bin/zxdb/client/stack_unittest.cc

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <map>

#include "garnet/bin/zxdb/client/frame_fingerprint.h"
#include "garnet/bin/zxdb/client/mock_frame.h"
#include "garnet/bin/zxdb/client/stack.h"
#include "garnet/bin/zxdb/common/err.h"
#include "garnet/bin/zxdb/common/test_with_loop.h"
#include "garnet/bin/zxdb/symbols/function.h"
#include "garnet/lib/debug_ipc/helper/message_loop.h"
#include "gtest/gtest.h"
#include "lib/fxl/logging.h"

namespace zxdb {

namespace {

class StackTest : public TestWithLoop {};

// Must call set_stack() after creating the Stack that uses this.
class MockStackDelegate : public Stack::Delegate {
 public:
  void set_stack(Stack* s) { stack_ = s; }

  // Adds the given location to the list of things returned by
  // GetSymbolizedLocationForStackFrame().
  void AddLocation(const Location& loc) { locations_[loc.address()] = loc; }

  // Sets the asynchronous resource to SyncFramesForStack(). Since this
  // transfers ownership, it will only affect the next call.
  void SetAsyncFrames(std::vector<std::unique_ptr<Frame>> frames) {
    async_frames_ = std::move(frames);
  }

  void SyncFramesForStack(std::function<void(const Err&)> cb) override {
    debug_ipc::MessageLoop::Current()->PostTask(
        FROM_HERE, [ cb = std::move(cb), this ]() {
          stack_->SetFramesForTest(std::move(async_frames_), true);
          cb(Err());
        });
  }

  std::unique_ptr<Frame> MakeFrameForStack(const debug_ipc::StackFrame& input,
                                           Location location) override {
    return std::make_unique<MockFrame>(nullptr, nullptr, input, location);
  }

  Location GetSymbolizedLocationForStackFrame(
      const debug_ipc::StackFrame& input) override {
    auto found = locations_.find(input.ip);
    if (found == locations_.end())
      return Location(Location::State::kSymbolized, input.ip);
    return found->second;
  }

 private:
  Stack* stack_ = nullptr;
  std::map<uint64_t, Location> locations_;
  std::vector<std::unique_ptr<Frame>> async_frames_;
};

// Stack pointers used by MakeInlineStackFrames.
constexpr uint64_t kTopSP = 0x2000;
constexpr uint64_t kMiddleSP = 0x2020;
constexpr uint64_t kBottomSP = 0x2040;

// Returns a set of stack frames:
//   [0] =   inline #2 from frame 2
//   [1] =   inline #1 from frame 2
//   [2] = physical frame at kTopSP
//   [3] =   inline from frame 4
//   [4] = physical frame at kMiddleSP
//   [5] = physical frame at kBottomSP
std::vector<std::unique_ptr<Frame>> MakeInlineStackFrames() {
  // Create three physical frames.
  debug_ipc::StackFrame phys_top_record(0x1000, kTopSP, kTopSP);
  Location top_location(Location::State::kSymbolized, phys_top_record.ip);
  debug_ipc::StackFrame phys_middle_record(0x1010, kMiddleSP, kMiddleSP);
  Location middle_location(Location::State::kSymbolized, phys_middle_record.ip);
  debug_ipc::StackFrame phys_bottom_record(0x1020, kBottomSP, kBottomSP);
  Location bottom_location(Location::State::kSymbolized, phys_bottom_record.ip);

  auto phys_top = std::make_unique<MockFrame>(nullptr, nullptr, phys_top_record,
                                              top_location);
  auto phys_middle = std::make_unique<MockFrame>(
      nullptr, nullptr, phys_middle_record, middle_location);
  auto phys_bottom = std::make_unique<MockFrame>(
      nullptr, nullptr, phys_bottom_record, bottom_location);

  std::vector<std::unique_ptr<Frame>> frames;

  // Top frame has two inline functions expanded on top of it. This uses the
  // same Location object for simplicity, in real life these will be different.
  frames.push_back(std::make_unique<MockFrame>(
      nullptr, nullptr, phys_top_record, top_location, phys_top.get()));
  frames.push_back(std::make_unique<MockFrame>(
      nullptr, nullptr, phys_top_record, top_location, phys_top.get()));

  // Physical top frame below those.
  frames.push_back(std::move(phys_top));

  // Middle frame has one inline function expanded on top of it.
  frames.push_back(
      std::make_unique<MockFrame>(nullptr, nullptr, phys_middle_record,
                                  middle_location, phys_middle.get()));
  frames.push_back(std::move(phys_middle));

