The test enum e { E = 0 * (1 / 0) }; should yield an error with -pedantic-errors. Not a regression.
Confirmed.
Hi Roger, I am not sure how we are going to handle this. First, the 1/0 is detected at int_const_binop at line 1509 -------------------------------------- case ROUND_DIV_EXPR: if (int2h == 0 && int2l == 0) return NULL_TREE; -------------------------------------- I don't think we can return something different from NULL_TREE here. But we cannot set TREE_OVERFLOW on a NULL_TREE. Second, when int_const_binop returns to fold_binary we have another opportunity to detect this at line 10026, but again we return NULL_TREE ---------------------------- case ROUND_DIV_EXPR: case CEIL_DIV_EXPR: case EXACT_DIV_EXPR: if (integer_onep (arg1)) return non_lvalue (fold_convert (type, arg0)); if (integer_zerop (arg1)) return NULL_TREE; ---------------------------- Next, fold_build2_stat uses build2_stat to construct a valid tree node (code=TRUNC_DIV_EXPR) but I don't see anything that can be used to detect that there was a division by zero. Finally, that tree node is simply omitted when folding 0*expr . I really don't see how TREE_OVERFLOW could help here. Unless we change 1/0 to be the same as INT_MAX+1, that is, a constant overflow. However, then we will need something else to not warn about constant overflow but only for division by zero. Another option could be to build a TRUNC_DIV_EXPR node with TREE_OVERFLOW set instead of returning NULL_TREE. But how and when? I am running out of ideas...
Hi Manual, This needs to be handled in the front-ends, and in fact is already handled by the front-ends. In c-typeck.c:build_binary_op, I see: case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR: case ROUND_DIV_EXPR: case EXACT_DIV_EXPR: /* Floating point division by zero is a legitimate way to obtain infinities and NaNs. */ if (skip_evaluation == 0 && integer_zerop (op1)) warning (OPT_Wdiv_by_zero, "division by zero"); Likewise, there are several references to OPT_Wdiv_by_zero in cp/typeck.c. The real issue is that OPT_Wdiv_by_zero needs to be enabled by -pedantic in order to generate an error for -pedantic-errors, as requested by Joseph in comment #1. I hope this helps.
Subject: Re: integer division by zero in subexpression should be overflow > Hi Manual, > > This needs to be handled in the front-ends, and in fact is already handled ^^^^^ should > by the front-ends. In c-typeck.c:build_binary_op, I see: > > case TRUNC_DIV_EXPR: > case CEIL_DIV_EXPR: > case FLOOR_DIV_EXPR: > case ROUND_DIV_EXPR: > case EXACT_DIV_EXPR: > /* Floating point division by zero is a legitimate way to obtain > infinities and NaNs. */ > if (skip_evaluation == 0 && integer_zerop (op1)) > warning (OPT_Wdiv_by_zero, "division by zero"); > > Likewise, there are several references to OPT_Wdiv_by_zero in cp/typeck.c. > The real issue is that OPT_Wdiv_by_zero needs to be enabled by -pedantic > in order to generate an error for -pedantic-errors, as requested by > Joseph in comment #1. Actually it is only a diagnostic problem if we are in a constant expression. Thanks, Andrew Pinski
>> This needs to be handled in the front-ends... > ^^^^^ should ^^^^^^ can only be I was thinking of a slightly weaker form of need/must. But there are two issues here. The division by zero is one, but its also a red herring, we really shouldn't be accepting the code: int x; enum e { E = 0 * x }; which currently compiles without even a warning using -pedantic-errors. This is exactly the sort of thing that Joseph's struct c_expr were intended to handle. I don't think is unreasonable for fold to convert "0 * x" into 0, the issue is that a front-end can't really look at a folded tree and determine anything much about the original source code.
(In reply to comment #3) > Hi Manual, Manuel (or Manu) http://en.wikipedia.org/wiki/Manuel not manual: http://en.wikipedia.org/wiki/Manual :-) > The real issue is that OPT_Wdiv_by_zero needs to be enabled by -pedantic > in order to generate an error for -pedantic-errors, as requested by > Joseph in comment #1. So, we just have to replace warning by pedwarn, don't we?
