v8/test/cctest/wasm/test-liftoff-inspection.cc

// Copyright 2019 the V8 project 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 "src/wasm/baseline/liftoff-compiler.h"
#include "src/wasm/wasm-debug.h"
#include "test/cctest/cctest.h"
#include "test/cctest/wasm/wasm-run-utils.h"
#include "test/common/wasm/test-signatures.h"
#include "test/common/wasm/wasm-macro-gen.h"

namespace v8 {
namespace internal {
namespace wasm {

namespace {

class LiftoffCompileEnvironment {
 public:
  LiftoffCompileEnvironment()
      : isolate_(CcTest::InitIsolateOnce()),
        handle_scope_(isolate_),
        zone_(isolate_->allocator(), ZONE_NAME),
        wasm_runner_(nullptr, TestExecutionTier::kLiftoff, 0,
                     kRuntimeExceptionSupport, kNoLowerSimd) {
    // Add a table of length 1, for indirect calls.
    wasm_runner_.builder().AddIndirectFunctionTable(nullptr, 1);
    // Set tiered down such that we generate debugging code.
    wasm_runner_.builder().SetTieredDown();
  }

  struct TestFunction {
    WasmCode* code;
    FunctionBody body;
  };

  void CheckDeterministicCompilation(
      std::initializer_list<ValueType> return_types,
      std::initializer_list<ValueType> param_types,
      std::initializer_list<uint8_t> raw_function_bytes) {
    auto test_func = AddFunction(return_types, param_types, raw_function_bytes);

    // Now compile the function with Liftoff two times.
    CompilationEnv env = wasm_runner_.builder().CreateCompilationEnv();
    WasmFeatures detected1;
    WasmFeatures detected2;
    WasmCompilationResult result1 = ExecuteLiftoffCompilation(
        isolate_->allocator(), &env, test_func.body, test_func.code->index(),
        kNoDebugging, isolate_->counters(), &detected1);
    WasmCompilationResult result2 = ExecuteLiftoffCompilation(
        isolate_->allocator(), &env, test_func.body, test_func.code->index(),
        kNoDebugging, isolate_->counters(), &detected2);

    CHECK(result1.succeeded());
    CHECK(result2.succeeded());

    // Check that the generated code matches.
    auto code1 =
        VectorOf(result1.code_desc.buffer, result1.code_desc.instr_size);
    auto code2 =
        VectorOf(result2.code_desc.buffer, result2.code_desc.instr_size);
    CHECK_EQ(code1, code2);
    CHECK_EQ(detected1, detected2);
  }

  std::unique_ptr<DebugSideTable> GenerateDebugSideTable(
      std::initializer_list<ValueType> return_types,
      std::initializer_list<ValueType> param_types,
      std::initializer_list<uint8_t> raw_function_bytes,
      std::vector<int> breakpoints = {}) {
    auto test_func = AddFunction(return_types, param_types, raw_function_bytes);

    CompilationEnv env = wasm_runner_.builder().CreateCompilationEnv();
    WasmFeatures detected;
    std::unique_ptr<DebugSideTable> debug_side_table_via_compilation;
    auto result = ExecuteLiftoffCompilation(
        CcTest::i_isolate()->allocator(), &env, test_func.body, 0,
        kForDebugging, nullptr, &detected, VectorOf(breakpoints),
        &debug_side_table_via_compilation);
    CHECK(result.succeeded());

    // If there are no breakpoint, then {ExecuteLiftoffCompilation} should
    // provide the same debug side table.
    if (breakpoints.empty()) {
      std::unique_ptr<DebugSideTable> debug_side_table =
          GenerateLiftoffDebugSideTable(test_func.code);
      CheckTableEquals(*debug_side_table, *debug_side_table_via_compilation);
    }

    return debug_side_table_via_compilation;
  }

  TestingModuleBuilder* builder() { return &wasm_runner_.builder(); }

 private:
  static void CheckTableEquals(const DebugSideTable& a,
                               const DebugSideTable& b) {
    CHECK_EQ(a.num_locals(), b.num_locals());
    CHECK_EQ(a.entries().size(), b.entries().size());
    CHECK(std::equal(a.entries().begin(), a.entries().end(),
                     b.entries().begin(), b.entries().end(),
                     &CheckEntryEquals));
  }

  static bool CheckEntryEquals(const DebugSideTable::Entry& a,
                               const DebugSideTable::Entry& b) {
    CHECK_EQ(a.pc_offset(), b.pc_offset());
    CHECK_EQ(a.stack_height(), b.stack_height());
    CHECK_EQ(a.changed_values(), b.changed_values());
    return true;
  }

