type_node, 0, 0, 0, 1); + TREE_CHAIN (field) = field_list; + field_list = field; + null_list = tree_cons (field, null_pointer_node, null_list); + } + + finish_record_type (fdesc_type_node, nreverse (field_list), 0, false); + null_fdesc_node = gnat_build_constructor (fdesc_type_node, null_list); + } + + /* Now declare runtime functions. */ + endlink = tree_cons (NULL_TREE, void_type_node, NULL_TREE); + + /* malloc is a function declaration tree for a function to allocate + memory. */ + malloc_decl = create_subprog_decl (get_identifier ("__gnat_malloc"), + NULL_TREE, + build_function_type (ptr_void_type_node, + tree_cons (NULL_TREE, + sizetype, + endlink)), + NULL_TREE, false, true, true, NULL, + Empty); + DECL_IS_MALLOC (malloc_decl) = 1; + + /* malloc32 is a function declaration tree for a function to allocate + 32bit memory on a 64bit system. Needed only on 64bit VMS. */ + malloc32_decl = create_subprog_decl (get_identifier ("__gnat_malloc32"), + NULL_TREE, + build_function_type (ptr_void_type_node, + tree_cons (NULL_TREE, + sizetype, + endlink)), + NULL_TREE, false, true, true, NULL, + Empty); + DECL_IS_MALLOC (malloc32_decl) = 1; + + /* free is a function declaration tree for a function to free memory. */ + free_decl + = create_subprog_decl (get_identifier ("__gnat_free"), NULL_TREE, + build_function_type (void_type_node, + tree_cons (NULL_TREE, + ptr_void_type_node, + endlink)), + NULL_TREE, false, true, true, NULL, Empty); + + /* Make the types and functions used for exception processing. */ + jmpbuf_type + = build_array_type (gnat_type_for_mode (Pmode, 0), + build_index_type (build_int_cst (NULL_TREE, 5))); + create_type_decl (get_identifier ("JMPBUF_T"), jmpbuf_type, NULL, + true, true, Empty); + jmpbuf_ptr_type = build_pointer_type (jmpbuf_type); + + /* Functions to get and set the jumpbuf pointer for the current thread. */ + get_jmpbuf_decl + = create_subprog_decl + (get_identifier ("system__soft_links__get_jmpbuf_address_soft"), + NULL_TREE, build_function_type (jmpbuf_ptr_type, NULL_TREE), + NULL_TREE, false, true, true, NULL, Empty); + /* Avoid creating superfluous edges to __builtin_setjmp receivers. */ + DECL_PURE_P (get_jmpbuf_decl) = 1; + + set_jmpbuf_decl + = create_subprog_decl + (get_identifier ("system__soft_links__set_jmpbuf_address_soft"), + NULL_TREE, + build_function_type (void_type_node, + tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)), + NULL_TREE, false, true, true, NULL, Empty); + + /* Function to get the current exception. */ + get_excptr_decl + = create_subprog_decl + (get_identifier ("system__soft_links__get_gnat_exception"), + NULL_TREE, + build_function_type (build_pointer_type (except_type_node), NULL_TREE), + NULL_TREE, false, true, true, NULL, Empty); + /* Avoid creating superfluous edges to __builtin_setjmp receivers. */ + DECL_PURE_P (get_excptr_decl) = 1; + + /* Functions that raise exceptions. */ + raise_nodefer_decl + = create_subprog_decl + (get_identifier ("__gnat_raise_nodefer_with_msg"), NULL_TREE, + build_function_type (void_type_node, + tree_cons (NULL_TREE, + build_pointer_type (except_type_node), + endlink)), + NULL_TREE, false, true, true, NULL, Empty); + + /* Dummy objects to materialize "others" and "all others" in the exception + tables. These are exported by a-exexpr.adb, so see this unit for the + types to use. */ + + others_decl + = create_var_decl (get_identifier ("OTHERS"), + get_identifier ("__gnat_others_value"), + integer_type_node, 0, 1, 0, 1, 1, 0, Empty); + + all_others_decl + = create_var_decl (get_identifier ("ALL_OTHERS"), + get_identifier ("__gnat_all_others_value"), + integer_type_node, 0, 1, 0, 1, 1, 0, Empty); + + /* Hooks to call when entering/leaving an exception handler. */ + begin_handler_decl + = create_subprog_decl (get_identifier ("__gnat_begin_handler"), NULL_TREE, + build_function_type (void_type_node, + tree_cons (NULL_TREE, + ptr_void_type_node, + endlink)), + NULL_TREE, false, true, true, NULL, Empty); + + end_handler_decl + = create_subprog_decl (get_identifier ("__gnat_end_handler"), NULL_TREE, + build_function_type (void_type_node, + tree_cons (NULL_TREE, + ptr_void_type_node, + endlink)), + NULL_TREE, false, true, true, NULL, Empty); + + /* If in no exception handlers mode, all raise statements are redirected to + __gnat_last_chance_handler. No need to redefine raise_nodefer_decl, since + this procedure will never be called in this mode. */ + if (No_Exception_Handlers_Set ()) + { + decl + = create_subprog_decl + (get_identifier ("__gnat_last_chance_handler"), NULL_TREE, + build_function_type (void_type_node, + tree_cons (NULL_TREE, + build_pointer_type (char_type_node), + tree_cons (NULL_TREE, + integer_type_node, + endlink))), + NULL_TREE, false, true, true, NULL, Empty); + + for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++) + gnat_raise_decls[i] = decl; + } + else + /* Otherwise, make one decl for each exception reason. */ + for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++) + { + char name[17]; + + sprintf (name, "__gnat_rcheck_%.2d", i); + gnat_raise_decls[i] + = create_subprog_decl + (get_identifier (name), NULL_TREE, + build_function_type (void_type_node, + tree_cons (NULL_TREE, + build_pointer_type + (char_type_node), + tree_cons (NULL_TREE, + integer_type_node, + endlink))), + NULL_TREE, false, true, true, NULL, Empty); + } + + /* Indicate that these never return. */ + TREE_THIS_VOLATILE (raise_nodefer_decl) = 1; + TREE_SIDE_EFFECTS (raise_nodefer_decl) = 1; + TREE_TYPE (raise_nodefer_decl) + = build_qualified_type (TREE_TYPE (raise_nodefer_decl), + TYPE_QUAL_VOLATILE); + + for (i = 0; i < ARRAY_SIZE (gnat_raise_decls); i++) + { + TREE_THIS_VOLATILE (gnat_raise_decls[i]) = 1; + TREE_SIDE_EFFECTS (gnat_raise_decls[i]) = 1; + TREE_TYPE (gnat_raise_decls[i]) + = build_qualified_type (TREE_TYPE (gnat_raise_decls[i]), + TYPE_QUAL_VOLATILE); + } + + /* setjmp returns an integer and has one operand, which is a pointer to + a jmpbuf. */ + setjmp_decl + = create_subprog_decl + (get_identifier ("__builtin_setjmp"), NULL_TREE, + build_function_type (integer_type_node, + tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)), + NULL_TREE, false, true, true, NULL, Empty); + + DECL_BUILT_IN_CLASS (setjmp_decl) = BUILT_IN_NORMAL; + DECL_FUNCTION_CODE (setjmp_decl) = BUILT_IN_SETJMP; + + /* update_setjmp_buf updates a setjmp buffer from the current stack pointer + address. */ + update_setjmp_buf_decl + = create_subprog_decl + (get_identifier ("__builtin_update_setjmp_buf"), NULL_TREE, + build_function_type (void_type_node, + tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)), + NULL_TREE, false, true, true, NULL, Empty); + + DECL_BUILT_IN_CLASS (update_setjmp_buf_decl) = BUILT_IN_NORMAL; + DECL_FUNCTION_CODE (update_setjmp_buf_decl) = BUILT_IN_UPDATE_SETJMP_BUF; + + main_identifier_node = get_identifier ("main"); + + /* Install the builtins we might need, either internally or as + user available facilities for Intrinsic imports. */ + gnat_install_builtins (); +} + +/* Given a record type RECORD_TYPE and a chain of FIELD_DECL nodes FIELDLIST, + finish constructing the record or union type. If REP_LEVEL is zero, this + record has no representation clause and so will be entirely laid out here. + If REP_LEVEL is one, this record has a representation clause and has been + laid out already; only set the sizes and alignment. If REP_LEVEL is two, + this record is derived from a parent record and thus inherits its layout; + only make a pass on the fields to finalize them. If DO_NOT_FINALIZE is + true, the record type is expected to be modified afterwards so it will + not be sent to the back-end for finalization. */ + +void +finish_record_type (tree record_type, tree fieldlist, int rep_level, + bool do_not_finalize) +{ + enum tree_code code = TREE_CODE (record_type); + tree name = TYPE_NAME (record_type); + tree ada_size = bitsize_zero_node; + tree size = bitsize_zero_node; + bool had_size = TYPE_SIZE (record_type) != 0; + bool had_size_unit = TYPE_SIZE_UNIT (record_type) != 0; + bool had_align = TYPE_ALIGN (record_type) != 0; + tree field; + + if (name && TREE_CODE (name) == TYPE_DECL) + name = DECL_NAME (name); + + TYPE_FIELDS (record_type) = fieldlist; + TYPE_STUB_DECL (record_type) = build_decl (TYPE_DECL, name, record_type); + + /* We don't need both the typedef name and the record name output in + the debugging information, since they are the same. */ + DECL_ARTIFICIAL (TYPE_STUB_DECL (record_type)) = 1; + + /* Globally initialize the record first. If this is a rep'ed record, + that just means some initializations; otherwise, layout the record. */ + if (rep_level > 0) + { + TYPE_ALIGN (record_type) = MAX (BITS_PER_UNIT, TYPE_ALIGN (record_type)); + TYPE_MODE (record_type) = BLKmode; + + if (!had_size_unit) + TYPE_SIZE_UNIT (record_type) = size_zero_node; + if (!had_size) + TYPE_SIZE (record_type) = bitsize_zero_node; + + /* For all-repped records with a size specified, lay the QUAL_UNION_TYPE + out just like a UNION_TYPE, since the size will be fixed. */ + else if (code == QUAL_UNION_TYPE) + code = UNION_TYPE; + } + else + { + /* Ensure there isn't a size already set. There can be in an error + case where there is a rep clause but all fields have errors and + no longer have a position. */ + TYPE_SIZE (record_type) = 0; + layout_type (record_type); + } + + /* At this point, the position and size of each field is known. It was + either set before entry by a rep clause, or by laying out the type above. + + We now run a pass over the fields (in reverse order for QUAL_UNION_TYPEs) + to compute the Ada size; the GCC size and alignment (for rep'ed records + that are not padding types); and the mode (for rep'ed records). We also + clear the DECL_BIT_FIELD indication for the cases we know have not been + handled yet, and adjust DECL_NONADDRESSABLE_P accordingly. */ + + if (code == QUAL_UNION_TYPE) + fieldlist = nreverse (fieldlist); + + for (field = fieldlist; field; field = TREE_CHAIN (field)) + { + tree type = TREE_TYPE (field); + tree pos = bit_position (field); + tree this_size = DECL_SIZE (field); + tree this_ada_size; + + if ((TREE_CODE (type) == RECORD_TYPE + || TREE_CODE (type) == UNION_TYPE + || TREE_CODE (type) == QUAL_UNION_TYPE) + && !TYPE_IS_FAT_POINTER_P (type) + && !TYPE_CONTAINS_TEMPLATE_P (type) + && TYPE_ADA_SIZE (type)) + this_ada_size = TYPE_ADA_SIZE (type); + else + this_ada_size = this_size; + + /* Clear DECL_BIT_FIELD for the cases layout_decl does not handle. */ + if (DECL_BIT_FIELD (field) + && operand_equal_p (this_size, TYPE_SIZE (type), 0)) + { + unsigned int align = TYPE_ALIGN (type); + + /* In the general case, type alignment is required. */ + if (value_factor_p (pos, align)) + { + /* The enclosing record type must be sufficiently aligned. + Otherwise, if no alignment was specified for it and it + has been laid out already, bump its alignment to the + desired one if this is compatible with its size. */ + if (TYPE_ALIGN (record_type) >= align) + { + DECL_ALIGN (field) = MAX (DECL_ALIGN (field), align); + DECL_BIT_FIELD (field) = 0; + } + else if (!had_align + && rep_level == 0 + && value_factor_p (TYPE_SIZE (record_type), align)) + { + TYPE_ALIGN (record_type) = align; + DECL_ALIGN (field) = MAX (DECL_ALIGN (field), align); + DECL_BIT_FIELD (field) = 0; + } + } + + /* In the non-strict alignment case, only byte alignment is. */ + if (!STRICT_ALIGNMENT + && DECL_BIT_FIELD (field) + && value_factor_p (pos, BITS_PER_UNIT)) + DECL_BIT_FIELD (field) = 0; + } + + /* If we still have DECL_BIT_FIELD set at this point, we know the field + is technically not addressable. Except that it can actually be + addressed if the field is BLKmode and happens to be properly + aligned. */ + DECL_NONADDRESSABLE_P (field) + |= DECL_BIT_FIELD (field) && DECL_MODE (field) != BLKmode; + + /* A type must be as aligned as its most aligned field that is not + a bit-field. But this is already enforced by layout_type. */ + if (rep_level > 0 && !DECL_BIT_FIELD (field)) + TYPE_ALIGN (record_type) + = MAX (TYPE_ALIGN (record_type), DECL_ALIGN (field)); + + switch (code) + { + case UNION_TYPE: + ada_size = size_binop (MAX_EXPR, ada_size, this_ada_size); + size = size_binop (MAX_EXPR, size, this_size); + break; + + case QUAL_UNION_TYPE: + ada_size + = fold_build3 (COND_EXPR, bitsizetype, DECL_QUALIFIER (field), + this_ada_size, ada_size); + size = fold_build3 (COND_EXPR, bitsizetype, DECL_QUALIFIER (field), + this_size, size); + break; + + case RECORD_TYPE: + /* Since we know here that all fields are sorted in order of + increasing bit position, the size of the record is one + higher than the ending bit of the last field processed + unless we have a rep clause, since in that case we might + have a field outside a QUAL_UNION_TYPE that has a higher ending + position. So use a MAX in that case. Also, if this field is a + QUAL_UNION_TYPE, we need to take into account the previous size in + the case of empty variants. */ + ada_size + = merge_sizes (ada_size, pos, this_ada_size, + TREE_CODE (type) == QUAL_UNION_TYPE, rep_level > 0); + size + = merge_sizes (size, pos, this_size, + TREE_CODE (type) == QUAL_UNION_TYPE, rep_level > 0); + break; + + default: + gcc_unreachable (); + } + } + + if (code == QUAL_UNION_TYPE) + nreverse (fieldlist); + + if (rep_level < 2) + { + /* If this is a padding record, we never want to make the size smaller + than what was specified in it, if any. */ + if (TREE_CODE (record_type) == RECORD_TYPE + && TYPE_IS_PADDING_P (record_type) && TYPE_SIZE (record_type)) + size = TYPE_SIZE (record_type); + + /* Now set any of the values we've just computed that apply. */ + if (!TYPE_IS_FAT_POINTER_P (record_type) + && !TYPE_CONTAINS_TEMPLATE_P (record_type)) + SET_TYPE_ADA_SIZE (record_type, ada_size); + + if (rep_level > 0) + { + tree size_unit = had_size_unit + ? TYPE_SIZE_UNIT (record_type) + : convert (sizetype, + size_binop (CEIL_DIV_EXPR, size, + bitsize_unit_node)); + unsigned int align = TYPE_ALIGN (record_type); + + TYPE_SIZE (record_type) = variable_size (round_up (size, align)); + TYPE_SIZE_UNIT (record_type) + = variable_size (round_up (size_unit, align / BITS_PER_UNIT)); + + compute_record_mode (record_type); + } + } + + if (!do_not_finalize) + rest_of_record_type_compilation (record_type); +} + +/* Wrap up compilation of RECORD_TYPE, i.e. most notably output all + the debug information associated with it. It need not be invoked + directly in most cases since finish_record_type takes care of doing + so, unless explicitly requested not to through DO_NOT_FINALIZE. */ + +void +rest_of_record_type_compilation (tree record_type) +{ + tree fieldlist = TYPE_FIELDS (record_type); + tree field; + enum tree_code code = TREE_CODE (record_type); + bool var_size = false; + + for (field = fieldlist; field; field = TREE_CHAIN (field)) + { + /* We need to make an XVE/XVU record if any field has variable size, + whether or not the record does. For example, if we have a union, + it may be that all fields, rounded up to the alignment, have the + same size, in which case we'll use that size. But the debug + output routines (except Dwarf2) won't be able to output the fields, + so we need to make the special record. */ + if (TREE_CODE (DECL_SIZE (field)) != INTEGER_CST + /* If a field has a non-constant qualifier, the record will have + variable size too. */ + || (code == QUAL_UNION_TYPE + && TREE_CODE (DECL_QUALIFIER (field)) != INTEGER_CST)) + { + var_size = true; + break; + } + } + + /* If this record is of variable size, rename it so that the + debugger knows it is and make a new, parallel, record + that tells the debugger how the record is laid out. See + exp_dbug.ads. But don't do this for records that are padding + since they confuse GDB. */ + if (var_size + && !