Subject: Re: integer division by zero in subexpression should be overflow On Sun, 3 Dec 2006, manu at gcc dot gnu dot org wrote: > > The real issue is that OPT_Wdiv_by_zero needs to be enabled by -pedantic > > in order to generate an error for -pedantic-errors, as requested by > > Joseph in comment #1. > > So, we just have to replace warning by pedwarn, don't we? No, because except in evaluated parts of constant expressions this is only runtime undefined and so must be accepted.
(In reply to comment #5) > int x; > > enum e { E = 0 * x }; > > > which currently compiles without even a warning using -pedantic-errors. > This is exactly the sort of thing that Joseph's struct c_expr were intended > to handle. I don't think is unreasonable for fold to convert "0 * x" into > 0, the issue is that a front-end can't really look at a folded tree and > determine anything much about the original source code. Should it warn? But back to the original case, we detect enum e { E = 0 * (INT_MAX + 1) }; by setting TREE_OVERFLOW. We could do the same for 1/0 and we just don't emit an overflow warning but a division by zero one. But this could be tricky. However, an alternative would be to prevent the folding for this specific case, so the resulting tree is not constant. We could try to detect this when folding 0*x (not sure how), or we could build something from 1/0 that will prevent folding 0*x (if such thing exists). Am I missing any other alternatives?
I tried setting TREE_OVERFLOW on a new node created from the zero of the division by zero and then replacing the zero in 1/0 by this new node. It didn't work, it seems that somehow the node that represents the result of 1/0 is built in some way that ignores TREE_OVERFLOW.
I think for the 0*x case, we need the infrastructure provided by PR 32643 and then set folding_initializer when we are inside an enum.
Testing a patch for 4.5.
Subject: Bug 19976 Author: jsm28 Date: Fri Oct 24 19:34:52 2008 New Revision: 141349 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=141349 Log: PR c/456 PR c/5675 PR c/19976 PR c/29116 PR c/31871 PR c/35198 fixincludes: * inclhack.def (glibc_tgmath): New fix. * fixincl.x: Regenerate. * tests/base/tgmath.h: New. gcc: * builtins.c (fold_call_expr): Return a NOP_EXPR from folding rather than the contained expression. * c-common.c (c_save_expr): New. (c_common_truthvalue_conversion): Use c_save_expr. Do not fold conditional expressions for C. * c-common.def (C_MAYBE_CONST_EXPR): New. * c-common.h (c_fully_fold, c_save_expr): New prototypes. (C_MAYBE_CONST_EXPR_PRE, C_MAYBE_CONST_EXPR_EXPR, C_MAYBE_CONST_EXPR_INT_OPERANDS, C_MAYBE_CONST_EXPR_NON_CONST, EXPR_INT_CONST_OPERANDS): Define. * c-convert.c (convert): Strip nops from expression. * c-decl.c (groktypename): Take extra parameters expr and expr_const_operands. Update call to grokdeclarator. (start_decl): Update call to grokdeclarator. Add statement for expressions used in type of decl. (grokparm): Update call to grokdeclarator. (push_parm_decl): Update call to grokdeclarator. (build_compound_literal): Add parameter non_const and build a C_MAYBE_COSNT_EXPR if applicable. (grokdeclarator): Take extra parameters expr and expr_const_operands. Track expressions used in declaration specifiers and declarators. Fold array sizes and track whether they are constant expressions and whether they are integer constant expressions. (parser_xref_tag): Set expr and expr_const_operands fields in return value. (grokfield): Update call to grokdeclarator. (start_function): Update call to grokdeclarator. (build_null_declspecs): Set expr and expr_const_operands fields in return value. (declspecs_add_type): Handle expressions in typeof specifiers. * c-parser.c (c_parser_declspecs): Set expr and expr_const_operands fields