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Diffstat (limited to 'gcc/ada/utils.c')
| -rw-r--r-- | gcc/ada/utils.c | 3350 |
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diff --git a/gcc/ada/utils.c b/gcc/ada/utils.c new file mode 100644 index 0000000..b23bbe9 --- /dev/null +++ b/gcc/ada/utils.c @@ -0,0 +1,3350 @@ +/**************************************************************************** + * * + * GNAT COMPILER COMPONENTS * + * * + * U T I L S * + * * + * C Implementation File * + * * + * $Revision: 1.4 $ + * * + * Copyright (C) 1992-2001, 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 2, 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 distributed with GNAT; see file COPYING. If not, write * + * to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, * + * MA 02111-1307, USA. * + * * + * GNAT was originally developed by the GNAT team at New York University. * + * It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). * + * * + ****************************************************************************/ + +#include "config.h" +#include "system.h" +#include "tree.h" +#include "flags.h" +#include "defaults.h" +#include "toplev.h" +#include "output.h" +#include "ggc.h" +#include "convert.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; + +/* Global Variables for the various types we create. */ +tree gnat_std_decls[(int) ADT_LAST]; + +/* 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 tree *associate_gnat_to_gnu; + +/* This listhead is used to record any global objects that need elaboration. + TREE_PURPOSE is the variable to be elaborated and TREE_VALUE is the + initial value to assign. */ + +static tree pending_elaborations; + +/* This stack allows us to momentarily switch to generating elaboration + lists for an inner context. */ + +static struct e_stack {struct e_stack *next; tree elab_list; } *elist_stack; + +/* 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 tree signed_and_unsigned_types[2 * MAX_BITS_PER_WORD + 1][2]; + +/* Likewise for float types, but record these by mode. */ +static tree float_types[NUM_MACHINE_MODES]; + +/* For each binding contour we allocate a binding_level structure which records + the entities defined or declared in that contour. Contours include: + + the global one + one for each subprogram definition + one for each compound statement (declare block) + + Binding contours are used to create GCC tree BLOCK nodes. */ + +struct binding_level +{ + /* A chain of ..._DECL nodes for all variables, constants, functions, + parameters and type declarations. These ..._DECL nodes are chained + through the TREE_CHAIN field. Note that these ..._DECL nodes are stored + in the reverse of the order supplied to be compatible with the + back-end. */ + tree names; + /* For each level (except the global one), a chain of BLOCK nodes for all + the levels that were entered and exited one level down from this one. */ + tree blocks; + /* The BLOCK node for this level, if one has been preallocated. + If 0, the BLOCK is allocated (if needed) when the level is popped. */ + tree this_block; + /* The binding level containing this one (the enclosing binding level). */ + struct binding_level *level_chain; +}; + +/* The binding level currently in effect. */ +static struct binding_level *current_binding_level = NULL; + +/* A chain of binding_level structures awaiting reuse. */ +static struct binding_level *free_binding_level = NULL; + +/* The outermost binding level. This binding level is created when the + compiler is started and it will exist through the entire compilation. */ +static struct binding_level *global_binding_level; + +/* Binding level structures are initialized by copying this one. */ +static struct binding_level clear_binding_level = {NULL, NULL, NULL, NULL}; + + +static tree merge_sizes PARAMS ((tree, tree, tree, int, int)); +static tree compute_related_constant PARAMS ((tree, tree)); +static tree split_plus PARAMS ((tree, tree *)); +static int value_zerop PARAMS ((tree)); +static tree float_type_for_size PARAMS ((int, enum machine_mode)); +static tree convert_to_fat_pointer PARAMS ((tree, tree)); +static tree convert_to_thin_pointer PARAMS ((tree, tree)); +static tree make_descriptor_field PARAMS ((const char *,tree, tree, + tree)); +static void mark_binding_level PARAMS((PTR)); +static void mark_e_stack PARAMS((PTR)); + +/* Initialize the association of GNAT nodes to GCC trees. */ + +void +init_gnat_to_gnu () +{ + Node_Id gnat_node; + + associate_gnat_to_gnu = (tree *) xmalloc (max_gnat_nodes * sizeof (tree)); + ggc_add_tree_root (associate_gnat_to_gnu, max_gnat_nodes); + + for (gnat_node = 0; gnat_node < max_gnat_nodes; gnat_node++) + associate_gnat_to_gnu [gnat_node] = NULL_TREE; + + associate_gnat_to_gnu -= First_Node_Id; + + pending_elaborations = build_tree_list (NULL_TREE, NULL_TREE); + ggc_add_tree_root (&pending_elaborations, 1); + ggc_add_root ((PTR) &elist_stack, 1, sizeof (struct e_stack), mark_e_stack); + ggc_add_tree_root (&signed_and_unsigned_types[0][0], + (sizeof signed_and_unsigned_types + / sizeof signed_and_unsigned_types[0][0])); + ggc_add_tree_root (float_types, sizeof float_types / sizeof float_types[0]); + + ggc_add_root (¤t_binding_level, 1, sizeof current_binding_level, + mark_binding_level); +} + +/* 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 (gnat_entity, gnu_decl, no_check) + Entity_Id gnat_entity; + tree gnu_decl; + int no_check; +{ + if (gnu_decl + && (associate_gnat_to_gnu [gnat_entity] + || (! no_check && ! DECL_P (gnu_decl)))) + gigi_abort (401); + + associate_gnat_to_gnu [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 (gnat_entity) + Entity_Id gnat_entity; +{ + if (! associate_gnat_to_gnu [gnat_entity]) + gigi_abort (402); + + return associate_gnat_to_gnu [gnat_entity]; +} + +/* Return nonzero if a GCC tree has been associated with GNAT_ENTITY. */ + +int +present_gnu_tree (gnat_entity) + Entity_Id gnat_entity; +{ + return (associate_gnat_to_gnu [gnat_entity] != NULL_TREE); +} + + +/* Return non-zero if we are currently in the global binding level. */ + +int +global_bindings_p () +{ + return (force_global != 0 || current_binding_level == global_binding_level + ? -1 : 0); +} + +/* Return the list of declarations in the current level. Note that this list + is in reverse order (it has to be so for back-end compatibility). */ + +tree +getdecls () +{ + return current_binding_level->names; +} + +/* Nonzero if the current level needs to have a BLOCK made. */ + +int +kept_level_p () +{ + return (current_binding_level->names != 0); +} + +/* Enter a new binding level. The input parameter is ignored, but has to be + specified for back-end compatibility. */ + +void +pushlevel (ignore) + int ignore ATTRIBUTE_UNUSED; +{ + struct 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->level_chain; + } + else + newlevel + = (struct binding_level *) xmalloc (sizeof (struct binding_level)); + + *newlevel = clear_binding_level; + + /* Add this level to the front of the chain (stack) of levels that are + active. */ + newlevel->level_chain = current_binding_level; + current_binding_level = newlevel; +} + +/* Exit a binding level. + Pop the level off, and restore the state of the identifier-decl mappings + that were in effect when this level was entered. + + If KEEP is nonzero, this level had explicit declarations, so + and create a "block" (a BLOCK node) for the level + to record its declarations and subblocks for symbol table output. + + If FUNCTIONBODY is nonzero, this level is the body of a function, + so create a block as if KEEP were set and also clear out all + label names. + + If REVERSE is nonzero, reverse the order of decls before putting + them into the BLOCK. */ + +tree +poplevel (keep, reverse, functionbody) + int keep; + int reverse; + int functionbody; +{ + /* Points to a GCC BLOCK tree node. This is the BLOCK node construted for the + binding level that we are about to exit and which is returned by this + routine. */ + tree block = NULL_TREE; + tree decl_chain; + tree decl_node; + tree subblock_chain = current_binding_level->blocks; + tree subblock_node; + int block_previously_created; + + /* Reverse the list of XXXX_DECL nodes if desired. Note that the ..._DECL + nodes chained through the `names' field of current_binding_level are in + reverse order except for PARM_DECL node, which are explicitely stored in + the right order. */ + current_binding_level->names + = decl_chain = (reverse) ? nreverse (current_binding_level->names) + : current_binding_level->names; + + /* Output any nested inline functions within this block which must be + compiled because their address is needed. */ + for (decl_node = decl_chain; decl_node; decl_node = TREE_CHAIN (decl_node)) + if (TREE_CODE (decl_node) == FUNCTION_DECL + && ! TREE_ASM_WRITTEN (decl_node) && TREE_ADDRESSABLE (decl_node) + && DECL_INITIAL (decl_node) != 0) + { + push_function_context (); + output_inline_function (decl_node); + pop_function_context (); + } + + block = 0; + block_previously_created = (current_binding_level->this_block != 0); + if (block_previously_created) + block = current_binding_level->this_block; + else if (keep || functionbody) + block = make_node (BLOCK); + if (block != 0) + { + BLOCK_VARS (block) = keep ? decl_chain : 0; + BLOCK_SUBBLOCKS (block) = subblock_chain; + } + + /* Record the BLOCK node just built as the subblock its enclosing scope. */ + for (subblock_node = subblock_chain; subblock_node; + subblock_node = TREE_CHAIN (subblock_node)) + BLOCK_SUPERCONTEXT (subblock_node) = block; + + /* Clear out the meanings of the local variables of this level. */ + + for (subblock_node = decl_chain; subblock_node; + subblock_node = TREE_CHAIN (subblock_node)) + if (DECL_NAME (subblock_node) != 0) + /* If the identifier was used or addressed via a local extern decl, + don't forget that fact. */ + if (DECL_EXTERNAL (subblock_node)) + { + if (TREE_USED (subblock_node)) + TREE_USED (DECL_NAME (subblock_node)) = 1; + if (TREE_ADDRESSABLE (subblock_node)) + TREE_ADDRESSABLE (DECL_ASSEMBLER_NAME (subblock_node)) = 1; + } + + { + /* Pop the current level, and free the structure for reuse. */ + struct binding_level *level = current_binding_level; + current_binding_level = current_binding_level->level_chain; + level->level_chain = free_binding_level; + free_binding_level = level; + } + + if (functionbody) + { + /* This is the top level block of a function. The ..._DECL chain stored + in BLOCK_VARS are the function's parameters (PARM_DECL nodes). Don't + leave them in the BLOCK because they are found in the FUNCTION_DECL + instead. */ + DECL_INITIAL (current_function_decl) = block; + BLOCK_VARS (block) = 0; + } + else if (block) + { + if (!block_previously_created) + current_binding_level->blocks + = chainon (current_binding_level->blocks, block); + } + + /* If we did not make a block for the level just exited, any blocks made for + inner levels (since they cannot be recorded as subblocks in that level) + must be carried forward so they will later become subblocks of something + else. */ + else if (subblock_chain) + current_binding_level->blocks + = chainon (current_binding_level->blocks, subblock_chain); + if (block) + TREE_USED (block) = 1; + + return block; +} + +/* Insert BLOCK at the end of the list of subblocks of the + current binding level. This is used when a BIND_EXPR is expanded, + to handle the BLOCK node inside the BIND_EXPR. */ + +void +insert_block (block) + tree block; +{ + TREE_USED (block) = 1; + current_binding_level->blocks + = chainon (current_binding_level->blocks, block); +} + +/* Set the BLOCK node for the innermost scope + (the one we are currently in). */ + +void +set_block (block) + tree block; +{ + current_binding_level->this_block = block; + current_binding_level->names = chainon (current_binding_level->names, + BLOCK_VARS (block)); + current_binding_level->blocks = chainon (current_binding_level->blocks, + BLOCK_SUBBLOCKS (block)); +} + +/* Records a ..._DECL node DECL as belonging to the current lexical scope. + Returns the ..._DECL node. */ + +tree +pushdecl (decl) + tree decl; +{ + struct binding_level *b; + + /* If at top level, there is no context. But PARM_DECLs always go in the + level of its function. */ + if (global_bindings_p () && TREE_CODE (decl) != PARM_DECL) + { + b = global_binding_level; + DECL_CONTEXT (decl) = 0; + } + else + { + b = current_binding_level; + DECL_CONTEXT (decl) = current_function_decl; + } + + /* Put the declaration on the list. The list of declarations is in reverse + order. The list will be reversed later if necessary. This needs to be + this way for compatibility with the back-end. + + Don't put TYPE_DECLs for UNCONSTRAINED_ARRAY_TYPE into the list. 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) + { + TREE_CHAIN (decl) = b->names; + b->names = 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 this + function in c-decl.c makes a copy of the type node here, but that may + cause us trouble with incomplete types, so let's not try it (at least + for now). */ + + if (TREE_CODE (decl) == TYPE_DECL + && DECL_NAME (decl) != 0 + && (TYPE_NAME (TREE_TYPE (decl)) == 0 + || TREE_CODE (TYPE_NAME (TREE_TYPE (decl))) == IDENTIFIER_NODE + || (TREE_CODE (TYPE_NAME (TREE_TYPE (decl))) == TYPE_DECL + && DECL_ARTIFICIAL (TYPE_NAME (TREE_TYPE (decl))) + && ! DECL_ARTIFICIAL (decl)))) + TYPE_NAME (TREE_TYPE (decl)) = decl; + + return decl; +} + +/* Do little here. Set up the standard declarations later after the + front end has been run. */ + +void +init_decl_processing () +{ + /* The structure `tree_identifier' is the GCC tree data structure that holds + IDENTIFIER_NODE nodes. We need to call `set_identifier_size' to tell GCC + that we have not added any language specific fields to IDENTIFIER_NODE + nodes. */ + set_identifier_size (sizeof (struct tree_identifier)); + + lineno = 0; + + /* incomplete_decl_finalize_hook is defined in toplev.c. It needs to be set + by each front end to the appropriate routine that handles incomplete + VAR_DECL nodes. This routine will be invoked by compile_file when a + VAR_DECL node of DECL_SIZE zero is encountered. */ + incomplete_decl_finalize_hook = finish_incomplete_decl; + + /* Make the binding_level structure for global names. */ + current_function_decl = 0; + current_binding_level = 0; + free_binding_level = 0; + pushlevel (0); + global_binding_level = current_binding_level; + + build_common_tree_nodes (0); + + /* In Ada, we use a signed type for SIZETYPE. Use the signed type + corresponding to the size of ptr_mode. Make this here since we need + this before we can expand the GNAT types. */ + set_sizetype (type_for_size (GET_MODE_BITSIZE (ptr_mode), 0)); + build_common_tree_nodes_2 (0); + + pushdecl (build_decl (TYPE_DECL, get_identifier (SIZE_TYPE), sizetype)); + + /* We need to make the integer type before doing anything else. + We stitch this in to the appropriate GNAT type later. */ + pushdecl (build_decl (TYPE_DECL, get_identifier ("integer"), + integer_type_node)); + pushdecl (build_decl (TYPE_DECL, get_identifier ("unsigned char"), + char_type_node)); + + 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 (long_long_float_type, exception_type) + tree long_long_float_type, exception_type; +{ + tree endlink; + + /* 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); + pushdecl (build_decl (TYPE_DECL, get_identifier ("longest float type"), + longest_float_type_node)); + } + else + longest_float_type_node = TREE_TYPE (long_long_float_type); + + except_type_node = TREE_TYPE (exception_type); + + unsigned_type_node = type_for_size (INT_TYPE_SIZE, 1); + pushdecl (build_decl (TYPE_DECL, get_identifier ("unsigned int"), + unsigned_type_node)); + + void_type_decl_node + = pushdecl (build_decl (TYPE_DECL, get_identifier ("void"), + void_type_node)); + + void_ftype = build_function_type (void_type_node, NULL_TREE); + ptr_void_ftype = build_pointer_type (void_ftype); + + /* 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, 0, 1, 1, 0); + + /* 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, 0, 1, 1, 0); + + /* Make the types and functions used for exception processing. */ + jmpbuf_type + = build_array_type (type_for_mode (Pmode, 0), + build_index_type (build_int_2 (5, 0))); + pushdecl (build_decl (TYPE_DECL, get_identifier ("JMPBUF_T"), jmpbuf_type)); + 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, 0, 1, 1, 0); + + 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, 0, 1, 1, 0); + + /* 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, 0, 1, 1, 0); + + /* Function 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, 0, 1, 1, 0); + + + /* __gnat_raise_constraint_error takes a string, an integer and never + returns. */ + raise_constraint_error_decl + = create_subprog_decl + (get_identifier ("__gnat_raise_constraint_error"), 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, 0, 1, 1, 0); + + /* Likewise for __gnat_raise_program_error. */ + raise_program_error_decl + = create_subprog_decl + (get_identifier ("__gnat_raise_program_error"), 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, 0, 1, 1, 0); + + /* Likewise for __gnat_raise_storage_error. */ + raise_storage_error_decl + = create_subprog_decl + (get_identifier ("__gnat_raise_storage_error"), 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, 