  FunctionSig* AddSig(std::initializer_list<ValueType> return_types,
                      std::initializer_list<ValueType> param_types) {
    ValueType* storage =
        zone_.NewArray<ValueType>(return_types.size() + param_types.size());
    std::copy(return_types.begin(), return_types.end(), storage);
    std::copy(param_types.begin(), param_types.end(),
              storage + return_types.size());
    FunctionSig* sig = zone_.New<FunctionSig>(return_types.size(),
                                              param_types.size(), storage);
    return sig;
  }

  TestFunction AddFunction(std::initializer_list<ValueType> return_types,
                           std::initializer_list<ValueType> param_types,
                           std::initializer_list<uint8_t> function_bytes) {
    FunctionSig* sig = AddSig(return_types, param_types);
    // Compile the function so we can get the WasmCode* which is later used to
    // generate the debug side table lazily.
    auto& func_compiler = wasm_runner_.NewFunction(sig, "f");
    func_compiler.Build(function_bytes.begin(), function_bytes.end());

    WasmCode* code =
        wasm_runner_.builder().GetFunctionCode(func_compiler.function_index());

    // Get the wire bytes created by the function compiler (including locals
    // declaration and the trailing "end" opcode).
    NativeModule* native_module = code->native_module();
    auto* function = &native_module->module()->functions[code->index()];
    Vector<const uint8_t> function_wire_bytes =
        native_module->wire_bytes().SubVector(function->code.offset(),
                                              function->code.end_offset());

    FunctionBody body{sig, 0, function_wire_bytes.begin(),
                      function_wire_bytes.end()};
    return {code, body};
  }

  Isolate* isolate_;
  HandleScope handle_scope_;
  Zone zone_;
  // wasm_runner_ is used to build actual code objects needed to request lazy
  // generation of debug side tables.
  WasmRunnerBase wasm_runner_;
  WasmCodeRefScope code_ref_scope_;
};

struct DebugSideTableEntry {
  int stack_height;
  std::vector<DebugSideTable::Entry::Value> changed_values;

  // Construct via vector or implicitly via initializer list.
  DebugSideTableEntry(int stack_height,
                      std::vector<DebugSideTable::Entry::Value> changed_values)
      : stack_height(stack_height), changed_values(std::move(changed_values)) {}

  DebugSideTableEntry(
      int stack_height,
      std::initializer_list<DebugSideTable::Entry::Value> changed_values)
      : stack_height(stack_height), changed_values(changed_values) {}

  bool operator==(const DebugSideTableEntry& other) const {
    return stack_height == other.stack_height &&
           std::equal(changed_values.begin(), changed_values.end(),
                      other.changed_values.begin(), other.changed_values.end(),
                      CheckValueEquals);
  }

  // Check for equality, but ignore exact register and stack offset.
  static bool CheckValueEquals(const DebugSideTable::Entry::Value& a,
                               const DebugSideTable::Entry::Value& b) {
    return a.index == b.index && a.type == b.type && a.storage == b.storage &&
           (a.storage != DebugSideTable::Entry::kConstant ||
            a.i32_const == b.i32_const);
  }
};

// Debug builds will print the vector of DebugSideTableEntry.
#ifdef DEBUG
std::ostream& operator<<(std::ostream& out, const DebugSideTableEntry& entry) {
  out << "stack height " << entry.stack_height << ", changed: {";
  const char* comma = "";
  for (auto& v : entry.changed_values) {
    out << comma << v.index << ":" << v.type.name() << " ";
    switch (v.storage) {
      case DebugSideTable::Entry::kConstant:
        out << "const:" << v.i32_const;
        break;
      case DebugSideTable::Entry::kRegister:
        out << "reg";
        break;
      case DebugSideTable::Entry::kStack:
        out << "stack";
        break;
    }
    comma = ", ";
  }
  return out << "}";
}

std::ostream& operator<<(std::ostream& out,
                         const std::vector<DebugSideTableEntry>& entries) {
  return out << PrintCollection(entries);
}
#endif  // DEBUG