for declaration specifiers. (c_parser_enum_specifier): Likewise. (c_parser_struct_or_union_specifier): Likewise. (c_parser_typeof_specifier): Likewise. Update call to groktypename. Fold expression as needed. Return expressions with type instead of adding statements. (c_parser_attributes): Update calls to c_parser_expr_list. (c_parser_statement_after_labels): Fold expression before passing to objc_build_throw_stmt. (c_parser_condition): Fold expression. (c_parser_asm_operands): Fold expression. (c_parser_conditional_expression): Use c_save_expr. Update call to build_conditional_expr. (c_parser_alignof_expression): Update call to groktypename. (c_parser_postfix_expression): Preserve C_MAYBE_CONST_EXPR as original_code. Fold expression argument of va_arg. Create C_MAYBE_CONST_EXPR to preserve side effects of expressions in type argument to va_arg. Update calls to groktypename. Fold array index for offsetof. Verify that first argument to __builtin_choose_expr has integer type. (c_parser_postfix_expression_after_paren_type): Update calls to groktypename and build_compound_literal. Handle expressions with side effects in type name. (c_parser_postfix_expression_after_primary): Update call to c_parser_expr_list. Set original_code for calls to __builtin_constant_p. (c_parser_expr_list): Take extra parameter fold_p. Fold expressions if requested. (c_parser_objc_type_name): Update call to groktypename. (c_parser_objc_synchronized_statement): Fold expression. (c_parser_objc_receiver): Fold expression. (c_parser_objc_keywordexpr): Update call to c_parser_expr_list. (c_parser_omp_clause_num_threads, c_parser_omp_clause_schedule, c_parser_omp_atomic, c_parser_omp_for_loop): Fold expressions. * c-tree.h (CONSTRUCTOR_NON_CONST): Define. (struct c_typespec): Add elements expr and expr_const_operands. (struct c_declspecs): Add elements expr and expr_const_operands. (groktypename, build_conditional_expr, build_compound_literal): Update prototypes. * c-typeck.c (c_fully_fold, c_fully_fold_internal, note_integer_operands): New functions. (decl_constant_value_for_broken_optimization): Rename to decl_constant_value_for_optimization: Check whether optimizing and that the expression is a VAR_DECL not of array type instead of doing such checks in the caller. Do not check pedantic. (default_function_array_conversion): Do not strip nops. (default_conversion): Do not call decl_constant_value_for_broken_optimization. (build_array_ref): Do not fold result. (c_expr_sizeof_expr): Fold operand. Use C_MAYBE_CONST_EXPR for result when operand is a VLA. (c_expr_sizeof_type): Update call to groktypename. Handle expressions included in type name. Use C_MAYBE_CONST_EXPR for result when operand names a VLA type. (build_function_call): Update call to build_compound_literal. Only fold result for calls to __builtin_* functions. Strip NOP_EXPR from INTEGER_CST returned from such functions. (convert_arguments): Fold arguments. Update call to convert_for_assignment. (build_unary_op): Handle increment and decrement of C_MAYBE_CONST_EXPR. Move lvalue checks for increment and decrement earlier. Fold operand of increment and decrement. Handle address of C_MAYBE_CONST_EXPR. Only fold expression being built for integer operand. Wrap returns that are INTEGER_CSTs without being integer constant expressions or that have integer constant operands without being INTEGER_CSTs. (lvalue_p): Handle C_MAYBE_CONST_EXPR. (build_conditional_expr): Add operand ifexp_bcp. Track whether result is an integer constant expression or can be used in unevaluated parts of one and avoid folding and wrap as appropriate. (build_compound_expr): Wrap result for C99 if operands can be used in integer constant expressions. (build_c_cast): Update call to digest_init. Do not ignore overflow