(TREE_CODE (record_type) == RECORD_TYPE + && TYPE_IS_PADDING_P (record_type))) + { + tree new_record_type + = make_node (TREE_CODE (record_type) == QUAL_UNION_TYPE + ? UNION_TYPE : TREE_CODE (record_type)); + tree orig_name = TYPE_NAME (record_type); + tree orig_id + = (TREE_CODE (orig_name) == TYPE_DECL ? DECL_NAME (orig_name) + : orig_name); + tree new_id + = concat_id_with_name (orig_id, + TREE_CODE (record_type) == QUAL_UNION_TYPE + ? "XVU" : "XVE"); + tree last_pos = bitsize_zero_node; + tree old_field; + tree prev_old_field = 0; + + TYPE_NAME (new_record_type) = new_id; + TYPE_ALIGN (new_record_type) = BIGGEST_ALIGNMENT; + TYPE_STUB_DECL (new_record_type) + = build_decl (TYPE_DECL, new_id, new_record_type); + DECL_ARTIFICIAL (TYPE_STUB_DECL (new_record_type)) = 1; + DECL_IGNORED_P (TYPE_STUB_DECL (new_record_type)) + = DECL_IGNORED_P (TYPE_STUB_DECL (record_type)); + TYPE_SIZE (new_record_type) = size_int (TYPE_ALIGN (record_type)); + TYPE_SIZE_UNIT (new_record_type) + = size_int (TYPE_ALIGN (record_type) / BITS_PER_UNIT); + + add_parallel_type (TYPE_STUB_DECL (record_type), new_record_type); + + /* Now scan all the fields, replacing each field with a new + field corresponding to the new encoding. */ + for (old_field = TYPE_FIELDS (record_type); old_field; + old_field = TREE_CHAIN (old_field)) + { + tree field_type = TREE_TYPE (old_field); + tree field_name = DECL_NAME (old_field); + tree new_field; + tree curpos = bit_position (old_field); + bool var = false; + unsigned int align = 0; + tree pos; + + /* See how the position was modified from the last position. + + There are two basic cases we support: a value was added + to the last position or the last position was rounded to + a boundary and they something was added. Check for the + first case first. If not, see if there is any evidence + of rounding. If so, round the last position and try + again. + + If this is a union, the position can be taken as zero. */ + + /* Some computations depend on the shape of the position expression, + so strip conversions to make sure it's exposed. */ + curpos = remove_conversions (curpos, true); + + if (TREE_CODE (new_record_type) == UNION_TYPE) + pos = bitsize_zero_node, align = 0; + else + pos = compute_related_constant (curpos, last_pos); + + if (!pos && TREE_CODE (curpos) == MULT_EXPR + && host_integerp (TREE_OPERAND (curpos, 1), 1)) + { + tree offset = TREE_OPERAND (curpos, 0); + align = tree_low_cst (TREE_OPERAND (curpos, 1), 1); + + /* An offset which is a bitwise AND with a negative power of 2 + means an alignment corresponding to this power of 2. */ + offset = remove_conversions (offset, true); + if (TREE_CODE (offset) == BIT_AND_EXPR + && host_integerp (TREE_OPERAND (offset, 1), 0) + && tree_int_cst_sgn (TREE_OPERAND (offset, 1)) < 0) + { + unsigned int pow + = - tree_low_cst (TREE_OPERAND (offset, 1), 0); + if (exact_log2 (pow) > 0) + align *= pow; + } + + pos = compute_related_constant (curpos, + round_up (last_pos, align)); + } + else if (!pos && TREE_CODE (curpos) == PLUS_EXPR + && TREE_CODE (TREE_OPERAND (curpos, 1)) == INTEGER_CST + && TREE_CODE (TREE_OPERAND (curpos, 0)) == MULT_EXPR + && host_integerp (TREE_OPERAND + (TREE_OPERAND (curpos, 0), 1), + 1)) + { + align + = tree_low_cst + (TREE_OPERAND (TREE_OPERAND (curpos, 0), 1), 1); + pos = compute_related_constant (curpos, + round_up (last_pos, align)); + } + else if (potential_alignment_gap (prev_old_field, old_field, + pos)) + { + align = TYPE_ALIGN (field_type); + pos = compute_related_constant (curpos, + round_up (last_pos, align)); + } + + /* If we can't compute a position, set it to zero. + + ??? We really should abort here, but it's too much work + to get this correct for all cases. */ + + if (!pos) + pos = bitsize_zero_node; + + /* See if this type is variable-sized and make a pointer type + and indicate the indirection if so. Beware that the debug + back-end may adjust the position computed above according + to the alignment of the field type, i.e. the pointer type + in this case, if we don't preventively counter that. */ + if (TREE_CODE (DECL_SIZE (old_field)) != INTEGER_CST) + { + field_type = build_pointer_type (field_type); + if (align != 0 && TYPE_ALIGN (field_type) > align) + { + field_type = copy_node (field_type); + TYPE_ALIGN (field_type) = align; + } + var = true; + } + + /* Make a new field name, if necessary. */ + if (var || align != 0) + { + char suffix[16]; + + if (align != 0) + sprintf (suffix, "XV%c%u", var ? 'L' : 'A', + align / BITS_PER_UNIT); + else + strcpy (suffix, "XVL"); + + field_name = concat_id_with_name (field_name, suffix); + } + + new_field = create_field_decl (field_name, field_type, + new_record_type, 0, + DECL_SIZE (old_field), pos, 0); + TREE_CHAIN (new_field) = TYPE_FIELDS (new_record_type); + TYPE_FIELDS (new_record_type) = new_field; + + /* If old_field is a QUAL_UNION_TYPE, take its size as being + zero. The only time it's not the last field of the record + is when there are other components at fixed positions after + it (meaning there was a rep clause for every field) and we + want to be able to encode them. */ + last_pos = size_binop (PLUS_EXPR, bit_position (old_field), + (TREE_CODE (TREE_TYPE (old_field)) + == QUAL_UNION_TYPE) + ? bitsize_zero_node + : DECL_SIZE (old_field)); + prev_old_field = old_field; + } + + TYPE_FIELDS (new_record_type) + = nreverse (TYPE_FIELDS (new_record_type)); + + rest_of_type_decl_compilation (TYPE_STUB_DECL (new_record_type)); + } + + rest_of_type_decl_compilation (TYPE_STUB_DECL (record_type)); +} + +/* Append PARALLEL_TYPE on the chain of parallel types for decl. */ + +void +add_parallel_type (tree decl, tree parallel_type) +{ + tree d = decl; + + while (DECL_PARALLEL_TYPE (d)) + d = TYPE_STUB_DECL (DECL_PARALLEL_TYPE (d)); + + SET_DECL_PARALLEL_TYPE (d, parallel_type); +} + +/* Return the parallel type associated to a type, if any. */ + +tree +get_parallel_type (tree type) +{ + if (TYPE_STUB_DECL (type)) + return DECL_PARALLEL_TYPE (TYPE_STUB_DECL (type)); + else + return NULL_TREE; +} + +/* Utility function of above to merge LAST_SIZE, the previous size of a record + with FIRST_BIT and SIZE that describe a field. SPECIAL is nonzero + if this represents a QUAL_UNION_TYPE in which case we must look for + COND_EXPRs and replace a value of zero with the old size. If HAS_REP + is nonzero, we must take the MAX of the end position of this field + with LAST_SIZE. In all other cases, we use FIRST_BIT plus SIZE. + + We return an expression for the size. */ + +static tree +merge_sizes (tree last_size, tree first_bit, tree size, bool special, + bool has_rep) +{ + tree type = TREE_TYPE (last_size); + tree new; + + if (!special || TREE_CODE (size) != COND_EXPR) + { + new = size_binop (PLUS_EXPR, first_bit, size); + if (has_rep) + new = size_binop (MAX_EXPR, last_size, new); + } + + else + new = fold_build3 (COND_EXPR, type, TREE_OPERAND (size, 0), + integer_zerop (TREE_OPERAND (size, 1)) + ? last_size : merge_sizes (last_size, first_bit, + TREE_OPERAND (size, 1), + 1, has_rep), + integer_zerop (TREE_OPERAND (size, 2)) + ? last_size : merge_sizes (last_size, first_bit, + TREE_OPERAND (size, 2), + 1, has_rep)); + + /* We don't need any NON_VALUE_EXPRs and they can confuse us (especially + when fed through substitute_in_expr) into thinking that a constant + size is not constant. */ + while (TREE_CODE (new) == NON_LVALUE_EXPR) + new = TREE_OPERAND (new, 0); + + return new; +} + +/* Utility function of above to see if OP0 and OP1, both of SIZETYPE, are + related by the addition of a constant. Return that constant if so. */ + +static tree +compute_related_constant (tree op0, tree op1) +{ + tree op0_var, op1_var; + tree op0_con = split_plus (op0, &op0_var); + tree op1_con = split_plus (op1, &op1_var); + tree result = size_binop (MINUS_EXPR, op0_con, op1_con); + + if (operand_equal_p (op0_var, op1_var, 0)) + return result; + else if (operand_equal_p (op0, size_binop (PLUS_EXPR, op1_var, result), 0)) + return result; + else + return 0; +} + +/* Utility function of above to split a tree OP which may be a sum, into a + constant part, which is returned, and a variable part, which is stored + in *PVAR. *PVAR may be bitsize_zero_node. All operations must be of + bitsizetype. */ + +static tree +split_plus (tree in, tree *pvar) +{ + /* Strip NOPS in order to ease the tree traversal and maximize the + potential for constant or plus/minus discovery. We need to be careful + to always return and set *pvar to bitsizetype trees, but it's worth + the effort. */ + STRIP_NOPS (in); + + *pvar = convert (bitsizetype, in); + + if (TREE_CODE (in) == INTEGER_CST) + { + *pvar = bitsize_zero_node; + return convert (bitsizetype, in); + } + else if (TREE_CODE (in) == PLUS_EXPR || TREE_CODE (in) == MINUS_EXPR) + { + tree lhs_var, rhs_var; + tree lhs_con = split_plus (TREE_OPERAND (in, 0), &lhs_var); + tree rhs_con = split_plus (TREE_OPERAND (in, 1), &rhs_var); + + if (lhs_var == TREE_OPERAND (in, 0) + && rhs_var == TREE_OPERAND (in, 1)) + return bitsize_zero_node; + + *pvar = size_binop (TREE_CODE (in), lhs_var, rhs_var); + return size_binop (TREE_CODE (in), lhs_con, rhs_con); + } + else + return bitsize_zero_node; +} + +/* Return a FUNCTION_TYPE node. RETURN_TYPE is the type returned by the + subprogram. If it is void_type_node, then we are dealing with a procedure, + otherwise we are dealing with a function. PARAM_DECL_LIST is a list of + PARM_DECL nodes that are the subprogram arguments. CICO_LIST is the + copy-in/copy-out list to be stored into TYPE_CICO_LIST. + RETURNS_UNCONSTRAINED is true if the function returns an unconstrained + object. RETURNS_BY_REF is true if the function returns by reference. + RETURNS_BY_TARGET_PTR is true if the function is to be passed (as its + first parameter) the address of the place to copy its result. */ + +tree +create_subprog_type (tree return_type, tree param_decl_list, tree cico_list, + bool returns_unconstrained, bool returns_by_ref, + bool returns_by_target_ptr) +{ + /* A chain of TREE_LIST nodes whose TREE_VALUEs are the data type nodes of + the subprogram formal parameters. This list is generated by traversing the + input list of PARM_DECL nodes. */ + tree param_type_list = NULL; + tree param_decl; + tree type; + + for (param_decl = param_decl_list; param_decl; + param_decl = TREE_CHAIN (param_decl)) + param_type_list = tree_cons (NULL_TREE, TREE_TYPE (param_decl), + param_type_list); + + /* The list of the function parameter types has to be terminated by the void + type to signal to the back-end that we are not dealing with a variable + parameter subprogram, but that the subprogram has a fixed number of + parameters. */ + param_type_list = tree_cons (NULL_TREE, void_type_node, param_type_list); + + /* The list of argument types has been created in reverse + so nreverse it. */ + param_type_list = nreverse (param_type_list); + + type = build_function_type (return_type, param_type_list); + + /* TYPE may have been shared since GCC hashes types. If it has a CICO_LIST + or the new type should, make a copy of TYPE. Likewise for + RETURNS_UNCONSTRAINED and RETURNS_BY_REF. */ + if (TYPE_CI_CO_LIST (type) || cico_list + || TYPE_RETURNS_UNCONSTRAINED_P (type) != returns_unconstrained + || TYPE_RETURNS_BY_REF_P (type) != returns_by_ref + || TYPE_RETURNS_BY_TARGET_PTR_P (type) != returns_by_target_ptr) + type = copy_type (type); + + TYPE_CI_CO_LIST (type) = cico_list; + TYPE_RETURNS_UNCONSTRAINED_P (type) = returns_unconstrained; + TYPE_RETURNS_BY_REF_P (type) = returns_by_ref; + TYPE_RETURNS_BY_TARGET_PTR_P (type) = returns_by_target_ptr; + return type; +} + +/* Return a copy of TYPE but safe to modify in any way. */ + +tree +copy_type (tree type) +{ + tree new = copy_node (type); + + /* copy_node clears this field instead of copying it, because it is + aliased with TREE_CHAIN. */ + TYPE_STUB_DECL (new) = TYPE_STUB_DECL (type); + + TYPE_POINTER_TO (new) = 0; + TYPE_REFERENCE_TO (new) = 0; + TYPE_MAIN_VARIANT (new) = new; + TYPE_NEXT_VARIANT (new) = 0; + + return new; +} + +/* Return an INTEGER_TYPE of SIZETYPE with range MIN to MAX and whose + TYPE_INDEX_TYPE is INDEX. GNAT_NODE is used for the position of + the decl. */ + +tree +create_index_type (tree min, tree max, tree index, Node_Id gnat_node) +{ + /* First build a type for the desired range. */ + tree type = build_index_2_type (min, max); + + /* If this type has the TYPE_INDEX_TYPE we want, return it. Otherwise, if it + doesn't have TYPE_INDEX_TYPE set, set it to INDEX. If TYPE_INDEX_TYPE + is set, but not to INDEX, make a copy of this type with the requested + index type. Note that we have no way of sharing these types, but that's + only a small hole. */ + if (TYPE_INDEX_TYPE (type) == index) + return type; + else if (TYPE_INDEX_TYPE (type)) + type = copy_type (type); + + SET_TYPE_INDEX_TYPE (type, index); + create_type_decl (NULL_TREE, type, NULL, true, false, gnat_node); + return type; +} + +/* Return a TYPE_DECL node. TYPE_NAME gives the name of the type (a character + string) and TYPE is a ..._TYPE node giving its data type. + ARTIFICIAL_P is true if this is a declaration that was generated + by the compiler. DEBUG_INFO_P is true if we need to write debugging + information about this type. GNAT_NODE is used for the position of + the decl. */ + +tree +create_type_decl (tree type_name, tree type, struct attrib *attr_list, + bool artificial_p, bool debug_info_p, Node_Id gnat_node) +{ + tree type_decl = build_decl (TYPE_DECL, type_name, type); + enum tree_code code = TREE_CODE (type); + + DECL_ARTIFICIAL (type_decl) = artificial_p; + + if (!TYPE_IS_DUMMY_P (type)) + gnat_pushdecl (type_decl, gnat_node); + + process_attributes (type_decl, attr_list); + + /* Pass type declaration information to the debugger unless this is an + UNCONSTRAINED_ARRAY_TYPE, which the debugger does not support, + and ENUMERAL_TYPE or RECORD_TYPE which is handled separately, or + type for which debugging information was not requested. */ + if (code == UNCONSTRAINED_ARRAY_TYPE || !debug_info_p) + DECL_IGNORED_P (type_decl) = 1; + else if (code != ENUMERAL_TYPE + && (code != RECORD_TYPE || TYPE_IS_FAT_POINTER_P (type)) + && !((code == POINTER_TYPE || code == REFERENCE_TYPE) + && TYPE_IS_DUMMY_P (TREE_TYPE (type)))) + rest_of_type_decl_compilation (type_decl); + + return type_decl; +} + +/* Return a VAR_DECL or CONST_DECL node. + + VAR_NAME gives the name of the variable. ASM_NAME is its assembler name + (if provided). TYPE is its data type (a GCC ..._TYPE node). VAR_INIT is + the GCC tree for an optional initial expression; NULL_TREE if none. + + CONST_FLAG is true if this variable is constant, in which case we might + return a CONST_DECL node unless CONST_DECL_ALLOWED_P is false. + + PUBLIC_FLAG is true if this is for a reference to a public entity or for a + definition to be made visible outside of the current compilation unit, for + instance variable definitions in a package specification. + + EXTERN_FLAG is nonzero when processing an external variable declaration (as + opposed to a definition: no storage is to be allocated for the variable). + + STATIC_FLAG is only relevant when not at top level. In that case + it indicates whether to always allocate storage to the variable. + + GNAT_NODE is used for the position of the decl. */ + +tree +create_var_decl_1 (tree var_name, tree asm_name, tree type, tree var_init, + bool const_flag, bool public_flag, bool extern_flag, + bool static_flag, bool const_decl_allowed_p, + struct attrib *attr_list, Node_Id gnat_node) +{ + bool init_const + = (var_init != 0 + && gnat_types_compatible_p (type, TREE_TYPE (var_init)) + && (global_bindings_p () || static_flag + ? initializer_constant_valid_p (var_init, TREE_TYPE (var_init)) != 0 + : TREE_CONSTANT (var_init))); + + /* Whether we will make TREE_CONSTANT the DECL we produce here, in which + case the initializer may be used in-lieu of the DECL node (as done in + Identifier_to_gnu). This is useful to prevent the need of elaboration + code when an identifier for which such a decl is made is in turn used as + an initializer. We used to rely on CONST vs VAR_DECL for this purpose, + but extra constraints apply to this choice (see below) and are not + relevant to the distinction we wish to make. */ + bool constant_p = const_flag && init_const; + + /* The actual DECL node. CONST_DECL was initially intended for enumerals + and may be used for scalars in general but not for aggregates. */ + tree var_decl + = build_decl ((constant_p && const_decl_allowed_p + && !AGGREGATE_TYPE_P (type)) ? CONST_DECL : VAR_DECL, + var_name, type); + + /* If this is external, throw away any initializations (they will be done + elsewhere) unless this is a constant for which we would like to remain + able to get the initializer. If we are defining a global here, leave a + constant initialization and save any variable elaborations for the + elaboration routine. If we are just annotating types, throw away the + initialization if it isn't a constant. */ + if ((extern_flag && !constant_p) + || (type_annotate_only && var_init && !TREE_CONSTANT (var_init))) + var_init = NULL_TREE; + + /* At the global level, an initializer requiring code to be generated + produces elaboration statements. Check that such statements are allowed, + that is, not violating a No_Elaboration_Code restriction. */ + if (global_bindings_p () && var_init != 0 && ! init_const) + Check_Elaboration_Code_Allowed (gnat_node); + + /* Ada doesn't feature Fortran-like COMMON variables so we shouldn't + try to fiddle with DECL_COMMON. However, on platforms that don't + support global BSS sections, uninitialized global variables would + go in DATA instead, thus increasing the size of the executable. */ + if (!flag_no_common + && TREE_CODE (var_decl) == VAR_DECL + && !have_global_bss_p ()) + DECL_COMMON (var_decl) = 1; + DECL_INITIAL (var_decl) = var_init; + TREE_READONLY (var_decl) = const_flag; + DECL_EXTERNAL (var_decl) = extern_flag; + TREE_PUBLIC (var_decl) = public_flag || extern_flag; + TREE_CONSTANT (var_decl) = constant_p; + TREE_THIS_VOLATILE (var_decl) = TREE_SIDE_EFFECTS (var_decl) + = TYPE_VOLATILE (type); + + /* If it's public and not external, always allocate storage for it. + At the global binding level we need to allocate static storage for the + variable if and only if it's not external. If we are not at the top level + we allocate automatic storage unless requested not to. */ + TREE_STATIC (var_decl) + = !extern_flag && (public_flag || static_flag || global_bindings_p ()); + + if (asm_name && VAR_OR_FUNCTION_DECL_P (var_decl)) + SET_DECL_ASSEMBLER_NAME (var_decl, asm_name); + + process_attributes (var_decl, attr_list); + + /* Add this decl to the current binding level. */ + gnat_pushdecl (var_decl, gnat_node); + + if (TREE_SIDE_EFFECTS (var_decl)) + TREE_ADDRESSABLE (var_decl) = 1; + + if (TREE_CODE (var_decl) != CONST_DECL) + { + if (global_bindings_p ()) + rest_of_decl_compilation (var_decl, true, 0); + } + else + expand_decl (var_decl); + + return var_decl; +} + +/* Return true if TYPE, an aggregate type, contains (or is) an array. */ + +static bool +aggregate_type_contains_array_p (tree type) +{ + switch (TREE_CODE (type)) + { + case RECORD_TYPE: + case UNION_TYPE: + case QUAL_UNION_TYPE: + { + tree field; + for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) + if (AGGREGATE_TYPE_P (TREE_TYPE (field)) + && aggregate_type_contains_array_p (TREE_TYPE (field))) + return true; + return false; + } + + case ARRAY_TYPE: + return true; + + default: + gcc_unreachable (); + } +} + +/* Returns