./:

	* common.opt: Add Wstrict-overflow and Wstrict-overflow=.
	* flags.h (warn_strict_overflow): Declare.
	(enum warn_strict_overflow_code): Define.
	(issue_strict_overflow_warning): New static inline function.
	* opts.c (warn_strict_overflow): New variable.
	(common_handle_option): Handle OPT_Wstrict_overflow and
	OPT_Wstrict_overflow_.
	* c-opts.c (c_common_handle_option): Set warn_strict_overflow for
	OPT_Wall.
	* fold-const.c: Include intl.h.
	(fold_deferring_overflow_warnings): New static variable.
	(fold_deferred_overflow_warning): New static variable.
	(fold_deferred_overflow_code): New static variable.
	(fold_defer_overflow_warnings): New function.
	(fold_undefer_overflow_warnings): New function.
	(fold_undefer_and_ignore_overflow_warnings): New function.
	(fold_deferring_overflow_warnings_p): New function.
	(fold_overflow_warning): New static function.
	(make_range): Add strict_overflow_p parameter.  Change all
	callers.
	(extract_muldiv, extract_muldiv_1): Likewise.
	(fold_unary) [ABS_EXPR]: Check ABS_EXPR before calling
	tree_expr_nonnegative_p.
	(fold_negate_expr): Call fold_overflow_warning.
	(fold_range_test): Likewise.
	(fold_comparison): Likewise.
	(fold_binary): Likewise.  Call tree_expr_nonnegative_warnv_p
	instead of tree_expr_nonnegative_p.
	(tree_expr_nonnegative_warnv_p): Rename from
	tree_expr_nonnegative_p, add strict_overflow_p parameter.
	(tree_expr_nonnegative_p): New function.
	(tree_expr_nonzero_warnv_p): Rename from tree_expr_nonzero_p, add
	strict_overflow_p parameter.
	(tree_expr_nonzero_p): New function.
	* passes.c (verify_interpass_invariants): New static function.
	(execute_one_pass): Call it.
	* tree-ssa-loop-niter.c (expand_simple_operations): Ignore fold
	warnings.
	(number_of_iterations_exit, loop_niter_by_eval): Likewise.
	(estimate_numbers_of_iterations): Likewise.
	(scev_probably_wraps_p): Likewise.
	* tree-ssa-ccp.c: Include "toplev.h".
	(evaluate_stmt): Defer fold overflow warnings until we know we are
	going to optimize.
	(struct fold_stmt_r_data): Add stmt field.
	(fold_stmt_r): Defer fold overflow warnings until we know we
	optimized.
	(fold_stmt): Initialize stmt field of fold_stmt_r_data.
	(fold_stmt_inplace): Likewise.
	* tree-cfgcleanup.c: Include "toplev.h" rather than "errors.h".
	(cleanup_control_expr_graph): Defer fold overflow warnings until
	we know we are going to optimize.
	* tree-cfg.c (fold_cond_expr_cond): Likewise.
	* tree-ssa-threadedge.c (simplify_control_stmt_condition):
	Likewise.
	* tree-vrp.c (vrp_expr_computes_nonnegative): Call
	tree_expr_nonnegative_warnv_p instead of tree_expr_nonnegative_p.
	* tree-ssa-loop-manip.c (create_iv): Likewise.
	* c-typeck.c (build_conditional_expr): Likewise.
	(build_binary_op): Likewise.
	* tree-vrp.c (vrp_expr_computes_nonzero): Call
	tree_expr_nonzero_warnv_p instead of tree_expr_nonzero_p.
	(extract_range_from_unary_expr): Likewise.
	* simplify-rtx.c (simplify_const_relational_operation): Warn when
	assuming that signed overflow does not occur.
	* c-common.c (pointer_int_sum): Ignore fold overflow warnings.
	* tree.h (tree_expr_nonnegative_warnv_p): Declare.
	(fold_defer_overflow_warnings): Declare.
	(fold_undefer_overflow_warnings): Declare.
	(fold_undefer_and_ignore_overflow_warnings): Declare.
	(fold_deferring_overflow_warnings_p): Declare.
	(tree_expr_nonzero_warnv_p): Declare.
	* doc/invoke.texi (Option Summary): Add -Wstrict-overflow to list
	of warning options.
	(Warning Options): Document -Wstrict-overflow.
	* Makefile.in (tree-ssa-threadedge.o): Depend on toplev.h.
	(tree-ssa-ccp.o): Likewise.
	(tree-cfgcleanup.o): Change errors.h dependency to toplev.h.
	(fold-const.o): Depend on intl.h.
testsuite/:
	* gcc.dg/Wstrict-overflow-1.c: New test.
	* gcc.dg/Wstrict-overflow-2.c: New test.
	* gcc.dg/Wstrict-overflow-3.c: New test.
	* gcc.dg/Wstrict-overflow-4.c: New test.
	* gcc.dg/Wstrict-overflow-5.c: New test.
	* gcc.dg/Wstrict-overflow-6.c: New test.
	* gcc.dg/Wstrict-overflow-7.c: New test.
	* gcc.dg/Wstrict-overflow-8.c: New test.
	* gcc.dg/Wstrict-overflow-9.c: New test.
	* gcc.dg/Wstrict-overflow-10.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@121895 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 24 insertions, 4 deletions

