blob: a2303613d64c9ba818024bc08107537cd24341f0 [file] [log] [blame]
// Copyright 2006-2008 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 <errno.h>
#include <signal.h>
#include <stdio.h>
#include "include/libplatform/libplatform.h"
#include "src/assembler-arch.h"
#include "src/base/platform/platform.h"
#include "src/flags.h"
#include "src/msan.h"
#include "src/snapshot/natives.h"
#include "src/snapshot/partial-serializer.h"
#include "src/snapshot/snapshot.h"
#include "src/snapshot/startup-serializer.h"
namespace {
class SnapshotWriter {
public:
SnapshotWriter()
: snapshot_cpp_path_(nullptr), snapshot_blob_path_(nullptr) {}
void SetEmbeddedFile(const char* embedded_cpp_file) {
embedded_cpp_path_ = embedded_cpp_file;
}
void SetEmbeddedVariant(const char* embedded_variant) {
embedded_variant_ = embedded_variant;
}
void SetSnapshotFile(const char* snapshot_cpp_file) {
snapshot_cpp_path_ = snapshot_cpp_file;
}
void SetStartupBlobFile(const char* snapshot_blob_file) {
snapshot_blob_path_ = snapshot_blob_file;
}
void WriteSnapshot(v8::StartupData blob) const {
// TODO(crbug/633159): if we crash before the files have been fully created,
// we end up with a corrupted snapshot file. The build step would succeed,
// but the build target is unusable. Ideally we would write out temporary
// files and only move them to the final destination as last step.
i::Vector<const i::byte> blob_vector(
reinterpret_cast<const i::byte*>(blob.data), blob.raw_size);
MaybeWriteSnapshotFile(blob_vector);
MaybeWriteStartupBlob(blob_vector);
}
void WriteEmbedded(const i::EmbeddedData* blob) const {
MaybeWriteEmbeddedFile(blob);
}
private:
void MaybeWriteStartupBlob(const i::Vector<const i::byte>& blob) const {
if (!snapshot_blob_path_) return;
FILE* fp = GetFileDescriptorOrDie(snapshot_blob_path_);
size_t written = fwrite(blob.begin(), 1, blob.length(), fp);
fclose(fp);
if (written != static_cast<size_t>(blob.length())) {
i::PrintF("Writing snapshot file failed.. Aborting.\n");
remove(snapshot_blob_path_);
exit(1);
}
}
void MaybeWriteSnapshotFile(const i::Vector<const i::byte>& blob) const {
if (!snapshot_cpp_path_) return;
FILE* fp = GetFileDescriptorOrDie(snapshot_cpp_path_);
WriteSnapshotFilePrefix(fp);
WriteSnapshotFileData(fp, blob);
WriteSnapshotFileSuffix(fp);
fclose(fp);
}
static void WriteSnapshotFilePrefix(FILE* fp) {
fprintf(fp, "// Autogenerated snapshot file. Do not edit.\n\n");
fprintf(fp, "#include \"src/v8.h\"\n");
fprintf(fp, "#include \"src/base/platform/platform.h\"\n\n");
fprintf(fp, "#include \"src/snapshot/snapshot.h\"\n\n");
fprintf(fp, "namespace v8 {\n");
fprintf(fp, "namespace internal {\n\n");
}
static void WriteSnapshotFileSuffix(FILE* fp) {
fprintf(fp, "const v8::StartupData* Snapshot::DefaultSnapshotBlob() {\n");
fprintf(fp, " return &blob;\n");
fprintf(fp, "}\n\n");
fprintf(fp, "} // namespace internal\n");
fprintf(fp, "} // namespace v8\n");
}
static void WriteSnapshotFileData(FILE* fp,
const i::Vector<const i::byte>& blob) {
fprintf(fp, "static const byte blob_data[] = {\n");
WriteBinaryContentsAsCArray(fp, blob);
fprintf(fp, "};\n");
fprintf(fp, "static const int blob_size = %d;\n", blob.length());