  // Bottom frame has no inline frame.
  frames.push_back(std::move(phys_bottom));

  return frames;
}

}  // namespace

// Tests fingerprint computations involving inline frames.
TEST_F(StackTest, InlineFingerprint) {
  MockStackDelegate delegate;
  Stack stack(&delegate);
  delegate.set_stack(&stack);
  stack.SetFramesForTest(MakeInlineStackFrames(), true);

  // The top frames (physical and inline) have the middle frame's SP as their
  // fingerprint, along with the inline count.
  EXPECT_EQ(FrameFingerprint(kMiddleSP, 2), *stack.GetFrameFingerprint(0));
  EXPECT_EQ(FrameFingerprint(kMiddleSP, 1), *stack.GetFrameFingerprint(1));
  EXPECT_EQ(FrameFingerprint(kMiddleSP, 0), *stack.GetFrameFingerprint(2));

  // Middle frames have the bottom frame's SP.
  EXPECT_EQ(FrameFingerprint(kBottomSP, 1), *stack.GetFrameFingerprint(3));
  EXPECT_EQ(FrameFingerprint(kBottomSP, 0), *stack.GetFrameFingerprint(4));

  // Since there's nothing below the bottom frame, it gets its own SP.
  EXPECT_EQ(FrameFingerprint(kBottomSP, 0), *stack.GetFrameFingerprint(5));
}

// Tests basic requesting of asynchronous frame fingerprints.
TEST_F(StackTest, AsyncFingerprint) {
  MockStackDelegate delegate;
  Stack stack(&delegate);
  delegate.set_stack(&stack);

  // Only send the top two physical stack frames (with their inlined
  // expansions) for the initial data, and mark stack as incomplete.
  auto frames = MakeInlineStackFrames();
  frames.pop_back();
  stack.SetFramesForTest(std::move(frames), false);

  // Fingerprint for top physical frames and its inlines should be OK.
  auto found = stack.GetFrameFingerprint(2);
  ASSERT_TRUE(found);
  EXPECT_EQ(FrameFingerprint(kMiddleSP, 0), *found);

  // Fingerprint for the middle frame and its inline should fail.
  found = stack.GetFrameFingerprint(3);
  EXPECT_FALSE(found);
  found = stack.GetFrameFingerprint(4);
  EXPECT_FALSE(found);

  // Set the full stack as the reply.
  delegate.SetAsyncFrames(MakeInlineStackFrames());

  // Ask for the middle inline function fingerprint.
  bool called = false;
  stack.GetFrameFingerprint(3, [&called](const Err& err, size_t new_index,
                                         FrameFingerprint fingerprint) {
    EXPECT_FALSE(err.has_error()) << err.msg();
    called = true;

    // Index should not have changed.
    EXPECT_EQ(3u, new_index);
    EXPECT_EQ(FrameFingerprint(kBottomSP, 1), fingerprint);

    debug_ipc::MessageLoop::Current()->QuitNow();
  });

  // Should not be called synchronously.
  EXPECT_FALSE(called);

  // Running the message loop should run the lambda.
  debug_ipc::MessageLoop::Current()->Run();
  EXPECT_TRUE(called);

  // Ask for the middle non-inline fingerprint. The stack should be fully
  // synced so it should not try to re-sync (if it does, the new stack stored
  // in the delegate will be empty and getting the frame fingerprint will
  // fail.
  called = false;
  stack.GetFrameFingerprint(4, [&called](const Err& err, size_t new_index,
                                         FrameFingerprint fingerprint) {
    EXPECT_FALSE(err.has_error()) << err.msg();
    called = true;

    // Index should not have changed.
    EXPECT_EQ(4u, new_index);
    EXPECT_EQ(FrameFingerprint(kBottomSP, 0), fingerprint);

    debug_ipc::MessageLoop::Current()->QuitNow();
  });
  EXPECT_FALSE(called);
  debug_ipc::MessageLoop::Current()->Run();
  EXPECT_TRUE(called);
}

// Tests that the frame is found when the index changes across updates.
TEST_F(StackTest, AsyncFingerprintMoved) {
  MockStackDelegate delegate;
  Stack stack(&delegate);
  delegate.set_stack(&stack);

  // Only send the top two physical stack frames (with their inline expansions)
  // for the initial data, and mark stack as incomplete.
  auto frames = MakeInlineStackFrames();
  frames.pop_back();
  stack.SetFramesForTest(std::move(frames), false);