0, 1, 1, 0); + + /* Indicate that these never return. */ + + TREE_THIS_VOLATILE (raise_nodefer_decl) = 1; + TREE_THIS_VOLATILE (raise_constraint_error_decl) = 1; + TREE_THIS_VOLATILE (raise_program_error_decl) = 1; + TREE_THIS_VOLATILE (raise_storage_error_decl) = 1; + + TREE_SIDE_EFFECTS (raise_nodefer_decl) = 1; + TREE_SIDE_EFFECTS (raise_constraint_error_decl) = 1; + TREE_SIDE_EFFECTS (raise_program_error_decl) = 1; + TREE_SIDE_EFFECTS (raise_storage_error_decl) = 1; + + TREE_TYPE (raise_nodefer_decl) + = build_qualified_type (TREE_TYPE (raise_nodefer_decl), + TYPE_QUAL_VOLATILE); + TREE_TYPE (raise_constraint_error_decl) + = build_qualified_type (TREE_TYPE (raise_constraint_error_decl), + TYPE_QUAL_VOLATILE); + TREE_TYPE (raise_program_error_decl) + = build_qualified_type (TREE_TYPE (raise_program_error_decl), + TYPE_QUAL_VOLATILE); + TREE_TYPE (raise_storage_error_decl) + = build_qualified_type (TREE_TYPE (raise_storage_error_decl), + 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 ("setjmp"), NULL_TREE, + build_function_type (integer_type_node, + tree_cons (NULL_TREE, jmpbuf_ptr_type, endlink)), + NULL_TREE, 0, 1, 1, 0); + + DECL_BUILT_IN_CLASS (setjmp_decl) = BUILT_IN_NORMAL; + DECL_FUNCTION_CODE (setjmp_decl) = BUILT_IN_SETJMP; + + ggc_add_tree_root (gnat_std_decls, + sizeof gnat_std_decls / sizeof gnat_std_decls[0]); +} + +/* This routine is called in tree.c to print an error message for invalid use + of an incomplete type. */ + +void +incomplete_type_error (dont_care_1, dont_care_2) + tree dont_care_1 ATTRIBUTE_UNUSED; + tree dont_care_2 ATTRIBUTE_UNUSED; +{ + gigi_abort (404); +} + +/* This function is called indirectly from toplev.c to handle incomplete + declarations, i.e. VAR_DECL nodes whose DECL_SIZE is zero. To be precise, + compile_file in toplev.c makes an indirect call through the function pointer + incomplete_decl_finalize_hook which is initialized to this routine in + init_decl_processing. */ + +void +finish_incomplete_decl (dont_care) + tree dont_care ATTRIBUTE_UNUSED; +{ + gigi_abort (405); +} + +/* Given a record type (RECORD_TYPE) and a chain of FIELD_DECL + nodes (FIELDLIST), finish constructing the record or union type. + If HAS_REP is nonzero, this record has a rep clause; don't call + layout_type but merely set the size and alignment ourselves. + If DEFER_DEBUG is nonzero, do not call the debugging routines + on this type; it will be done later. */ + +void +finish_record_type (record_type, fieldlist, has_rep, defer_debug) + tree record_type; + tree fieldlist; + int has_rep; + int defer_debug; +{ + enum tree_code code = TREE_CODE (record_type); + tree ada_size = bitsize_zero_node; + tree size = bitsize_zero_node; + tree size_unit = size_zero_node; + tree field; + + TYPE_FIELDS (record_type) = fieldlist; + + if (TYPE_NAME (record_type) != 0 + && TREE_CODE (TYPE_NAME (record_type)) == TYPE_DECL) + TYPE_STUB_DECL (record_type) = TYPE_NAME (record_type); + else + TYPE_STUB_DECL (record_type) + = pushdecl (build_decl (TYPE_DECL, TYPE_NAME (record_type), + 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 (has_rep) + { + TYPE_ALIGN (record_type) = MAX (BITS_PER_UNIT, TYPE_ALIGN (record_type)); + TYPE_MODE (record_type) = BLKmode; + if (TYPE_SIZE (record_type) == 0) + { + TYPE_SIZE (record_type) = bitsize_zero_node; + TYPE_SIZE_UNIT (record_type) = size_zero_node; + } + } + 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 make a pass through 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). */ + + if (code == QUAL_UNION_TYPE) + fieldlist = nreverse (fieldlist); + + for (field = fieldlist; field; field = TREE_CHAIN (field)) + { + tree type = TREE_TYPE (field); + tree this_size = DECL_SIZE (field); + tree this_size_unit = DECL_SIZE_UNIT (field); + tree this_ada_size = DECL_SIZE (field); + + 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) != 0) + this_ada_size = TYPE_ADA_SIZE (type); + + if (has_rep && ! 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); + size_unit = size_binop (MAX_EXPR, size_unit, this_size_unit); + break; + + case QUAL_UNION_TYPE: + ada_size + = fold (build (COND_EXPR, bitsizetype, DECL_QUALIFIER (field), + this_ada_size, ada_size)); + size = fold (build (COND_EXPR, bitsizetype, DECL_QUALIFIER (field), + this_size, size)); + size_unit = fold (build (COND_EXPR, sizetype, DECL_QUALIFIER (field), + this_size_unit, size_unit)); + 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, bit_position (field), this_ada_size, + TREE_CODE (type) == QUAL_UNION_TYPE, has_rep); + size = merge_sizes (size, bit_position (field), this_size, + TREE_CODE (type) == QUAL_UNION_TYPE, has_rep); + size_unit + = merge_sizes (size_unit, byte_position (field), this_size_unit, + TREE_CODE (type) == QUAL_UNION_TYPE, has_rep); + break; + + default: + abort (); + } + } + + if (code == QUAL_UNION_TYPE) + nreverse (fieldlist); + + /* 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) != 0) + { + size = TYPE_SIZE (record_type); + size_unit = TYPE_SIZE_UNIT (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)) + TYPE_ADA_SIZE (record_type) = ada_size; + +#ifdef ROUND_TYPE_SIZE + size = ROUND_TYPE_SIZE (record_type, size, TYPE_ALIGN (record_type)); + size_unit = ROUND_TYPE_SIZE_UNIT (record_size, size_unit, + TYPE_ALIGN (record_type) / BITS_PER_UNIT); +#else + size = round_up (size, TYPE_ALIGN (record_type)); + size_unit = round_up (size_unit, TYPE_ALIGN (record_type) / BITS_PER_UNIT); +#endif + + if (has_rep + && ! (TREE_CODE (record_type) == RECORD_TYPE + && TYPE_IS_PADDING_P (record_type) + && TREE_CODE (size) != INTEGER_CST + && contains_placeholder_p (size))) + { + TYPE_SIZE (record_type) = size; + TYPE_SIZE_UNIT (record_type) = size_unit; + } + + if (has_rep) + compute_record_mode (record_type); + + if (! defer_debug) + { + /* 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. */ + if (TREE_CODE (TYPE_SIZE (record_type)) != INTEGER_CST) + { + tree new_record_type + = make_node (TREE_CODE (record_type) == QUAL_UNION_TYPE + ? UNION_TYPE : TREE_CODE (record_type)); + tree orig_id = DECL_NAME (TYPE_STUB_DECL (record_type)); + 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; + + TYPE_NAME (new_record_type) = new_id; + TYPE_ALIGN (new_record_type) = BIGGEST_ALIGNMENT; + TYPE_STUB_DECL (new_record_type) + = pushdecl (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)); + + /* 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 != 0; + 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); + int var = 0; + 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. */ + + if (TREE_CODE (new_record_type) == UNION_TYPE) + pos = bitsize_zero_node, align = 0; + else + pos = compute_related_constant (curpos, last_pos); + + if (pos == 0 && TREE_CODE (curpos) == MULT_EXPR + && TREE_CODE (TREE_OPERAND (curpos, 1)) == INTEGER_CST) + { + align = TREE_INT_CST_LOW (TREE_OPERAND (curpos, 1)); + pos = compute_related_constant (curpos, + round_up (last_pos, align)); + } + else if (pos == 0 && 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)); + } + + /* 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 == 0) + pos = bitsize_zero_node; + + /* See if this type is variable-size and make a new type + and indicate the indirection if so. */ + if (TREE_CODE (TYPE_SIZE (field_type)) != INTEGER_CST) + { + field_type = build_pointer_type (field_type); + var = 1; + } + + /* Make a new field name, if necessary. */ + if (var || align != 0) + { + char suffix[6]; + + 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, + TYPE_SIZE (field_type), 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 + : TYPE_SIZE (TREE_TYPE (old_field))); + } + + TYPE_FIELDS (new_record_type) + = nreverse (TYPE_FIELDS (new_record_type)); + + rest_of_type_compilation (new_record_type, global_bindings_p ()); + } + + rest_of_type_compilation (record_type, global_bindings_p ()); + } +} + +/* 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 (last_size, first_bit, size, special, has_rep) + tree last_size; + tree first_bit, size; + int special; + int has_rep; +{ + tree type = TREE_TYPE (last_size); + + if (! special || TREE_CODE (size) != COND_EXPR) + { + tree new = size_binop (PLUS_EXPR, first_bit, size); + + if (has_rep) + new = size_binop (MAX_EXPR, last_size, new); + + return new; + } + + return fold (build (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))); +} + +/* 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 (op0, op1) + tree op0, 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 size_zero_node. All operations must be of + sizetype. */ + +static tree +split_plus (in, pvar) + tree in; + tree *pvar; +{ + tree result = bitsize_zero_node; + + while (TREE_CODE (in) == NON_LVALUE_EXPR) + in = TREE_OPERAND (in, 0); + + *pvar = in; + if (TREE_CODE (in) == INTEGER_CST) + { + *pvar = bitsize_zero_node; + return 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); + + result = size_binop (PLUS_EXPR, result, lhs_con); + result = size_binop (TREE_CODE (in), result, rhs_con); + + 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 result; + } + 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 nonzero if the function returns an unconstrained + object. RETURNS_BY_REF is nonzero if the function returns by reference. + RETURNS_WITH_DSP is nonzero if the function is to return with a + depressed stack pointer. */ + +tree +create_subprog_type (return_type, param_decl_list, cico_list, + returns_unconstrained, returns_by_ref, returns_with_dsp) + tree return_type; + tree param_decl_list; + tree cico_list; + int returns_unconstrained, returns_by_ref, returns_with_dsp; +{ + /* 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) != 0 || cico_list != 0 + || TYPE_RETURNS_UNCONSTRAINED_P (type) != returns_unconstrained + || TYPE_RETURNS_BY_REF_P (type) != returns_by_ref) + type = copy_type (type); + + TYPE_CI_CO_LIST (type) = cico_list; + TYPE_RETURNS_UNCONSTRAINED_P (type) = returns_unconstrained; + TYPE_RETURNS_STACK_DEPRESSED (type) = returns_with_dsp; + TYPE_RETURNS_BY_REF_P (type) = returns_by_ref; + return type; +} + +/* Return a copy of TYPE but safe to modify in any way. */ + +tree +copy_type (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. */ + +tree +create_index_type (min, max, index) + tree min, max; + tree index; +{ + /* 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) != 0) + type = copy_type (type); + + TYPE_INDEX_TYPE (type) = index; + 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 nonzero if this is a declaration that was generated + by the compiler. DEBUG_INFO_P is nonzero if we need to write debugging + information about this type. */ + +tree +create_type_decl (type_name, type, attr_list, artificial_p, debug_info_p) + tree type_name; + tree type; + struct attrib *attr_list; + int artificial_p; + int debug_info_p; +{ + tree type_decl = build_decl (TYPE_DECL, type_name, type); + enum tree_code code = TREE_CODE (type); + + DECL_ARTIFICIAL (type_decl) = artificial_p; + pushdecl (type_decl); + 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, + a dummy type, which will be completed later, or a type for which + debugging information was not requested. */ + if (code == UNCONSTRAINED_ARRAY_TYPE || TYPE_IS_DUMMY_P (type) + || ! debug_info_p) + DECL_IGNORED_P (type_decl) = 1; + else if (code != ENUMERAL_TYPE && code != RECORD_TYPE + && ! ((code == POINTER_TYPE || code == REFERENCE_TYPE) + && TYPE_IS_DUMMY_P (TREE_TYPE (type)))) + rest_of_decl_compilation (type_decl, NULL, global_bindings_p (), 0); + + return type_decl; +} + +/* Returns a GCC VAR_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 nonzero if this variable is constant. + + PUBLIC_FLAG is nonzero if this definition is to be made visible outside of + the current compilation unit. This flag should be set when processing the + 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 here). + + STATIC_FLAG is only relevant when not at top level. In that case + it indicates whether to always allocate storage to the variable. */ + +tree +create_var_decl (var_name, asm_name, type, var_init, const_flag, public_flag, + extern_flag, static_flag, attr_list) + tree var_name; + tree asm_name; + tree type; + tree var_init; + int const_flag; + int public_flag; + int extern_flag; + int static_flag; + struct attrib *attr_list; +{ + int init_const + = (var_init == 0 + ? 0 + : (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (var_init)) + && (global_bindings_p () || static_flag + ? 0 != initializer_constant_valid_p (var_init, + TREE_TYPE (var_init)) + : TREE_CONSTANT (var_init)))); + tree var_decl + = build_decl ((const_flag && init_const + /* Only make a CONST_DECL for sufficiently-small objects. + We consider complex double "sufficiently-small" */ + && TYPE_SIZE (type) != 0 + && host_integerp (TYPE_SIZE_UNIT (type), 1) + && 0 >= compare_tree_int (TYPE_SIZE_UNIT (type), + GET_MODE_SIZE (DCmode))) + ? CONST_DECL : VAR_DECL, var_name, type); + tree assign_init = 0; + + /* If this is external, throw away any initializations unless this is a + CONST_DECL (meaning we have a constant); they will be done elsewhere. If + we are defining a global here, leave a constant initialization and save + any variable elaborations for the elaboration routine. Otherwise, if + the initializing expression is not the same as TYPE, generate the + initialization with an assignment statement, since it knows how + to do the required adjustents. */ + + if (extern_flag && TREE_CODE (var_decl) != CONST_DECL) + var_init = 0; + + if (global_bindings_p () && var_init != 0 && ! init_const) + { + add_pending_elaborations (var_decl, var_init); + var_init = 0; + } + + else if (var_init != 0 + && ((TYPE_MAIN_VARIANT (TREE_TYPE (var_init)) + != TYPE_MAIN_VARIANT (type)) + || (static_flag && ! init_const))) + assign_init = var_init, var_init = 0; + + DECL_COMMON (var_decl) = !flag_no_common; + 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) = TREE_CODE (var_decl) == CONST_DECL; + TREE_THIS_VOLATILE (var_decl) = TREE_SIDE_EFFECTS (var_decl) + = TYPE_VOLATILE (type); + + /* At the global binding level we need to allocate static storage for the + variable if and only if its not external. If we are not at the top level + we allocate automatic storage unless requested not to. */ + TREE_STATIC (var_decl) = global_bindings_p () ? !extern_flag : static_flag; + + if (asm_name != 0) + SET_DECL_ASSEMBLER_NAME (var_decl, asm_name); + + process_attributes (var_decl, attr_list); + + /* Add this decl to the current binding level and generate any + needed code and RTL. */ + var_decl = pushdecl (var_decl); + expand_decl (var_decl); + + if (DECL_CONTEXT (var_decl) != 0) + expand_decl_init (var_decl); + + /* If this is volatile, force it into memory. */ + if (TREE_SIDE_EFFECTS (var_decl)) + mark_addressable (var_decl); + + if (TREE_CODE (var_decl) != CONST_DECL) + rest_of_decl_compilation (var_decl, 0, global_bindings_p (), 0); + + if (assign_init != 0) + { + /* If VAR_DECL has a padded type, convert it to the unpadded + type so the assignment is done properly. */ + tree lhs = var_decl; + + if (TREE_CODE (TREE_TYPE (lhs)) == RECORD_TYPE + && TYPE_IS_PADDING_P (TREE_TYPE (lhs))) + lhs = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (lhs))), lhs); + + expand_expr_stmt (build_binary_op (MODIFY_EXPR, NULL_TREE, lhs, + assign_init)); + } + + return var_decl; +} + +/* 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. */ + +tree +create_field_decl (field_name, field_type, record_type, packed, size, pos, + addressable) + tree field_name; + tree field_type; + tree record_type; + int packed; + tree size, pos; + int addressable; +{ + tree field_decl = build_decl (FIELD_DECL, field_name, field_type); + + DECL_CONTEXT (field_decl) = record_type; + TREE_READONLY (field_decl) = TREE_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. + If it is a padding type where the inner field is of variable size, it + must be at its natural alignment. Just handle the packed case here; we + will disallow non-aligned rep clauses elsewhere. */ + if (packed && TYPE_MODE (field_type) == BLKmode) + DECL_ALIGN (field_decl) + = ((TREE_CODE (field_type) == RECORD_TYPE + && TYPE_IS_PADDING_P (field_type) + && ! TREE_CONSTANT (DECL_SIZE (TYPE_FIELDS (field_type)))) + ? TYPE_ALIGN (field_type) : BITS_PER_UNIT); + + /* If a size is specified, use it. Otherwise, see if we have a size + to use that may differ from the natural size of the object. */ + if (size != 0) + size = convert (bitsizetype, size); + else if (packed) + { + if (packed == 1 && ! operand_equal_p (rm_size (field_type), + TYPE_SIZE (field_type), 0)) + size = rm_size (field_type); + + /* For a constant size larger than MAX_FIXED_MODE_SIZE, round up to + byte. */ + if (size != 0 && TREE_CODE (size) == INTEGER_CST + && compare_tree_int (size, MAX_FIXED_MODE_SIZE) > 0) + size = round_up (size, BITS_PER_UNIT); + } + + /* 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. But never make a + bitfield if the type of the field has a nonconstant size. */ + + if (size != 0 && TREE_CODE (size) == INTEGER_CST + && TREE_CODE (TYPE_SIZE (field_type)) == INTEGER_CST + && (! operand_equal_p (TYPE_SIZE (field_type), size, 0) + || (pos != 0 + && ! value_zerop (size_binop (TRUNC_MOD_EXPR, pos, + bitsize_int (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 == 0) + 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 != 0 ? DECL_BIT_FIELD (field_decl) : packed; + DECL_ALIGN (field_decl) + = MAX (DECL_ALIGN (field_decl), + DECL_BIT_FIELD (field_decl) ? 