diff --git a/gcc/tree-cfgcleanup.c b/gcc/tree-cfgcleanup.c
index f78be8ecf68..8cf66cb4a27 100644
--- a/gcc/tree-cfgcleanup.c
+++ b/gcc/tree-cfgcleanup.c
@@ -1,5 +1,6 @@
 /* CFG cleanup for trees.
-   Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
+   Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -28,7 +29,7 @@ Boston, MA 02110-1301, USA.  */
 #include "hard-reg-set.h"
 #include "basic-block.h"
 #include "output.h"
-#include "errors.h"
+#include "toplev.h"
 #include "flags.h"
 #include "function.h"
 #include "expr.h"
@@ -78,6 +79,9 @@ cleanup_control_expr_graph (basic_block bb, block_stmt_iterator bsi)
     {
       edge e;
       edge_iterator ei;
+      bool warned;
+
+      fold_defer_overflow_warnings ();
 
       switch (TREE_CODE (expr))
 	{
@@ -88,7 +92,10 @@ cleanup_control_expr_graph (basic_block bb, block_stmt_iterator bsi)
 	case SWITCH_EXPR:
 	  val = fold (SWITCH_COND (expr));
 	  if (TREE_CODE (val) != INTEGER_CST)
-	    return false;
+	    {
+	      fold_undefer_and_ignore_overflow_warnings ();
+	      return false;
+	    }
 	  break;
 
 	default:
@@ -97,13 +104,24 @@ cleanup_control_expr_graph (basic_block bb, block_stmt_iterator bsi)
 
       taken_edge = find_taken_edge (bb, val);
       if (!taken_edge)
-	return false;
+	{
+	  fold_undefer_and_ignore_overflow_warnings ();
+	  return false;
+	}
 
       /* Remove all the edges except the one that is always executed.  */
+      warned = false;
       for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
 	{
 	  if (e != taken_edge)
 	    {
+	      if (!warned)
+		{
+		  fold_undefer_overflow_warnings
+		    (true, expr, WARN_STRICT_OVERFLOW_CONDITIONAL);
+		  warned = true;
+		}
+
 	      taken_edge->probability += e->probability;
 	      taken_edge->count += e->count;
 	      remove_edge (e);
@@ -112,6 +130,8 @@ cleanup_control_expr_graph (basic_block bb, block_stmt_iterator bsi)
 	  else
 	    ei_next (&ei);
 	}
+      if (!warned)
+	fold_undefer_and_ignore_overflow_warnings ();
       if (taken_edge->probability > REG_BR_PROB_BASE)
 	taken_edge->probability = REG_BR_PROB_BASE;
     }