[asan] add a run-time flag detect_container_overflow=true/false

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@206753 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 9 insertions, 1 deletions

diff --git a/lib/asan/asan_flags.h b/lib/asan/asan_flags.h
index 523302b96..7dc781581 100644
--- a/lib/asan/asan_flags.h
+++ b/lib/asan/asan_flags.h
@@ -63,6 +63,7 @@ struct Flags {
   bool strict_init_order;
   bool start_deactivated;
   int detect_invalid_pointer_pairs;
+  bool detect_container_overflow;
 };
 
 extern Flags asan_flags_dont_use_directly;
diff --git a/lib/asan/asan_poisoning.cc b/lib/asan/asan_poisoning.cc
index f75ac0a4e..a545769bd 100644
--- a/lib/asan/asan_poisoning.cc
+++ b/lib/asan/asan_poisoning.cc
@@ -266,6 +266,7 @@ void __sanitizer_annotate_contiguous_container(const void *beg_p,
                                                const void *end_p,
                                                const void *old_mid_p,
                                                const void *new_mid_p) {
+  if (!flags()->detect_container_overflow) return;
   VPrintf(2, "contiguous_container: %p %p %p %p\n", beg_p, end_p, old_mid_p,
           new_mid_p);
   uptr beg = reinterpret_cast<uptr>(beg_p);
diff --git a/lib/asan/asan_report.cc b/lib/asan/asan_report.cc
index 9d1742202..bece6eab3 100644
--- a/lib/asan/asan_report.cc
+++ b/lib/asan/asan_report.cc
@@ -141,7 +141,7 @@ static void PrintLegend(InternalScopedString *str) {
                   kAsanInitializationOrderMagic);
   PrintShadowByte(str, "  Poisoned by user:        ",
                   kAsanUserPoisonedMemoryMagic);
-  PrintShadowByte(str, "  Contiguous container OOB:",
+  PrintShadowByte(str, "  Container overflow:      ",
                   kAsanContiguousContainerOOBMagic);
   PrintShadowByte(str, "  ASan internal:           ", kAsanInternalHeapMagic);
 }
diff --git a/lib/asan/asan_rtl.cc b/lib/asan/asan_rtl.cc
index d608dd711..4b11f2a51 100644
--- a/lib/asan/asan_rtl.cc
+++ b/lib/asan/asan_rtl.cc
@@ -220,6 +220,11 @@ static void ParseFlagsFromString(Flags *f, const char *str) {
       "If non-zero, try to detect operations like <, <=, >, >= and - on "
       "invalid pointer pairs (e.g. when pointers belong to different objects). "
       "The bigger the value the harder we try.");
+
+  ParseFlag(str, &f->detect_container_overflow,
+      "detect_container_overflow",
+      "If true, honor the container overflow  annotations. "
+      "See https://code.google.com/p/address-sanitizer/wiki/ContainerOverflow");
 }
 
 void InitializeFlags(Flags *f, const char *env) {
@@ -267,6 +272,7 @@ void InitializeFlags(Flags *f, const char *env) {
   f->strict_init_order = false;
   f->start_deactivated = false;
   f->detect_invalid_pointer_pairs = 0;
+  f->detect_container_overflow = true;
 
   // Override from compile definition.
   ParseFlagsFromString(f, MaybeUseAsanDefaultOptionsCompileDefiniton());