from casting floating-point constants to integers. Wrap results that could be confused with integer constant expressions, null pointer constants or floating-point constants. (c_cast_expr): Update call to groktypename. Handle expressions included in type name. (build_modify_expr): Handle modifying a C_MAYBE_CONST_EXPR. Fold lhs inside possible SAVE_EXPR. Fold RHS before assignment. Update calls to convert_for_assignment. (convert_for_assignment): Take new parameter null_pointer_constant. Do not strip nops or call decl_constant_value_for_broken_optimization. (store_init_value): Update call to digest_init. (digest_init): Take new parameter null_pointer_constant. Do not call decl_constant_value_for_broken_optimization. pedwarn for initializers not constant expressions. Update calls to convert_for_assignment. (constructor_nonconst): New. (struct constructor_stack): Add nonconst element. (really_start_incremental_init, push_init_level, pop_init_level): Handle constructor_nonconst and nonconst element. (set_init_index): Call constant_expression_warning for array designators. (output_init_element): Fold value. Set constructor_nonconst as applicable. pedwarn for initializers not constant expressions. Update call to digest_init. Call constant_expression_warning where constant initializers are required. (process_init_element): Use c_save_expr. (c_finish_goto_ptr): Fold expression. (c_finish_return): Fold return value. Update call to convert_for_assignment. (c_start_case): Fold switch expression. (c_process_expr_stmt): Fold expression. (c_finish_stmt_expr): Create C_MAYBE_CONST_EXPR as needed to ensure statement expression is not evaluated in constant expression. (build_binary_op): Track whether results are integer constant expressions or may occur in such, disable folding and wrap results as applicable. (c_objc_common_truthvalue_conversion): Handle results folded to integer constants that are not integer constant expressions. * doc/extend.texi: Document when typeof operands are evaluated, that condition of __builtin_choose_expr is an integer constant expression, and more about use of __builtin_constant_p in initializers. gcc/cp: * typeck.c (c_fully_fold): New. gcc/testsuite: * gcc.dg/bconstp-2.c, gcc.dg/c90-const-expr-6.c, gcc.dg/c90-const-expr-7.c, gcc.dg/c90-const-expr-8.c, gcc.dg/c90-const-expr-9.c, gcc.dg/c90-const-expr-10.c, gcc.dg/c90-const-expr-11.c, gcc.dg/c99-const-expr-6.c, gcc.dg/c99-const-expr-7.c, gcc.dg/c99-const-expr-8.c, gcc.dg/c99-const-expr-9.c, gcc.dg/c99-const-expr-10.c, gcc.dg/c99-const-expr-11.c, gcc.dg/c99-const-expr-12.c, gcc.dg/c99-const-expr-13.c, gcc.dg/gnu89-const-expr-1.c, gcc.dg/gnu89-const-expr-2.c, gcc.dg/gnu99-const-expr-1.c, gcc.dg/gnu99-const-expr-2.c, gcc.dg/gnu99-const-expr-3.c, gcc.dg/vla-11.c, gcc.dg/vla-12.c, gcc.dg/vla-13.c, gcc.dg/vla-14.c, gcc.dg/vla-15.c: New tests. * gcc.dg/c90-const-expr-1.c, gcc.dg/c90-const-expr-2.c, gcc.dg/c90-const-expr-3.c, gcc.dg/c99-const-expr-2.c, gcc.dg/c99-const-expr-3.c, gcc.dg/c99-static-1.c: Remove XFAILs. * gcc.dg/overflow-warn-1.c, gcc.dg/overflow-warn-2.c, gcc.dg/overflow-warn-3.c, gcc.dg/overflow-warn-4.c: Remove XFAILs. Update expected messages. * gcc.dg/pr14649-1.c, gcc.dg/pr19984.c, gcc.dg/pr25682.c: Update expected messages. * gcc.dg/real-const-1.c: Replace with test from original PR. Added: branches/c-4_5-branch/fixincludes/ChangeLog.c45 branches/c-4_5-branch/fixincludes/tests/base/tgmath.h branches/c-4_5-branch/gcc/ChangeLog.c45 branches/c-4_5-branch/gcc/cp/ChangeLog.c45 branches/c-4_5-branch/gcc/testsuite/ChangeLog.c45 branches/c-4_5-branch/gcc/testsuite/gcc.dg/bconstp-2.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-10.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-11.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-6.