a FIELD_DECL node. FIELD_NAME the field name, FIELD_TYPE is its + type, and RECORD_TYPE is the type of the parent. PACKED is nonzero if + this field is in a record type with a "pragma pack". If SIZE is nonzero + it is the specified size for this field. If POS is nonzero, it is the bit + position. If ADDRESSABLE is nonzero, it means we are allowed to take + the address of this field for aliasing purposes. If it is negative, we + should not make a bitfield, which is used by make_aligning_type. */ + +tree +create_field_decl (tree field_name, tree field_type, tree record_type, + int packed, tree size, tree pos, int addressable) +{ + tree field_decl = build_decl (FIELD_DECL, field_name, field_type); + + DECL_CONTEXT (field_decl) = record_type; + TREE_READONLY (field_decl) = TYPE_READONLY (field_type); + + /* If FIELD_TYPE is BLKmode, we must ensure this is aligned to at least a + byte boundary since GCC cannot handle less-aligned BLKmode bitfields. + Likewise for an aggregate without specified position that contains an + array, because in this case slices of variable length of this array + must be handled by GCC and variable-sized objects need to be aligned + to at least a byte boundary. */ + if (packed && (TYPE_MODE (field_type) == BLKmode + || (!pos + && AGGREGATE_TYPE_P (field_type) + && aggregate_type_contains_array_p (field_type)))) + DECL_ALIGN (field_decl) = BITS_PER_UNIT; + + /* If a size is specified, use it. Otherwise, if the record type is packed + compute a size to use, which may differ from the object's natural size. + We always set a size in this case to trigger the checks for bitfield + creation below, which is typically required when no position has been + specified. */ + if (size) + size = convert (bitsizetype, size); + else if (packed == 1) + { + size = rm_size (field_type); + + /* For a constant size larger than MAX_FIXED_MODE_SIZE, round up to + byte. */ + if (TREE_CODE (size) == INTEGER_CST + && compare_tree_int (size, MAX_FIXED_MODE_SIZE) > 0) + size = round_up (size, BITS_PER_UNIT); + } + + /* If we may, according to ADDRESSABLE, make a bitfield if a size is + specified for two reasons: first if the size differs from the natural + size. Second, if the alignment is insufficient. There are a number of + ways the latter can be true. + + We never make a bitfield if the type of the field has a nonconstant size, + because no such entity requiring bitfield operations should reach here. + + We do *preventively* make a bitfield when there might be the need for it + but we don't have all the necessary information to decide, as is the case + of a field with no specified position in a packed record. + + We also don't look at STRICT_ALIGNMENT here, and rely on later processing + in layout_decl or finish_record_type to clear the bit_field indication if + it is in fact not needed. */ + if (addressable >= 0 + && size + && TREE_CODE (size) == INTEGER_CST + && TREE_CODE (TYPE_SIZE (field_type)) == INTEGER_CST + && (!tree_int_cst_equal (size, TYPE_SIZE (field_type)) + || (pos && !value_factor_p (pos, TYPE_ALIGN (field_type))) + || packed + || (TYPE_ALIGN (record_type) != 0 + && TYPE_ALIGN (record_type) < TYPE_ALIGN (field_type)))) + { + DECL_BIT_FIELD (field_decl) = 1; + DECL_SIZE (field_decl) = size; + if (!packed && !pos) + DECL_ALIGN (field_decl) + = (TYPE_ALIGN (record_type) != 0 + ? MIN (TYPE_ALIGN (record_type), TYPE_ALIGN (field_type)) + : TYPE_ALIGN (field_type)); + } + + DECL_PACKED (field_decl) = pos ? DECL_BIT_FIELD (field_decl) : packed; + + /* Bump the alignment if need be, either for bitfield/packing purposes or + to satisfy the type requirements if no such consideration applies. When + we get the alignment from the type, indicate if this is from an explicit + user request, which prevents stor-layout from lowering it later on. */ + { + int bit_align + = (DECL_BIT_FIELD (field_decl) ? 1 + : packed && TYPE_MODE (field_type) != BLKmode ? BITS_PER_UNIT : 0); + + if (bit_align > DECL_ALIGN (field_decl)) + DECL_ALIGN (field_decl) = bit_align; + else if (!bit_align && TYPE_ALIGN (field_type) > DECL_ALIGN (field_decl)) + { + DECL_ALIGN (field_decl) = TYPE_ALIGN (field_type); + DECL_USER_ALIGN (field_decl) = TYPE_USER_ALIGN (field_type); + } + } + + if (pos) + { + /* We need to pass in the alignment the DECL is known to have. + This is the lowest-order bit set in POS, but no more than + the alignment of the record, if one is specified. Note + that an alignment of 0 is taken as infinite. */ + unsigned int known_align; + + if (host_integerp (pos, 1)) + known_align = tree_low_cst (pos, 1) & - tree_low_cst (pos, 1); + else + known_align = BITS_PER_UNIT; + + if (TYPE_ALIGN (record_type) + && (known_align == 0 || known_align > TYPE_ALIGN (record_type))) + known_align = TYPE_ALIGN (record_type); + + layout_decl (field_decl, known_align); + SET_DECL_OFFSET_ALIGN (field_decl, + host_integerp (pos, 1) ? BIGGEST_ALIGNMENT + : BITS_PER_UNIT); + pos_from_bit (&DECL_FIELD_OFFSET (field_decl), + &DECL_FIELD_BIT_OFFSET (field_decl), + DECL_OFFSET_ALIGN (field_decl), pos); + + DECL_HAS_REP_P (field_decl) = 1; + } + + /* In addition to what our caller says, claim the field is addressable if we + know that its type is not suitable. + + The field may also be "technically" nonaddressable, meaning that even if + we attempt to take the field's address we will actually get the address + of a copy. This is the case for true bitfields, but the DECL_BIT_FIELD + value we have at this point is not accurate enough, so we don't account + for this here and let finish_record_type decide. */ + if (!type_for_nonaliased_component_p (field_type)) + addressable = 1; + + DECL_NONADDRESSABLE_P (field_decl) = !addressable; + + return field_decl; +} + +/* Returns a PARM_DECL node. PARAM_NAME is the name of the parameter, + PARAM_TYPE is its type. READONLY is true if the parameter is + readonly (either an In parameter or an address of a pass-by-ref + parameter). */ + +tree +create_param_decl (tree param_name, tree param_type, bool readonly) +{ + tree param_decl = build_decl (PARM_DECL, param_name, param_type); + + /* Honor targetm.calls.promote_prototypes(), as not doing so can + lead to various ABI violations. */ + if (targetm.calls.promote_prototypes (param_type) + && (TREE_CODE (param_type) == INTEGER_TYPE + || TREE_CODE (param_type) == ENUMERAL_TYPE) + && TYPE_PRECISION (param_type) < TYPE_PRECISION (integer_type_node)) + { + /* We have to be careful about biased types here. Make a subtype + of integer_type_node with the proper biasing. */ + if (TREE_CODE (param_type) == INTEGER_TYPE + && TYPE_BIASED_REPRESENTATION_P (param_type)) + { + param_type + = copy_type (build_range_type (integer_type_node, + TYPE_MIN_VALUE (param_type), + TYPE_MAX_VALUE (param_type))); + + TYPE_BIASED_REPRESENTATION_P (param_type) = 1; + } + else + param_type = integer_type_node; + } + + DECL_ARG_TYPE (param_decl) = param_type; + TREE_READONLY (param_decl) = readonly; + return param_decl; +} + +/* Given a DECL and ATTR_LIST, process the listed attributes. */ + +void +process_attributes (tree decl, struct attrib *attr_list) +{ + for (; attr_list; attr_list = attr_list->next) + switch (attr_list->type) + { + case ATTR_MACHINE_ATTRIBUTE: + decl_attributes (&decl, tree_cons (attr_list->name, attr_list->args, + NULL_TREE), + ATTR_FLAG_TYPE_IN_PLACE); + break; + + case ATTR_LINK_ALIAS: + if (! DECL_EXTERNAL (decl)) + { + TREE_STATIC (decl) = 1; + assemble_alias (decl, attr_list->name); + } + break; + + case ATTR_WEAK_EXTERNAL: + if (SUPPORTS_WEAK) + declare_weak (decl); + else + post_error ("?weak declarations not supported on this target", + attr_list->error_point); + break; + + case ATTR_LINK_SECTION: + if (targetm.have_named_sections) + { + DECL_SECTION_NAME (decl) + = build_string (IDENTIFIER_LENGTH (attr_list->name), + IDENTIFIER_POINTER (attr_list->name)); + DECL_COMMON (decl) = 0; + } + else + post_error ("?section attributes are not supported for this target", + attr_list->error_point); + break; + + case ATTR_LINK_CONSTRUCTOR: + DECL_STATIC_CONSTRUCTOR (decl) = 1; + TREE_USED (decl) = 1; + break; + + case ATTR_LINK_DESTRUCTOR: + DECL_STATIC_DESTRUCTOR (decl) = 1; + TREE_USED (decl) = 1; + break; + } +} + +/* Record a global renaming pointer. */ + +void +record_global_renaming_pointer (tree decl) +{ + gcc_assert (DECL_RENAMED_OBJECT (decl)); + VEC_safe_push (tree, gc, global_renaming_pointers, decl); +} + +/* Invalidate the global renaming pointers. */ + +void +invalidate_global_renaming_pointers (void) +{ + unsigned int i; + tree iter; + + for (i = 0; VEC_iterate(tree, global_renaming_pointers, i, iter); i++) + SET_DECL_RENAMED_OBJECT (iter, NULL_TREE); + + VEC_free (tree, gc, global_renaming_pointers); +} + +/* Return true if VALUE is a known to be a multiple of FACTOR, which must be + a power of 2. */ + +bool +value_factor_p (tree value, HOST_WIDE_INT factor) +{ + if (host_integerp (value, 1)) + return tree_low_cst (value, 1) % factor == 0; + + if (TREE_CODE (value) == MULT_EXPR) + return (value_factor_p (TREE_OPERAND (value, 0), factor) + || value_factor_p (TREE_OPERAND (value, 1), factor)); + + return false; +} + +/* Given 2 consecutive field decls PREV_FIELD and CURR_FIELD, return true + unless we can prove these 2 fields are laid out in such a way that no gap + exist between the end of PREV_FIELD and the beginning of CURR_FIELD. OFFSET + is the distance in bits between the end of PREV_FIELD and the starting + position of CURR_FIELD. It is ignored if null. */ + +static bool +potential_alignment_gap (tree prev_field, tree curr_field, tree offset) +{ + /* If this is the first field of the record, there cannot be any gap */ + if (!prev_field) + return false; + + /* If the previous field is a union type, then return False: The only + time when such a field is not the last field of the record is when + there are other components at fixed positions after it (meaning there + was a rep clause for every field), in which case we don't want the + alignment constraint to override them. */ + if (TREE_CODE (TREE_TYPE (prev_field)) == QUAL_UNION_TYPE) + return false; + + /* If the distance between the end of prev_field and the beginning of + curr_field is constant, then there is a gap if the value of this + constant is not null. */ + if (offset && host_integerp (offset, 1)) + return !integer_zerop (offset); + + /* If the size and position of the previous field are constant, + then check the sum of this size and position. There will be a gap + iff it is not multiple of the current field alignment. */ + if (host_integerp (DECL_SIZE (prev_field), 1) + && host_integerp (bit_position (prev_field), 1)) + return ((tree_low_cst (bit_position (prev_field), 1) + + tree_low_cst (DECL_SIZE (prev_field), 1)) + % DECL_ALIGN (curr_field) != 0); + + /* If both the position and size of the previous field are multiples + of the current field alignment, there cannot be any gap. */ + if (value_factor_p (bit_position (prev_field), DECL_ALIGN (curr_field)) + && value_factor_p (DECL_SIZE (prev_field), DECL_ALIGN (curr_field))) + return false; + + /* Fallback, return that there may be a potential gap */ + return true; +} + +/* Returns a LABEL_DECL node for LABEL_NAME. */ + +tree +create_label_decl (tree label_name) +{ + tree label_decl = build_decl (LABEL_DECL, label_name, void_type_node); + + DECL_CONTEXT (label_decl) = current_function_decl; + DECL_MODE (label_decl) = VOIDmode; + DECL_SOURCE_LOCATION (label_decl) = input_location; + + return label_decl; +} + +/* Returns a FUNCTION_DECL node. SUBPROG_NAME is the name of the subprogram, + ASM_NAME is its assembler name, SUBPROG_TYPE is its type (a FUNCTION_TYPE + node), PARAM_DECL_LIST is the list of the subprogram arguments (a list of + PARM_DECL nodes chained through the TREE_CHAIN field). + + INLINE_FLAG, PUBLIC_FLAG, EXTERN_FLAG, and ATTR_LIST are used to set the + appropriate fields in the FUNCTION_DECL. GNAT_NODE gives the location. */ + +tree +create_subprog_decl (tree subprog_name, tree asm_name, + tree subprog_type, tree param_decl_list, bool inline_flag, + bool public_flag, bool extern_flag, + struct attrib *attr_list, Node_Id gnat_node) +{ + tree return_type = TREE_TYPE (subprog_type); + tree subprog_decl = build_decl (FUNCTION_DECL, subprog_name, subprog_type); + + /* If this is a function nested inside an inlined external function, it + means we aren't going to compile the outer function unless it is + actually inlined, so do the same for us. */ + if (current_function_decl && DECL_INLINE (current_function_decl) + && DECL_EXTERNAL (current_function_decl)) + extern_flag = true; + + DECL_EXTERNAL (subprog_decl) = extern_flag; + TREE_PUBLIC (subprog_decl) = public_flag; + TREE_STATIC (subprog_decl) = 1; + TREE_READONLY (subprog_decl) = TYPE_READONLY (subprog_type); + TREE_THIS_VOLATILE (subprog_decl) = TYPE_VOLATILE (subprog_type); + TREE_SIDE_EFFECTS (subprog_decl) = TYPE_VOLATILE (subprog_type); + DECL_ARGUMENTS (subprog_decl) = param_decl_list; + DECL_RESULT (subprog_decl) = build_decl (RESULT_DECL, 0, return_type); + DECL_ARTIFICIAL (DECL_RESULT (subprog_decl)) = 1; + DECL_IGNORED_P (DECL_RESULT (subprog_decl)) = 1; + + /* TREE_ADDRESSABLE is set on the result type to request the use of the + target by-reference return mechanism. This is not supported all the + way down to RTL expansion with GCC 4, which ICEs on temporary creation + attempts with such a type and expects DECL_BY_REFERENCE to be set on + the RESULT_DECL instead - see gnat_genericize for more details. */ + if (TREE_ADDRESSABLE (TREE_TYPE (DECL_RESULT (subprog_decl)))) + { + tree result_decl = DECL_RESULT (subprog_decl); + + TREE_ADDRESSABLE (TREE_TYPE (result_decl)) = 0; + DECL_BY_REFERENCE (result_decl) = 1; + } + + if (inline_flag) + DECL_DECLARED_INLINE_P (subprog_decl) = 1; + + if (asm_name) + { + SET_DECL_ASSEMBLER_NAME (subprog_decl, asm_name); + + /* The expand_main_function circuitry expects "main_identifier_node" to + designate the DECL_NAME of the 'main' entry point, in turn expected + to be declared as the "main" function literally by default. Ada + program entry points are typically declared with a different name + within the binder generated file, exported as 'main' to satisfy the + system expectations. Redirect main_identifier_node in this case. */ + if (asm_name == main_identifier_node) + main_identifier_node = DECL_NAME (subprog_decl); + } + + process_attributes (subprog_decl, attr_list); + + /* Add this decl to the current binding level. */ + gnat_pushdecl (subprog_decl, gnat_node); + + /* Output the assembler code and/or RTL for the declaration. */ + rest_of_decl_compilation (subprog_decl, global_bindings_p (), 0); + + return subprog_decl; +} + +/* Set up the framework for generating code for SUBPROG_DECL, a subprogram + body. This routine needs to be invoked before processing the declarations + appearing in the subprogram. */ + +void +begin_subprog_body (tree subprog_decl) +{ + tree param_decl; + + current_function_decl = subprog_decl; + announce_function (subprog_decl); + + /* Enter a new binding level and show that all the parameters belong to + this function. */ + gnat_pushlevel (); + for (param_decl = DECL_ARGUMENTS (subprog_decl); param_decl; + param_decl = TREE_CHAIN (param_decl)) + DECL_CONTEXT (param_decl) = subprog_decl; + + make_decl_rtl (subprog_decl); + + /* We handle pending sizes via the elaboration of types, so we don't need to + save them. This causes them to be marked as part of the outer function + and then discarded. */ + get_pending_sizes (); +} + + +/* Helper for the genericization callback. Return a dereference of VAL + if it is of a reference type. */ + +static tree +convert_from_reference (tree val) +{ + tree value_type, ref; + + if (TREE_CODE (TREE_TYPE (val)) != REFERENCE_TYPE) + return val; + + value_type = TREE_TYPE (TREE_TYPE (val)); + ref = build1 (INDIRECT_REF, value_type, val); + + /* See if what we reference is CONST or VOLATILE, which requires + looking into array types to get to the component type. */ + + while (TREE_CODE (value_type) == ARRAY_TYPE) + value_type = TREE_TYPE (value_type); + + TREE_READONLY (ref) + = (TYPE_QUALS (value_type) & TYPE_QUAL_CONST); + TREE_THIS_VOLATILE (ref) + = (TYPE_QUALS (value_type) & TYPE_QUAL_VOLATILE); + + TREE_SIDE_EFFECTS (ref) + = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (val)); + + return ref; +} + +/* Helper for the genericization callback. Returns true if T denotes + a RESULT_DECL with DECL_BY_REFERENCE set. */ + +static inline bool +is_byref_result (tree t) +{ + return (TREE_CODE (t) == RESULT_DECL && DECL_BY_REFERENCE (t)); +} + + +/* Tree walking callback for gnat_genericize. Currently ... + + o Adjust references to the function's DECL_RESULT if it is marked + DECL_BY_REFERENCE and so has had its type turned into a reference + type at the end of the function compilation. */ + +static tree +gnat_genericize_r (tree *stmt_p, int *walk_subtrees, void *data) +{ + /* This implementation is modeled after what the C++ front-end is + doing, basis of the downstream passes behavior. */ + + tree stmt = *stmt_p; + struct pointer_set_t *p_set = (struct pointer_set_t*) data; + + /* If we have a direct mention of the result decl, dereference. */ + if (is_byref_result (stmt)) + { + *stmt_p = convert_from_reference (stmt); + *walk_subtrees = 0; + return NULL; + } + + /* Otherwise, no need to walk the same tree twice. */ + if (pointer_set_contains (p_set, stmt)) + { + *walk_subtrees = 0; + return NULL_TREE; + } + + /* If we are taking the address of what now is a reference, just get the + reference value. */ + if (TREE_CODE (stmt) == ADDR_EXPR + && is_byref_result (TREE_OPERAND (stmt, 