[Sanitizer] Make StackTrace::Unwind the only public way to unwind a stack trace.

llvm-svn: 194196

compiler-rt/lib/msan/msan.cc

@@ -180,16 +180,15 @@ static void GetCurrentStackBounds(uptr *stack_top, uptr *stack_bottom) {
 }
 
 void GetStackTrace(StackTrace *stack, uptr max_s, uptr pc, uptr bp,
-                   bool fast) {
-  if (!fast) {
+                   bool request_fast_unwind) {
+  if (!StackTrace::WillUseFastUnwind(request_fast_unwind)) {
     // Block reports from our interceptors during _Unwind_Backtrace.
     SymbolizerScope sym_scope;
-    return stack->SlowUnwindStack(pc, max_s);
+    return stack->Unwind(max_s, pc, bp, 0, 0, request_fast_unwind);
   }
-
   uptr stack_top, stack_bottom;
   GetCurrentStackBounds(&stack_top, &stack_bottom);
-  stack->FastUnwindStack(pc, bp, stack_top, stack_bottom, max_s);
+  stack->Unwind(max_s, pc, bp, stack_top, stack_bottom, request_fast_unwind);
 }
 
 void PrintWarning(uptr pc, uptr bp) {

compiler-rt/lib/msan/msan.h

@@ -72,7 +72,7 @@ void PrintWarning(uptr pc, uptr bp);
 void PrintWarningWithOrigin(uptr pc, uptr bp, u32 origin);
 
 void GetStackTrace(StackTrace *stack, uptr max_s, uptr pc, uptr bp,
-                   bool fast);
+                   bool request_fast_unwind);
 
 void ReportUMR(StackTrace *stack, u32 origin);
 void ReportExpectedUMRNotFound(StackTrace *stack);

compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h

@@ -47,17 +47,26 @@ struct StackTrace {
       trace[i] = src[i];
   }
 
-  void Unwind(uptr max_depth, uptr pc, uptr bp, uptr stack_top,
-              uptr stack_bottom, bool fast);
-  // FIXME: Make FastUnwindStack and SlowUnwindStack private methods.
-  void FastUnwindStack(uptr pc, uptr bp, uptr stack_top, uptr stack_bottom,
-                       uptr max_depth);
-  void SlowUnwindStack(uptr pc, uptr max_depth);
+  static bool WillUseFastUnwind(bool request_fast_unwind) {
+    // Check if fast unwind is available. Fast unwind is the only option on Mac.
+    if (!SANITIZER_CAN_FAST_UNWIND)
+      return false;
+    else if (SANITIZER_MAC)
+      return true;
+    return request_fast_unwind;
+  }
 
-  void PopStackFrames(uptr count);
+  void Unwind(uptr max_depth, uptr pc, uptr bp, uptr stack_top,
+              uptr stack_bottom, bool request_fast_unwind);
 
   static uptr GetCurrentPc();
   static uptr GetPreviousInstructionPc(uptr pc);
+
+ private:
+  void FastUnwindStack(uptr pc, uptr bp, uptr stack_top, uptr stack_bottom,
+                       uptr max_depth);
+  void SlowUnwindStack(uptr pc, uptr max_depth);
+  void PopStackFrames(uptr count);
 };
 
 }  // namespace __sanitizer

compiler-rt/lib/sanitizer_common/sanitizer_stacktrace_libcdep.cc

@@ -16,14 +16,8 @@
 namespace __sanitizer {
 
 void StackTrace::Unwind(uptr max_depth, uptr pc, uptr bp, uptr stack_top,
-                        uptr stack_bottom, bool fast) {
-  // Check if fast unwind is available. Fast unwind is the only option on Mac.
-  if (!SANITIZER_CAN_FAST_UNWIND)
-    fast = false;
-  else if (SANITIZER_MAC)
-    fast = true;
-
-  if (!fast)
+                        uptr stack_bottom, bool request_fast_unwind) {
+  if (!WillUseFastUnwind(request_fast_unwind))
     SlowUnwindStack(pc, max_depth);
   else
     FastUnwindStack(pc, bp, stack_top, stack_bottom, max_depth);