1 + : packed && TYPE_MODE (field_type) != BLKmode ? BITS_PER_UNIT + : TYPE_ALIGN (field_type)); + + if (pos != 0) + { + /* 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, BIGGEST_ALIGNMENT); + pos_from_bit (&DECL_FIELD_OFFSET (field_decl), + &DECL_FIELD_BIT_OFFSET (field_decl), + BIGGEST_ALIGNMENT, pos); + + DECL_HAS_REP_P (field_decl) = 1; + } + + /* Mark the decl as nonaddressable if it either is indicated so semantically + or if it is a bit field. */ + DECL_NONADDRESSABLE_P (field_decl) + = ! addressable || DECL_BIT_FIELD (field_decl); + + return field_decl; +} + +/* Subroutine of previous function: return nonzero if EXP, ignoring any side + effects, has the value of zero. */ + +static int +value_zerop (exp) + tree exp; +{ + if (TREE_CODE (exp) == COMPOUND_EXPR) + return value_zerop (TREE_OPERAND (exp, 1)); + + return integer_zerop (exp); +} + +/* Returns a PARM_DECL node. PARAM_NAME is the name of the parameter, + PARAM_TYPE is its type. READONLY is nonzero if the parameter is + readonly (either an IN parameter or an address of a pass-by-ref + parameter). */ + +tree +create_param_decl (param_name, param_type, readonly) + tree param_name; + tree param_type; + int readonly; +{ + tree param_decl = build_decl (PARM_DECL, param_name, param_type); + + DECL_ARG_TYPE (param_decl) = param_type; + DECL_ARG_TYPE_AS_WRITTEN (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 (decl, attr_list) + 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->arg, + NULL_TREE), + ATTR_FLAG_TYPE_IN_PLACE); + break; + + case ATTR_LINK_ALIAS: + 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: +#ifdef ASM_OUTPUT_SECTION_NAME + 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); +#endif + break; + } +} + +/* Add some pending elaborations on the list. */ + +void +add_pending_elaborations (var_decl, var_init) + tree var_decl; + tree var_init; +{ + if (var_init != 0) + Check_Elaboration_Code_Allowed (error_gnat_node); + + pending_elaborations + = chainon (pending_elaborations, build_tree_list (var_decl, var_init)); +} + +/* Obtain any pending elaborations and clear the old list. */ + +tree +get_pending_elaborations () +{ + /* Each thing added to the list went on the end; we want it on the + beginning. */ + tree result = TREE_CHAIN (pending_elaborations); + + TREE_CHAIN (pending_elaborations) = 0; + return result; +} + +/* Mark the binding level stack. */ + +static void +mark_binding_level (arg) + PTR arg; +{ + struct binding_level *level = *(struct binding_level **) arg; + + for (; level != 0; level = level->level_chain) + { + ggc_mark_tree (level->names); + ggc_mark_tree (level->blocks); + ggc_mark_tree (level->this_block); + } +} + +/* Mark the pending elaboration list. */ + +static void +mark_e_stack (data) + PTR data; +{ + struct e_stack *p = *((struct e_stack **) data); + + if (p != 0) + { + ggc_mark_tree (p->elab_list); + mark_e_stack (&p->next); + } +} + +/* Return nonzero if there are pending elaborations. */ + +int +pending_elaborations_p () +{ + return TREE_CHAIN (pending_elaborations) != 0; +} + +/* Save a copy of the current pending elaboration list and make a new + one. */ + +void +push_pending_elaborations () +{ + struct e_stack *p = (struct e_stack *) xmalloc (sizeof (struct e_stack)); + + p->next = elist_stack; + p->elab_list = pending_elaborations; + elist_stack = p; + pending_elaborations = build_tree_list (NULL_TREE, NULL_TREE); +} + +/* Pop the stack of pending elaborations. */ + +void +pop_pending_elaborations () +{ + struct e_stack *p = elist_stack; + + pending_elaborations = p->elab_list; + elist_stack = p->next; + free (p); +} + +/* Return the current position in pending_elaborations so we can insert + elaborations after that point. */ + +tree +get_elaboration_location () +{ + return tree_last (pending_elaborations); +} + +/* Insert the current elaborations after ELAB, which is in some elaboration + list. */ + +void +insert_elaboration_list (elab) + tree elab; +{ + tree next = TREE_CHAIN (elab); + + if (TREE_CHAIN (pending_elaborations)) + { + TREE_CHAIN (elab) = TREE_CHAIN (pending_elaborations); + TREE_CHAIN (tree_last (pending_elaborations)) = next; + TREE_CHAIN (pending_elaborations) = 0; + } +} + +/* Returns a LABEL_DECL node for LABEL_NAME. */ + +tree +create_label_decl (label_name) + 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_LINE (label_decl) = lineno; + DECL_SOURCE_FILE (label_decl) = input_filename; + + 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, and EXTERN_FLAG are used to set the appropriate + fields in the FUNCTION_DECL. */ + +tree +create_subprog_decl (subprog_name, asm_name, subprog_type, param_decl_list, + inline_flag, public_flag, extern_flag, attr_list) + tree subprog_name; + tree asm_name; + tree subprog_type; + tree param_decl_list; + int inline_flag; + int public_flag; + int extern_flag; + struct attrib *attr_list; +{ + 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 != 0 && DECL_INLINE (current_function_decl) + && DECL_EXTERNAL (current_function_decl)) + extern_flag = 1; + + DECL_EXTERNAL (subprog_decl) = extern_flag; + TREE_PUBLIC (subprog_decl) = public_flag; + DECL_INLINE (subprog_decl) = inline_flag; + 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); + + if (asm_name != 0) + DECL_ASSEMBLER_NAME (subprog_decl) = asm_name; + + process_attributes (subprog_decl, attr_list); + + /* Add this decl to the current binding level. */ + subprog_decl = pushdecl (subprog_decl); + + /* Output the assembler code and/or RTL for the declaration. */ + rest_of_decl_compilation (subprog_decl, 0, global_bindings_p (), 0); + + return subprog_decl; +} + +/* Count how deep we are into nested functions. This is because + we shouldn't call the backend function context routines unless we + are in a nested function. */ + +static int function_nesting_depth; + +/* 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 (subprog_decl) + tree subprog_decl; +{ + tree param_decl_list; + tree param_decl; + tree next_param; + + if (function_nesting_depth++ != 0) + push_function_context (); + + announce_function (subprog_decl); + + /* Make this field nonzero so further routines know that this is not + tentative. error_mark_node is replaced below (in poplevel) with the + adequate BLOCK. */ + DECL_INITIAL (subprog_decl) = error_mark_node; + + /* This function exists in static storage. This does not mean `static' in + the C sense! */ + TREE_STATIC (subprog_decl) = 1; + + /* Enter a new binding level. */ + current_function_decl = subprog_decl; + pushlevel (0); + + /* Push all the PARM_DECL nodes onto the current scope (i.e. the scope of the + subprogram body) so that they can be recognized as local variables in the + subprogram. + + The list of PARM_DECL nodes is stored in the right order in + DECL_ARGUMENTS. Since ..._DECL nodes get stored in the reverse order in + which they are transmitted to `pushdecl' we need to reverse the list of + PARM_DECLs if we want it to be stored in the right order. The reason why + we want to make sure the PARM_DECLs are stored in the correct order is + that this list will be retrieved in a few lines with a call to `getdecl' + to store it back into the DECL_ARGUMENTS field. */ + param_decl_list = nreverse (DECL_ARGUMENTS (subprog_decl)); + + for (param_decl = param_decl_list; param_decl; param_decl = next_param) + { + next_param = TREE_CHAIN (param_decl); + TREE_CHAIN (param_decl) = NULL; + pushdecl (param_decl); + } + + /* Store back the PARM_DECL nodes. They appear in the right order. */ + DECL_ARGUMENTS (subprog_decl) = getdecls (); + + init_function_start (subprog_decl, input_filename, lineno); + expand_function_start (subprog_decl, 0); +} + + +/* Finish the definition of the current subprogram and compile it all the way + to assembler language output. */ + +void +end_subprog_body (void) +{ + tree decl; + tree cico_list; + + poplevel (1, 0, 1); + BLOCK_SUPERCONTEXT (DECL_INITIAL (current_function_decl)) + = current_function_decl; + + /* Mark the RESULT_DECL as being in this subprogram. */ + DECL_CONTEXT (DECL_RESULT (current_function_decl)) = current_function_decl; + + expand_function_end (input_filename, lineno, 0); + rest_of_compilation (current_function_decl); + +#if 0 + /* If we're sure this function is defined in this file then mark it + as such */ + if (TREE_ASM_WRITTEN (current_function_decl)) + mark_fn_defined_in_this_file (current_function_decl); +#endif + + /* Throw away any VAR_DECLs we made for OUT parameters; they must + not be seen when we call this function and will be in + unallocated memory anyway. */ + for (cico_list = TYPE_CI_CO_LIST (TREE_TYPE (current_function_decl)); + cico_list != 0; cico_list = TREE_CHAIN (cico_list)) + TREE_VALUE (cico_list) = 0; + + if (DECL_SAVED_INSNS (current_function_decl) == 0) + { + /* Throw away DECL_RTL in any PARM_DECLs unless this function + was saved for inline, in which case the DECL_RTLs are in + preserved memory. */ + for (decl = DECL_ARGUMENTS (current_function_decl); + decl != 0; decl = TREE_CHAIN (decl)) + { + SET_DECL_RTL (decl, 0); + DECL_INCOMING_RTL (decl) = 0; + } + + /* Similarly, discard DECL_RTL of the return value. */ + SET_DECL_RTL (DECL_RESULT (current_function_decl), 0); + + /* But DECL_INITIAL must remain nonzero so we know this + was an actual function definition unless toplev.c decided not + to inline it. */ + if (DECL_INITIAL (current_function_decl) != 0) + DECL_INITIAL (current_function_decl) = error_mark_node; + + DECL_ARGUMENTS (current_function_decl) = 0; + } + + /* If we are not at the bottom of the function nesting stack, pop up to + the containing function. Otherwise show we aren't in any function. */ + if (--function_nesting_depth != 0) + pop_function_context (); + else + current_function_decl = 0; +} + +/* Return a definition for a builtin function named NAME and whose data type + is TYPE. TYPE should be a function type with argument types. + FUNCTION_CODE tells later passes how to compile calls to this function. + See tree.h for its possible values. + + If LIBRARY_NAME is nonzero, use that for DECL_ASSEMBLER_NAME, + the name to be called if we can't opencode the function. */ + +tree +builtin_function (name, type, function_code, class, library_name) + const char *name; + tree type; + int function_code; + enum built_in_class class; + const char *library_name; +{ + tree decl = build_decl (FUNCTION_DECL, get_identifier (name), type); + + DECL_EXTERNAL (decl) = 1; + TREE_PUBLIC (decl) = 1; + if (library_name) + DECL_ASSEMBLER_NAME (decl) = get_identifier (library_name); + + pushdecl (decl); + DECL_BUILT_IN_CLASS (decl) = class; + DECL_FUNCTION_CODE (decl) = function_code; + 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 +type_for_size (precision, unsignedp) + unsigned precision; + int unsignedp; +{ + tree t; + char type_name[20]; + + if (precision <= 2 * MAX_BITS_PER_WORD + && signed_and_unsigned_types[precision][unsignedp] != 0) + 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) == 0) + { + 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_size (precision, mode) + int precision; + enum machine_mode mode; +{ + tree t; + char type_name[20]; + + if (float_types[(int) mode] != 0) + return float_types[(int) mode]; + + float_types[(int) mode] = t = make_node (REAL_TYPE); + TYPE_PRECISION (t) = precision; + layout_type (t); + + if (TYPE_MODE (t) != mode) + gigi_abort (414); + + if (TYPE_NAME (t) == 0) + { + 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 +type_for_mode (mode, unsignedp) + enum machine_mode mode; + int unsignedp; +{ + if (GET_MODE_CLASS (mode) == MODE_FLOAT) + return float_type_for_size (GET_MODE_BITSIZE (mode), mode); + else + return type_for_size (GET_MODE_BITSIZE (mode), unsignedp); +} + +/* Return the unsigned version of a TYPE_NODE, a scalar type. */ + +tree +unsigned_type (type_node) + tree type_node; +{ + tree type = 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) != 0 + && 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 +signed_type (type_node) + tree type_node; +{ + tree type = 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) != 0 + && 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 a type the same as TYPE except unsigned or signed according to + UNSIGNEDP. */ + +tree +signed_or_unsigned_type (unsignedp, type) + int unsignedp; + tree type; +{ + if (! INTEGRAL_TYPE_P (type) || TREE_UNSIGNED (type) == unsignedp) + return type; + else + return type_for_size (TYPE_PRECISION (type), unsignedp); +} + +/* 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 (exp, max_p) + tree exp; + int max_p; +{ + enum tree_code code = TREE_CODE (exp); + tree type = TREE_TYPE (exp); + + switch (TREE_CODE_CLASS (code)) + { + case 'd': + case 'c': + return exp; + + case 'x': + if (code == TREE_LIST) + return tree_cons (TREE_PURPOSE (exp), + max_size (TREE_VALUE (exp), max_p), + TREE_CHAIN (exp) != 0 + ? max_size (TREE_CHAIN (exp), max_p) : 0); + break; + + case 'r': + /* If this contains a PLACEHOLDER_EXPR, it is the thing we want to + modify. Otherwise, we abort since it is something we can't + handle. */ + if (! contains_placeholder_p (exp)) + gigi_abort (406); + + type = TREE_TYPE (TREE_OPERAND (exp, 1)); + return + max_size (max_p ? TYPE_MAX_VALUE (type) : TYPE_MIN_VALUE (type), 1); + + case '<': + return max_p ? size_one_node : size_zero_node; + + case '1': + case '2': + case 'e': + 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 == RTL_EXPR) + gigi_abort (407); + else if (code == COMPOUND_EXPR) + return max_size (TREE_OPERAND (exp, 1), max_p); + else if (code == WITH_RECORD_EXPR) + return exp; + + { + 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_OVERFLOW (rhs)) + return lhs; + else if (max_p && code == MIN_EXPR && TREE_OVERFLOW (lhs)) + return rhs; + else if ((code == MINUS_EXPR || code == PLUS_EXPR) + && (TREE_OVERFLOW (lhs) + || operand_equal_p (lhs, TYPE_MAX_VALUE (type), 0)) + && ! TREE_CONSTANT (rhs)) + return lhs; + else + return fold (build (code, type, lhs, rhs)); + } + + case 3: + if (code == SAVE_EXPR) + return exp; + else if (code == COND_EXPR) + return fold (build (MAX_EXPR, type, + max_size (TREE_OPERAND (exp, 1), max_p), + max_size (TREE_OPERAND (exp, 2), max_p))); + else if (code == CALL_EXPR && TREE_OPERAND (exp, 1) != 0) + return build (CALL_EXPR, type, TREE_OPERAND (exp, 0), + max_size (TREE_OPERAND (exp, 1), max_p)); + } + } + + gigi_abort (408); +} + +/* 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 (template_type, array_type, expr) + tree template_type; + tree array_type; + tree expr; +{ + tree template_elts = NULL_TREE; + tree bound_list = NULL_TREE; + tree field; + + if (TREE_CODE (array_type) == RECORD_TYPE + && (TYPE_IS_PADDING_P (array_type) + || TYPE_LEFT_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 != 0 + ? (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 != 0) + bounds = TREE_VALUE (bound_list); + else if (TREE_CODE (array_type) == ARRAY_TYPE) + bounds = TYPE_INDEX_TYPE (TYPE_DOMAIN (array_type)); + else if (expr != 0 && TREE_CODE (expr) == PARM_DECL + && DECL_BY_COMPONENT_PTR_P (expr)) + bounds = TREE_TYPE (field); + else + gigi_abort (411); + + min = convert (TREE_TYPE (TREE_CHAIN (field)), TYPE_MIN_VALUE (bounds)); + max = convert (TREE_TYPE (field), TYPE_MAX_VALUE (bounds)); + + /* If either MIN or MAX involve a PLACEHOLDER_EXPR, we must + surround them with a WITH_RECORD_EXPR giving EXPR as the + OBJECT. */ + if (! TREE_CONSTANT (min) && contains_placeholder_p (min)) + min = build (WITH_RECORD_EXPR, TREE_TYPE (min), min, expr); + if (! TREE_CONSTANT (max) && contains_placeholder_p (max)) + max = build (WITH_RECORD_EXPR, TREE_TYPE (max), max, expr); + + template_elts = tree_cons (TREE_CHAIN (field), max, + tree_cons (field, min, template_elts)); + } + + return 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 a gnat node 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 (type, mech, gnat_entity) + tree type; + Mechanism_Type mech; + Entity_Id gnat_entity; +{ + tree record_type = make_node (RECORD_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 ((int) TYPE_DIGITS_VALUE (type)) + { + 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 = TREE_UNSIGNED (type) ? 2 : 6; + break; + case 16: + dtype = TREE_UNSIGNED (type) ? 3 : 7; + break; + case 32: + dtype = TREE_UNSIGNED (type) ? 4 : 8; + break; + case 64: + dtype = TREE_UNSIGNED (type) ? 