0))) + { + *stmt_p = convert (TREE_TYPE (stmt), TREE_OPERAND (stmt, 0)); + *walk_subtrees = 0; + } + + /* Don't dereference an by-reference RESULT_DECL inside a RETURN_EXPR. */ + else if (TREE_CODE (stmt) == RETURN_EXPR + && TREE_OPERAND (stmt, 0) + && is_byref_result (TREE_OPERAND (stmt, 0))) + *walk_subtrees = 0; + + /* Don't look inside trees that cannot embed references of interest. */ + else if (IS_TYPE_OR_DECL_P (stmt)) + *walk_subtrees = 0; + + pointer_set_insert (p_set, *stmt_p); + + return NULL; +} + +/* Perform lowering of Ada trees to GENERIC. In particular: + + o Turn a DECL_BY_REFERENCE RESULT_DECL into a real by-reference decl + and adjust all the references to this decl accordingly. */ + +static void +gnat_genericize (tree fndecl) +{ + /* Prior to GCC 4, an explicit By_Reference result mechanism for a function + was handled by simply setting TREE_ADDRESSABLE on the result type. + Everything required to actually pass by invisible ref using the target + mechanism (e.g. extra parameter) was handled at RTL expansion time. + + This doesn't work with GCC 4 any more for several reasons. First, the + gimplification process might need the creation of temporaries of this + type, and the gimplifier ICEs on such attempts. Second, the middle-end + now relies on a different attribute for such cases (DECL_BY_REFERENCE on + RESULT/PARM_DECLs), and expects the user invisible by-reference-ness to + be explicitly accounted for by the front-end in the function body. + + We achieve the complete transformation in two steps: + + 1/ create_subprog_decl performs early attribute tweaks: it clears + TREE_ADDRESSABLE from the result type and sets DECL_BY_REFERENCE on + the result decl. The former ensures that the bit isn't set in the GCC + tree saved for the function, so prevents ICEs on temporary creation. + The latter we use here to trigger the rest of the processing. + + 2/ This function performs the type transformation on the result decl + and adjusts all the references to this decl from the function body + accordingly. + + Clearing TREE_ADDRESSABLE from the type differs from the C++ front-end + strategy, which escapes the gimplifier temporary creation issues by + creating it's own temporaries using TARGET_EXPR nodes. Our way relies + on simple specific support code in aggregate_value_p to look at the + target function result decl explicitly. */ + + struct pointer_set_t *p_set; + tree decl_result = DECL_RESULT (fndecl); + + if (!DECL_BY_REFERENCE (decl_result)) + return; + + /* Make the DECL_RESULT explicitly by-reference and adjust all the + occurrences in the function body using the common tree-walking facility. + We want to see every occurrence of the result decl to adjust the + referencing tree, so need to use our own pointer set to control which + trees should be visited again or not. */ + + p_set = pointer_set_create (); + + TREE_TYPE (decl_result) = build_reference_type (TREE_TYPE (decl_result)); + TREE_ADDRESSABLE (decl_result) = 0; + relayout_decl (decl_result); + + walk_tree (&DECL_SAVED_TREE (fndecl), gnat_genericize_r, p_set, NULL); + + pointer_set_destroy (p_set); +} + +/* Finish the definition of the current subprogram BODY and compile it all the + way to assembler language output. ELAB_P tells if this is called for an + elaboration routine, to be entirely discarded if empty. */ + +void +end_subprog_body (tree body, bool elab_p) +{ + tree fndecl = current_function_decl; + + /* Mark the BLOCK for this level as being for this function and pop the + level. Since the vars in it are the parameters, clear them. */ + BLOCK_VARS (current_binding_level->block) = 0; + BLOCK_SUPERCONTEXT (current_binding_level->block) = fndecl; + DECL_INITIAL (fndecl) = current_binding_level->block; + gnat_poplevel (); + + /* Deal with inline. If declared inline or we should default to inline, + set the flag in the decl. */ + DECL_INLINE (fndecl) = 1; + + /* We handle pending sizes via the elaboration of types, so we don't + need to save them. */ + get_pending_sizes (); + + /* Mark the RESULT_DECL as being in this subprogram. */ + DECL_CONTEXT (DECL_RESULT (fndecl)) = fndecl; + + DECL_SAVED_TREE (fndecl) = body; + + current_function_decl = DECL_CONTEXT (fndecl); + set_cfun (NULL); + + /* We cannot track the location of errors past this point. */ + error_gnat_node = Empty; + + /* If we're only annotating types, don't actually compile this function. */ + if (type_annotate_only) + return; + + /* Perform the required pre-gimplification transformations on the tree. */ + gnat_genericize (fndecl); + + /* We do different things for nested and non-nested functions. + ??? This should be in cgraph. */ + if (!DECL_CONTEXT (fndecl)) + { + gnat_gimplify_function (fndecl); + + /* If this is an empty elaboration proc, just discard the node. + Otherwise, compile further. */ + if (elab_p && empty_body_p (gimple_body (fndecl))) + cgraph_remove_node (cgraph_node (fndecl)); + else + cgraph_finalize_function (fndecl, false); + } + else + /* Register this function with cgraph just far enough to get it + added to our parent's nested function list. */ + (void) cgraph_node (fndecl); +} + +/* Convert FNDECL's code to GIMPLE and handle any nested functions. */ + +static void +gnat_gimplify_function (tree fndecl) +{ + struct cgraph_node *cgn; + + dump_function (TDI_original, fndecl); + gimplify_function_tree (fndecl); + dump_function (TDI_generic, fndecl); + + /* Convert all nested functions to GIMPLE now. We do things in this order + so that items like VLA sizes are expanded properly in the context of the + correct function. */ + cgn = cgraph_node (fndecl); + for (cgn = cgn->nested; cgn; cgn = cgn->next_nested) + gnat_gimplify_function (cgn->decl); +} + + +tree +gnat_builtin_function (tree decl) +{ + gnat_pushdecl (decl, Empty); + return decl; +} + +/* Return an integer type with the number of bits of precision given by + PRECISION. UNSIGNEDP is nonzero if the type is unsigned; otherwise + it is a signed type. */ + +tree +gnat_type_for_size (unsigned precision, int unsignedp) +{ + tree t; + char type_name[20]; + + if (precision <= 2 * MAX_BITS_PER_WORD + && signed_and_unsigned_types[precision][unsignedp]) + return signed_and_unsigned_types[precision][unsignedp]; + + if (unsignedp) + t = make_unsigned_type (precision); + else + t = make_signed_type (precision); + + if (precision <= 2 * MAX_BITS_PER_WORD) + signed_and_unsigned_types[precision][unsignedp] = t; + + if (!TYPE_NAME (t)) + { + sprintf (type_name, "%sSIGNED_%d", unsignedp ? "UN" : "", precision); + TYPE_NAME (t) = get_identifier (type_name); + } + + return t; +} + +/* Likewise for floating-point types. */ + +static tree +float_type_for_precision (int precision, enum machine_mode mode) +{ + tree t; + char type_name[20]; + + if (float_types[(int) mode]) + return float_types[(int) mode]; + + float_types[(int) mode] = t = make_node (REAL_TYPE); + TYPE_PRECISION (t) = precision; + layout_type (t); + + gcc_assert (TYPE_MODE (t) == mode); + if (!TYPE_NAME (t)) + { + sprintf (type_name, "FLOAT_%d", precision); + TYPE_NAME (t) = get_identifier (type_name); + } + + return t; +} + +/* Return a data type that has machine mode MODE. UNSIGNEDP selects + an unsigned type; otherwise a signed type is returned. */ + +tree +gnat_type_for_mode (enum machine_mode mode, int unsignedp) +{ + if (mode == BLKmode) + return NULL_TREE; + else if (mode == VOIDmode) + return void_type_node; + else if (COMPLEX_MODE_P (mode)) + return NULL_TREE; + else if (SCALAR_FLOAT_MODE_P (mode)) + return float_type_for_precision (GET_MODE_PRECISION (mode), mode); + else if (SCALAR_INT_MODE_P (mode)) + return gnat_type_for_size (GET_MODE_BITSIZE (mode), unsignedp); + else + return NULL_TREE; +} + +/* Return the unsigned version of a TYPE_NODE, a scalar type. */ + +tree +gnat_unsigned_type (tree type_node) +{ + tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 1); + + if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node)) + { + type = copy_node (type); + TREE_TYPE (type) = type_node; + } + else if (TREE_TYPE (type_node) + && TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE + && TYPE_MODULAR_P (TREE_TYPE (type_node))) + { + type = copy_node (type); + TREE_TYPE (type) = TREE_TYPE (type_node); + } + + return type; +} + +/* Return the signed version of a TYPE_NODE, a scalar type. */ + +tree +gnat_signed_type (tree type_node) +{ + tree type = gnat_type_for_size (TYPE_PRECISION (type_node), 0); + + if (TREE_CODE (type_node) == INTEGER_TYPE && TYPE_MODULAR_P (type_node)) + { + type = copy_node (type); + TREE_TYPE (type) = type_node; + } + else if (TREE_TYPE (type_node) + && TREE_CODE (TREE_TYPE (type_node)) == INTEGER_TYPE + && TYPE_MODULAR_P (TREE_TYPE (type_node))) + { + type = copy_node (type); + TREE_TYPE (type) = TREE_TYPE (type_node); + } + + return type; +} + +/* Return 1 if the types T1 and T2 are compatible, i.e. if they can be + transparently converted to each other. */ + +int +gnat_types_compatible_p (tree t1, tree t2) +{ + enum tree_code code; + + /* This is the default criterion. */ + if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) + return 1; + + /* We only check structural equivalence here. */ + if ((code = TREE_CODE (t1)) != TREE_CODE (t2)) + return 0; + + /* Array types are also compatible if they are constrained and have + the same component type and the same domain. */ + if (code == ARRAY_TYPE + && TREE_TYPE (t1) == TREE_TYPE (t2) + && tree_int_cst_equal (TYPE_MIN_VALUE (TYPE_DOMAIN (t1)), + TYPE_MIN_VALUE (TYPE_DOMAIN (t2))) + && tree_int_cst_equal (TYPE_MAX_VALUE (TYPE_DOMAIN (t1)), + TYPE_MAX_VALUE (TYPE_DOMAIN (t2)))) + return 1; + + /* Padding record types are also compatible if they pad the same + type and have the same constant size. */ + if (code == RECORD_TYPE + && TYPE_IS_PADDING_P (t1) && TYPE_IS_PADDING_P (t2) + && TREE_TYPE (TYPE_FIELDS (t1)) == TREE_TYPE (TYPE_FIELDS (t2)) + && tree_int_cst_equal (TYPE_SIZE (t1), TYPE_SIZE (t2))) + return 1; + + return 0; +} + +/* EXP is an expression for the size of an object. If this size contains + discriminant references, replace them with the maximum (if MAX_P) or + minimum (if !MAX_P) possible value of the discriminant. */ + +tree +max_size (tree exp, bool max_p) +{ + enum tree_code code = TREE_CODE (exp); + tree type = TREE_TYPE (exp); + + switch (TREE_CODE_CLASS (code)) + { + case tcc_declaration: + case tcc_constant: + return exp; + + case tcc_vl_exp: + if (code == CALL_EXPR) + { + tree *argarray; + int i, n = call_expr_nargs (exp); + gcc_assert (n > 0); + + argarray = (tree *) alloca (n * sizeof (tree)); + for (i = 0; i < n; i++) + argarray[i] = max_size (CALL_EXPR_ARG (exp, i), max_p); + return build_call_array (type, CALL_EXPR_FN (exp), n, argarray); + } + break; + + case tcc_reference: + /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to + modify. Otherwise, we treat it like a variable. */ + if (!CONTAINS_PLACEHOLDER_P (exp)) + return exp; + + type = TREE_TYPE (TREE_OPERAND (exp, 1)); + return + max_size (max_p ? TYPE_MAX_VALUE (type) : TYPE_MIN_VALUE (type), true); + + case tcc_comparison: + return max_p ? size_one_node : size_zero_node; + + case tcc_unary: + case tcc_binary: + case tcc_expression: + switch (TREE_CODE_LENGTH (code)) + { + case 1: + if (code == NON_LVALUE_EXPR) + return max_size (TREE_OPERAND (exp, 0), max_p); + else + return + fold_build1 (code, type, + max_size (TREE_OPERAND (exp, 0), + code == NEGATE_EXPR ? !max_p : max_p)); + + case 2: + if (code == COMPOUND_EXPR) + return max_size (TREE_OPERAND (exp, 1), max_p); + + /* Calculate "(A ? B : C) - D" as "A ? B - D : C - D" which + may provide a tighter bound on max_size. */ + if (code == MINUS_EXPR + && TREE_CODE (TREE_OPERAND (exp, 0)) == COND_EXPR) + { + tree lhs = fold_build2 (MINUS_EXPR, type, + TREE_OPERAND (TREE_OPERAND (exp, 0), 1), + TREE_OPERAND (exp, 1)); + tree rhs = fold_build2 (MINUS_EXPR, type, + TREE_OPERAND (TREE_OPERAND (exp, 0), 2), + TREE_OPERAND (exp, 1)); + return fold_build2 (max_p ? MAX_EXPR : MIN_EXPR, type, + max_size (lhs, max_p), + max_size (rhs, max_p)); + } + + { + tree lhs = max_size (TREE_OPERAND (exp, 0), max_p); + tree rhs = max_size (TREE_OPERAND (exp, 1), + code == MINUS_EXPR ? !max_p : max_p); + + /* Special-case wanting the maximum value of a MIN_EXPR. + In that case, if one side overflows, return the other. + sizetype is signed, but we know sizes are non-negative. + Likewise, handle a MINUS_EXPR or PLUS_EXPR with the LHS + overflowing or the maximum possible value and the RHS + a variable. */ + if (max_p + && code == MIN_EXPR + && TREE_CODE (rhs) == INTEGER_CST + && TREE_OVERFLOW (rhs)) + return lhs; + else if (max_p + && code == MIN_EXPR + && TREE_CODE (lhs) == INTEGER_CST + && TREE_OVERFLOW (lhs)) + return rhs; + else if ((code == MINUS_EXPR || code == PLUS_EXPR) + && ((TREE_CODE (lhs) == INTEGER_CST + && TREE_OVERFLOW (lhs)) + || operand_equal_p (lhs, TYPE_MAX_VALUE (type), 0)) + && !TREE_CONSTANT (rhs)) + return lhs; + else + return fold_build2 (code, type, lhs, rhs); + } + + case 3: + if (code == SAVE_EXPR) + return exp; + else if (code == COND_EXPR) + return fold_build2 (max_p ? MAX_EXPR : MIN_EXPR, type, + max_size (TREE_OPERAND (exp, 1), max_p), + max_size (TREE_OPERAND (exp, 2), max_p)); + } + + /* Other tree classes cannot happen. */ + default: + break; + } + + gcc_unreachable (); +} + +/* Build a template of type TEMPLATE_TYPE from the array bounds of ARRAY_TYPE. + EXPR is an expression that we can use to locate any PLACEHOLDER_EXPRs. + Return a constructor for the template. */ + +tree +build_template (tree template_type, tree array_type, tree expr) +{ + tree template_elts = NULL_TREE; + tree bound_list = NULL_TREE; + tree field; + + while (TREE_CODE (array_type) == RECORD_TYPE + && (TYPE_IS_PADDING_P (array_type) + || TYPE_JUSTIFIED_MODULAR_P (array_type))) + array_type = TREE_TYPE (TYPE_FIELDS (array_type)); + + if (TREE_CODE (array_type) == ARRAY_TYPE + || (TREE_CODE (array_type) == INTEGER_TYPE + && TYPE_HAS_ACTUAL_BOUNDS_P (array_type))) + bound_list = TYPE_ACTUAL_BOUNDS (array_type); + + /* First make the list for a CONSTRUCTOR for the template. Go down the + field list of the template instead of the type chain because this + array might be an Ada array of arrays and we can't tell where the + nested arrays stop being the underlying object. */ + + for (field = TYPE_FIELDS (template_type); field; + (bound_list + ? (bound_list = TREE_CHAIN (bound_list)) + : (array_type = TREE_TYPE (array_type))), + field = TREE_CHAIN (TREE_CHAIN (field))) + { + tree bounds, min, max; + + /* If we have a bound list, get the bounds from there. Likewise + for an ARRAY_TYPE. Otherwise, if expr is a PARM_DECL with + DECL_BY_COMPONENT_PTR_P, use the bounds of the field in the template. + This will give us a maximum range. */ + if (bound_list) + bounds = TREE_VALUE (bound_list); + else if (TREE_CODE (array_type) == ARRAY_TYPE) + bounds = TYPE_INDEX_TYPE (TYPE_DOMAIN (array_type)); + else if (expr && TREE_CODE (expr) == PARM_DECL + && DECL_BY_COMPONENT_PTR_P (expr)) + bounds = TREE_TYPE (field); + else + gcc_unreachable (); + + min = convert (TREE_TYPE (field), TYPE_MIN_VALUE (bounds)); + max = convert (TREE_TYPE (TREE_CHAIN (field)), TYPE_MAX_VALUE (bounds)); + + /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must + substitute it from OBJECT. */ + min = SUBSTITUTE_PLACEHOLDER_IN_EXPR (min, expr); + max = SUBSTITUTE_PLACEHOLDER_IN_EXPR (max, expr); + + template_elts = tree_cons (TREE_CHAIN (field), max, + tree_cons (field, min, template_elts)); + } + + return gnat_build_constructor (template_type, nreverse (template_elts)); +} + +/* Build a VMS descriptor from a Mechanism_Type, which must specify + a descriptor type, and the GCC type of an object. Each FIELD_DECL + in the type contains in its DECL_INITIAL the expression to use when + a constructor is made for the type. GNAT_ENTITY is an entity used + to print out an error message if the mechanism cannot be applied to + an object of that type and also for the name. */ + +tree +build_vms_descriptor (tree type, Mechanism_Type mech, Entity_Id gnat_entity) +{ + tree record_type = make_node (RECORD_TYPE); + tree pointer32_type; + tree field_list = 0; + int class; + int dtype = 0; + tree inner_type; + int ndim; + int i; + tree *idx_arr; + tree tem; + + /* If TYPE is an unconstrained array, use the underlying array type. */ + if (TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE) + type = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (type)))); + + /* If this is an array, compute the number of dimensions in the array, + get the index types, and point to the inner type. */ + if (TREE_CODE (type) != ARRAY_TYPE) + ndim = 0; + else + for (ndim = 1, inner_type = type; + TREE_CODE (TREE_TYPE (inner_type)) == ARRAY_TYPE + && TYPE_MULTI_ARRAY_P (TREE_TYPE (inner_type)); + ndim++, inner_type = TREE_TYPE (inner_type)) + ; + + idx_arr = (tree *) alloca (ndim * sizeof (tree)); + + if (mech != By_Descriptor_NCA + && TREE_CODE (type) == ARRAY_TYPE && TYPE_CONVENTION_FORTRAN_P (type)) + for (i = ndim - 1, inner_type = type; + i >= 0; + i--, inner_type = TREE_TYPE (inner_type)) + idx_arr[i] = TYPE_DOMAIN (inner_type); + else + for (i = 0, inner_type = type; + i < ndim; + i++, inner_type = TREE_TYPE (inner_type)) + idx_arr[i] = TYPE_DOMAIN (inner_type); + + /* Now get the DTYPE value. */ + switch (TREE_CODE (type)) + { + case INTEGER_TYPE: + case ENUMERAL_TYPE: + if (TYPE_VAX_FLOATING_POINT_P (type)) + switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1)) + { + case 6: + dtype = 10; + break; + case 9: + dtype = 11; + break; + case 15: + dtype = 27; + break; + } + else + switch (GET_MODE_BITSIZE (TYPE_MODE (type))) + { + case 8: + dtype = TYPE_UNSIGNED (type) ? 