| Summary: | [4.2/4.3/4.4/4.5 Regression] missed evaluation of VM array type when used as a cast | ||
|---|---|---|---|
| Product: | gcc | Reporter: | Mike Stump <mikestump> |
| Component: | c | Assignee: | Joseph S. Myers <jsm28> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | ebotcazou, fang, gcc-bugs, pinskia |
| Priority: | P4 | Keywords: | wrong-code |
| Version: | 4.2.1 | ||
| Target Milestone: | 4.5.0 | ||
| Host: | Target: | ||
| Build: | Known to work: | 2.95.4 4.5.0 | |
| Known to fail: | 3.3.6 4.1.3 4.3.0 | Last reconfirmed: | 2008-10-24 00:09:23 |
Confirmed. This used to work with gcc 2.95 at least. There are a few different cases. For
int foo(void);
void *a(void *p)
{
return (int (*)[foo()])p;
}
the frontend already got rid of the intermediate casts (and side-effects). For
int foo(void);
void a(void *p)
{
(int (*)[foo()])p;
}
the frontend retains the cast and the side-effects, but the gimplifier removes
them.
One error is certainly:
Breakpoint 3, fold_unary (code=NOP_EXPR, type=0xb7cee2d8, op0=0xb7d46140)
at /home/richard/src/trunk/gcc/fold-const.c:7932
7932 enum tree_code_class kind = TREE_CODE_CLASS (code);
(int[0:(unsigned int) (SAVE_EXPR <foo ()> + -1)] *) p
(gdb) call debug_generic_expr (type)
void *
(gdb) print op0->base.side_effects_flag
$1 = 0
that is, the conversion is not marked as producing side-effects (possibly
because the side-effect is wrapped in a SAVE_EXPR).
It is also not clear to me whether we should do so (wrap the call inside
a SAVE_EXPR). What is supposed to happen for
int foo(void);
void a(void *p)
{
(int (*)[foo()])p;
(int (*)[foo()])p;
}
? Is foo supposed to be called twice?
I think the burden should be on the side of the frontend to instead emit
a COMPOUND_EXPR like
( SAVE_EXPR<foo()>, (int (*)[SAVE_EXPR<foo()>])p )
here. At least marking the whole conversion as having no side-effects
doesn't tell the truth really, likewise if SAVE_EXPRs have no side-effects,
as that wouldn't guarantee it is evaluated at least once.
But maybe I am missing parts of GCC history here.
> At least marking the whole conversion as having no side-effects doesn't tell
> the truth really, likewise if SAVE_EXPRs have no side-effects, as that
> wouldn't guarantee it is evaluated at least once.
SAVE_EXPRs can have side-effects like every other expression, and save_expr
automatically sets the flag.
Subject: Re: [4.1/4.2/4.3 Regression] missed evaluation of VM array type when used as a cast My view remains as I said in <http://gcc.gnu.org/ml/gcc-patches/2006-09/msg00039.html>: front ends should make the internal variable for VLA sizes explicit. This is not however suitable for implementing in development stage 3, let alone in regression-only mode or on release branches. There may of course be a simpler fix for this particular bug. I don't think side effects in VLA size expressions (let alone in VLA size expressions in casts) are that likely to be used in real code outside of conformance testsuites, so I wouldn't consider this regression (worked with 2.95.3, failed with 3.0.4) of great importance. The variables get made explicit by the gimplifier. The problem here seems to be that we lose the cast before we can do so and that the gimplifier only makes the variables explicit if they are used (which they are not for casts - apart from side-effects). 4.2.4 is being released, changing milestones to 4.2.5. Closing 4.1 branch. Testing a patch for 4.5. Subject: Bug 35198 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 Although technically wrong-code, side effects in VLA size expressions are a very dubious practice I don't expect to be used like this outside of testsuites. The fix is clearly unsuitable for any development stage other than Stage 1; downgrading to P4 to reflect this. Subject: Bug 35198 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. Fix not suitable for backporting. |
void* a(void* x) {return (int (*)[10][printf("hi\n")])x;} int main() { int i; a(&i); } should print hi. This was still broken in 4.3 in July, 2007.