[wasm] Remove obsolete function name table

The function name table is not used any more since
https://chromiumcodereview.appspot.com/2424623002, so remove it.

R=titzer@chromium.org,ahaas@chromium.org

Review-Url: https://codereview.chromium.org/2451693002
Cr-Commit-Position: refs/heads/master@{#40552}

BUILD.gn

@@ -1722,8 +1722,6 @@ v8_source_set("v8_base") {
     "src/wasm/wasm-debug.h",
     "src/wasm/wasm-external-refs.cc",
     "src/wasm/wasm-external-refs.h",
-    "src/wasm/wasm-function-name-table.cc",
-    "src/wasm/wasm-function-name-table.h",
     "src/wasm/wasm-interpreter.cc",
     "src/wasm/wasm-interpreter.h",
     "src/wasm/wasm-js.cc",

src/v8.gyp

@@ -1262,8 +1262,6 @@
         'wasm/wasm-debug.h',
         'wasm/wasm-external-refs.cc',
         'wasm/wasm-external-refs.h',
-        'wasm/wasm-function-name-table.cc',
-        'wasm/wasm-function-name-table.h',
         'wasm/wasm-js.cc',
         'wasm/wasm-js.h',
         'wasm/wasm-macro-gen.h',

src/wasm/wasm-function-name-table.cc

-// Copyright 2016 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/wasm-function-name-table.h"
-
-#include "src/wasm/wasm-module.h"
-
-namespace v8 {
-namespace internal {
-namespace wasm {
-
-// Build an array with all function names. If there are N functions in the
-// module, then the first (kIntSize * (N+1)) bytes are integer entries.
-// The first integer entry encodes the number of functions in the module.
-// The entries 1 to N contain offsets into the second part of this array.
-// If a function is unnamed (not to be confused with an empty name), then the
-// integer entry is the negative offset of the next function name.
-// After these N+1 integer entries, the second part begins, which holds a
-// concatenation of all function names.
-Handle<ByteArray> BuildFunctionNamesTable(Isolate* isolate,
-                                          const WasmModule* module) {
-  uint64_t func_names_length = 0;
-  for (auto& func : module->functions) func_names_length += func.name_length;
-  int num_funcs_int = static_cast<int>(module->functions.size());
-  int current_offset = (num_funcs_int + 1) * kIntSize;
-  uint64_t total_array_length = current_offset + func_names_length;
-  int total_array_length_int = static_cast<int>(total_array_length);
-  // Check for overflow.
-  CHECK(total_array_length_int == total_array_length && num_funcs_int >= 0 &&
-        num_funcs_int == module->functions.size());
-  Handle<ByteArray> func_names_array =
-      isolate->factory()->NewByteArray(total_array_length_int, TENURED);
-  func_names_array->set_int(0, num_funcs_int);
-  int func_index = 0;
-  for (const WasmFunction& fun : module->functions) {
-    WasmName name = module->GetNameOrNull(&fun);
-    if (name.start() == nullptr) {
-      func_names_array->set_int(func_index + 1, -current_offset);
-    } else {
-      func_names_array->copy_in(current_offset,
-                                reinterpret_cast<const byte*>(name.start()),
-                                name.length());
-      func_names_array->set_int(func_index + 1, current_offset);
-      current_offset += name.length();
-    }
-    ++func_index;
-  }
-  return func_names_array;
-}
-
-MaybeHandle<String> GetWasmFunctionNameFromTable(
-    Handle<ByteArray> func_names_array, uint32_t func_index) {
-  uint32_t num_funcs = static_cast<uint32_t>(func_names_array->get_int(0));
-  DCHECK(static_cast<int>(num_funcs) >= 0);
-  Factory* factory = func_names_array->GetIsolate()->factory();
-  DCHECK(func_index < num_funcs);
-  int offset = func_names_array->get_int(func_index + 1);
-  if (offset < 0) return {};
-  int next_offset = func_index == num_funcs - 1
-                        ? func_names_array->length()
-                        : abs(func_names_array->get_int(func_index + 2));
-  ScopedVector<byte> buffer(next_offset - offset);
-  func_names_array->copy_out(offset, buffer.start(), next_offset - offset);
-  if (!unibrow::Utf8::Validate(buffer.start(), buffer.length())) return {};
-  return factory->NewStringFromUtf8(Vector<const char>::cast(buffer));
-}
-
-}  // namespace wasm
-}  // namespace internal
-}  // namespace v8

src/wasm/wasm-function-name-table.h

-// Copyright 2016 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.
-
-#ifndef V8_WASM_FUNCTION_NAME_TABLE_H_
-#define V8_WASM_FUNCTION_NAME_TABLE_H_
-
-#include "src/handles.h"
-#include "src/objects.h"
-
-namespace v8 {
-namespace internal {
-namespace wasm {
-
-// Forward declarations for some WASM data structures.
-struct WasmModule;
-
-// Encode all function names of the WasmModule into one ByteArray.
-Handle<ByteArray> BuildFunctionNamesTable(Isolate* isolate,
-                                          const WasmModule* module);
-
-// Extract the function name for the given func_index from the function name
-// table.
-// Returns a null handle if the respective function is unnamed (not to be
-// confused with empty names) or the function name is not a valid UTF-8 string.
-MaybeHandle<String> GetWasmFunctionNameFromTable(
-    Handle<ByteArray> wasm_names_table, uint32_t func_index);
-
-}  // namespace wasm
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_WASM_FUNCTION_NAME_TABLE_H_

