diff options
Diffstat (limited to 'gcc/c-decl.c')
| -rw-r--r-- | gcc/c-decl.c | 115 |
1 files changed, 96 insertions, 19 deletions
diff --git a/gcc/c-decl.c b/gcc/c-decl.c index 885fcdd..588b75c 100644 --- a/gcc/c-decl.c +++ b/gcc/c-decl.c @@ -410,8 +410,8 @@ static tree lookup_name_in_scope (tree, struct c_scope *); static tree c_make_fname_decl (tree, int); static tree grokdeclarator (const struct c_declarator *, struct c_declspecs *, - enum decl_context, bool, tree *, tree *, - enum deprecated_states); + enum decl_context, bool, tree *, tree *, tree *, + bool *, enum deprecated_states); static tree grokparms (struct c_arg_info *, bool); static void layout_array_type (tree); @@ -3128,10 +3128,15 @@ add_flexible_array_elts_to_size (tree decl, tree init) } } -/* Decode a "typename", such as "int **", returning a ..._TYPE node. */ +/* Decode a "typename", such as "int **", returning a ..._TYPE node. + Set *EXPR, if EXPR not NULL, to any expression to be evaluated + before the type name, and set *EXPR_CONST_OPERANDS, if + EXPR_CONST_OPERANDS not NULL, to indicate whether the type name may + appear in a constant expression. */ tree -groktypename (struct c_type_name *type_name) +groktypename (struct c_type_name *type_name, tree *expr, + bool *expr_const_operands) { tree type; tree attrs = type_name->specs->attrs; @@ -3139,7 +3144,8 @@ groktypename (struct c_type_name *type_name) type_name->specs->attrs = NULL_TREE; type = grokdeclarator (type_name->declarator, type_name->specs, TYPENAME, - false, NULL, &attrs, DEPRECATED_NORMAL); + false, NULL, &attrs, expr, expr_const_operands, + DEPRECATED_NORMAL); /* Apply attributes. */ decl_attributes (&type, attrs, 0); @@ -3168,6 +3174,7 @@ start_decl (struct c_declarator *declarator, struct c_declspecs *declspecs, { tree decl; tree tem; + tree expr = NULL_TREE; enum deprecated_states deprecated_state = DEPRECATED_NORMAL; /* An object declared as __attribute__((deprecated)) suppresses @@ -3176,11 +3183,14 @@ start_decl (struct c_declarator *declarator, struct c_declspecs *declspecs, deprecated_state = DEPRECATED_SUPPRESS; decl = grokdeclarator (declarator, declspecs, - NORMAL, initialized, NULL, &attributes, + NORMAL, initialized, NULL, &attributes, &expr, NULL, deprecated_state); if (!decl) return 0; + if (expr) + add_stmt (expr); + if (TREE_CODE (decl) != FUNCTION_DECL && MAIN_NAME_P (DECL_NAME (decl))) warning (OPT_Wmain, "%q+D is usually a function", decl); @@ -3668,7 +3678,7 @@ grokparm (const struct c_parm *parm) { tree attrs = parm->attrs; tree decl = grokdeclarator (parm->declarator, parm->specs, PARM, false, - NULL, &attrs, DEPRECATED_NORMAL); + NULL, &attrs, NULL, NULL, DEPRECATED_NORMAL); decl_attributes (&decl, attrs, 0); @@ -3685,7 +3695,7 @@ push_parm_decl (const struct c_parm *parm) tree decl; decl = grokdeclarator (parm->declarator, parm->specs, PARM, false, NULL, - &attrs, DEPRECATED_NORMAL); + &attrs, NULL, NULL, DEPRECATED_NORMAL); decl_attributes (&decl, attrs, 0); decl = pushdecl (decl); @@ -3716,10 +3726,11 @@ mark_forward_parm_decls (void) /* Build a COMPOUND_LITERAL_EXPR. TYPE is the type given in the compound literal, which may be an incomplete array type completed by the initializer; INIT is a CONSTRUCTOR that initializes the compound - literal. */ + literal. NON_CONST is true if the initializers contain something + that cannot occur in a constant expression. */ tree -build_compound_literal (tree type, tree init) +build_compound_literal (tree type, tree init, bool non_const) { /* We do not use start_decl here because we have a type, not a declarator; and do not use finish_decl because the decl should be stored inside @@ -3772,6 +3783,12 @@ build_compound_literal (tree type, tree init) rest_of_decl_compilation (decl, 1, 0); } + if (non_const) + { + complit = build2 (C_MAYBE_CONST_EXPR, type, NULL, complit); + C_MAYBE_CONST_EXPR_NON_CONST (complit) = 1; + } + return complit; } @@ -3958,6 +3975,11 @@ warn_variable_length_array (const char *name, tree size) DECL_ATTRS points to the list of attributes that should be added to this decl. Any nested attributes that belong on the decl itself will be added to this list. + If EXPR is not NULL, any expressions that need to be evaluated as + part of evaluating variably modified types will be stored in *EXPR. + If EXPR_CONST_OPERANDS is not NULL, *EXPR_CONST_OPERANDS will be + set to indicate whether operands in *EXPR can be used in constant + expressions. DEPRECATED_STATE is a deprecated_states value indicating whether deprecation warnings should be suppressed. @@ -3972,7 +3994,8 @@ static tree grokdeclarator (const struct c_declarator *declarator, struct c_declspecs *declspecs, enum decl_context decl_context, bool initialized, tree *width, - tree *decl_attrs, enum deprecated_states deprecated_state) + tree *decl_attrs, tree *expr, bool *expr_const_operands, + enum deprecated_states deprecated_state) { tree type = declspecs->type; bool threadp = declspecs->thread_p; @@ -3994,6 +4017,16 @@ grokdeclarator (const struct c_declarator *declarator, bool