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enable -Wformat-truncation with -Og (PR 79691)
- From: Martin Sebor <msebor at gmail dot com>
- To: Gcc Patch List <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 23 Feb 2017 17:35:18 -0700
- Subject: enable -Wformat-truncation with -Og (PR 79691)
- Authentication-results: sourceware.org; auth=none
Bug 79691 - -Wformat-truncation suppressed by (and only by) -Og
points out that the gimple-ssa-sprintf pass doesn't run when
this optimization option is used. That's because I forgot to
add it to the set of optimization passes that run with that
option. The attached trivial patch tested on x86_64 corrects
the oversight.
Is this okay for 7.0?
Martin
PR tree-optimization/79691 - -Wformat-truncation suppressed by (and only by) -Og
gcc/ChangeLog:
PR c/79691
* passes.def (pass_all_optimizations_g): Enable pass_sprintf_length.
gcc/testsuite/ChangeLog:
PR c/79691
* gcc.dg/tree-ssa/pr79691.c: New test.
diff --git a/gcc/passes.def b/gcc/passes.def
index c09ec22..6b0f05b 100644
--- a/gcc/passes.def
+++ b/gcc/passes.def
@@ -364,6 +364,7 @@ along with GCC; see the file COPYING3. If not see
NEXT_PASS (pass_object_sizes);
/* Fold remaining builtins. */
NEXT_PASS (pass_fold_builtins);
+ NEXT_PASS (pass_sprintf_length, true);
/* Copy propagation also copy-propagates constants, this is necessary
to forward object-size and builtin folding results properly. */
NEXT_PASS (pass_copy_prop);
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr79691.c b/gcc/testsuite/gcc.dg/tree-ssa/pr79691.c
new file mode 100644
index 0000000..badbfcd
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr79691.c
@@ -0,0 +1,27 @@
+/* PR tree-optimization/79691 - -Wformat-truncation suppressed by
+ (and only by) -Og
+
+ { dg-compile }
+ { dg-options "-Og -Wall" } */
+
+char d[2];
+
+/* Verify -Wformat-overflow works. */
+void f (void)
+{
+ __builtin_sprintf (d, "%i", 123); /* { dg-warning "directive writing 3 bytes" } */
+}
+
+/* Verify -Wformat-truncation works. */
+void g (void)
+{
+ __builtin_snprintf (d, sizeof d, "%i", 1234); /* { dg-warning "output truncated writing 4 bytes" } */
+}
+
+/* Verify -fprintf-return-value works. */
+int h (void)
+{
+ return __builtin_snprintf (0, 0, "%i", 12345);
+}
+
+/* { dg-final { scan-tree-dump-not "snprintf" "optimized" } } */