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-7.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-8.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-9.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-10.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-11.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-12.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-13.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-6.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-7.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-8.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-9.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/gnu89-const-expr-1.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/gnu89-const-expr-2.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/gnu99-const-expr-1.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/gnu99-const-expr-2.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/gnu99-const-expr-3.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/vla-11.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/vla-12.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/vla-13.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/vla-14.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/vla-15.c Modified: branches/c-4_5-branch/fixincludes/fixincl.x branches/c-4_5-branch/fixincludes/inclhack.def branches/c-4_5-branch/gcc/builtins.c branches/c-4_5-branch/gcc/c-common.c branches/c-4_5-branch/gcc/c-common.def branches/c-4_5-branch/gcc/c-common.h branches/c-4_5-branch/gcc/c-convert.c branches/c-4_5-branch/gcc/c-decl.c branches/c-4_5-branch/gcc/c-parser.c branches/c-4_5-branch/gcc/c-tree.h branches/c-4_5-branch/gcc/c-typeck.c branches/c-4_5-branch/gcc/cp/typeck.c branches/c-4_5-branch/gcc/doc/extend.texi branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-1.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-2.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-3.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-2.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-3.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-static-1.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/overflow-warn-1.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/overflow-warn-2.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/overflow-warn-3.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/overflow-warn-4.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/pr14649-1.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/pr19984.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/pr25682.c branches/c-4_5-branch/gcc/testsuite/gcc.dg/real-const-1.c
Subject: Bug 19976 Author: jsm28 Date: Sun Mar 29 18:13:43 2009 New Revision: 145254 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=145254 Log: PR c/456 PR c/5675 PR c/19976 PR c/29116 PR c/31871 PR c/35198 fixincludes: * inclhack.def (glibc_tgmath): New fix. * fixincl.x: Regenerate. * tests/base/tgmath.h: New. gcc: * builtins.c (fold_builtin_sincos): Build COMPOUND_EXPR in void_type_node. (fold_call_expr): Return a NOP_EXPR from folding rather than the contained expression. * c-common.c (c_fully_fold, c_fully_fold_internal, c_save_expr): New. (c_common_truthvalue_conversion): Use c_save_expr. Do not fold conditional expressions for C. (decl_constant_value_for_optimization): Move from decl_constant_value_for_broken_optimization in c-typeck.c. Check whether optimizing and that the expression is a VAR_DECL not of array type instead of doing such checks in the caller. Do not check pedantic. Call gcc_unreachable for C++. * c-common.def (C_MAYBE_CONST_EXPR): New. * c-common.h (c_fully_fold, c_save_expr, decl_constant_value_for_optimization): New