// Named constructors to make the tests more readable.
DebugSideTable::Entry::Value Constant(int index, ValueType type,
                                      int32_t constant) {
  DebugSideTable::Entry::Value value;
  value.index = index;
  value.type = type;
  value.storage = DebugSideTable::Entry::kConstant;
  value.i32_const = constant;
  return value;
}
DebugSideTable::Entry::Value Register(int index, ValueType type) {
  DebugSideTable::Entry::Value value;
  value.index = index;
  value.type = type;
  value.storage = DebugSideTable::Entry::kRegister;
  return value;
}
DebugSideTable::Entry::Value Stack(int index, ValueType type) {
  DebugSideTable::Entry::Value value;
  value.index = index;
  value.type = type;
  value.storage = DebugSideTable::Entry::kStack;
  return value;
}

void CheckDebugSideTable(std::vector<DebugSideTableEntry> expected_entries,
                         const wasm::DebugSideTable* debug_side_table) {
  std::vector<DebugSideTableEntry> entries;
  for (auto& entry : debug_side_table->entries()) {
    entries.emplace_back(
        entry.stack_height(),
        std::vector<DebugSideTable::Entry::Value>{
            entry.changed_values().begin(), entry.changed_values().end()});
  }
  CHECK_EQ(expected_entries, entries);
}

}  // namespace

TEST(Liftoff_deterministic_simple) {
  LiftoffCompileEnvironment env;
  env.CheckDeterministicCompilation(
      {kWasmI32}, {kWasmI32, kWasmI32},
      {WASM_I32_ADD(WASM_LOCAL_GET(0), WASM_LOCAL_GET(1))});
}

TEST(Liftoff_deterministic_call) {
  LiftoffCompileEnvironment env;
  env.CheckDeterministicCompilation(
      {kWasmI32}, {kWasmI32},
      {WASM_I32_ADD(WASM_CALL_FUNCTION(0, WASM_LOCAL_GET(0)),
                    WASM_LOCAL_GET(0))});
}

TEST(Liftoff_deterministic_indirect_call) {
  LiftoffCompileEnvironment env;
  env.CheckDeterministicCompilation(
      {kWasmI32}, {kWasmI32},
      {WASM_I32_ADD(WASM_CALL_INDIRECT(0, WASM_LOCAL_GET(0), WASM_I32V_1(47)),
                    WASM_LOCAL_GET(0))});
}

TEST(Liftoff_deterministic_loop) {
  LiftoffCompileEnvironment env;
  env.CheckDeterministicCompilation(
      {kWasmI32}, {kWasmI32},
      {WASM_LOOP(WASM_BR_IF(0, WASM_LOCAL_GET(0))), WASM_LOCAL_GET(0)});
}

TEST(Liftoff_deterministic_trap) {
  LiftoffCompileEnvironment env;
  env.CheckDeterministicCompilation(
      {kWasmI32}, {kWasmI32, kWasmI32},
      {WASM_I32_DIVS(WASM_LOCAL_GET(0), WASM_LOCAL_GET(1))});
}

TEST(Liftoff_debug_side_table_simple) {
  LiftoffCompileEnvironment env;
  auto debug_side_table = env.GenerateDebugSideTable(
      {kWasmI32}, {kWasmI32, kWasmI32},
      {WASM_I32_ADD(WASM_LOCAL_GET(0), WASM_LOCAL_GET(1))});
  CheckDebugSideTable(
      {
          // function entry, locals in registers.
          {2, {Register(0, kWasmI32), Register(1, kWasmI32)}},
          // OOL stack check, locals spilled, stack still empty.
          {2, {Stack(0, kWasmI32), Stack(1, kWasmI32)}},
      },
      debug_side_table.get());
}

TEST(Liftoff_debug_side_table_call) {
  LiftoffCompileEnvironment env;
  auto debug_side_table = env.GenerateDebugSideTable(
      {kWasmI32}, {kWasmI32},
      {WASM_I32_ADD(WASM_CALL_FUNCTION(0, WASM_LOCAL_GET(0)),
                    WASM_LOCAL_GET(0))});
  CheckDebugSideTable(
      {
          // function entry, local in register.
          {1, {Register(0, kWasmI32)}},
          // call, local spilled, stack empty.
          {1, {Stack(0, kWasmI32)}},
          // OOL stack check, local spilled as before, stack empty.
          {1, {}},
      },
      debug_side_table.get());
}

TEST(Liftoff_debug_side_table_call_const) {
  LiftoffCompileEnvironment env;
  constexpr int kConst = 13;
  auto debug_side_table = env.GenerateDebugSideTable(
      {kWasmI32}, {kWasmI32},
      {WASM_LOCAL_SET(0, WASM_I32V_1(kConst)),
       WASM_I32_ADD(WASM_CALL_FUNCTION(0, WASM_LOCAL_GET(0)),
                    WASM_LOCAL_GET(0))});
  CheckDebugSideTable(
      {
          // function entry, local in register.
          {1, {Register(0, kWasmI32)}},
          // call, local is kConst.
          {1, {Constant(0, kWasmI32, kConst)}},
          // OOL stack check, local spilled.
          {1, {Stack(0, kWasmI32)}},
      },
      debug_side_table.get());
}