5 : 9; + break; + case 128: + dtype = TREE_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 ((int) TYPE_DIGITS_VALUE (type)) + { + 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; + default: + class = 1; + } + + /* 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", 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", type_for_size (8, 1), + record_type, size_int (dtype))); + field_list = chainon (field_list, + make_descriptor_field ("CLASS", type_for_size (8, 1), + record_type, size_int (class))); + + field_list + = chainon (field_list, + make_descriptor_field ("POINTER", + build_pointer_type (type), + record_type, + build1 (ADDR_EXPR, + build_pointer_type (type), + build (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", 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_L2", 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", + type_for_size (8, 1), + record_type, + size_zero_node)); + + field_list = chainon (field_list, + make_descriptor_field ("DIGITS", + type_for_size (8, 1), + record_type, + size_zero_node)); + + field_list + = chainon (field_list, + make_descriptor_field + ("AFLAGS", 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", + type_for_size (8, 1), + record_type, + size_int (ndim))); + + field_list = chainon (field_list, + make_descriptor_field ("ARSIZE", + type_for_size (32, 1), + record_type, + size_in_bytes (type))); + + /* Now build a pointer to the 0,0,0... element. */ + tem = build (PLACEHOLDER_EXPR, type); + for (i = 0, inner_type = type; i < ndim; + i++, inner_type = TREE_TYPE (inner_type)) + tem = build (ARRAY_REF, TREE_TYPE (inner_type), tem, + convert (TYPE_DOMAIN (inner_type), size_zero_node)); + + field_list + = chainon (field_list, + make_descriptor_field + ("A0", build_pointer_type (inner_type), record_type, + build1 (ADDR_EXPR, build_pointer_type (inner_type), tem))); + + /* Next come the addressing coefficients. */ + tem = size_int (1); + 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, + 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, 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, 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, 1); + pushdecl (build_decl (TYPE_DECL, create_concat_name (gnat_entity, "DESC"), + record_type)); + + return record_type; +} + +/* Utility routine for above code to make a field. */ + +static tree +make_descriptor_field (name, type, rec_type, initial) + 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; +} + +/* 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 (template_type, object_type, name) + 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, 0); + + return type; +} + +/* 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 (old_type, new_type) + tree old_type; + tree new_type; +{ + tree ptr = TYPE_POINTER_TO (old_type); + tree ref = TYPE_REFERENCE_TO (old_type); + + if ((ptr == 0 && ref == 0) || old_type == new_type) + return; + + /* First handle the simple case. */ + if (TREE_CODE (new_type) != UNCONSTRAINED_ARRAY_TYPE) + { + if (ptr != 0) + TREE_TYPE (ptr) = new_type; + TYPE_POINTER_TO (new_type) = ptr; + + if (ref != 0) + TREE_TYPE (ref) = new_type; + TYPE_REFERENCE_TO (new_type) = ref; + + if (ptr != 0 && TYPE_NAME (ptr) != 0 + && TREE_CODE (TYPE_NAME (ptr)) == TYPE_DECL + && TREE_CODE (new_type) != ENUMERAL_TYPE) + rest_of_decl_compilation (TYPE_NAME (ptr), NULL, + global_bindings_p (), 0); + if (ref != 0 && TYPE_NAME (ref) != 0 + && TREE_CODE (TYPE_NAME (ref)) == TYPE_DECL + && TREE_CODE (new_type) != ENUMERAL_TYPE) + rest_of_decl_compilation (TYPE_NAME (ref), NULL, + global_bindings_p (), 0); + } + + /* Now deal with the unconstrained array case. In this case the "pointer" + is actually a RECORD_TYPE where the types of both fields are + pointers to void. In that case, copy the field list from the + old type to the new one and update the fields' context. */ + else if (TREE_CODE (ptr) != RECORD_TYPE || ! TYPE_IS_FAT_POINTER_P (ptr)) + gigi_abort (412); + + else + { + tree new_obj_rec = TYPE_OBJECT_RECORD_TYPE (new_type); + tree ptr_temp_type; + tree new_ref; + tree var; + + TYPE_FIELDS (ptr) = TYPE_FIELDS (TYPE_POINTER_TO (new_type)); + DECL_CONTEXT (TYPE_FIELDS (ptr)) = ptr; + DECL_CONTEXT (TREE_CHAIN (TYPE_FIELDS (ptr))) = ptr; + + /* Rework the PLACEHOLDER_EXPR inside the reference to the + template bounds. + + ??? This is now the only use of gnat_substitute_in_type, which + is now a very "heavy" routine to do this, so it should be replaced + at some point. */ + ptr_temp_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (ptr))); + new_ref = build (COMPONENT_REF, ptr_temp_type, + build (PLACEHOLDER_EXPR, ptr), + TREE_CHAIN (TYPE_FIELDS (ptr))); + + update_pointer_to + (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))), + gnat_substitute_in_type (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))), + TREE_CHAIN (TYPE_FIELDS (ptr)), new_ref)); + + for (var = TYPE_MAIN_VARIANT (ptr); var; var = TYPE_NEXT_VARIANT (var)) + TYPE_UNCONSTRAINED_ARRAY (var) = new_type; + + TYPE_POINTER_TO (new_type) = TYPE_REFERENCE_TO (new_type) + = TREE_TYPE (new_type) = ptr; + + /* 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 types of the fields, and recompute the size. */ + + update_pointer_to (TYPE_OBJECT_RECORD_TYPE (old_type), new_obj_rec); + + TREE_TYPE (TYPE_FIELDS (new_obj_rec)) = TREE_TYPE (ptr_temp_type); + TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))) + = TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr))); + DECL_SIZE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))) + = TYPE_SIZE (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr)))); + DECL_SIZE_UNIT (TREE_CHAIN (TYPE_FIELDS (new_obj_rec))) + = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (TYPE_FIELDS (ptr)))); + + TYPE_SIZE (new_obj_rec) + = size_binop (PLUS_EXPR, + DECL_SIZE (TYPE_FIELDS (new_obj_rec)), + DECL_SIZE (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))); + TYPE_SIZE_UNIT (new_obj_rec) + = size_binop (PLUS_EXPR, + DECL_SIZE_UNIT (TYPE_FIELDS (new_obj_rec)), + DECL_SIZE_UNIT (TREE_CHAIN (TYPE_FIELDS (new_obj_rec)))); + rest_of_type_compilation (ptr, global_bindings_p ()); + } +} + +/* 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 (type, expr) + 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 + 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); + expr = build_unary_op (ADDR_EXPR, NULL_TREE, + build_component_ref (expr, NULL_TREE, + TREE_CHAIN (fields))); + } + 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. */ + return + build_constructor (type, + tree_cons (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 (type, expr) + 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))); + 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 (type, expr) + tree type, expr; +{ + enum tree_code code = TREE_CODE (type); + tree etype = TREE_TYPE (expr); + enum tree_code ecode = TREE_CODE (etype); + tree tem; + + /* If EXPR is already the right type, we are done. */ + if (type == etype) + return expr; + + /* If EXPR is a WITH_RECORD_EXPR, do the conversion inside and then make a + new one. */ + if (TREE_CODE (expr) == WITH_RECORD_EXPR) + return build (WITH_RECORD_EXPR, type, + convert (type, TREE_OPERAND (expr, 0)), + TREE_OPERAND (expr, 1)); + + /* If the input type has padding, remove it by doing a component reference + to the field. If the output type has padding, make a constructor + to build the record. If both input and output have padding and are + of variable size, do this as an unchecked conversion. */ + if (ecode == RECORD_TYPE && code == RECORD_TYPE + && TYPE_IS_PADDING_P (type) && TYPE_IS_PADDING_P (etype) + && (! TREE_CONSTANT (TYPE_SIZE (type)) + || ! TREE_CONSTANT (TYPE_SIZE (etype)))) + ; + else if (ecode == RECORD_TYPE && TYPE_IS_PADDING_P (etype)) + { + /* If we have just converted to this padded type, just get + the inner expression. */ + if (TREE_CODE (expr) == CONSTRUCTOR + && CONSTRUCTOR_ELTS (expr) != 0 + && TREE_PURPOSE (CONSTRUCTOR_ELTS (expr)) == TYPE_FIELDS (etype)) + return TREE_VALUE (CONSTRUCTOR_ELTS (expr)); + else + return convert (type, build_component_ref (expr, NULL_TREE, + TYPE_FIELDS (etype))); + } + 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. */ + if (TREE_CODE (expr) == UNCHECKED_CONVERT_EXPR + && ! TREE_CONSTANT (TYPE_SIZE (type))) + expr = TREE_OPERAND (expr, 0); + + /* If we are just removing the padding from expr, convert the original + object if we have variable size. That will avoid the need + for some variable-size temporaries. */ + 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))) + 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 converstion. */ + else if (TREE_CODE (DECL_SIZE (TYPE_FIELDS (type))) != INTEGER_CST + && contains_placeholder_p (DECL_SIZE (TYPE_FIELDS (type))) + && TREE_CODE (etype) == RECORD_TYPE) + return unchecked_convert (type, expr); + + else + return + build_constructor (type, + tree_cons (TYPE_FIELDS (type), + convert (TREE_TYPE + (TYPE_FIELDS (type)), + expr), + NULL_TREE)); + } + + /* If the input is a biased type, adjust first. */ + if (ecode == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (etype)) + return convert (type, fold (build (PLUS_EXPR, TREE_TYPE (etype), + fold (build1 (GNAT_NOP_EXPR, + TREE_TYPE (etype), expr)), + TYPE_MIN_VALUE (etype)))); + + /* If the input is a left-justified modular type, we need to extract + the actual object before converting it to any other