fprintf(fp, "static const v8::StartupData blob =\n");
fprintf(fp, "{ (const char*) blob_data, blob_size };\n");
}
static void WriteBinaryContentsAsCArray(
FILE* fp, const i::Vector<const i::byte>& blob) {
for (int i = 0; i < blob.length(); i++) {
if ((i & 0x1F) == 0x1F) fprintf(fp, "\n");
if (i > 0) fprintf(fp, ",");
fprintf(fp, "%u", static_cast<unsigned char>(blob.at(i)));
}
fprintf(fp, "\n");
}
void MaybeWriteEmbeddedFile(const i::EmbeddedData* blob) const {
if (embedded_cpp_path_ == nullptr) return;
FILE* fp = GetFileDescriptorOrDie(embedded_cpp_path_);
WriteEmbeddedFilePrefix(fp);
WriteEmbeddedFileData(fp, blob, embedded_variant_);
WriteEmbeddedFileSuffix(fp, embedded_variant_);
fclose(fp);
}
static void WriteEmbeddedFilePrefix(FILE* fp) {
fprintf(fp, "// Autogenerated file. Do not edit.\n\n");
fprintf(fp, "#include <cstdint>\n\n");
fprintf(fp, "#include \"src/snapshot/macros.h\"\n\n");
fprintf(fp, "namespace v8 {\n");
fprintf(fp, "namespace internal {\n\n");
fprintf(fp, "namespace {\n\n");
}
static void WriteEmbeddedFileSuffix(FILE* fp, const char* embedded_variant) {
fprintf(fp, "} // namespace\n\n");
fprintf(fp,
"const uint8_t* %sEmbeddedBlob() { return "
"v8_%s_embedded_blob_; }\n",
embedded_variant, embedded_variant);
fprintf(fp,
"uint32_t %sEmbeddedBlobSize() { return "
"v8_embedded_blob_size_; }\n\n",
embedded_variant);
fprintf(fp, "} // namespace internal\n");
fprintf(fp, "} // namespace v8\n");
}
static void WriteEmbeddedFileData(FILE* fp, const i::EmbeddedData* blob,
const char* embedded_variant) {
fprintf(fp, "V8_EMBEDDED_TEXT_HEADER(v8_%s_embedded_blob_)\n",
embedded_variant);
#ifdef V8_OS_MACOSX
// Note: On some platforms (observed on mac64), inserting labels into the
// .byte stream causes the compiler to reorder symbols, invalidating stored
// offsets.
// We either need to avoid doing so, or stop relying on our own offset table
// and directly reference symbols instead. But there is another complication
// there since the chrome build process on mac verifies the order of symbols
// present in the binary.
// For now, the straight-forward solution seems to be to just emit a pure
// .byte stream on OSX.
WriteBinaryContentsAsByteDirective(fp, blob->data(), blob->size());
#else
WriteBinaryContentsAsByteDirective(fp, blob->data(),
i::EmbeddedData::RawDataOffset());
WriteBuiltins(fp, blob, embedded_variant);
#endif
fprintf(fp, "extern \"C\" const uint8_t v8_%s_embedded_blob_[];\n",
embedded_variant);
fprintf(fp, "static const uint32_t v8_embedded_blob_size_ = %d;\n\n",
blob->size());
}
static void WriteBuiltins(FILE* fp, const i::EmbeddedData* blob,
const char* embedded_variant) {
const bool is_default_variant =
std::strcmp(embedded_variant, "Default") == 0;
for (int i = 0; i < i::Builtins::builtin_count; i++) {
if (!blob->ContainsBuiltin(i)) continue;
// Labels created here will show up in backtraces. We check in
// Isolate::SetEmbeddedBlob that the blob layout remains unchanged, i.e.
// that labels do not insert bytes into the middle of the blob byte
// stream.
if (is_default_variant) {
// Create nicer symbol names for the default mode.
