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[PATCH 8/17] Optimization of strlen instrumentation
- From: Yury Gribov <y dot gribov at samsung dot com>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Cc: Jakub Jelinek <jakub at redhat dot com>, Dmitry Vyukov <dvyukov at google dot com>, Konstantin Khlebnikov <k dot khlebnikov at samsung dot com>, Andrey Ryabinin <a dot ryabinin at samsung dot com>, Viacheslav Garbuzov <v dot garbuzov at samsung dot com>
- Date: Thu, 16 Oct 2014 12:39:17 +0400
- Subject: [PATCH 8/17] Optimization of strlen instrumentation
- Authentication-results: sourceware.org; auth=none
- References: <543F831B dot 4090502 at samsung dot com>
Difference from mainline: replaced non-C-friendly bool with unsigned
char (see patch 0001 for explanation).
Do not instrument first byte in strlen if already instrumented.
2014-10-15 Yury Gribov <y.gribov@samsung.com>
Backport from mainline
2014-06-24 Max Ostapenko <m.ostapenko@partner.samsung.com>
* asan.c (instrument_strlen_call): Do not instrument first byte in strlen
if already instrumented.
* c-c++-common/asan/no-redundant-instrumentation-9.c: New test.
diff --git a/gcc/asan.c b/gcc/asan.c
index 06177ac..0789ad3 100644
--- a/gcc/asan.c
+++ b/gcc/asan.c
@@ -2026,6 +2026,7 @@ instrument_strlen_call (gimple_stmt_iterator *iter)
location_t loc = gimple_location (call);
tree str_arg = gimple_call_arg (call, 0);
+ bool start_instrumented = has_mem_ref_been_instrumented (str_arg, 1);
tree cptr_type = build_pointer_type (char_type_node);
gimple str_arg_ssa =
@@ -2037,7 +2038,8 @@ instrument_strlen_call (gimple_stmt_iterator *iter)
build_check_stmt (loc, gimple_assign_lhs (str_arg_ssa), NULL_TREE, 1, iter,
/*non_zero_len_p*/true, /*before_p=*/true,
- /*is_store=*/false, /*is_scalar_access*/true, /*align*/0);
+ /*is_store=*/false, /*is_scalar_access*/true, /*align*/0,
+ start_instrumented, start_instrumented);
gimple g =
gimple_build_assign_with_ops (POINTER_PLUS_EXPR,
diff --git a/gcc/testsuite/c-c++-common/asan/no-redundant-instrumentation-9.c b/gcc/testsuite/c-c++-common/asan/no-redundant-instrumentation-9.c
new file mode 100644
index 0000000..c6575ad
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/asan/no-redundant-instrumentation-9.c
@@ -0,0 +1,13 @@
+/* { dg-options "-fdump-tree-asan0" } */
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "*" } { "-O0" } } */
+
+__SIZE_TYPE__
+f (char *a)
+{
+ a[0] = '1';
+ return __builtin_strlen (a);
+}
+
+/* { dg-final { scan-tree-dump-times "__asan_report_load1" 1 "asan0" } } */
+/* { dg-final { cleanup-tree-dump "asan0" } } */