prototypes. (C_MAYBE_CONST_EXPR_PRE, C_MAYBE_CONST_EXPR_EXPR, C_MAYBE_CONST_EXPR_INT_OPERANDS, C_MAYBE_CONST_EXPR_NON_CONST, EXPR_INT_CONST_OPERANDS): Define. * c-convert.c (convert): Strip nops from expression. * c-decl.c (groktypename): Take extra parameters expr and expr_const_operands. Update call to grokdeclarator. (start_decl): Update call to grokdeclarator. Add statement for expressions used in type of decl. (grokparm): Update call to grokdeclarator. (push_parm_decl): Update call to grokdeclarator. (build_compound_literal): Add parameter non_const and build a C_MAYBE_COSNT_EXPR if applicable. (grokdeclarator): Take extra parameters expr and expr_const_operands. Track expressions used in declaration specifiers and declarators. Fold array sizes and track whether they are constant expressions and whether they are integer constant expressions. (parser_xref_tag): Set expr and expr_const_operands fields in return value. (grokfield): Update call to grokdeclarator. (start_function): Update call to grokdeclarator. (build_null_declspecs): Set expr and expr_const_operands fields in return value. (declspecs_add_type): Handle expressions in typeof specifiers. * c-parser.c (c_parser_declspecs): Set expr and expr_const_operands fields for declaration specifiers. (c_parser_enum_specifier): Likewise. (c_parser_struct_or_union_specifier): Likewise. (c_parser_typeof_specifier): Likewise. Update call to groktypename. Fold expression as needed. Return expressions with type instead of adding statements. (c_parser_attributes): Update calls to c_parser_expr_list. (c_parser_statement_after_labels): Fold expression before passing to objc_build_throw_stmt. (c_parser_condition): Fold expression. (c_parser_asm_operands): Fold expression. (c_parser_conditional_expression): Use c_save_expr. Update call to build_conditional_expr. (c_parser_alignof_expression): Update call to groktypename. (c_parser_postfix_expression): Preserve C_MAYBE_CONST_EXPR as original_code. Fold expression argument of va_arg. Create C_MAYBE_CONST_EXPR to preserve side effects of expressions in type argument to va_arg. Update calls to groktypename. Fold array index for offsetof. Verify that first argument to __builtin_choose_expr has integer type. (c_parser_postfix_expression_after_paren_type): Update calls to groktypename and build_compound_literal. Handle expressions with side effects in type name. (c_parser_postfix_expression_after_primary): Update call to c_parser_expr_list. Set original_code for calls to __builtin_constant_p. (c_parser_expr_list): Take extra parameter fold_p. Fold expressions if requested. (c_parser_objc_type_name): Update call to groktypename. (c_parser_objc_synchronized_statement): Fold expression. (c_parser_objc_receiver): Fold expression. (c_parser_objc_keywordexpr): Update call to c_parser_expr_list. (c_parser_omp_clause_num_threads, c_parser_omp_clause_schedule, c_parser_omp_atomic, c_parser_omp_for_loop): Fold expressions. * c-tree.h (CONSTRUCTOR_NON_CONST): Define. (struct c_typespec): Add elements expr and expr_const_operands. (struct c_declspecs): Add elements expr and expr_const_operands. (groktypename, build_conditional_expr, build_compound_literal): Update prototypes. (in_late_binary_op): Declare. * c-typeck.c (note_integer_operands): New function. (in_late_binary_op): New variable. (decl_constant_value_for_broken_optimization): Move to c-common.c and rename to decl_constant_value_for_optimization. (default_function_array_conversion): Do not strip nops. (default_conversion): Do not call decl_constant_value_for_broken_optimization. (build_array_ref): Do not fold result. (c_expr_sizeof_expr): Fold operand. Use C_MAYBE_CONST_EXPR for result when operand is a VLA. (c_expr_sizeof_type): Update call to groktypename. Handle expressions included in type