2 : 6; + break; + case 16: + dtype = TYPE_UNSIGNED (type) ? 3 : 7; + break; + case 32: + dtype = TYPE_UNSIGNED (type) ? 4 : 8; + break; + case 64: + dtype = TYPE_UNSIGNED (type) ? 5 : 9; + break; + case 128: + dtype = TYPE_UNSIGNED (type) ? 25 : 26; + break; + } + break; + + case REAL_TYPE: + dtype = GET_MODE_BITSIZE (TYPE_MODE (type)) == 32 ? 52 : 53; + break; + + case COMPLEX_TYPE: + if (TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE + && TYPE_VAX_FLOATING_POINT_P (type)) + switch (tree_low_cst (TYPE_DIGITS_VALUE (type), 1)) + { + case 6: + dtype = 12; + break; + case 9: + dtype = 13; + break; + case 15: + dtype = 29; + } + else + dtype = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (type))) == 32 ? 54: 55; + break; + + case ARRAY_TYPE: + dtype = 14; + break; + + default: + break; + } + + /* Get the CLASS value. */ + switch (mech) + { + case By_Descriptor_A: + class = 4; + break; + case By_Descriptor_NCA: + class = 10; + break; + case By_Descriptor_SB: + class = 15; + break; + case By_Descriptor: + case By_Descriptor_S: + default: + class = 1; + break; + } + + /* Make the type for a descriptor for VMS. The first four fields + are the same for all types. */ + + field_list + = chainon (field_list, + make_descriptor_field + ("LENGTH", gnat_type_for_size (16, 1), record_type, + size_in_bytes (mech == By_Descriptor_A ? inner_type : type))); + + field_list = chainon (field_list, + make_descriptor_field ("DTYPE", + gnat_type_for_size (8, 1), + record_type, size_int (dtype))); + field_list = chainon (field_list, + make_descriptor_field ("CLASS", + gnat_type_for_size (8, 1), + record_type, size_int (class))); + + /* Of course this will crash at run-time if the address space is not + within the low 32 bits, but there is nothing else we can do. */ + pointer32_type = build_pointer_type_for_mode (type, SImode, false); + + field_list + = chainon (field_list, + make_descriptor_field + ("POINTER", pointer32_type, record_type, + build_unary_op (ADDR_EXPR, + pointer32_type, + build0 (PLACEHOLDER_EXPR, type)))); + + switch (mech) + { + case By_Descriptor: + case By_Descriptor_S: + break; + + case By_Descriptor_SB: + field_list + = chainon (field_list, + make_descriptor_field + ("SB_L1", gnat_type_for_size (32, 1), record_type, + TREE_CODE (type) == ARRAY_TYPE + ? TYPE_MIN_VALUE (TYPE_DOMAIN (type)) : size_zero_node)); + field_list + = chainon (field_list, + make_descriptor_field + ("SB_U1", gnat_type_for_size (32, 1), record_type, + TREE_CODE (type) == ARRAY_TYPE + ? TYPE_MAX_VALUE (TYPE_DOMAIN (type)) : size_zero_node)); + break; + + case By_Descriptor_A: + case By_Descriptor_NCA: + field_list = chainon (field_list, + make_descriptor_field ("SCALE", + gnat_type_for_size (8, 1), + record_type, + size_zero_node)); + + field_list = chainon (field_list, + make_descriptor_field ("DIGITS", + gnat_type_for_size (8, 1), + record_type, + size_zero_node)); + + field_list + = chainon (field_list, + make_descriptor_field + ("AFLAGS", gnat_type_for_size (8, 1), record_type, + size_int (mech == By_Descriptor_NCA + ? 0 + /* Set FL_COLUMN, FL_COEFF, and FL_BOUNDS. */ + : (TREE_CODE (type) == ARRAY_TYPE + && TYPE_CONVENTION_FORTRAN_P (type) + ? 224 : 192)))); + + field_list = chainon (field_list, + make_descriptor_field ("DIMCT", + gnat_type_for_size (8, 1), + record_type, + size_int (ndim))); + + field_list = chainon (field_list, + make_descriptor_field ("ARSIZE", + gnat_type_for_size (32, 1), + record_type, + size_in_bytes (type))); + + /* Now build a pointer to the 0,0,0... element. */ + tem = build0 (PLACEHOLDER_EXPR, type); + for (i = 0, inner_type = type; i < ndim; + i++, inner_type = TREE_TYPE (inner_type)) + tem = build4 (ARRAY_REF, TREE_TYPE (inner_type), tem, + convert (TYPE_DOMAIN (inner_type), size_zero_node), + NULL_TREE, NULL_TREE); + + field_list + = chainon (field_list, + make_descriptor_field + ("A0", + build_pointer_type_for_mode (inner_type, SImode, false), + record_type, + build1 (ADDR_EXPR, + build_pointer_type_for_mode (inner_type, SImode, + false), + tem))); + + /* Next come the addressing coefficients. */ + tem = size_one_node; + for (i = 0; i < ndim; i++) + { + char fname[3]; + tree idx_length + = size_binop (MULT_EXPR, tem, + size_binop (PLUS_EXPR, + size_binop (MINUS_EXPR, + TYPE_MAX_VALUE (idx_arr[i]), + TYPE_MIN_VALUE (idx_arr[i])), + size_int (1))); + + fname[0] = (mech == By_Descriptor_NCA ? 'S' : 'M'); + fname[1] = '0' + i, fname[2] = 0; + field_list + = chainon (field_list, + make_descriptor_field (fname, + gnat_type_for_size (32, 1), + record_type, idx_length)); + + if (mech == By_Descriptor_NCA) + tem = idx_length; + } + + /* Finally here are the bounds. */ + for (i = 0; i < ndim; i++) + { + char fname[3]; + + fname[0] = 'L', fname[1] = '0' + i, fname[2] = 0; + field_list + = chainon (field_list, + make_descriptor_field + (fname, gnat_type_for_size (32, 1), record_type, + TYPE_MIN_VALUE (idx_arr[i]))); + + fname[0] = 'U'; + field_list + = chainon (field_list, + make_descriptor_field + (fname, gnat_type_for_size (32, 1), record_type, + TYPE_MAX_VALUE (idx_arr[i]))); + } + break; + + default: + post_error ("unsupported descriptor type for &", gnat_entity); + } + + finish_record_type (record_type, field_list, 0, true); + create_type_decl (create_concat_name (gnat_entity, "DESC"), record_type, + NULL, true, false, gnat_entity); + + return record_type; +} + +/* Utility routine for above code to make a field. */ + +static tree +make_descriptor_field (const char *name, tree type, + tree rec_type, tree initial) +{ + tree field + = create_field_decl (get_identifier (name), type, rec_type, 0, 0, 0, 0); + + DECL_INITIAL (field) = initial; + return field; +} + +/* Convert GNU_EXPR, a pointer to a VMS descriptor, to GNU_TYPE, a regular + pointer or fat pointer type. GNAT_SUBPROG is the subprogram to which + the VMS descriptor is passed. */ + +static tree +convert_vms_descriptor (tree gnu_type, tree gnu_expr, Entity_Id gnat_subprog) +{ + tree desc_type = TREE_TYPE (TREE_TYPE (gnu_expr)); + tree desc = build1 (INDIRECT_REF, desc_type, gnu_expr); + /* The CLASS field is the 3rd field in the descriptor. */ + tree class = TREE_CHAIN (TREE_CHAIN (TYPE_FIELDS (desc_type))); + /* The POINTER field is the 4th field in the descriptor. */ + tree pointer = TREE_CHAIN (class); + + /* Retrieve the value of the POINTER field. */ + gnu_expr + = build3 (COMPONENT_REF, TREE_TYPE (pointer), desc, pointer, NULL_TREE); + + if (POINTER_TYPE_P (gnu_type)) + return convert (gnu_type, gnu_expr); + + else if (TYPE_FAT_POINTER_P (gnu_type)) + { + tree p_array_type = TREE_TYPE (TYPE_FIELDS (gnu_type)); + tree p_bounds_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (gnu_type))); + tree template_type = TREE_TYPE (p_bounds_type); + tree min_field = TYPE_FIELDS (template_type); + tree max_field = TREE_CHAIN (TYPE_FIELDS (template_type)); + tree template, template_addr, aflags, dimct, t, u; + /* See the head comment of build_vms_descriptor. */ + int iclass = TREE_INT_CST_LOW (DECL_INITIAL (class)); + + /* Convert POINTER to the type of the P_ARRAY field. */ + gnu_expr = convert (p_array_type, gnu_expr); + + switch (iclass) + { + case 1: /* Class S */ + case 15: /* Class SB */ + /* Build {1, LENGTH} template; LENGTH is the 1st field. */ + t = TYPE_FIELDS (desc_type); + t = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE); + t = tree_cons (min_field, + convert (TREE_TYPE (min_field), integer_one_node), + tree_cons (max_field, + convert (TREE_TYPE (max_field), t), + NULL_TREE)); + template = gnat_build_constructor (template_type, t); + template_addr = build_unary_op (ADDR_EXPR, NULL_TREE, template); + + /* For class S, we are done. */ + if (iclass == 1) + break; + + /* Test that we really have a SB descriptor, like DEC Ada. */ + t = build3 (COMPONENT_REF, TREE_TYPE (class), desc, class, NULL); + u = convert (TREE_TYPE (class), DECL_INITIAL (class)); + u = build_binary_op (EQ_EXPR, integer_type_node, t, u); + /* If so, there is already a template in the descriptor and + it is located right after the POINTER field. */ + t = TREE_CHAIN (pointer); + template = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE); + /* Otherwise use the {1, LENGTH} template we build above. */ + template_addr = build3 (COND_EXPR, p_bounds_type, u, + build_unary_op (ADDR_EXPR, p_bounds_type, + template), + template_addr); + break; + + case 4: /* Class A */ + /* The AFLAGS field is the 7th field in the descriptor. */ + t = TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (pointer))); + aflags = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE); + /* The DIMCT field is the 8th field in the descriptor. */ + t = TREE_CHAIN (t); + dimct = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE); + /* Raise CONSTRAINT_ERROR if either more than 1 dimension + or FL_COEFF or FL_BOUNDS not set. */ + u = build_int_cst (TREE_TYPE (aflags), 192); + u = build_binary_op (TRUTH_OR_EXPR, integer_type_node, + build_binary_op (NE_EXPR, integer_type_node, + dimct, + convert (TREE_TYPE (dimct), + size_one_node)), + build_binary_op (NE_EXPR, integer_type_node, + build2 (BIT_AND_EXPR, + TREE_TYPE (aflags), + aflags, u), + u)); + add_stmt (build3 (COND_EXPR, void_type_node, u, + build_call_raise (CE_Length_Check_Failed, Empty, + N_Raise_Constraint_Error), + NULL_TREE)); + /* There is already a template in the descriptor and it is + located at the start of block 3 (12th field). */ + t = TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (TREE_CHAIN (t)))); + template = build3 (COMPONENT_REF, TREE_TYPE (t), desc, t, NULL_TREE); + template_addr = build_unary_op (ADDR_EXPR, p_bounds_type, template); + break; + + case 10: /* Class NCA */ + default: + post_error ("unsupported descriptor type for &", gnat_subprog); + template_addr = integer_zero_node; + break; + } + + /* Build the fat pointer in the form of a constructor. */ + t = tree_cons (TYPE_FIELDS (gnu_type), gnu_expr, + tree_cons (TREE_CHAIN (TYPE_FIELDS (gnu_type)), + template_addr, NULL_TREE)); + return gnat_build_constructor (gnu_type, t); + } + + else + gcc_unreachable (); +} + +/* Build a stub for the subprogram specified by the GCC tree GNU_SUBPROG + and the GNAT node GNAT_SUBPROG. */ + +void +build_function_stub (tree gnu_subprog, Entity_Id gnat_subprog) +{ + tree gnu_subprog_type, gnu_subprog_addr, gnu_subprog_call; + tree gnu_stub_param, gnu_param_list, gnu_arg_types, gnu_param; + tree gnu_stub_decl = DECL_FUNCTION_STUB (gnu_subprog); + tree gnu_body; + + gnu_subprog_type = TREE_TYPE (gnu_subprog); + gnu_param_list = NULL_TREE; + + begin_subprog_body (gnu_stub_decl); + gnat_pushlevel (); + + start_stmt_group (); + + /* Loop over the parameters of the stub and translate any of them + passed by descriptor into a by reference one. */ + for (gnu_stub_param = DECL_ARGUMENTS (gnu_stub_decl), + gnu_arg_types = TYPE_ARG_TYPES (gnu_subprog_type); + gnu_stub_param; + gnu_stub_param = TREE_CHAIN (gnu_stub_param), + gnu_arg_types = TREE_CHAIN (gnu_arg_types)) + { + if (DECL_BY_DESCRIPTOR_P (gnu_stub_param)) + gnu_param = convert_vms_descriptor (TREE_VALUE (gnu_arg_types), + gnu_stub_param, gnat_subprog); + else + gnu_param = gnu_stub_param; + + gnu_param_list = tree_cons (NULL_TREE, gnu_param, gnu_param_list); + } + + gnu_body = end_stmt_group (); + + /* Invoke the internal subprogram. */ + gnu_subprog_addr = build1 (ADDR_EXPR, build_pointer_type (gnu_subprog_type), + gnu_subprog); + gnu_subprog_call = build_call_list (TREE_TYPE (gnu_subprog_type), + gnu_subprog_addr, + nreverse (gnu_param_list)); + + /* Propagate the return value, if any. */ + if (VOID_TYPE_P (TREE_TYPE (gnu_subprog_type))) + append_to_statement_list (gnu_subprog_call, &gnu_body); + else + append_to_statement_list (build_return_expr (DECL_RESULT (gnu_stub_decl), + gnu_subprog_call), + &gnu_body); + + gnat_poplevel (); + + allocate_struct_function (gnu_stub_decl, false); + end_subprog_body (gnu_body, false); +} + +/* Build a type to be used to represent an aliased object whose nominal + type is an unconstrained array. This consists of a RECORD_TYPE containing + a field of TEMPLATE_TYPE and a field of OBJECT_TYPE, which is an + ARRAY_TYPE. If ARRAY_TYPE is that of the unconstrained array, this + is used to represent an arbitrary unconstrained object. Use NAME + as the name of the record. */ + +tree +build_unc_object_type (tree template_type, tree object_type, tree name) +{ + tree type = make_node (RECORD_TYPE); + tree template_field = create_field_decl (get_identifier ("BOUNDS"), + template_type, type, 0, 0, 0, 1); + tree array_field = create_field_decl (get_identifier ("ARRAY"), object_type, + type, 0, 0, 0, 1); + + TYPE_NAME (type) = name; + TYPE_CONTAINS_TEMPLATE_P (type) = 1; + finish_record_type (type, + chainon (chainon (NULL_TREE, template_field), + array_field), + 0, false); + + return type; +} + +/* Same, taking a thin or fat pointer type instead of a template type. */ + +tree +build_unc_object_type_from_ptr (tree thin_fat_ptr_type, tree object_type, + tree name) +{ + tree template_type; + + gcc_assert (TYPE_FAT_OR_THIN_POINTER_P (thin_fat_ptr_type)); + + template_type + = (TYPE_FAT_POINTER_P (thin_fat_ptr_type) + ? TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (thin_fat_ptr_type)))) + : TREE_TYPE (TYPE_FIELDS (TREE_TYPE (thin_fat_ptr_type)))); + return build_unc_object_type (template_type, object_type, name); +} + +/* Shift the component offsets within an unconstrained object TYPE to make it + suitable for use as a designated type for thin pointers. */ + +void +shift_unc_components_for_thin_pointers (tree type) +{ + /* Thin pointer values designate the ARRAY data of an unconstrained object, + allocated past the BOUNDS template. The designated type is adjusted to + have ARRAY at position zero and the template at a negative offset, so + that COMPONENT_REFs on (*thin_ptr) designate the proper location. */ + + tree bounds_field = TYPE_FIELDS (type); + tree array_field = TREE_CHAIN (TYPE_FIELDS (type)); + + DECL_FIELD_OFFSET (bounds_field) + = size_binop (MINUS_EXPR, size_zero_node, byte_position (array_field)); + + DECL_FIELD_OFFSET (array_field) = size_zero_node; + DECL_FIELD_BIT_OFFSET (array_field) = bitsize_zero_node; +} + +/* Update anything previously pointing to OLD_TYPE to point to NEW_TYPE. In + the normal case this is just two adjustments, but we have more to do + if NEW is an UNCONSTRAINED_ARRAY_TYPE. */ + +void +update_pointer_to (tree old_type, tree new_type) +{ + tree ptr = TYPE_POINTER_TO (old_type); + tree ref = TYPE_REFERENCE_TO (old_type); + tree ptr1, ref1; + tree type; + + /* If this is the main variant, process all the other variants first. */ + if (TYPE_MAIN_VARIANT (old_type) == old_type) + for (type = TYPE_NEXT_VARIANT (old_type); type; + type = TYPE_NEXT_VARIANT (type)) + update_pointer_to (type, new_type); + + /* If no pointer or reference, we are done. */ + if (!ptr && !ref) + return; + + /* Merge the old type qualifiers in the new type. + + Each old variant has qualifiers for specific reasons, and the new + designated type as well. Each set of qualifiers represents useful + information grabbed at some point, and merging the two simply unifies + these inputs into the final type description. + + Consider for instance a volatile type frozen after an access to constant + type designating it. After the designated type freeze, we get here with a + volatile new_type and a dummy old_type with a readonly variant, created + when the access type was processed. We shall make a volatile and readonly + designated type, because that's what it really is. + + We might also get here for a non-dummy old_type variant with different + qualifiers than the new_type ones, for instance in some cases of pointers + to private record type elaboration (see the comments around the call to + this routine from gnat_to_gnu_entity/E_Access_Type). We have to merge the + qualifiers in those cases too, to avoid accidentally discarding the + initial set, and will often end up with old_type == new_type then. */ + new_type = build_qualified_type (new_type, + TYPE_QUALS (old_type) + | TYPE_QUALS (new_type)); + + /* If the new type and the old one are identical, there is nothing to + update. */ + if (old_type == new_type) + return; + + /* Otherwise, first handle the simple case. */ + if (TREE_CODE (new_type) != UNCONSTRAINED_ARRAY_TYPE) + { + TYPE_POINTER_TO (new_type) = ptr; + TYPE_REFERENCE_TO (new_type) = ref; + + for (; ptr; ptr = TYPE_NEXT_PTR_TO (ptr)) + for (ptr1 = TYPE_MAIN_VARIANT (ptr); ptr1; + ptr1 = TYPE_NEXT_VARIANT (ptr1)) + TREE_TYPE (ptr1) = new_type; + + for (; ref; ref = TYPE_NEXT_REF_TO (ref)) + for (ref1 = TYPE_MAIN_VARIANT (ref); ref1; + ref1 = TYPE_NEXT_VARIANT (ref1)) + TREE_TYPE (ref1) = new_type; + } + + /* Now deal with the unconstrained array case. In this case the "pointer" + is actually a RECORD_TYPE where both fields are pointers to dummy nodes. + Turn them into pointers to the correct types using update_pointer_to. */ + else if (TREE_CODE (ptr) != RECORD_TYPE || !TYPE_IS_FAT_POINTER_P (ptr)) + gcc_unreachable (); + + else + { + tree new_obj_rec = TYPE_OBJECT_RECORD_TYPE (new_type); + tree array_field = TYPE_FIELDS (ptr); + tree bounds_field = TREE_CHAIN (TYPE_FIELDS (ptr)); + tree new_ptr = TYPE_POINTER_TO (new_type); + tree new_ref; + tree var; + + /* Make pointers to the dummy template point to the real template. */ + update_pointer_to + (TREE_TYPE (TREE_TYPE (bounds_field)), + TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (new_ptr))))); + + /* The references to the template bounds present in the array type + are made through a PLACEHOLDER_EXPR of type new_ptr. Since we + are