[sanitizer] Expose __sanitizer_print_stack_trace().

Expose a new interface function for debugging code built with sanitizer tools.
Add an ASan implementation.

llvm-svn: 196302

4 files changed, 29 insertions, 5 deletions

diff --git a/compiler-rt/include/sanitizer/common_interface_defs.h b/compiler-rt/include/sanitizer/common_interface_defs.h
index 801fe48a93b..ce4f75ad5c8 100644
--- a/compiler-rt/include/sanitizer/common_interface_defs.h
+++ b/compiler-rt/include/sanitizer/common_interface_defs.h
@@ -85,6 +85,9 @@ extern "C" {
                                                  const void *old_mid,
                                                  const void *new_mid);
 
+  // Print the stack trace leading to this call. Useful for debugging user code.
+  void __sanitizer_print_stack_trace();
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif
diff --git a/compiler-rt/lib/asan/asan_stack.cc b/compiler-rt/lib/asan/asan_stack.cc
index 0bc5a5f2d03..f5fba4b2d6b 100644
--- a/compiler-rt/lib/asan/asan_stack.cc
+++ b/compiler-rt/lib/asan/asan_stack.cc
@@ -45,3 +45,9 @@ bool __asan_symbolize(const void *pc, char *out_buffer, int out_size) {
   return false;
 }
 #endif
+
+SANITIZER_INTERFACE_ATTRIBUTE
+extern "C" void __sanitizer_print_stack_trace() {
+  using namespace __asan;
+  PRINT_CURRENT_STACK();
+}
diff --git a/compiler-rt/lib/asan/asan_stack.h b/compiler-rt/lib/asan/asan_stack.h
index dedc5930219..6a6ffe44e96 100644
--- a/compiler-rt/lib/asan/asan_stack.h
+++ b/compiler-rt/lib/asan/asan_stack.h
@@ -77,11 +77,10 @@ void PrintStack(const uptr *trace, uptr size);
 
 #define GET_STACK_TRACE_FREE GET_STACK_TRACE_MALLOC
 
-#define PRINT_CURRENT_STACK()                    \
-  {                                              \
-    GET_STACK_TRACE(kStackTraceMax,              \
-      common_flags()->fast_unwind_on_fatal);     \
-    PrintStack(&stack);                          \
+#define PRINT_CURRENT_STACK()   \
+  {                             \
+    GET_STACK_TRACE_FATAL_HERE; \
+    PrintStack(&stack);         \
   }
 
 #endif  // ASAN_STACK_H
diff --git a/compiler-rt/lib/asan/lit_tests/TestCases/print-stack-trace.cc b/compiler-rt/lib/asan/lit_tests/TestCases/print-stack-trace.cc
new file mode 100644
index 00000000000..923fa6580e5
--- /dev/null
+++ b/compiler-rt/lib/asan/lit_tests/TestCases/print-stack-trace.cc
@@ -0,0 +1,16 @@
+// RUN: %clangxx_asan -O0 %s -o %t && %t 2>&1 | FileCheck %s
+// RUN: %clangxx_asan -O3 %s -o %t && %t 2>&1 | FileCheck %s
+
+#include <sanitizer/asan_interface.h>
+
+void FooBarBaz() {
+  __sanitizer_print_stack_trace();
+}
+
+int main() {
+  FooBarBaz();
+  return 0;
+}
+// CHECK: {{    #0 0x.* in __sanitizer_print_stack_trace}}
+// CHECK: {{    #1 0x.* in FooBarBaz\(\) .*print-stack-trace.cc:7}}
+// CHECK: {{    #2 0x.* in main .*print-stack-trace.cc:11}}