[SanitizerCoverage] Add stack depth tracing instrumentation.

Summary:
Augment SanitizerCoverage to insert maximum stack depth tracing for
use by libFuzzer.  The new instrumentation is enabled by the flag
-fsanitize-coverage=stack-depth and is compatible with the existing
trace-pc-guard coverage.  The user must also declare the following
global variable in their code:
  thread_local uintptr_t __sancov_lowest_stack

https://bugs.llvm.org/show_bug.cgi?id=33857

Reviewers: vitalybuka, kcc

Reviewed By: vitalybuka

Subscribers: kubamracek, hiraditya, cfe-commits, llvm-commits

Differential Revision: https://reviews.llvm.org/D36839

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@311186 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 32 insertions, 0 deletions

diff --git a/test/sanitizer_common/TestCases/sanitizer_coverage_stack_depth.cc b/test/sanitizer_common/TestCases/sanitizer_coverage_stack_depth.cc
new file mode 100644
index 000000000..90959ef5b
--- /dev/null
+++ b/test/sanitizer_common/TestCases/sanitizer_coverage_stack_depth.cc
@@ -0,0 +1,32 @@
+// Tests -fsanitize-coverage=stack-depth
+//
+// XFAIL: tsan
+//
+// RUN: %clangxx -O0 -std=c++11 -fsanitize-coverage=stack-depth %s -o %t
+// RUN: %run %t 2>&1 | FileCheck %s --implicit-check-not Assertion{{.*}}failed
+// RUN: %clangxx -O0 -std=c++11 -fsanitize-coverage=trace-pc-guard,stack-depth \
+// RUN:     %s -o %t
+// RUN: %run %t 2>&1 | FileCheck %s --implicit-check-not Assertion{{.*}}failed
+
+#include <cstdint>
+#include <cstdio>
+#include <cassert>
+
+thread_local uintptr_t __sancov_lowest_stack;
+uintptr_t last_stack;
+
+void foo(int recurse) {
+  assert(__sancov_lowest_stack < last_stack);
+  last_stack = __sancov_lowest_stack;
+  if (recurse <= 0) return;
+  foo(recurse - 1);
+}
+
+int main() {
+  last_stack = __sancov_lowest_stack;
+  foo(100);
+  printf("Success!\n");
+  return 0;
+}
+
+// CHECK: Success!