compiler-rt/lib/sanitizer_common/tests/sanitizer_stacktrace_test.cc

@@ -20,6 +20,13 @@ namespace __sanitizer {
 class FastUnwindTest : public ::testing::Test {
  protected:
   virtual void SetUp();
+  bool TryFastUnwind(uptr max_depth) {
+    if (!StackTrace::WillUseFastUnwind(true))
+      return false;
+    trace.Unwind(max_depth, start_pc, (uptr)&fake_stack[0], fake_top,
+                 fake_bottom, true);
+    return true;
+  }
 
   uptr fake_stack[10];
   uptr start_pc;
@@ -50,8 +57,8 @@ void FastUnwindTest::SetUp() {
 }
 
 TEST_F(FastUnwindTest, Basic) {
-  trace.FastUnwindStack(start_pc, (uptr)&fake_stack[0],
-                        fake_top, fake_bottom, kStackTraceMax);
+  if (!TryFastUnwind(kStackTraceMax))
+    return;
   // Should get all on-stack retaddrs and start_pc.
   EXPECT_EQ(6U, trace.size);
   EXPECT_EQ(start_pc, trace.trace[0]);
@@ -64,8 +71,8 @@ TEST_F(FastUnwindTest, Basic) {
 TEST_F(FastUnwindTest, FramePointerLoop) {
   // Make one fp point to itself.
   fake_stack[4] = (uptr)&fake_stack[4];
-  trace.FastUnwindStack(start_pc, (uptr)&fake_stack[0],
-                        fake_top, fake_bottom, kStackTraceMax);
+  if (!TryFastUnwind(kStackTraceMax))
+    return;
   // Should get all on-stack retaddrs up to the 4th slot and start_pc.
   EXPECT_EQ(4U, trace.size);
   EXPECT_EQ(start_pc, trace.trace[0]);
@@ -77,8 +84,8 @@ TEST_F(FastUnwindTest, FramePointerLoop) {
 TEST_F(FastUnwindTest, MisalignedFramePointer) {
   // Make one fp misaligned.
   fake_stack[4] += 3;
-  trace.FastUnwindStack(start_pc, (uptr)&fake_stack[0],
-                        fake_top, fake_bottom, kStackTraceMax);
+  if (!TryFastUnwind(kStackTraceMax))
+    return;
   // Should get all on-stack retaddrs up to the 4th slot and start_pc.
   EXPECT_EQ(4U, trace.size);
   EXPECT_EQ(start_pc, trace.trace[0]);
@@ -88,8 +95,8 @@ TEST_F(FastUnwindTest, MisalignedFramePointer) {
 }
 
 TEST_F(FastUnwindTest, OneFrameStackTrace) {
-  trace.FastUnwindStack(start_pc, (uptr)&fake_stack[0],
-                        fake_top, fake_bottom, 1);
+  if (!TryFastUnwind(1))
+    return;
   EXPECT_EQ(1U, trace.size);
   EXPECT_EQ(start_pc, trace.trace[0]);
 }

compiler-rt/lib/tsan/rtl/tsan_rtl_report.cc

@@ -726,8 +726,8 @@ void PrintCurrentStackSlow() {
 #ifndef TSAN_GO
   __sanitizer::StackTrace *ptrace = new(internal_alloc(MBlockStackTrace,
       sizeof(__sanitizer::StackTrace))) __sanitizer::StackTrace;
-  ptrace->SlowUnwindStack(__sanitizer::StackTrace::GetCurrentPc(),
-      kStackTraceMax);
+  ptrace->Unwind(kStackTraceMax, __sanitizer::StackTrace::GetCurrentPc(),
+                 0, 0, 0, false);
   for (uptr i = 0; i < ptrace->size / 2; i++) {
     uptr tmp = ptrace->trace[i];
     ptrace->trace[i] = ptrace->trace[ptrace->size - i - 1];