src/wasm/wasm-module.cc

@@ -17,7 +17,6 @@
 #include "src/wasm/ast-decoder.h"
 #include "src/wasm/module-decoder.h"
 #include "src/wasm/wasm-debug.h"
-#include "src/wasm/wasm-function-name-table.h"
 #include "src/wasm/wasm-js.h"
 #include "src/wasm/wasm-module.h"
 #include "src/wasm/wasm-result.h"

test/cctest/BUILD.gn

@@ -190,7 +190,6 @@ v8_executable("cctest") {
     "wasm/test-run-wasm-module.cc",
     "wasm/test-run-wasm-relocation.cc",
     "wasm/test-run-wasm.cc",
-    "wasm/test-wasm-function-name-table.cc",
     "wasm/test-wasm-stack.cc",
     "wasm/test-wasm-trap-position.cc",
     "wasm/wasm-run-utils.h",

test/cctest/cctest.gyp

@@ -211,7 +211,6 @@
       'wasm/test-run-wasm-js.cc',
       'wasm/test-run-wasm-module.cc',
       'wasm/test-run-wasm-relocation.cc',
-      'wasm/test-wasm-function-name-table.cc',
       'wasm/test-wasm-stack.cc',
       'wasm/test-wasm-trap-position.cc',
       'wasm/wasm-run-utils.h',

test/cctest/wasm/test-wasm-function-name-table.cc

-// Copyright 2016 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/wasm-function-name-table.h"
-#include "src/wasm/wasm-module.h"
-
-#include "test/cctest/cctest.h"
-
-using namespace v8::internal;
-using namespace v8::internal::wasm;
-
-namespace {
-
-#define CHECK_STREQ(exp, found)                                                \
-  do {                                                                         \
-    Vector<const char> exp_ = (exp);                                           \
-    Vector<const char> found_ = (found);                                       \
-    if (V8_UNLIKELY(exp_.length() != found_.length() ||                        \
-                    memcmp(exp_.start(), found_.start(), exp_.length()))) {    \
-      V8_Fatal(__FILE__, __LINE__,                                             \
-               "Check failed: (%s) != (%s) ('%.*s' vs '%.*s').", #exp, #found, \
-               exp_.length(), exp_.start(), found_.length(), found_.start());  \
-    }                                                                          \
-  } while (0)
-
-void testFunctionNameTable(Vector<Vector<const char>> names) {
-  Isolate *isolate = CcTest::InitIsolateOnce();
-  HandleAndZoneScope scope;
-
-  WasmModule module;
-  std::vector<char> all_names;
-  // No name should have offset 0, because that encodes unnamed functions.
-  // In real wasm binary, offset 0 is impossible anyway.
-  all_names.push_back('\0');
-
-  uint32_t func_index = 0;
-  for (Vector<const char> name : names) {
-    size_t name_offset = name.start() ? all_names.size() : 0;
-    all_names.insert(all_names.end(), name.start(),
-                     name.start() + name.length());
-    // Make every second function name null-terminated.
-    if (func_index % 2) all_names.push_back('\0');
-    module.functions.push_back(
-        {nullptr, 0, 0, static_cast<uint32_t>(name_offset),
-         static_cast<uint32_t>(name.length()), 0, 0, false, false});
-    ++func_index;
-  }
-
-  module.module_start = reinterpret_cast<byte *>(all_names.data());
-  module.module_end = module.module_start + all_names.size();
-
-  Handle<Object> wasm_function_name_table =
-      BuildFunctionNamesTable(isolate, &module);
-  CHECK(wasm_function_name_table->IsByteArray());
-
-  func_index = 0;
-  for (Vector<const char> name : names) {
-    MaybeHandle<String> string = GetWasmFunctionNameFromTable(
-        Handle<ByteArray>::cast(wasm_function_name_table), func_index);
-    if (name.start()) {
-      CHECK(string.ToHandleChecked()->IsUtf8EqualTo(name));
-    } else {
-      CHECK(string.is_null());
-    }
-    ++func_index;
-  }
-}
-
-void testFunctionNameTable(Vector<const char *> names) {
-  std::vector<Vector<const char>> names_vec;
-  for (const char *name : names)
-    names_vec.push_back(name ? CStrVector(name) : Vector<const char>());
-  testFunctionNameTable(Vector<Vector<const char>>(
-      names_vec.data(), static_cast<int>(names_vec.size())));
-}
-
-}  // namespace
-
-TEST(NoFunctions) { testFunctionNameTable(Vector<Vector<const char>>()); }
-
-TEST(OneFunctions) {
-  const char *names[] = {"foo"};
-  testFunctionNameTable(ArrayVector(names));
-}
-
-TEST(ThreeFunctions) {
-  const char *names[] = {"foo", "bar", "baz"};
-  testFunctionNameTable(ArrayVector(names));
-}
-
-TEST(OneUnnamedFunction) {
-  const char *names[] = {""};
-  testFunctionNameTable(ArrayVector(names));
-}
-
-TEST(UnnamedFirstFunction) {
-  const char *names[] = {"", "bar", "baz"};
-  testFunctionNameTable(ArrayVector(names));
-}
-
-TEST(UnnamedLastFunction) {
-  const char *names[] = {"bar", "baz", ""};
-  testFunctionNameTable(ArrayVector(names));
-}
-
-TEST(ThreeUnnamedFunctions) {
-  const char *names[] = {"", "", ""};
-  testFunctionNameTable(ArrayVector(names));
-}
-
-TEST(UTF8Names) {
-  const char *names[] = {"↱fun↰", "↺", "alpha:α beta:β"};
-  testFunctionNameTable(ArrayVector(names));
-}
-
-TEST(UnnamedVsEmptyNames) {
-  const char *names[] = {"", nullptr, nullptr, ""};
-  testFunctionNameTable(ArrayVector(names));
-}