updating ptr to make it a full replacement for new_ptr as + pointer to new_type, we must rework the PLACEHOLDER_EXPR so as + to make it of type ptr. */ + new_ref = build3 (COMPONENT_REF, TREE_TYPE (bounds_field), + build0 (PLACEHOLDER_EXPR, ptr), + bounds_field, NULL_TREE); + + /* Create the new array for the new PLACEHOLDER_EXPR and make + pointers to the dummy array point to it. + + ??? This is now the only use of substitute_in_type, + which is a very "heavy" routine to do this, so it + should be replaced at some point. */ + update_pointer_to + (TREE_TYPE (TREE_TYPE (array_field)), + substitute_in_type (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (new_ptr))), + TREE_CHAIN (TYPE_FIELDS (new_ptr)), new_ref)); + + /* Make ptr the pointer to new_type. */ + TYPE_POINTER_TO (new_type) = TYPE_REFERENCE_TO (new_type) + = TREE_TYPE (new_type) = ptr; + + for (var = TYPE_MAIN_VARIANT (ptr); var; var = TYPE_NEXT_VARIANT (var)) + SET_TYPE_UNCONSTRAINED_ARRAY (var, new_type); + + /* Now handle updating the allocation record, what the thin pointer + points to. Update all pointers from the old record into the new + one, update the type of the array field, and recompute the size. */ + update_pointer_to (TYPE_OBJECT_RECORD_TYPE (old_type), new_obj_rec); + + TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))) + = TREE_TYPE (TREE_TYPE (array_field)); + + /* The size recomputation needs to account for alignment constraints, so + we let layout_type work it out. This will reset the field offsets to + what they would be in a regular record, so we shift them back to what + we want them to be for a thin pointer designated type afterwards. */ + DECL_SIZE (TYPE_FIELDS (new_obj_rec)) = 0; + DECL_SIZE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))) = 0; + TYPE_SIZE (new_obj_rec) = 0; + layout_type (new_obj_rec); + + shift_unc_components_for_thin_pointers (new_obj_rec); + + /* We are done, at last. */ + rest_of_record_type_compilation (ptr); + } +} + +/* Convert a pointer to a constrained array into a pointer to a fat + pointer. This involves making or finding a template. */ + +static tree +convert_to_fat_pointer (tree type, tree expr) +{ + tree template_type = TREE_TYPE (TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type)))); + tree template, template_addr; + tree etype = TREE_TYPE (expr); + + /* If EXPR is a constant of zero, we make a fat pointer that has a null + pointer to the template and array. */ + if (integer_zerop (expr)) + return + gnat_build_constructor + (type, + tree_cons (TYPE_FIELDS (type), + convert (TREE_TYPE (TYPE_FIELDS (type)), expr), + tree_cons (TREE_CHAIN (TYPE_FIELDS (type)), + convert (build_pointer_type (template_type), + expr), + NULL_TREE))); + + /* If EXPR is a thin pointer, make the template and data from the record. */ + + else if (TYPE_THIN_POINTER_P (etype)) + { + tree fields = TYPE_FIELDS (TREE_TYPE (etype)); + + expr = save_expr (expr); + if (TREE_CODE (expr) == ADDR_EXPR) + expr = TREE_OPERAND (expr, 0); + else + expr = build1 (INDIRECT_REF, TREE_TYPE (etype), expr); + + template = build_component_ref (expr, NULL_TREE, fields, false); + expr = build_unary_op (ADDR_EXPR, NULL_TREE, + build_component_ref (expr, NULL_TREE, + TREE_CHAIN (fields), false)); + } + else + /* Otherwise, build the constructor for the template. */ + template = build_template (template_type, TREE_TYPE (etype), expr); + + template_addr = build_unary_op (ADDR_EXPR, NULL_TREE, template); + + /* The result is a CONSTRUCTOR for the fat pointer. + + If expr is an argument of a foreign convention subprogram, the type it + points to is directly the component type. In this case, the expression + type may not match the corresponding FIELD_DECL type at this point, so we + call "convert" here to fix that up if necessary. This type consistency is + required, for instance because it ensures that possible later folding of + component_refs against this constructor always yields something of the + same type as the initial reference. + + Note that the call to "build_template" above is still fine, because it + will only refer to the provided template_type in this case. */ + return + gnat_build_constructor + (type, tree_cons (TYPE_FIELDS (type), + convert (TREE_TYPE (TYPE_FIELDS (type)), expr), + tree_cons (TREE_CHAIN (TYPE_FIELDS (type)), + template_addr, NULL_TREE))); +} + +/* Convert to a thin pointer type, TYPE. The only thing we know how to convert + is something that is a fat pointer, so convert to it first if it EXPR + is not already a fat pointer. */ + +static tree +convert_to_thin_pointer (tree type, tree expr) +{ + if (!TYPE_FAT_POINTER_P (TREE_TYPE (expr))) + expr + = convert_to_fat_pointer + (TREE_TYPE (TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))), expr); + + /* We get the pointer to the data and use a NOP_EXPR to make it the + proper GCC type. */ + expr = build_component_ref (expr, NULL_TREE, TYPE_FIELDS (TREE_TYPE (expr)), + false); + expr = build1 (NOP_EXPR, type, expr); + + return expr; +} + +/* Create an expression whose value is that of EXPR, + converted to type TYPE. The TREE_TYPE of the value + is always TYPE. This function implements all reasonable + conversions; callers should filter out those that are + not permitted by the language being compiled. */ + +tree +convert (tree type, tree expr) +{ + enum tree_code code = TREE_CODE (type); + tree etype = TREE_TYPE (expr); + enum tree_code ecode = TREE_CODE (etype); + + /* If EXPR is already the right type, we are done. */ + if (type == etype) + return expr; + + /* If both input and output have padding and are of variable size, do this + as an unchecked conversion. Likewise if one is a mere variant of the + other, so we avoid a pointless unpad/repad sequence. */ + else if (code == RECORD_TYPE && ecode == RECORD_TYPE + && TYPE_IS_PADDING_P (type) && TYPE_IS_PADDING_P (etype) + && (!TREE_CONSTANT (TYPE_SIZE (type)) + || !TREE_CONSTANT (TYPE_SIZE (etype)) + || gnat_types_compatible_p (type, etype) + || TYPE_NAME (TREE_TYPE (TYPE_FIELDS (type))) + == TYPE_NAME (TREE_TYPE (TYPE_FIELDS (etype))))) + ; + + /* If the output type has padding, convert to the inner type and + make a constructor to build the record. */ + else if (code == RECORD_TYPE && TYPE_IS_PADDING_P (type)) + { + /* If we previously converted from another type and our type is + of variable size, remove the conversion to avoid the need for + variable-size temporaries. Likewise for a conversion between + original and packable version. */ + if (TREE_CODE (expr) == VIEW_CONVERT_EXPR + && (!TREE_CONSTANT (TYPE_SIZE (type)) + || (ecode == RECORD_TYPE + && TYPE_NAME (etype) + == TYPE_NAME (TREE_TYPE (TREE_OPERAND (expr, 0)))))) + expr = TREE_OPERAND (expr, 0); + + /* If we are just removing the padding from expr, convert the original + object if we have variable size in order to avoid the need for some + variable-size temporaries. Likewise if the padding is a mere variant + of the other, so we avoid a pointless unpad/repad sequence. */ + if (TREE_CODE (expr) == COMPONENT_REF + && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == RECORD_TYPE + && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (expr, 0))) + && (!TREE_CONSTANT (TYPE_SIZE (type)) + || gnat_types_compatible_p (type, + TREE_TYPE (TREE_OPERAND (expr, 0))) + || (ecode == RECORD_TYPE + && TYPE_NAME (etype) + == TYPE_NAME (TREE_TYPE (TYPE_FIELDS (type)))))) + return convert (type, TREE_OPERAND (expr, 0)); + + /* If the result type is a padded type with a self-referentially-sized + field and the expression type is a record, do this as an + unchecked conversion. */ + else if (TREE_CODE (etype) == RECORD_TYPE + && CONTAINS_PLACEHOLDER_P (DECL_SIZE (TYPE_FIELDS (type)))) + return unchecked_convert (type, expr, false); + + else + return + gnat_build_constructor (type, + tree_cons (TYPE_FIELDS (type), + convert (TREE_TYPE + (TYPE_FIELDS (type)), + expr), + NULL_TREE)); + } + + /* If the input type has padding, remove it and convert to the output type. + The conditions ordering is arranged to ensure that the output type is not + a padding type here, as it is not clear whether the conversion would + always be correct if this was to happen. */ + else if (ecode == RECORD_TYPE && TYPE_IS_PADDING_P (etype)) + { + tree unpadded; + + /* If we have just converted to this padded type, just get the + inner expression. */ + if (TREE_CODE (expr) == CONSTRUCTOR + && !VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (expr)) + && VEC_index (constructor_elt, CONSTRUCTOR_ELTS (expr), 0)->index + == TYPE_FIELDS (etype)) + unpadded + = VEC_index (constructor_elt, CONSTRUCTOR_ELTS (expr), 0)->value; + + /* Otherwise, build an explicit component reference. */ + else + unpadded + = build_component_ref (expr, NULL_TREE, TYPE_FIELDS (etype), false); + + return convert (type, unpadded); + } + + /* If the input is a biased type, adjust first. */ + if (ecode == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (etype)) + return convert (type, fold_build2 (PLUS_EXPR, TREE_TYPE (etype), + fold_convert (TREE_TYPE (etype), + expr), + TYPE_MIN_VALUE (etype))); + + /* If the input is a justified modular type, we need to extract the actual + object before converting it to any other type with the exceptions of an + unconstrained array or of a mere type variant. It is useful to avoid the + extraction and conversion in the type variant case because it could end + up replacing a VAR_DECL expr by a constructor and we might be about the + take the address of the result. */ + if (ecode == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (etype) + && code != UNCONSTRAINED_ARRAY_TYPE + && TYPE_MAIN_VARIANT (type) != TYPE_MAIN_VARIANT (etype)) + return convert (type, build_component_ref (expr, NULL_TREE, + TYPE_FIELDS (etype), false)); + + /* If converting to a type that contains a template, convert to the data + type and then build the template. */ + if (code == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (type)) + { + tree obj_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type))); + + /* If the source already has a template, get a reference to the + associated array only, as we are going to rebuild a template + for the target type anyway. */ + expr = maybe_unconstrained_array (expr); + + return + gnat_build_constructor + (type, + tree_cons (TYPE_FIELDS (type), + build_template (TREE_TYPE (TYPE_FIELDS (type)), + obj_type, NULL_TREE), + tree_cons (TREE_CHAIN (TYPE_FIELDS (type)), + convert (obj_type, expr), NULL_TREE))); + } + + /* There are some special cases of expressions that we process + specially. */ + switch (TREE_CODE (expr)) + { + case ERROR_MARK: + return expr; + + case NULL_EXPR: + /* Just set its type here. For TRANSFORM_EXPR, we will do the actual + conversion in gnat_expand_expr. NULL_EXPR does not represent + and actual value, so no conversion is needed. */ + expr = copy_node (expr); + TREE_TYPE (expr) = type; + return expr; + + case STRING_CST: + /* If we are converting a STRING_CST to another constrained array type, + just make a new one in the proper type. */ + if (code == ecode && AGGREGATE_TYPE_P (etype) + && !(TREE_CODE (TYPE_SIZE (etype)) == INTEGER_CST + && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)) + { + expr = copy_node (expr); + TREE_TYPE (expr) = type; + return expr; + } + break; + + case CONSTRUCTOR: + /* If we are converting a CONSTRUCTOR to a mere variant type, just make + a new one in the proper type. */ + if (code == ecode && gnat_types_compatible_p (type, etype)) + { + expr = copy_node (expr); + TREE_TYPE (expr) = type; + return expr; + } + + /* Likewise for a conversion between original and packable version, but + we have to work harder in order to preserve type consistency. */ + if (code == ecode + && code == RECORD_TYPE + && TYPE_NAME (type) == TYPE_NAME (etype)) + { + VEC(constructor_elt,gc) *e = CONSTRUCTOR_ELTS (expr); + unsigned HOST_WIDE_INT len = VEC_length (constructor_elt, e); + VEC(constructor_elt,gc) *v = VEC_alloc (constructor_elt, gc, len); + tree efield = TYPE_FIELDS (etype), field = TYPE_FIELDS (type); + unsigned HOST_WIDE_INT idx; + tree index, value; + + FOR_EACH_CONSTRUCTOR_ELT(e, idx, index, value) + { + constructor_elt *elt = VEC_quick_push (constructor_elt, v, NULL); + /* We expect only simple constructors. Otherwise, punt. */ + if (!(index == efield || index == DECL_ORIGINAL_FIELD (efield))) + break; + elt->index = field; + elt->value = convert (TREE_TYPE (field), value); + efield = TREE_CHAIN (efield); + field = TREE_CHAIN (field); + } + + if (idx == len) + { + expr = copy_node (expr); + TREE_TYPE (expr) = type; + CONSTRUCTOR_ELTS (expr) = v; + return expr; + } + } + break; + + case UNCONSTRAINED_ARRAY_REF: + /* Convert this to the type of the inner array by getting the address of + the array from the template. */ + expr = build_unary_op (INDIRECT_REF, NULL_TREE, + build_component_ref (TREE_OPERAND (expr, 0), + get_identifier ("P_ARRAY"), + NULL_TREE, false)); + etype = TREE_TYPE (expr); + ecode = TREE_CODE (etype); + break; + + case VIEW_CONVERT_EXPR: + { + /* GCC 4.x is very sensitive to type consistency overall, and view + conversions thus are very frequent. Even though just "convert"ing + the inner operand to the output type is fine in most cases, it + might expose unexpected input/output type mismatches in special + circumstances so we avoid such recursive calls when we can. */ + tree op0 = TREE_OPERAND (expr, 0); + + /* If we are converting back to the original type, we can just + lift the input conversion. This is a common occurrence with + switches back-and-forth amongst type variants. */ + if (type == TREE_TYPE (op0)) + return op0; + + /* Otherwise, if we're converting between two aggregate types, we + might be allowed to substitute the VIEW_CONVERT_EXPR target type + in place or to just convert the inner expression. */ + if (AGGREGATE_TYPE_P (type) && AGGREGATE_TYPE_P (etype)) + { + /* If we are converting between mere variants, we can just + substitute the VIEW_CONVERT_EXPR in place. */ + if (gnat_types_compatible_p (type, etype)) + return build1 (VIEW_CONVERT_EXPR, type, op0); + + /* Otherwise, we may just bypass the input view conversion unless + one of the types is a fat pointer, which is handled by + specialized code below which relies on exact type matching. */ + else if (!TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype)) + return convert (type, op0); + } + } + break; + + case INDIRECT_REF: + /* If both types are record types, just convert the pointer and + make a new INDIRECT_REF. + + ??? Disable this for now since it causes problems with the + code in build_binary_op for MODIFY_EXPR which wants to + strip off conversions. But that code really is a mess and + we need to do this a much better way some time. */ + if (0 + && (TREE_CODE (type) == RECORD_TYPE + || TREE_CODE (type) == UNION_TYPE) + && (TREE_CODE (etype) == RECORD_TYPE + || TREE_CODE (etype) == UNION_TYPE) + && !TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype)) + return build_unary_op (INDIRECT_REF, NULL_TREE, + convert (build_pointer_type (type), + TREE_OPERAND (expr, 0))); + break; + + default: + break; + } + + /* Check for converting to a pointer to an unconstrained array. */ + if (TYPE_FAT_POINTER_P (type) && !TYPE_FAT_POINTER_P (etype)) + return convert_to_fat_pointer (type, expr); + + /* If we are converting between two aggregate types that are mere + variants, just make a VIEW_CONVERT_EXPR. */ + else if (code == ecode + && AGGREGATE_TYPE_P (type) + && gnat_types_compatible_p (type, etype)) + return build1 (VIEW_CONVERT_EXPR, type, expr); + + /* In all other cases of related types, make a NOP_EXPR. */ + else if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype) + || (code == INTEGER_CST && ecode == INTEGER_CST + && (type == TREE_TYPE (etype) || etype == TREE_TYPE (type)))) + return fold_convert (type, expr); + + switch (code) + { + case VOID_TYPE: + return fold_build1 (CONVERT_EXPR, type, expr); + + case BOOLEAN_TYPE: + return fold_convert (type, gnat_truthvalue_conversion (expr)); + + case INTEGER_TYPE: + if (TYPE_HAS_ACTUAL_BOUNDS_P (type) + && (ecode == ARRAY_TYPE || ecode == UNCONSTRAINED_ARRAY_TYPE + || (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype)))) + return unchecked_convert (type, expr, false); + else if (TYPE_BIASED_REPRESENTATION_P (type)) + return fold_convert (type, + fold_build2 (MINUS_EXPR, TREE_TYPE (type), + convert (TREE_TYPE (type), expr), + TYPE_MIN_VALUE (type))); + + /* ... fall through ... */ + + case ENUMERAL_TYPE: + /* If we are converting an additive expression to an integer type + with lower precision, be wary of the optimization that can be + applied by convert_to_integer. There are 2 problematic cases: + - if the first operand was originally of a biased type, + because we could be recursively called to convert it + to an intermediate type and thus rematerialize the + additive operator endlessly, + - if the expression contains a placeholder, because an + intermediate conversion that changes the sign could + be inserted and thus introduce an artificial overflow + at compile time when the placeholder is substituted. */ + if (code == INTEGER_TYPE + && ecode == INTEGER_TYPE + && TYPE_PRECISION (type) < TYPE_PRECISION (etype) + && (TREE_CODE (expr) == PLUS_EXPR || TREE_CODE (expr) == MINUS_EXPR)) + { + tree op0 = get_unwidened (TREE_OPERAND (expr, 0), type); + + if ((TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE + && TYPE_BIASED_REPRESENTATION_P (TREE_TYPE (op0))) + || CONTAINS_PLACEHOLDER_P (expr)) + return build1 (NOP_EXPR, type, expr); + } + + return fold (convert_to_integer (type, expr)); + + case POINTER_TYPE: + case REFERENCE_TYPE: + /* If converting between two pointers to records denoting + both a template and type, adjust if needed to account + for any differing offsets, since one might be negative. */ + if (TYPE_THIN_POINTER_P (etype) && TYPE_THIN_POINTER_P (type)) + { + tree bit_diff + = size_diffop (bit_position (TYPE_FIELDS (TREE_TYPE (etype))), + bit_position (TYPE_FIELDS (TREE_TYPE (type)))); + tree byte_diff = size_binop (CEIL_DIV_EXPR, bit_diff, + sbitsize_int (BITS_PER_UNIT)); + + expr = build1 (NOP_EXPR, type, expr); + TREE_CONSTANT (expr) = TREE_CONSTANT (TREE_OPERAND (expr, 0)); + if (integer_zerop (byte_diff)) + return expr; + + return build_binary_op (POINTER_PLUS_EXPR, type, expr, + fold (convert (sizetype, byte_diff))); + } + + /* If converting to a thin pointer, handle specially. */ + if (TYPE_THIN_POINTER_P (type) + && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type))) + return convert_to_thin_pointer (type, expr); + + /* If converting fat pointer to normal pointer, get the pointer to the + array and then convert it. */ + else if (TYPE_FAT_POINTER_P (etype)) + expr = build_component_ref (expr, get_identifier ("P_ARRAY"), + NULL_TREE, false); + + return fold (convert_to_pointer (type, expr)); + + case REAL_TYPE: + return fold (convert_to_real (type, expr)); + + case RECORD_TYPE: + if (TYPE_JUSTIFIED_MODULAR_P (type) && !AGGREGATE_TYPE_P (etype)) + return + gnat_build_constructor + (type, tree_cons (TYPE_FIELDS (type), + convert (TREE_TYPE (TYPE_FIELDS (type)), expr), + NULL_TREE)); + + /* ... fall through ... */ + + case ARRAY_TYPE: + /* In these cases, assume the front-end has validated the conversion. + If the conversion is valid, it will be a bit-wise conversion, so + it can be viewed as an unchecked conversion. */ + return unchecked_convert (type, expr, false); + + case UNION_TYPE: + /* This is a either a conversion between a tagged type and some + subtype, which we have to mark as a UNION_TYPE because of + overlapping fields or a conversion of an Unchecked_Union. */ + return unchecked_convert (type, expr, false); + + case UNCONSTRAINED_ARRAY_TYPE: + /* If EXPR is a constrained array, take its address, convert it to a + fat pointer, and then dereference it. Likewise if EXPR is a + record containing both a template and a constrained array. + Note that a record representing a justified modular type + always represents a packed constrained array. */ + if (ecode == ARRAY_TYPE + || (ecode == INTEGER_TYPE && TYPE_HAS_ACTUAL_BOUNDS_P (etype)) + || (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype)) + || (ecode == RECORD_TYPE && TYPE_JUSTIFIED_MODULAR_P (etype))) + return + build_unary_op + (INDIRECT_REF, NULL_TREE, + convert_to_fat_pointer (TREE_TYPE (type), + build_unary_op (ADDR_EXPR, + NULL_TREE, expr))); + + /* Do something very similar for converting one unconstrained + array to another. */ + else if (ecode == UNCONSTRAINED_ARRAY_TYPE) + return + build_unary_op (INDIRECT_REF, NULL_TREE, + convert (TREE_TYPE (type), + build_unary_op (ADDR_EXPR, + NULL_TREE, expr))); + else + gcc_unreachable (); + + case COMPLEX_TYPE: + return fold (convert_to_complex (type, expr)); + + default: + gcc_unreachable (); + } +} + +/* Remove all conversions that are done in EXP. This includes converting + from a padded type or to a justified modular type. If TRUE_ADDRESS + is true, always return the address of the containing object even if + the address is not bit-aligned. */ + +tree +remove_conversions (tree exp, bool true_address) +{ + switch (TREE_CODE (exp)) + { + case CONSTRUCTOR: + if (true_address + && TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (TREE_TYPE (exp))) + return + remove_conversions (VEC_index (constructor_elt, + CONSTRUCTOR_ELTS (exp), 0)->value, + true); + break; + + case COMPONENT_REF: + if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == RECORD_TYPE + && TYPE_IS_PADDING_P (TREE_TYPE (TREE_OPERAND (exp, 0)))) + return remove_conversions (TREE_OPERAND (exp, 0), true_address); + break; + + case VIEW_CONVERT_EXPR: case NON_LVALUE_EXPR: + CASE_CONVERT: + return remove_conversions (TREE_OPERAND (exp, 0), true_address); + + default: + break; + } + + return exp; +} + +/* If EXP's type is an UNCONSTRAINED_ARRAY_TYPE, return an expression that + refers to the underlying array. If its type has TYPE_CONTAINS_TEMPLATE_P, + likewise return an expression pointing to the underlying array. */ + +tree +maybe_unconstrained_array (tree exp) +{ + enum tree_code code = TREE_CODE (exp); + tree new; + + switch (TREE_CODE (TREE_TYPE (exp))) + { + case UNCONSTRAINED_ARRAY_TYPE: + if (code == UNCONSTRAINED_ARRAY_REF) + { + new + = build_unary_op (INDIRECT_REF, NULL_TREE, + build_component_ref (TREE_OPERAND (exp, 0), + get_identifier ("P_ARRAY"), + NULL_TREE, false)); + TREE_READONLY (new) = TREE_STATIC (new) = TREE_READONLY (exp); + return new; + } + + else if (code == NULL_EXPR) + return build1 (NULL_EXPR, + TREE_TYPE (TREE_TYPE (TYPE_FIELDS + (TREE_TYPE (TREE_TYPE (exp))))), + TREE_OPERAND (exp, 0)); + + case RECORD_TYPE: + /* If this is a padded type, convert to the unpadded type and see if + it contains a template. */ + if (TYPE_IS_PADDING_P (TREE_TYPE (exp))) + { + new = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (exp))), exp); + if (TREE_CODE (TREE_TYPE (new)) == RECORD_TYPE + && TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (new))) + return + build_component_ref (new, NULL_TREE, + TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (new))), + 0); + } + else if (TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (exp))) + return + build_component_ref (exp, NULL_TREE, + TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (exp))), 0); + break; + + default: + break; + } + + return exp; +} + +/* Return an expression that does an unchecked conversion of EXPR to TYPE. + If NOTRUNC_P is true, truncation operations should be suppressed. */ + +tree +unchecked_convert (tree type, tree expr, bool notrunc_p) +{ + tree etype = TREE_TYPE (expr); + + /* If the expression is already the right type, we are done. */ + if (etype == type) + return expr; + + /* If both types types are integral just do a normal conversion. + Likewise for a conversion to an unconstrained array. */ + if ((((INTEGRAL_TYPE_P (type) + && !(TREE_CODE (type) == INTEGER_TYPE + && TYPE_VAX_FLOATING_POINT_P (type))) + || (POINTER_TYPE_P (type) && ! TYPE_THIN_POINTER_P (type)) + || (TREE_CODE (type) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (type))) + && ((INTEGRAL_TYPE_P (etype) + && !(TREE_CODE (etype) == INTEGER_TYPE + && TYPE_VAX_FLOATING_POINT_P (etype))) + || (POINTER_TYPE_P (etype) && !TYPE_THIN_POINTER_P (etype)) + || (TREE_CODE (etype) == RECORD_TYPE + && TYPE_JUSTIFIED_MODULAR_P (etype)))) + || TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE) + { + tree rtype = type; + bool final_unchecked = false; + + if (TREE_CODE (etype) == INTEGER_TYPE + && TYPE_BIASED_REPRESENTATION_P (etype)) + { + tree ntype = copy_type (etype); + + TYPE_BIASED_REPRESENTATION_P (ntype) = 0; + TYPE_MAIN_VARIANT (ntype) = ntype; + expr = build1 (NOP_EXPR, ntype, expr); + } + + if (TREE_CODE (type) == INTEGER_TYPE + && TYPE_BIASED_REPRESENTATION_P (type)) + { + rtype = copy_type (type); + TYPE_BIASED_REPRESENTATION_P (rtype) = 0; + TYPE_MAIN_VARIANT (rtype) = rtype; + } + + /* We have another special case: if we are unchecked converting subtype + into a base type, we need to ensure that VRP doesn't propagate range + information since this conversion may be done precisely to validate + that the object is within the range it is supposed to have. */ + else if (TREE_CODE (expr) != INTEGER_CST + && TREE_CODE (type) == INTEGER_TYPE && !TREE_TYPE (type) + && ((TREE_CODE (etype) == INTEGER_TYPE && TREE_TYPE (etype)) + || TREE_CODE (etype) == ENUMERAL_TYPE + || TREE_CODE (etype) == BOOLEAN_TYPE)) + { + /* The optimization barrier is a VIEW_CONVERT_EXPR node; moreover, + in order not to be deemed an useless type conversion, it must + be from subtype to base type. + + ??? This may raise addressability and/or aliasing issues because + VIEW_CONVERT_EXPR gets gimplified as an lvalue, thus causing the + address of its operand to be taken if it is deemed addressable + and not already in GIMPLE form. */ + rtype = gnat_type_for_mode (TYPE_MODE (type), TYPE_UNSIGNED (type)); + rtype = copy_type (rtype); + TYPE_MAIN_VARIANT (rtype) = rtype; + TREE_TYPE (rtype) = type; + final_unchecked = true; + } + + expr = convert (rtype, expr); + if (type != rtype) + expr = fold_build1 (final_unchecked ? VIEW_CONVERT_EXPR : NOP_EXPR, + type, expr); + } + + /* If we are converting TO an integral type whose precision is not the + same as its size, first unchecked convert to a record that contains + an object of the output type. Then extract the field. */ + else if (INTEGRAL_TYPE_P (type) && TYPE_RM_SIZE (type) + && 0 != compare_tree_int (TYPE_RM_SIZE (type), + GET_MODE_BITSIZE (TYPE_MODE (type)))) + { + tree rec_type = make_node (RECORD_TYPE); + tree field = create_field_decl (get_identifier ("OBJ"), type, + rec_type, 1, 0, 0, 0); + + TYPE_FIELDS (rec_type) = field; + layout_type (rec_type); + + expr = unchecked_convert (rec_type, expr, notrunc_p); + expr = build_component_ref (expr, NULL_TREE, field, 0); + } + + /* Similarly for integral input type whose precision is not equal to its + size. */ + else if (INTEGRAL_TYPE_P (etype) && TYPE_RM_SIZE (etype) + && 0 != compare_tree_int (TYPE_RM_SIZE (etype), + GET_MODE_BITSIZE (TYPE_MODE (etype)))) + { + tree rec_type = make_node (RECORD_TYPE); + tree field + = create_field_decl (get_identifier ("OBJ"), etype, rec_type, + 1, 0, 0, 0); + + TYPE_FIELDS (rec_type) = field; + layout_type (rec_type); + + expr = gnat_build_constructor (rec_type, build_tree_list (field, expr)); + expr = unchecked_convert (type, expr, notrunc_p); + } + + /* We have a special case when we are converting between two + unconstrained array types. In that case, take the address, + convert the fat pointer types, and dereference. */ + else if (TREE_CODE (etype) == UNCONSTRAINED_ARRAY_TYPE + && TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE) + expr = build_unary_op (INDIRECT_REF, NULL_TREE, + build1 (VIEW_CONVERT_EXPR, TREE_TYPE (type), + build_unary_op (ADDR_EXPR, NULL_TREE, + expr))); + else + { + expr = maybe_unconstrained_array (expr); + etype = TREE_TYPE (expr); + expr = fold_build1 (VIEW_CONVERT_EXPR, type, expr); + } + + /* If the result is an integral type whose size is not equal to + the size of the underlying machine type, sign- or zero-extend + the result. We need not do this in the case where the input is + an integral type of the same precision and signedness or if the output + is a biased type or if both the input and output are unsigned. */ + if (!notrunc_p + && INTEGRAL_TYPE_P (type) && TYPE_RM_SIZE (type) + && !(TREE_CODE (type) == INTEGER_TYPE + && TYPE_BIASED_REPRESENTATION_P (type)) + && 0 != compare_tree_int (TYPE_RM_SIZE (type), + GET_MODE_BITSIZE (TYPE_MODE (type))) + && !(INTEGRAL_TYPE_P (etype) + && TYPE_UNSIGNED (type) == TYPE_UNSIGNED (etype) + && operand_equal_p (TYPE_RM_SIZE (type), + (TYPE_RM_SIZE (etype) != 0 + ? TYPE_RM_SIZE (etype) : TYPE_SIZE (etype)), + 0)) + && !(TYPE_UNSIGNED (type) && TYPE_UNSIGNED (etype))) + { + tree base_type = gnat_type_for_mode (TYPE_MODE (type), + TYPE_UNSIGNED (type)); + tree shift_expr + = convert (base_type, + size_binop (MINUS_EXPR, + bitsize_int + (GET_MODE_BITSIZE (TYPE_MODE (type))), + TYPE_RM_SIZE (type))); + expr + = convert (type, + build_binary_op (RSHIFT_EXPR, base_type, + build_binary_op (LSHIFT_EXPR, base_type, + convert (base_type, expr), + shift_expr), + shift_expr)); + } + + /* An unchecked conversion should never raise Constraint_Error. The code + below assumes that GCC's conversion routines overflow the same way that + the underlying hardware does. This is probably true. In the rare case + when it is false, we can rely on the fact that such conversions are + erroneous anyway. */ + if (TREE_CODE (expr) == INTEGER_CST) + TREE_OVERFLOW (expr) = 0; + + /* If the sizes of the types differ and this is an VIEW_CONVERT_EXPR, + show no longer constant. */ + if (TREE_CODE (expr) == VIEW_CONVERT_EXPR + && !operand_equal_p (TYPE_SIZE_UNIT (type), TYPE_SIZE_UNIT (etype), + OEP_ONLY_CONST)) + TREE_CONSTANT (expr) = 0; + + return expr; +} + +/* Return the appropriate GCC tree code for the specified GNAT type, + the latter being a record type as predicated by Is_Record_Type. */ + +enum tree_code +tree_code_for_record_type (Entity_Id gnat_type) +{ + Node_Id component_list + = Component_List (Type_Definition + (Declaration_Node + (Implementation_Base_Type (gnat_type)))); + Node_Id component; + + /* Make this a UNION_TYPE unless it's either not an Unchecked_Union or + we have a non-discriminant field outside a variant. In either case, + it's a RECORD_TYPE. */ + + if (!Is_Unchecked_Union (gnat_type)) + return RECORD_TYPE; + + for (component = First_Non_Pragma (Component_Items (component_list)); + Present (component); + component = Next_Non_Pragma (component)) + if (Ekind (Defining_Entity (component)) == E_Component) + return RECORD_TYPE; + + return UNION_TYPE; +} + +/* Return true if GNU_TYPE is suitable as the type of a non-aliased + component of an aggregate type. */ + +bool +type_for_nonaliased_component_p (tree gnu_type) +{ + /* If the type is passed by reference, we may have pointers to the + component so it cannot be made non-aliased. */ + if (must_pass_by_ref (gnu_type) || default_pass_by_ref (gnu_type)) + return false; + + /* We used to say that any component of aggregate type is aliased + because the front-end may take 'Reference of it. The front-end + has been enhanced in the meantime so as to use a renaming instead + in most cases, but the back-end can probably take the address of + such a component too so we go for the conservative stance. + + For instance, we might need the address of any array type, even + if normally passed by copy, to construct a fat pointer if the + component is used as an actual for an unconstrained formal. + + Likewise for record types: even if a specific record subtype is + passed by copy, the parent type might be passed by ref (e.g. if + it's of variable size) and we might take the address of a child + component to pass to a parent formal. We have no way to check + for such conditions here. */ + if (AGGREGATE_TYPE_P (gnu_type)) + return false; + + return true; +} + +/* Perform final processing on global variables. */ + +void +gnat_write_global_declarations (void) +{ + /* Proceed to optimize and emit assembly. + FIXME: shouldn't be the front end's responsibility to call this. */ + cgraph_optimize (); + + /* Emit debug info for all global declarations. */ + emit_debug_global_declarations (VEC_address (tree, global_decls), + VEC_length (tree, global_decls)); +} + +/* ************************************************************************ + * * GCC builtins support * + * ************************************************************************ */ + +/* The general scheme is fairly simple: + + For each builtin function/type to be declared, gnat_install_builtins calls + internal facilities which eventually get to gnat_push_decl, which in turn + tracks the so declared builtin function decls in the 'builtin_decls' global + datastructure. When an Intrinsic subprogram declaration is processed, we + search this global datastructure to retrieve the associated BUILT_IN DECL + node. */ + +/* Search the chain of currently available builtin declarations for a node + corresponding to function NAME (an IDENTIFIER_NODE). Return the first node + found, if any, or NULL_TREE otherwise. */ +tree +builtin_decl_for (tree name) +{ + unsigned i; + tree decl; + + for (i = 0; VEC_iterate(tree, builtin_decls, i, decl); i++) + if (DECL_NAME (decl) == name) + return decl; + + return NULL_TREE; +} + +/* The code below eventually exposes gnat_install_builtins, which declares + the builtin types and functions we might need, either internally or as + user accessible facilities. + + ??? This is a first implementation shot, still in rough shape. It is + heavily inspired from the "C" family implementation, with chunks copied + verbatim from there. + + Two obvious TODO candidates are + o Use a more efficient name/decl mapping scheme + o Devise a middle-end infrastructure to avoid having to copy + pieces between front-ends. */ + +/* ----------------------------------------------------------------------- * + * BUILTIN ELEMENTARY TYPES * + * ----------------------------------------------------------------------- */ + +/* Standard data types to be used in builtin argument declarations. */ + +enum c_tree_index +{ + CTI_SIGNED_SIZE_TYPE, /* For format checking only. */ + CTI_STRING_TYPE, + CTI_CONST_STRING_TYPE, + + CTI_MAX +}; + +static tree c_global_trees[CTI_MAX]; + +#define signed_size_type_node c_global_trees[CTI_SIGNED_SIZE_TYPE] +#define string_type_node c_global_trees[CTI_STRING_TYPE] +#define const_string_type_node c_global_trees[CTI_CONST_STRING_TYPE] + +/* ??? In addition some attribute handlers, we currently don't support a + (small) number of builtin-types, which in turns inhibits support for a + number of builtin functions. */ +#define wint_type_node void_type_node +#define intmax_type_node void_type_node +#define uintmax_type_node void_type_node + +/* Build the void_list_node (void_type_node having been created). */ + +static tree +build_void_list_node (void) +{ + tree t = build_tree_list (NULL_TREE, void_type_node); + return t; +} + +/* Used to help initialize the builtin-types.def table. When a type of + the correct size doesn't exist, use error_mark_node instead of NULL. + The later