//===-- sanitizer_stacktrace_test.cc --------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a part of ThreadSanitizer/AddressSanitizer runtime.
//
//===----------------------------------------------------------------------===//

#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_stacktrace.h"
#include "gtest/gtest.h"

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], 0, fake_top,
                 fake_bottom, true);
    return true;
  }

  uptr fake_stack[10];
  uptr start_pc;
  uptr fake_top;
  uptr fake_bottom;
  StackTrace trace;
};

static uptr PC(uptr idx) {
  return (1<<20) + idx;
}

void FastUnwindTest::SetUp() {
  // Fill an array of pointers with fake fp+retaddr pairs.  Frame pointers have
  // even indices.
  for (uptr i = 0; i+1 < ARRAY_SIZE(fake_stack); i += 2) {
    fake_stack[i] = (uptr)&fake_stack[i+2];  // fp
    fake_stack[i+1] = PC(i + 1); // retaddr
  }
  // Mark the last fp as zero to terminate the stack trace.
  fake_stack[RoundDownTo(ARRAY_SIZE(fake_stack) - 1, 2)] = 0;

  // Top is two slots past the end because FastUnwindStack subtracts two.
  fake_top = (uptr)&fake_stack[ARRAY_SIZE(fake_stack) + 2];
  // Bottom is one slot before the start because FastUnwindStack uses >.
  fake_bottom = (uptr)&fake_stack[-1];
  start_pc = PC(0);
}

TEST_F(FastUnwindTest, Basic) {
  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]);
  for (uptr i = 1; i <= 5; i++) {
    EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
  }
}

// From: http://code.google.com/p/address-sanitizer/issues/detail?id=162
TEST_F(FastUnwindTest, FramePointerLoop) {
  // Make one fp point to itself.
  fake_stack[4] = (uptr)&fake_stack[4];
  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]);
  for (uptr i = 1; i <= 3; i++) {
    EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
  }
}

TEST_F(FastUnwindTest, MisalignedFramePointer) {
  // Make one fp misaligned.
  fake_stack[4] += 3;
  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]);
  for (uptr i = 1; i < 4U; i++) {
    EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
  }
}

TEST_F(FastUnwindTest, OneFrameStackTrace) {
  if (!TryFastUnwind(1))
    return;
  EXPECT_EQ(1U, trace.size);
  EXPECT_EQ(start_pc, trace.trace[0]);
  EXPECT_EQ((uptr)&fake_stack[0], trace.top_frame_bp);
}

TEST_F(FastUnwindTest, ZeroFramesStackTrace) {
  if (!TryFastUnwind(0))
    return;
  EXPECT_EQ(0U, trace.size);
  EXPECT_EQ(0U, trace.top_frame_bp);
}

TEST(SlowUnwindTest, ShortStackTrace) {
  if (StackTrace::WillUseFastUnwind(false))
    return;
  StackTrace stack;
  uptr pc = StackTrace::GetCurrentPc();
  uptr bp = GET_CURRENT_FRAME();
  stack.Unwind(0, pc, bp, 0, 0, 0, false);
  EXPECT_EQ(0U, stack.size);
  EXPECT_EQ(0U, stack.top_frame_bp);
  stack.Unwind(1, pc, bp, 0, 0, 0, false);
  EXPECT_EQ(1U, stack.size);
  EXPECT_EQ(pc, stack.trace[0]);
  EXPECT_EQ(bp, stack.top_frame_bp);
}

}  // namespace __sanitizer