bitfield = width != NULL; tree element_type; struct c_arg_info *arg_info = 0; + tree expr_dummy; + bool expr_const_operands_dummy; + + if (expr == NULL) + expr = &expr_dummy; + if (expr_const_operands == NULL) + expr_const_operands = &expr_const_operands_dummy; + + *expr = declspecs->expr; + *expr_const_operands = declspecs->expr_const_operands; if (decl_context == FUNCDEF) funcdef_flag = true, decl_context = NORMAL; @@ -4306,6 +4339,11 @@ grokdeclarator (const struct c_declarator *declarator, if (size) { + bool size_maybe_const = true; + bool size_int_const = (TREE_CODE (size) == INTEGER_CST + && !TREE_OVERFLOW (size)); + bool this_size_varies = false; + /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */ STRIP_TYPE_NOPS (size); @@ -4316,11 +4354,13 @@ grokdeclarator (const struct c_declarator *declarator, size = integer_one_node; } - if (pedantic && integer_zerop (size)) + size = c_fully_fold (size, false, &size_maybe_const); + + if (pedantic && size_maybe_const && integer_zerop (size)) pedwarn (input_location, OPT_pedantic, "ISO C forbids zero-size array %qs", name); - if (TREE_CODE (size) == INTEGER_CST) + if (TREE_CODE (size) == INTEGER_CST && size_maybe_const) { constant_expression_warning (size); if (tree_int_cst_sgn (size) < 0) @@ -4328,6 +4368,13 @@ grokdeclarator (const struct c_declarator *declarator, error ("size of array %qs is negative", name); size = integer_one_node; } + /* Handle a size folded to an integer constant but + not an integer constant expression. */ + if (!size_int_const) + { + this_size_varies = size_varies = 1; + warn_variable_length_array (orig_name, size); + } } else if ((decl_context == NORMAL || decl_context == FIELD) && current_scope == file_scope) @@ -4340,11 +4387,11 @@ grokdeclarator (const struct c_declarator *declarator, /* Make sure the array size remains visibly nonconstant even if it is (eg) a const variable with known value. */ - size_varies = 1; + this_size_varies = size_varies = 1; warn_variable_length_array (orig_name, size); } - if (integer_zerop (size)) + if (integer_zerop (size) && !this_size_varies) { /* A zero-length array cannot be represented with an unsigned index type, which is what we'll @@ -4359,6 +4406,9 @@ grokdeclarator (const struct c_declarator *declarator, with the +1 that happens when building TYPE_SIZE. */ if (size_varies) size = variable_size (size); + if (this_size_varies && TREE_CODE (size) == INTEGER_CST) + size = build2 (COMPOUND_EXPR, TREE_TYPE (size), + integer_zero_node, size); /* Compute the maximum valid index, that is, size - 1. Do the calculation in index_type, so that @@ -4386,6 +4436,15 @@ grokdeclarator (const struct c_declarator *declarator, itype = build_index_type (itype); } + if (this_size_varies) + { + if (*expr) + *expr = build2 (COMPOUND_EXPR, TREE_TYPE (size), + *expr, size); + else + *expr = size; + *expr_const_operands &= size_maybe_const; + } } else if (decl_context == FIELD) { @@ -5288,10 +5347,15 @@ struct c_typespec parser_xref_tag (enum tree_code code, tree name) { struct c_typespec ret; + tree ref; + + ret.expr = NULL_TREE; + ret.expr_const_operands = true; + /* If a cross reference is requested, look up the type already defined for this tag and return it. */ - tree ref = lookup_tag (code, name, 0); + ref = lookup_tag (code, name, 0); /* If this is the right type of tag, return what we found. (This reference will be shadowed by shadow_tag later if appropriate.) If this is the wrong type of tag, do not return it. If it was the @@ -5460,7 +5524,7 @@ grokfield (location_t loc, } value = grokdeclarator (declarator, declspecs, FIELD, false, - width ? &width : NULL, decl_attrs, + width ? &width : NULL, decl_attrs, NULL, NULL, DEPRECATED_NORMAL); finish_decl (value, NULL_TREE, NULL_TREE); @@ -6119,7 +6183,7 @@ start_function (struct c_declspecs *declspecs, struct c_declarator *declarator, c_break_label = c_cont_label = size_zero_node; decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, true, NULL, - &attributes, DEPRECATED_NORMAL); + &attributes, NULL, NULL, DEPRECATED_NORMAL); /* If the declarator is not suitable for a function definition, cause a syntax error. */ @@ -7132,10 +7196,12 @@ build_null_declspecs (void) { struct c_declspecs *ret = XOBNEW (&parser_obstack, struct c_declspecs); ret->type = 0; + ret->expr = 0; ret->decl_attr = 0; ret->attrs = 0; ret->typespec_word = cts_none; ret->storage_class = csc_none; + ret->expr_const_operands = true; ret->declspecs_seen_p = false; ret->type_seen_p = false; ret->non_sc_seen_p = false; @@ -7657,7 +7723,18 @@ declspecs_add_type (struct c_declspecs *specs, struct c_typespec spec) if (spec.kind == ctsk_tagdef || spec.kind == ctsk_tagfirstref) specs->tag_defined_p = true; if (spec.kind == ctsk_typeof) - specs->typedef_p = true; + { + specs->typedef_p = true; + if (spec.expr) + { + if (specs->expr) + specs->expr = build2 (COMPOUND_EXPR, TREE_TYPE (spec.expr), + specs->expr, spec.expr); + else + specs->expr = spec.expr; + specs->expr_const_operands &= spec.expr_const_operands; + } + } specs->type = type; } |