  // The async frames reply is the full stack but missing the top physical
  // frame (which has two inline frames above it).
  auto frame_reply = MakeInlineStackFrames();
  frame_reply.erase(frame_reply.begin(), frame_reply.begin() + 3);
  delegate.SetAsyncFrames(std::move(frame_reply));

  // Ask for the middle inline function fingerprint.
  bool called = false;
  stack.GetFrameFingerprint(3, [&called](const Err& err, size_t new_index,
                                         FrameFingerprint fingerprint) {
    EXPECT_FALSE(err.has_error()) << err.msg();
    called = true;

    // Index should now be at the top because the top physical frame was
    // deleted in the full stack reply.
    EXPECT_EQ(0u, new_index);
    EXPECT_EQ(FrameFingerprint(kBottomSP, 1), fingerprint);

    debug_ipc::MessageLoop::Current()->QuitNow();
  });

  // Should not be called synchronously.
  EXPECT_FALSE(called);

  // Running the message loop should run the lambda.
  debug_ipc::MessageLoop::Current()->Run();
  EXPECT_TRUE(called);
}

// Tests the case that a requested async fingerprint has been deleted by the
// time the async stack request has come back.
TEST_F(StackTest, AsyncFingerprintGone) {
  MockStackDelegate delegate;
  Stack stack(&delegate);
  delegate.set_stack(&stack);

  // Only send the top physical stack frame for the initial data, and mark
  // stack as incomplete. This will cause the topmost stack frame to require
  // an async fetch.
  auto frames = MakeInlineStackFrames();
  frames.erase(frames.begin() + 2, frames.begin() + 6);
  stack.SetFramesForTest(std::move(frames), false);

  // The async frames reply is the full stack but missing the top physical
  // frame (which has two inline frames above it).
  auto frame_reply = MakeInlineStackFrames();
  frame_reply.erase(frame_reply.begin(), frame_reply.begin() + 3);
  delegate.SetAsyncFrames(std::move(frame_reply));

  // Ask for the top function fingerprint.
  bool called = false;
  stack.GetFrameFingerprint(0, [&called](const Err& err, size_t new_index,
                                         FrameFingerprint fingerprint) {
    EXPECT_TRUE(err.has_error()) << err.msg();
    called = true;

    // These two values are the generic ones that should be set on error.
    EXPECT_EQ(0u, new_index);
    EXPECT_EQ(FrameFingerprint(), fingerprint);

    debug_ipc::MessageLoop::Current()->QuitNow();
  });

  // Should not be called synchronously.
  EXPECT_FALSE(called);

  // Running the message loop should run the lambda.
  debug_ipc::MessageLoop::Current()->Run();
  EXPECT_TRUE(called);
}

// Tests that stack frames inside inline functions are expanded so that the
// inline functions have their own "inline" frames.
TEST_F(StackTest, InlineExpansion) {
  constexpr uint64_t kBottomAddr = 0x127365;  // IP for bottom stack frame.
  constexpr uint64_t kTopAddr = 0x893746123;  // IP for top stack frale.

  const char kFileName[] = "file.cc";
  FileLine inline_call_line(kFileName, 10);
  FileLine inline_exec_line(kFileName, 20);
  FileLine top_line(kFileName, 30);

  MockStackDelegate delegate;
  SymbolContext symbol_context = SymbolContext::ForRelativeAddresses();

  // Non-inline location for the top stack frame.
  auto top_func = fxl::MakeRefCounted<Function>(Symbol::kTagSubprogram);
  top_func->set_assigned_name("Top");
  Location top_location(kTopAddr, top_line, 0, symbol_context,
                        LazySymbol(top_func));
  delegate.AddLocation(top_location);

  // Bottom stack frame has a real function and an inline function.
  auto bottom_inline_func =
      fxl::MakeRefCounted<Function>(Symbol::kTagInlinedSubroutine);
  bottom_inline_func->set_assigned_name("Inline");
  bottom_inline_func->set_code_ranges(
      AddressRanges(AddressRange(kBottomAddr, kBottomAddr + 8)));
  bottom_inline_func->set_call_line(inline_call_line);

  auto bottom_func = fxl::MakeRefCounted<Function>(Symbol::kTagSubprogram);
  bottom_func->set_assigned_name("Bottom");
  bottom_func->set_code_ranges(
      AddressRanges(AddressRange(kBottomAddr - 8, kBottomAddr + 16)));

  // For convenience, the inline function is nested inside the "bottom" func.
  // This is not something you can actually do in C++ and will give a name
  // "Bottom::Inline()". In real life the inline function will reference the
  // actualy function definition in the correct namespace.
  bottom_inline_func->set_parent(LazySymbol(bottom_func));