TEST(Liftoff_debug_side_table_indirect_call) {
  LiftoffCompileEnvironment env;
  constexpr int kConst = 47;
  auto debug_side_table = env.GenerateDebugSideTable(
      {kWasmI32}, {kWasmI32},
      {WASM_I32_ADD(WASM_CALL_INDIRECT(0, WASM_I32V_1(47), WASM_LOCAL_GET(0)),
                    WASM_LOCAL_GET(0))});
  CheckDebugSideTable(
      {
          // function entry, local in register.
          {1, {Register(0, kWasmI32)}},
          // indirect call, local spilled, stack empty.
          {1, {Stack(0, kWasmI32)}},
          // OOL stack check, local still spilled.
          {1, {}},
          // OOL trap (invalid index), local still spilled, stack has {kConst}.
          {2, {Constant(1, kWasmI32, kConst)}},
          // OOL trap (sig mismatch), stack unmodified.
          {2, {}},
      },
      debug_side_table.get());
}

TEST(Liftoff_debug_side_table_loop) {
  LiftoffCompileEnvironment env;
  constexpr int kConst = 42;
  auto debug_side_table = env.GenerateDebugSideTable(
      {kWasmI32}, {kWasmI32},
      {WASM_I32V_1(kConst), WASM_LOOP(WASM_BR_IF(0, WASM_LOCAL_GET(0)))});
  CheckDebugSideTable(
      {
          // function entry, local in register.
          {1, {Register(0, kWasmI32)}},
          // OOL stack check, local spilled, stack empty.
          {1, {Stack(0, kWasmI32)}},
          // OOL loop stack check, local still spilled, stack has {kConst}.
          {2, {Constant(1, kWasmI32, kConst)}},
      },
      debug_side_table.get());
}

TEST(Liftoff_debug_side_table_trap) {
  LiftoffCompileEnvironment env;
  auto debug_side_table = env.GenerateDebugSideTable(
      {kWasmI32}, {kWasmI32, kWasmI32},
      {WASM_I32_DIVS(WASM_LOCAL_GET(0), WASM_LOCAL_GET(1))});
  CheckDebugSideTable(
      {
          // function entry, locals in registers.
          {2, {Register(0, kWasmI32), Register(1, kWasmI32)}},
          // OOL stack check, local spilled, stack empty.
          {2, {Stack(0, kWasmI32), Stack(1, kWasmI32)}},
          // OOL trap (div by zero), stack as before.
          {2, {}},
          // OOL trap (unrepresentable), stack as before.
          {2, {}},
      },
      debug_side_table.get());
}

TEST(Liftoff_breakpoint_simple) {
  LiftoffCompileEnvironment env;
  // Set two breakpoints. At both locations, values are live in registers.
  auto debug_side_table = env.GenerateDebugSideTable(
      {kWasmI32}, {kWasmI32, kWasmI32},
      {WASM_I32_ADD(WASM_LOCAL_GET(0), WASM_LOCAL_GET(1))},
      {
          1,  // break at beginning of function (first local.get)
          5   // break at i32.add
      });
  CheckDebugSideTable(
      {
          // First break point, locals in registers.
          {2, {Register(0, kWasmI32), Register(1, kWasmI32)}},
          // Second break point, locals unchanged, two register stack values.
          {4, {Register(2, kWasmI32), Register(3, kWasmI32)}},
          // OOL stack check, locals spilled, stack empty.
          {2, {Stack(0, kWasmI32), Stack(1, kWasmI32)}},
      },
      debug_side_table.get());
}

TEST(Liftoff_debug_side_table_catch_all) {
  EXPERIMENTAL_FLAG_SCOPE(eh);
  LiftoffCompileEnvironment env;
  TestSignatures sigs;
  int ex = env.builder()->AddException(sigs.v_v());
  ValueType exception_type = ValueType::Ref(HeapType::kExtern, kNonNullable);
  auto debug_side_table = env.GenerateDebugSideTable(
      {}, {},
      {WASM_TRY_CATCH_ALL_T(kWasmI32, WASM_STMTS(WASM_I32V(0), WASM_THROW(ex)),
                            WASM_I32V(1)),
       WASM_DROP},
      {
          18  // Break at the end of the try block.
      });
  CheckDebugSideTable(
      {
          // function entry.
          {0, {}},
          // breakpoint.
          {2, {Register(0, exception_type), Constant(1, kWasmI32, 1)}},
          {0, {}},
      },
      debug_side_table.get());
}

}  // namespace wasm
}  // namespace internal
}  // namespace v8