re PR c/456 (constant expressions constraints (gcc.dg/c90-const-expr-1))

	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.

From-SVN: r145254

1 files changed, 11 insertions, 4 deletions

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 0e9d739..9500feb 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -663,6 +663,10 @@ A @code{typeof}-construct can be used anywhere a typedef name could be
 used.  For example, you can use it in a declaration, in a cast, or inside
 of @code{sizeof} or @code{typeof}.
 
+The operand of @code{typeof} is evaluated for its side effects if and
+only if it is an expression of variably modified type or the name of
+such a type.
+
 @code{typeof} is often useful in conjunction with the
 statements-within-expressions feature.  Here is how the two together can
 be used to define a safe ``maximum'' macro that operates on any
@@ -6635,9 +6639,8 @@ depending on the arguments' types.  For example:
 
 You can use the built-in function @code{__builtin_choose_expr} to
 evaluate code depending on the value of a constant expression.  This
-built-in function returns @var{exp1} if @var{const_exp}, which is a
-constant expression that must be able to be determined at compile time,
-is nonzero.  Otherwise it returns 0.
+built-in function returns @var{exp1} if @var{const_exp}, which is an
+integer constant expression, is nonzero.  Otherwise it returns 0.
 
 This built-in function is analogous to the @samp{? :} operator in C,
 except that the expression returned has its type unaltered by promotion
@@ -6716,7 +6719,11 @@ static const int table[] = @{
 
 @noindent
 This is an acceptable initializer even if @var{EXPRESSION} is not a
-constant expression.  GCC must be more conservative about evaluating the
+constant expression, including the case where
+@code{__builtin_constant_p} returns 1 because @var{EXPRESSION} can be
+folded to a constant but @var{EXPRESSION} contains operands that would
+not otherwize be permitted in a static initializer (for example,
+@code{0 && foo ()}).  GCC must be more conservative about evaluating the
 built-in in this case, because it has no opportunity to perform
 optimization.