name. Use C_MAYBE_CONST_EXPR for result when operand names a VLA type. (build_function_call): Update call to build_compound_literal. Only fold result for calls to __builtin_* functions. Strip NOP_EXPR from INTEGER_CST returned from such functions. Fold the function designator. (convert_arguments): Fold arguments. Update call to convert_for_assignment. (build_unary_op): Handle increment and decrement of C_MAYBE_CONST_EXPR. Move lvalue checks for increment and decrement earlier. Fold operand of increment and decrement. Handle address of C_MAYBE_CONST_EXPR. Only fold expression being built for integer operand. Wrap returns that are INTEGER_CSTs without being integer constant expressions or that have integer constant operands without being INTEGER_CSTs. (lvalue_p): Handle C_MAYBE_CONST_EXPR. (build_conditional_expr): Add operand ifexp_bcp. Track whether result is an integer constant expression or can be used in unevaluated parts of one and avoid folding and wrap as appropriate. Fold operands before possibly doing -Wsign-compare warnings. (build_compound_expr): Wrap result for C99 if operands can be used in integer constant expressions. (build_c_cast): Update call to digest_init. Do not ignore overflow from casting floating-point constants to integers. Wrap results that could be confused with integer constant expressions, null pointer constants or floating-point constants. (c_cast_expr): Update call to groktypename. Handle expressions included in type name. (build_modify_expr): Handle modifying a C_MAYBE_CONST_EXPR. Fold lhs inside possible SAVE_EXPR. Fold RHS before assignment. Update calls to convert_for_assignment. (convert_for_assignment): Take new parameter null_pointer_constant. Do not strip nops or call decl_constant_value_for_broken_optimization. Set in_late_binary_op for conversions to boolean. (store_init_value): Update call to digest_init. (digest_init): Take new parameter null_pointer_constant. Do not call decl_constant_value_for_broken_optimization. pedwarn for initializers not constant expressions. Update calls to convert_for_assignment. (constructor_nonconst): New. (struct constructor_stack): Add nonconst element. (really_start_incremental_init, push_init_level, pop_init_level): Handle constructor_nonconst and nonconst element. (set_init_index): Call constant_expression_warning for array designators. (output_init_element): Fold value. Set constructor_nonconst as applicable. pedwarn for initializers not constant expressions. Update call to digest_init. Call constant_expression_warning where constant initializers are required. (process_init_element): Use c_save_expr. (c_finish_goto_ptr): Fold expression. (c_finish_return): Fold return value. Update call to convert_for_assignment. (c_start_case): Fold switch expression. (c_process_expr_stmt): Fold expression. (c_finish_stmt_expr): Create C_MAYBE_CONST_EXPR as needed to ensure statement expression is not evaluated in constant expression. (build_binary_op): Track whether results are integer constant expressions or may occur in such, disable folding and wrap results as applicable. Fold operands for -Wsign-compare warnings unless in_late_binary_op. (c_objc_common_truthvalue_conversion): Handle results folded to integer constants that are not integer constant expressions. * doc/extend.texi: Document when typeof operands are evaluated, that condition of __builtin_choose_expr is an integer constant expression, and more about use of __builtin_constant_p in initializers. gcc/objc: * objc-act.c (objc_finish_try_stmt): Set in_late_binary_op. gcc/testsuite: * gcc.c-torture/compile/20081108-1.c, gcc.c-torture/compile/20081108-2.c, gcc.c-torture/compile/20081108-3.c, gcc.dg/bconstp-2.c, gcc.dg/bconstp-3.c, gcc.dg/bconstp-4.c, gcc.dg/c90-const-expr-6.c, gcc.dg/c90-const-expr-7.c, gcc.dg/c90-const-expr-8.c, gcc.dg/c90-const-expr-9.c, gcc.dg/c90-const-expr-10.c, gcc.dg/c90-const-expr-11.c, gcc.dg/c99-const-expr-6.c, gcc.dg/c99-const-expr-7.c, gcc.dg/c99-const-expr-8.c, gcc.dg/c99-const-expr-9.c, gcc.dg/c99-const-expr-10.c, gcc.dg/c99-const-expr-11.c, gcc.dg/c99-const-expr-12.c, gcc.dg/c99-const-expr-13.c, gcc.dg/compare10.c, gcc.dg/gnu89-const-expr-1.c, gcc.dg/gnu89-const-expr-2.c, gcc.dg/gnu99-const-expr-1.c, gcc.dg/gnu99-const-expr-2.c, gcc.dg/gnu99-const-expr-3.c, gcc.dg/vla-12.c, gcc.dg/vla-13.c, gcc.dg/vla-14.c, gcc.dg/vla-15.c, gcc.dg/vla-16.c: New tests. * gcc.dg/c90-const-expr-1.c, gcc.dg/c90-const-expr-2.c, gcc.dg/c90-const-expr-3.c, gcc.dg/c99-const-expr-2.c, gcc.dg/c99-const-expr-3.c, gcc.dg/c99-static-1.c: Remove XFAILs. * gcc.dg/c90-const-expr-2.c: Use ZERO in place of 0 in another case. * gcc.dg/overflow-warn-1.c, gcc.dg/overflow-warn-2.c, gcc.dg/overflow-warn-3.c, gcc.dg/overflow-warn-4.c: Remove XFAILs. Update expected messages. * gcc.dg/pr14649-1.c, gcc.dg/pr19984.c, gcc.dg/pr25682.c: Update expected messages. * gcc.dg/real-const-1.c: Replace with test from original PR. * gcc.dg/vect/pr32230.c: Use intermediate cast to __PTRDIFF_TYPE__ when casting from non-constant integer to pointer. Added: trunk/fixincludes/tests/base/tgmath.h trunk/gcc/testsuite/gcc.c-torture/compile/20081108-1.c trunk/gcc/testsuite/gcc.c-torture/compile/20081108-2.c trunk/gcc/testsuite/gcc.c-torture/compile/20081108-3.c trunk/gcc/testsuite/gcc.dg/bconstp-2.c trunk/gcc/testsuite/gcc.dg/bconstp-3.c trunk/gcc/testsuite/gcc.dg/bconstp-4.c trunk/gcc/testsuite/gcc.dg/c90-const-expr-10.c trunk/gcc/testsuite/gcc.dg/c90-const-expr-11.c trunk/gcc/testsuite/gcc.dg/c90-const-expr-6.c trunk/gcc/testsuite/gcc.dg/c90-const-expr-7.c trunk/gcc/testsuite/gcc.dg/c90-const-expr-8.c trunk/gcc/testsuite/gcc.dg/c90-const-expr-9.c trunk/gcc/testsuite/gcc.dg/c99-const-expr-10.c trunk/gcc/testsuite/gcc.dg/c99-const-expr-11.c trunk/gcc/testsuite/gcc.dg/c99-const-expr-12.c trunk/gcc/testsuite/gcc.dg/c99-const-expr-13.c trunk/gcc/testsuite/gcc.dg/c99-const-expr-6.c trunk/gcc/testsuite/gcc.dg/c99-const-expr-7.c trunk/gcc/testsuite/gcc.dg/c99-const-expr-8.c trunk/gcc/testsuite/gcc.dg/c99-const-expr-9.c trunk/gcc/testsuite/gcc.dg/compare10.c trunk/gcc/testsuite/gcc.dg/gnu89-const-expr-1.c trunk/gcc/testsuite/gcc.dg/gnu89-const-expr-2.c trunk/gcc/testsuite/gcc.dg/gnu99-const-expr-1.c trunk/gcc/testsuite/gcc.dg/gnu99-const-expr-2.c trunk/gcc/testsuite/gcc.dg/gnu99-const-expr-3.c trunk/gcc/testsuite/gcc.dg/vla-12.c trunk/gcc/testsuite/gcc.dg/vla-13.c trunk/gcc/testsuite/gcc.dg/vla-14.c trunk/gcc/testsuite/gcc.dg/vla-15.c trunk/gcc/testsuite/gcc.dg/vla-16.c Modified: trunk/fixincludes/ChangeLog trunk/fixincludes/fixincl.x trunk/fixincludes/inclhack.def trunk/gcc/ChangeLog trunk/gcc/builtins.c trunk/gcc/c-common.c trunk/gcc/c-common.def trunk/gcc/c-common.h trunk/gcc/c-convert.c trunk/gcc/c-decl.c trunk/gcc/c-parser.c trunk/gcc/c-tree.h trunk/gcc/c-typeck.c trunk/gcc/doc/extend.texi trunk/gcc/objc/ChangeLog trunk/gcc/objc/objc-act.c trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/gcc.dg/c90-const-expr-1.c trunk/gcc/testsuite/gcc.dg/c90-const-expr-2.c trunk/gcc/testsuite/gcc.dg/c90-const-expr-3.c trunk/gcc/testsuite/gcc.dg/c99-const-expr-2.c trunk/gcc/testsuite/gcc.dg/c99-const-expr-3.c trunk/gcc/testsuite/gcc.dg/c99-static-1.c trunk/gcc/testsuite/gcc.dg/overflow-warn-1.c trunk/gcc/testsuite/gcc.dg/overflow-warn-2.c trunk/gcc/testsuite/gcc.dg/overflow-warn-3.c trunk/gcc/testsuite/gcc.dg/overflow-warn-4.c trunk/gcc/testsuite/gcc.dg/pr14649-1.c trunk/gcc/testsuite/gcc.dg/pr19984.c trunk/gcc/testsuite/gcc.dg/pr25682.c trunk/gcc/testsuite/gcc.dg/real-const-1.c trunk/gcc/testsuite/gcc.dg/vect/pr32230.c
Fixed for 4.5.