results in segfaults even when a decl using the type doesn't + get invoked. */ + +static tree +builtin_type_for_size (int size, bool unsignedp) +{ + tree type = lang_hooks.types.type_for_size (size, unsignedp); + return type ? type : error_mark_node; +} + +/* Build/push the elementary type decls that builtin functions/types + will need. */ + +static void +install_builtin_elementary_types (void) +{ + signed_size_type_node = size_type_node; + pid_type_node = integer_type_node; + void_list_node = build_void_list_node (); + + string_type_node = build_pointer_type (char_type_node); + const_string_type_node + = build_pointer_type (build_qualified_type + (char_type_node, TYPE_QUAL_CONST)); +} + +/* ----------------------------------------------------------------------- * + * BUILTIN FUNCTION TYPES * + * ----------------------------------------------------------------------- */ + +/* Now, builtin function types per se. */ + +enum c_builtin_type +{ +#define DEF_PRIMITIVE_TYPE(NAME, VALUE) NAME, +#define DEF_FUNCTION_TYPE_0(NAME, RETURN) NAME, +#define DEF_FUNCTION_TYPE_1(NAME, RETURN, ARG1) NAME, +#define DEF_FUNCTION_TYPE_2(NAME, RETURN, ARG1, ARG2) NAME, +#define DEF_FUNCTION_TYPE_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME, +#define DEF_FUNCTION_TYPE_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME, +#define DEF_FUNCTION_TYPE_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) NAME, +#define DEF_FUNCTION_TYPE_6(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6) NAME, +#define DEF_FUNCTION_TYPE_7(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7) NAME, +#define DEF_FUNCTION_TYPE_VAR_0(NAME, RETURN) NAME, +#define DEF_FUNCTION_TYPE_VAR_1(NAME, RETURN, ARG1) NAME, +#define DEF_FUNCTION_TYPE_VAR_2(NAME, RETURN, ARG1, ARG2) NAME, +#define DEF_FUNCTION_TYPE_VAR_3(NAME, RETURN, ARG1, ARG2, ARG3) NAME, +#define DEF_FUNCTION_TYPE_VAR_4(NAME, RETURN, ARG1, ARG2, ARG3, ARG4) NAME, +#define DEF_FUNCTION_TYPE_VAR_5(NAME, RETURN, ARG1, ARG2, ARG3, ARG4, ARG6) \ + NAME, +#define DEF_POINTER_TYPE(NAME, TYPE) NAME, +#include "builtin-types.def" +#undef DEF_PRIMITIVE_TYPE +#undef DEF_FUNCTION_TYPE_0 +#undef DEF_FUNCTION_TYPE_1 +#undef DEF_FUNCTION_TYPE_2 +#undef DEF_FUNCTION_TYPE_3 +#undef DEF_FUNCTION_TYPE_4 +#undef DEF_FUNCTION_TYPE_5 +#undef DEF_FUNCTION_TYPE_6 +#undef DEF_FUNCTION_TYPE_7 +#undef DEF_FUNCTION_TYPE_VAR_0 +#undef DEF_FUNCTION_TYPE_VAR_1 +#undef DEF_FUNCTION_TYPE_VAR_2 +#undef DEF_FUNCTION_TYPE_VAR_3 +#undef DEF_FUNCTION_TYPE_VAR_4 +#undef DEF_FUNCTION_TYPE_VAR_5 +#undef DEF_POINTER_TYPE + BT_LAST +}; + +typedef enum c_builtin_type builtin_type; + +/* A temporary array used in communication with def_fn_type. */ +static GTY(()) tree builtin_types[(int) BT_LAST + 1]; + +/* A helper function for install_builtin_types. Build function type + for DEF with return type RET and N arguments. If VAR is true, then the + function should be variadic after those N arguments. + + Takes special care not to ICE if any of the types involved are + error_mark_node, which indicates that said type is not in fact available + (see builtin_type_for_size). In which case the function type as a whole + should be error_mark_node. */ + +static void +def_fn_type (builtin_type def, builtin_type ret, bool var, int n, ...) +{ + tree args = NULL, t; + va_list list; + int i; + + va_start (list, n); + for (i = 0; i < n; ++i) + { + builtin_type a = va_arg (list, builtin_type); + t = builtin_types[a]; + if (t == error_mark_node) + goto egress; + args = tree_cons (NULL_TREE, t, args); + } + va_end (list); + + args = nreverse (args); + if (!var) + args = chainon (args, void_list_node); + + t = builtin_types[ret]; + if (t == error_mark_node) + goto egress; + t = build_function_type (t, args); + + egress: + builtin_types[def] = t; +} + +/* Build the builtin function types and install them in the builtin_types + array for later use in builtin function decls. */ + +static void +install_builtin_function_types (void) +{ + tree va_list_ref_type_node; + tree va_list_arg_type_node; + + if (TREE_CODE (va_list_type_node) == ARRAY_TYPE) + { + va_list_arg_type_node = va_list_ref_type_node = + build_pointer_type (TREE_TYPE (va_list_type_node)); + } + else + { + va_list_arg_type_node = va_list_type_node; + va_list_ref_type_node = build_reference_type (va_list_type_node); + } + +#define DEF_PRIMITIVE_TYPE(ENUM, VALUE) \ + builtin_types[ENUM] = VALUE; +#define DEF_FUNCTION_TYPE_0(ENUM, RETURN) \ + def_fn_type (ENUM, RETURN, 0, 0); +#define DEF_FUNCTION_TYPE_1(ENUM, RETURN, ARG1) \ + def_fn_type (ENUM, RETURN, 0, 1, ARG1); +#define DEF_FUNCTION_TYPE_2(ENUM, RETURN, ARG1, ARG2) \ + def_fn_type (ENUM, RETURN, 0, 2, ARG1, ARG2); +#define DEF_FUNCTION_TYPE_3(ENUM, RETURN, ARG1, ARG2, ARG3) \ + def_fn_type (ENUM, RETURN, 0, 3, ARG1, ARG2, ARG3); +#define DEF_FUNCTION_TYPE_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \ + def_fn_type (ENUM, RETURN, 0, 4, ARG1, ARG2, ARG3, ARG4); +#define DEF_FUNCTION_TYPE_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \ + def_fn_type (ENUM, RETURN, 0, 5, ARG1, ARG2, ARG3, ARG4, ARG5); +#define DEF_FUNCTION_TYPE_6(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6) \ + def_fn_type (ENUM, RETURN, 0, 6, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6); +#define DEF_FUNCTION_TYPE_7(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5, \ + ARG6, ARG7) \ + def_fn_type (ENUM, RETURN, 0, 7, ARG1, ARG2, ARG3, ARG4, ARG5, ARG6, ARG7); +#define DEF_FUNCTION_TYPE_VAR_0(ENUM, RETURN) \ + def_fn_type (ENUM, RETURN, 1, 0); +#define DEF_FUNCTION_TYPE_VAR_1(ENUM, RETURN, ARG1) \ + def_fn_type (ENUM, RETURN, 1, 1, ARG1); +#define DEF_FUNCTION_TYPE_VAR_2(ENUM, RETURN, ARG1, ARG2) \ + def_fn_type (ENUM, RETURN, 1, 2, ARG1, ARG2); +#define DEF_FUNCTION_TYPE_VAR_3(ENUM, RETURN, ARG1, ARG2, ARG3) \ + def_fn_type (ENUM, RETURN, 1, 3, ARG1, ARG2, ARG3); +#define DEF_FUNCTION_TYPE_VAR_4(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4) \ + def_fn_type (ENUM, RETURN, 1, 4, ARG1, ARG2, ARG3, ARG4); +#define DEF_FUNCTION_TYPE_VAR_5(ENUM, RETURN, ARG1, ARG2, ARG3, ARG4, ARG5) \ + def_fn_type (ENUM, RETURN, 1, 5, ARG1, ARG2, ARG3, ARG4, ARG5); +#define DEF_POINTER_TYPE(ENUM, TYPE) \ + builtin_types[(int) ENUM] = build_pointer_type (builtin_types[(int) TYPE]); + +#include "builtin-types.def" + +#undef DEF_PRIMITIVE_TYPE +#undef DEF_FUNCTION_TYPE_1 +#undef DEF_FUNCTION_TYPE_2 +#undef DEF_FUNCTION_TYPE_3 +#undef DEF_FUNCTION_TYPE_4 +#undef DEF_FUNCTION_TYPE_5 +#undef DEF_FUNCTION_TYPE_6 +#undef DEF_FUNCTION_TYPE_VAR_0 +#undef DEF_FUNCTION_TYPE_VAR_1 +#undef DEF_FUNCTION_TYPE_VAR_2 +#undef DEF_FUNCTION_TYPE_VAR_3 +#undef DEF_FUNCTION_TYPE_VAR_4 +#undef DEF_FUNCTION_TYPE_VAR_5 +#undef DEF_POINTER_TYPE + builtin_types[(int) BT_LAST] = NULL_TREE; +} + +/* ----------------------------------------------------------------------- * + * BUILTIN ATTRIBUTES * + * ----------------------------------------------------------------------- */ + +enum built_in_attribute +{ +#define DEF_ATTR_NULL_TREE(ENUM) ENUM, +#define DEF_ATTR_INT(ENUM, VALUE) ENUM, +#define DEF_ATTR_IDENT(ENUM, STRING) ENUM, +#define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) ENUM, +#include "builtin-attrs.def" +#undef DEF_ATTR_NULL_TREE +#undef DEF_ATTR_INT +#undef DEF_ATTR_IDENT +#undef DEF_ATTR_TREE_LIST + ATTR_LAST +}; + +static GTY(()) tree built_in_attributes[(int) ATTR_LAST]; + +static void +install_builtin_attributes (void) +{ + /* Fill in the built_in_attributes array. */ +#define DEF_ATTR_NULL_TREE(ENUM) \ + built_in_attributes[(int) ENUM] = NULL_TREE; +#define DEF_ATTR_INT(ENUM, VALUE) \ + built_in_attributes[(int) ENUM] = build_int_cst (NULL_TREE, VALUE); +#define DEF_ATTR_IDENT(ENUM, STRING) \ + built_in_attributes[(int) ENUM] = get_identifier (STRING); +#define DEF_ATTR_TREE_LIST(ENUM, PURPOSE, VALUE, CHAIN) \ + built_in_attributes[(int) ENUM] \ + = tree_cons (built_in_attributes[(int) PURPOSE], \ + built_in_attributes[(int) VALUE], \ + built_in_attributes[(int) CHAIN]); +#include "builtin-attrs.def" +#undef DEF_ATTR_NULL_TREE +#undef DEF_ATTR_INT +#undef DEF_ATTR_IDENT +#undef DEF_ATTR_TREE_LIST +} + +/* Handle a "const" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_const_attribute (tree *node, tree ARG_UNUSED (name), + tree ARG_UNUSED (args), int ARG_UNUSED (flags), + bool *no_add_attrs) +{ + if (TREE_CODE (*node) == FUNCTION_DECL) + TREE_READONLY (*node) = 1; + else + *no_add_attrs = true; + + return NULL_TREE; +} + +/* Handle a "nothrow" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_nothrow_attribute (tree *node, tree ARG_UNUSED (name), + tree ARG_UNUSED (args), int ARG_UNUSED (flags), + bool *no_add_attrs) +{ + if (TREE_CODE (*node) == FUNCTION_DECL) + TREE_NOTHROW (*node) = 1; + else + *no_add_attrs = true; + + return NULL_TREE; +} + +/* Handle a "pure" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_pure_attribute (tree *node, tree name, tree ARG_UNUSED (args), + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + if (TREE_CODE (*node) == FUNCTION_DECL) + DECL_PURE_P (*node) = 1; + /* ??? TODO: Support types. */ + else + { + warning (OPT_Wattributes, "%qE attribute ignored", name); + *no_add_attrs = true; + } + + return NULL_TREE; +} + +/* Handle a "no vops" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_novops_attribute (tree *node, tree ARG_UNUSED (name), + tree ARG_UNUSED (args), int ARG_UNUSED (flags), + bool *ARG_UNUSED (no_add_attrs)) +{ + gcc_assert (TREE_CODE (*node) == FUNCTION_DECL); + DECL_IS_NOVOPS (*node) = 1; + return NULL_TREE; +} + +/* Helper for nonnull attribute handling; fetch the operand number + from the attribute argument list. */ + +static bool +get_nonnull_operand (tree arg_num_expr, unsigned HOST_WIDE_INT *valp) +{ + /* Verify the arg number is a constant. */ + if (TREE_CODE (arg_num_expr) != INTEGER_CST + || TREE_INT_CST_HIGH (arg_num_expr) != 0) + return false; + + *valp = TREE_INT_CST_LOW (arg_num_expr); + return true; +} + +/* Handle the "nonnull" attribute. */ +static tree +handle_nonnull_attribute (tree *node, tree ARG_UNUSED (name), + tree args, int ARG_UNUSED (flags), + bool *no_add_attrs) +{ + tree type = *node; + unsigned HOST_WIDE_INT attr_arg_num; + + /* If no arguments are specified, all pointer arguments should be + non-null. Verify a full prototype is given so that the arguments + will have the correct types when we actually check them later. */ + if (!args) + { + if (!TYPE_ARG_TYPES (type)) + { + error ("nonnull attribute without arguments on a non-prototype"); + *no_add_attrs = true; + } + return NULL_TREE; + } + + /* Argument list specified. Verify that each argument number references + a pointer argument. */ + for (attr_arg_num = 1; args; args = TREE_CHAIN (args)) + { + tree argument; + unsigned HOST_WIDE_INT arg_num = 0, ck_num; + + if (!get_nonnull_operand (TREE_VALUE (args), &arg_num)) + { + error ("nonnull argument has invalid operand number (argument %lu)", + (unsigned long) attr_arg_num); + *no_add_attrs = true; + return NULL_TREE; + } + + argument = TYPE_ARG_TYPES (type); + if (argument) + { + for (ck_num = 1; ; ck_num++) + { + if (!argument || ck_num == arg_num) + break; + argument = TREE_CHAIN (argument); + } + + if (!argument + || TREE_CODE (TREE_VALUE (argument)) == VOID_TYPE) + { + error ("nonnull argument with out-of-range operand number (argument %lu, operand %lu)", + (unsigned long) attr_arg_num, (unsigned long) arg_num); + *no_add_attrs = true; + return NULL_TREE; + } + + if (TREE_CODE (TREE_VALUE (argument)) != POINTER_TYPE) + { + error ("nonnull argument references non-pointer operand (argument %lu, operand %lu)", + (unsigned long) attr_arg_num, (unsigned long) arg_num); + *no_add_attrs = true; + return NULL_TREE; + } + } + } + + return NULL_TREE; +} + +/* Handle a "sentinel" attribute. */ + +static tree +handle_sentinel_attribute (tree *node, tree name, tree args, + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + tree params = TYPE_ARG_TYPES (*node); + + if (!params) + { + warning (OPT_Wattributes, + "%qE attribute requires prototypes with named arguments", name); + *no_add_attrs = true; + } + else + { + while (TREE_CHAIN (params)) + params = TREE_CHAIN (params); + + if (VOID_TYPE_P (TREE_VALUE (params))) + { + warning (OPT_Wattributes, + "%qE attribute only applies to variadic functions", name); + *no_add_attrs = true; + } + } + + if (args) + { + tree position = TREE_VALUE (args); + + if (TREE_CODE (position) != INTEGER_CST) + { + warning (0, "requested position is not an integer constant"); + *no_add_attrs = true; + } + else + { + if (tree_int_cst_lt (position, integer_zero_node)) + { + warning (0, "requested position is less than zero"); + *no_add_attrs = true; + } + } + } + + return NULL_TREE; +} + +/* Handle a "noreturn" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_noreturn_attribute (tree *node, tree name, tree ARG_UNUSED (args), + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + tree type = TREE_TYPE (*node); + + /* See FIXME comment in c_common_attribute_table. */ + if (TREE_CODE (*node) == FUNCTION_DECL) + TREE_THIS_VOLATILE (*node) = 1; + else if (TREE_CODE (type) == POINTER_TYPE + && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE) + TREE_TYPE (*node) + = build_pointer_type + (build_type_variant (TREE_TYPE (type), + TYPE_READONLY (TREE_TYPE (type)), 1)); + else + { + warning (OPT_Wattributes, "%qE attribute ignored", name); + *no_add_attrs = true; + } + + return NULL_TREE; +} + +/* Handle a "malloc" attribute; arguments as in + struct attribute_spec.handler. */ + +static tree +handle_malloc_attribute (tree *node, tree name, tree ARG_UNUSED (args), + int ARG_UNUSED (flags), bool *no_add_attrs) +{ + if (TREE_CODE (*node) == FUNCTION_DECL + && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (*node)))) + DECL_IS_MALLOC (*node) = 1; + else + { + warning (OPT_Wattributes, "%qE attribute ignored", name); + *no_add_attrs = true; + } + + return NULL_TREE; +} + +/* Fake handler for attributes we don't properly support. */ + +tree +fake_attribute_handler (tree * ARG_UNUSED (node), + tree ARG_UNUSED (name), + tree ARG_UNUSED (args), + int ARG_UNUSED (flags), + bool * ARG_UNUSED (no_add_attrs)) +{ + return NULL_TREE; +} + +/* Handle a "type_generic" attribute. */ + +static tree +handle_type_generic_attribute (tree *node, tree ARG_UNUSED (name), + tree ARG_UNUSED (args), int ARG_UNUSED (flags), + bool * ARG_UNUSED (no_add_attrs)) +{ + tree params; + + /* Ensure we have a function type. */ + gcc_assert (TREE_CODE (*node) == FUNCTION_TYPE); + + params = TYPE_ARG_TYPES (*node); + while (params && ! VOID_TYPE_P (TREE_VALUE (params))) + params = TREE_CHAIN (params); + + /* Ensure we have a variadic function. */ + gcc_assert (!params); + + return NULL_TREE; +} + +/* ----------------------------------------------------------------------- * + * BUILTIN FUNCTIONS * + * ----------------------------------------------------------------------- */ + +/* Worker for DEF_BUILTIN. Possibly define a builtin function with one or two + names. Does not declare a non-__builtin_ function if flag_no_builtin, or + if nonansi_p and flag_no_nonansi_builtin. */ + +static void +def_builtin_1 (enum built_in_function fncode, + const char *name, + enum built_in_class fnclass, + tree fntype, tree libtype, + bool both_p, bool fallback_p, + bool nonansi_p ATTRIBUTE_UNUSED, + tree fnattrs, bool implicit_p) +{ + tree decl; + const char *libname; + + /* Preserve an already installed decl. It most likely was setup in advance + (e.g. as part of the internal builtins) for specific reasons. */ + if (built_in_decls[(int) fncode] != NULL_TREE) + return; + + gcc_assert ((!both_p && !fallback_p) + || !strncmp (name, "__builtin_", + strlen ("__builtin_"))); + + libname = name + strlen ("__builtin_"); + decl = add_builtin_function (name, fntype, fncode, fnclass, + (fallback_p ? libname : NULL), + fnattrs); + if (both_p) + /* ??? This is normally further controlled by command-line options + like -fno-builtin, but we don't have them for Ada. */ + add_builtin_function (libname, libtype, fncode, fnclass, + NULL, fnattrs); + + built_in_decls[(int) fncode] = decl; + if (implicit_p) + implicit_built_in_decls[(int) fncode] = decl; +} + +static int flag_isoc94 = 0; +static int flag_isoc99 = 0; + +/* Install what the common builtins.def offers. */ + +static void +install_builtin_functions (void) +{ +#define DEF_BUILTIN(ENUM, NAME, CLASS, TYPE, LIBTYPE, BOTH_P, FALLBACK_P, \ + NONANSI_P, ATTRS, IMPLICIT, COND) \ + if (NAME && COND) \ + def_builtin_1 (ENUM, NAME, CLASS, \ + builtin_types[(int) TYPE], \ + builtin_types[(int) LIBTYPE], \ + BOTH_P, FALLBACK_P, NONANSI_P, \ + built_in_attributes[(int) ATTRS], IMPLICIT); +#include "builtins.def" +#undef DEF_BUILTIN +} + +/* ----------------------------------------------------------------------- * + * BUILTIN FUNCTIONS * + * ----------------------------------------------------------------------- */ + +/* Install the builtin functions we might need. */ + +void +gnat_install_builtins (void) +{ + install_builtin_elementary_types (); + install_builtin_function_types (); + install_builtin_attributes (); + + /* Install builtins used by generic middle-end pieces first. Some of these + know about internal specificities and control attributes accordingly, for + instance __builtin_alloca vs no-throw and -fstack-check. We will ignore + the generic definition from builtins.def. */ + build_common_builtin_nodes (); + + /* Now, install the target specific builtins, such as the AltiVec family on + ppc, and the common set as exposed by builtins.def. */ + targetm.init_builtins (); + install_builtin_functions (); +} + +#include "gt-ada-utils.h" +#include "gtype-ada.h" |