  // The location returned by the symbol function will have the file/line
  // inside the inline function.
  Location bottom_location(kBottomAddr, inline_exec_line, 0, symbol_context,
                           LazySymbol(bottom_inline_func));
  delegate.AddLocation(bottom_location);

  Stack stack(&delegate);
  delegate.set_stack(&stack);

  // Send IPs that will map to the bottom and top addresses.
  stack.SetFrames(debug_ipc::ThreadRecord::StackAmount::kFull,
                  {debug_ipc::StackFrame(kTopAddr, 0x100, 0x100),
                   debug_ipc::StackFrame(kBottomAddr, 0x200, 0x200)});

  // This should expand to tree stack entries, the one in the middle should
  // be the inline function expanded from the "bottom".
  EXPECT_EQ(3u, stack.size());

  // Bottom stack frame should be the non-inline bottom function.
  EXPECT_FALSE(stack[2]->IsInline());
  EXPECT_EQ(stack[2], stack[2]->GetPhysicalFrame());
  EXPECT_EQ(kBottomAddr, stack[2]->GetAddress());
  Location loc = stack[2]->GetLocation();
  EXPECT_EQ(kBottomAddr, loc.address());
  EXPECT_EQ(inline_call_line, loc.file_line());
  EXPECT_EQ(bottom_func.get(), loc.symbol().Get()->AsFunction());

  // Middle stack frame should be the inline bottom function at the same
  // address, referencing the bottom one as the physical frame.
  EXPECT_TRUE(stack[1]->IsInline());
  EXPECT_EQ(stack[2], stack[1]->GetPhysicalFrame());
  EXPECT_EQ(kBottomAddr, stack[1]->GetAddress());
  loc = stack[1]->GetLocation();
  EXPECT_EQ(kBottomAddr, loc.address());
  EXPECT_EQ(inline_exec_line, loc.file_line());
  EXPECT_EQ(bottom_inline_func.get(), loc.symbol().Get()->AsFunction());

  // Top stack frame.
  EXPECT_FALSE(stack[0]->IsInline());
  EXPECT_EQ(stack[0], stack[0]->GetPhysicalFrame());
  EXPECT_EQ(kTopAddr, stack[0]->GetAddress());
  loc = stack[0]->GetLocation();
  EXPECT_EQ(kTopAddr, loc.address());
  EXPECT_EQ(top_line, loc.file_line());
  EXPECT_EQ(top_func.get(), loc.symbol().Get()->AsFunction());
}

TEST_F(StackTest, InlineHiding) {
  constexpr uint64_t kTopSP = 0x2000;
  constexpr uint64_t kBottomSP = 0x2020;

  // Create two physical frames.
  debug_ipc::StackFrame phys_top_record(0x1000, kTopSP, kTopSP);
  Location top_location(Location::State::kSymbolized, phys_top_record.ip);
  debug_ipc::StackFrame phys_bottom_record(0x1020, kBottomSP, kBottomSP);
  Location bottom_location(Location::State::kSymbolized, phys_bottom_record.ip);

  auto phys_top = std::make_unique<MockFrame>(nullptr, nullptr, phys_top_record,
                                              top_location);
  auto phys_bottom = std::make_unique<MockFrame>(
      nullptr, nullptr, phys_bottom_record, bottom_location);

  std::vector<std::unique_ptr<Frame>> frames;

  // Top frame has two inline functions expanded on top of it.
  frames.push_back(std::make_unique<MockFrame>(
      nullptr, nullptr, phys_top_record, top_location, phys_top.get()));
  frames.push_back(std::make_unique<MockFrame>(
      nullptr, nullptr, phys_top_record, top_location, phys_top.get()));

  // Physical top frame below those.
  frames.push_back(std::move(phys_top));

  // Bottom frame has no inline frame.
  frames.push_back(std::move(phys_bottom));

  MockStackDelegate delegate;
  Stack stack(&delegate);
  delegate.set_stack(&stack);

  // With no frames, there should be no inline frames.
  EXPECT_EQ(0u, stack.GetTopInlineFrameCount());

  // Setting the frames should give the two inline ones, followed by two
  // physical ones.
  stack.SetFramesForTest(std::move(frames), true);
  EXPECT_EQ(4u, stack.size());
  EXPECT_EQ(2u, stack.GetTopInlineFrameCount());

  // Hide both inline frames, the top frame should now be the physical one.
  stack.SetHideTopInlineFrameCount(2);
  EXPECT_EQ(2u, stack.size());
  EXPECT_EQ(2u, stack.GetTopInlineFrameCount());
}

}  // namespace zxdb