type with the + exception of an unconstrained array. */ + if (ecode == RECORD_TYPE && TYPE_LEFT_JUSTIFIED_MODULAR_P (etype) + && code != UNCONSTRAINED_ARRAY_TYPE) + return convert (type, build_component_ref (expr, NULL_TREE, + TYPE_FIELDS (etype))); + + /* If converting a type that does not contain a template into one + that does, convert to the data type and then build the template. */ + if (code == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (type) + && ! (ecode == RECORD_TYPE && TYPE_CONTAINS_TEMPLATE_P (etype))) + { + tree obj_type = TREE_TYPE (TREE_CHAIN (TYPE_FIELDS (type))); + + return + 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 TRANSFORM_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. */ + TREE_TYPE (expr) = type; + return expr; + + case STRING_CST: + case CONSTRUCTOR: + /* If we are converting a STRING_CST to another constrained array type, + just make a new one in the proper type. Likewise for a + CONSTRUCTOR. But if the mode of the type is different, we must + ensure a new RTL is made for the constant. */ + 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; + + if (TYPE_MODE (type) != TYPE_MODE (etype)) + TREE_CST_RTL (expr) = 0; + + return expr; + } + break; + + case COMPONENT_REF: + /* If we are converting between two aggregate types of the same + kind, size, mode, and alignment, just make a new COMPONENT_REF. + This avoid unneeded conversions which makes reference computations + more complex. */ + if (code == ecode && TYPE_MODE (type) == TYPE_MODE (etype) + && AGGREGATE_TYPE_P (type) && AGGREGATE_TYPE_P (etype) + && TYPE_ALIGN (type) == TYPE_ALIGN (etype) + && operand_equal_p (TYPE_SIZE (type), TYPE_SIZE (etype), 0)) + return build (COMPONENT_REF, type, TREE_OPERAND (expr, 0), + TREE_OPERAND (expr, 1)); + + 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)); + etype = TREE_TYPE (expr); + ecode = TREE_CODE (etype); + break; + + case UNCHECKED_CONVERT_EXPR: + if (AGGREGATE_TYPE_P (type) && AGGREGATE_TYPE_P (etype) + && ! TYPE_FAT_POINTER_P (type) && ! TYPE_FAT_POINTER_P (etype)) + return convert (type, TREE_OPERAND (expr, 0)); + 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 (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (etype) + || (code == INTEGER_CST && ecode == INTEGER_CST + && (type == TREE_TYPE (etype) || etype == TREE_TYPE (type)))) + return fold (build1 (NOP_EXPR, type, expr)); + + switch (code) + { + case VOID_TYPE: + return build1 (CONVERT_EXPR, type, expr); + + case INTEGER_TYPE: + if (TYPE_HAS_ACTUAL_BOUNDS_P (type) + && (ecode == ARRAY_TYPE || ecode == UNCONSTRAINED_ARRAY_TYPE)) + return unchecked_convert (type, expr); + else if (TYPE_BIASED_REPRESENTATION_P (type)) + return fold (build1 (CONVERT_EXPR, type, + fold (build (MINUS_EXPR, TREE_TYPE (type), + convert (TREE_TYPE (type), expr), + TYPE_MIN_VALUE (type))))); + + /* ... fall through ... */ + + case ENUMERAL_TYPE: + 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 (PLUS_EXPR, type, expr, + fold (convert_to_pointer (type, byte_diff))); + } + + /* If converting to a thin pointer, handle specially. */ + if (TYPE_THIN_POINTER_P (type) + && TYPE_UNCONSTRAINED_ARRAY (TREE_TYPE (type)) != 0) + 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); + + return fold (convert_to_pointer (type, expr)); + + case REAL_TYPE: + return fold (convert_to_real (type, expr)); + + case RECORD_TYPE: + if (TYPE_LEFT_JUSTIFIED_MODULAR_P (type) && ! AGGREGATE_TYPE_P (etype)) + return + 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); + + case UNION_TYPE: + /* Just validate that the type is indeed that of a field + of the type. Then make the simple conversion. */ + for (tem = TYPE_FIELDS (type); tem; tem = TREE_CHAIN (tem)) + if (TREE_TYPE (tem) == etype) + return build1 (CONVERT_EXPR, type, expr); + + gigi_abort (413); + + 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 left 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_LEFT_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 + gigi_abort (409); + + case COMPLEX_TYPE: + return fold (convert_to_complex (type, expr)); + + default: + gigi_abort (410); + } +} + +/* Remove all conversions that are done in EXP. This includes converting + from a padded type or converting to a left-justified modular type. */ + +tree +remove_conversions (exp) + tree exp; +{ + switch (TREE_CODE (exp)) + { + case CONSTRUCTOR: + if (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE + && TYPE_LEFT_JUSTIFIED_MODULAR_P (TREE_TYPE (exp))) + return remove_conversions (TREE_VALUE (CONSTRUCTOR_ELTS (exp))); + 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)); + break; + + case UNCHECKED_CONVERT_EXPR: + case NOP_EXPR: case CONVERT_EXPR: + return remove_conversions (TREE_OPERAND (exp, 0)); + + 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 (exp) + 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)); + 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)); + + else if (code == WITH_RECORD_EXPR + && (TREE_OPERAND (exp, 0) + != (new = maybe_unconstrained_array + (TREE_OPERAND (exp, 0))))) + return build (WITH_RECORD_EXPR, TREE_TYPE (new), new, + TREE_OPERAND (exp, 1)); + + case RECORD_TYPE: + if (TYPE_CONTAINS_TEMPLATE_P (TREE_TYPE (exp))) + { + new + = build_component_ref (exp, NULL_TREE, + TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (exp)))); + if (TREE_CODE (TREE_TYPE (new)) == RECORD_TYPE + && TYPE_IS_PADDING_P (TREE_TYPE (new))) + new = convert (TREE_TYPE (TYPE_FIELDS (TREE_TYPE (new))), new); + + return new; + } + break; + + default: + break; + } + + return exp; +} + +/* Return an expression that does an unchecked converstion of EXPR to TYPE. */ + +tree +unchecked_convert (type, expr) + tree type; + tree expr; +{ + tree etype = TREE_TYPE (expr); + + /* If the expression is already the right type, we are done. */ + if (etype == type) + return expr; + + /* If EXPR is a WITH_RECORD_EXPR, do the conversion inside and then make a + new one. */ + if (TREE_CODE (expr) == WITH_RECORD_EXPR) + return build (WITH_RECORD_EXPR, type, + unchecked_convert (type, TREE_OPERAND (expr, 0)), + TREE_OPERAND (expr, 1)); + + /* 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_LEFT_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_LEFT_JUSTIFIED_MODULAR_P (etype)))) + || TREE_CODE (type) == UNCONSTRAINED_ARRAY_TYPE) + { + tree rtype = type; + + 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 (GNAT_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; + } + + expr = convert (rtype, expr); + if (type != rtype) + expr = build1 (GNAT_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 + && 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); + expr = build_component_ref (expr, NULL_TREE, field); + } + + /* Similarly for integral input type whose precision is not equal to its + size. */ + else if (INTEGRAL_TYPE_P (etype) && TYPE_RM_SIZE (etype) != 0 + && 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 = build_constructor (rec_type, build_tree_list (field, expr)); + expr = unchecked_convert (type, expr); + } + + /* 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 (UNCHECKED_CONVERT_EXPR, TREE_TYPE (type), + build_unary_op (ADDR_EXPR, NULL_TREE, + expr))); + + /* If both types are aggregates with the same mode and alignment (except + if the result is a UNION_TYPE), we can do this as a normal conversion. */ + else if (AGGREGATE_TYPE_P (type) && AGGREGATE_TYPE_P (etype) + && TREE_CODE (type) != UNION_TYPE + && TYPE_ALIGN (type) == TYPE_ALIGN (etype) + && TYPE_MODE (type) == TYPE_MODE (etype)) + expr = build1 (CONVERT_EXPR, type, expr); + + else + { + expr = maybe_unconstrained_array (expr); + etype = TREE_TYPE (expr); + expr = build1 (UNCHECKED_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 (INTEGRAL_TYPE_P (type) && TYPE_RM_SIZE (type) != 0 + && ! (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) + && TREE_UNSIGNED (type) == TREE_UNSIGNED (etype) + && operand_equal_p (TYPE_RM_SIZE (type), + (TYPE_RM_SIZE (etype) != 0 + ? TYPE_RM_SIZE (etype) : TYPE_SIZE (etype)), + 0)) + && ! (TREE_UNSIGNED (type) && TREE_UNSIGNED (etype))) + { + tree base_type = type_for_mode (TYPE_MODE (type), TREE_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 isn't, we can rely on the fact that such + conversions are erroneous anyway. */ + if (TREE_CODE (expr) == INTEGER_CST) + TREE_OVERFLOW (expr) = TREE_CONSTANT_OVERFLOW (expr) = 0; + + /* If the sizes of the types differ and this is an UNCHECKED_CONVERT_EXPR, + show no longer constant. */ + if (TREE_CODE (expr) == UNCHECKED_CONVERT_EXPR + && ! operand_equal_p (TYPE_SIZE_UNIT (type), TYPE_SIZE_UNIT (etype), 1)) + TREE_CONSTANT (expr) = 0; + + return expr; +} |