fprintf(fp, "__asm__(V8_ASM_LABEL(\"Builtins_%s\"));\n",
i::Builtins::name(i));
} else {
fprintf(fp, "__asm__(V8_ASM_LABEL(\"%s_Builtins_%s\"));\n",
embedded_variant, i::Builtins::name(i));
}
WriteBinaryContentsAsByteDirective(
fp,
reinterpret_cast<const uint8_t*>(blob->InstructionStartOfBuiltin(i)),
blob->PaddedInstructionSizeOfBuiltin(i));
}
fprintf(fp, "\n");
}
static void WriteBinaryContentsAsByteDirective(FILE* fp, const uint8_t* data,
uint32_t size) {
static const int kTextWidth = 80;
int current_line_length = 0;
int printed_chars;
fprintf(fp, "__asm__(\n");
for (uint32_t i = 0; i < size; i++) {
if (current_line_length == 0) {
printed_chars = fprintf(fp, "%s", " \".byte ");
DCHECK_LT(0, printed_chars);
current_line_length += printed_chars;
} else {
printed_chars = fprintf(fp, ",");
DCHECK_EQ(1, printed_chars);
current_line_length += printed_chars;
}
printed_chars = fprintf(fp, "0x%02x", data[i]);
DCHECK_LT(0, printed_chars);
current_line_length += printed_chars;
if (current_line_length + strlen(",0xFF\\n\"") > kTextWidth) {
fprintf(fp, "\\n\"\n");
current_line_length = 0;
}
}
if (current_line_length != 0) fprintf(fp, "\\n\"\n");
fprintf(fp, ");\n");
}
static FILE* GetFileDescriptorOrDie(const char* filename) {
FILE* fp = v8::base::OS::FOpen(filename, "wb");
if (fp == nullptr) {
i::PrintF("Unable to open file \"%s\" for writing.\n", filename);
exit(1);
}
return fp;
}
const char* embedded_cpp_path_ = nullptr;
const char* embedded_variant_ = "Default";
const char* snapshot_cpp_path_;
const char* snapshot_blob_path_;
};
char* GetExtraCode(char* filename, const char* description) {
if (filename == nullptr || strlen(filename) == 0) return nullptr;
::printf("Loading script for %s: %s\n", description, filename);
FILE* file = v8::base::OS::FOpen(filename, "rb");
if (file == nullptr) {
fprintf(stderr, "Failed to open '%s': errno %d\n", filename, errno);
exit(1);
}
fseek(file, 0, SEEK_END);
size_t size = ftell(file);
rewind(file);
char* chars = new char[size + 1];
chars[size] = '\0';
for (size_t i = 0; i < size;) {
size_t read = fread(&chars[i], 1, size - i, file);
if (ferror(file)) {
fprintf(stderr, "Failed to read '%s': errno %d\n", filename, errno);
exit(1);
}
i += read;
}
fclose(file);
return chars;
}
bool RunExtraCode(v8::Isolate* isolate, v8::Local<v8::Context> context,
const char* utf8_source, const char* name) {
v8::base::ElapsedTimer timer;
timer.Start();
v8::Context::Scope context_scope(context);
v8::TryCatch try_catch(isolate);
v8::Local<v8::String> source_string;
if (!v8::String::NewFromUtf8(isolate, utf8_source, v8::NewStringType::kNormal)
.ToLocal(&source_string)) {
return false;
}
v8::Local<v8::String> resource_name =
v8::String::NewFromUtf8(isolate, name, v8::NewStringType::kNormal)
.ToLocalChecked();
v8::ScriptOrigin origin(resource_name);
v8::ScriptCompiler::Source source(source_string, origin);
v8::Local<v8::Script> script;
if (!v8::ScriptCompiler::Compile(context, &source).ToLocal(&script))
return false;
if (script->Run(context).IsEmpty()) return false;
if (i::FLAG_profile_deserialization) {
i::PrintF("Executing custom snapshot script %s took %0.3f ms\n", name,
timer.Elapsed().InMillisecondsF());
}
timer.Stop();
CHECK(!try_catch.HasCaught());
return true;
}
v8::StartupData CreateSnapshotDataBlob(v8::SnapshotCreator* snapshot_creator,
const char* script_source = NULL) {
// Create a new isolate and a new context from scratch, optionally run
// a script to embed, and serialize to create a snapshot blob.
v8::StartupData result = {nullptr, 0};
v8::base::ElapsedTimer timer;
timer.Start();
{
v8::Isolate* isolate = snapshot_creator->GetIsolate();
{
v8::HandleScope scope(isolate);
v8::Local<v8::Context> context = v8::Context::New(isolate);
if (script_source != nullptr &&
!RunExtraCode(isolate, context, script_source, "<embedded>")) {
return result;
}
snapshot_creator->SetDefaultContext(context);
}
result = snapshot_creator->CreateBlob(
v8::SnapshotCreator::FunctionCodeHandling::kClear);
}
if (i::FLAG_profile_deserialization) {
i::PrintF("Creating snapshot took %0.3f ms\n",
timer.Elapsed().InMillisecondsF());
}
timer.Stop();
return result;
}
v8::StartupData WarmUpSnapshotDataBlob(v8::SnapshotCreator* snapshot_creator,
const char* warmup_source) {
CHECK_NOT_NULL(warmup_source);
// Use following steps to create a warmed up snapshot blob from a cold one:
// - Create a new isolate from the cold snapshot.
// - Create a new context to run the warmup script. This will trigger
// compilation of executed functions.
// - Create a new context. This context will be unpolluted.
// - Serialize the isolate and the second context into a new snapshot blob.
v8::StartupData result = {nullptr, 0};
v8::base::ElapsedTimer timer;
timer.Start();
{
v8::Isolate* isolate = snapshot_creator->GetIsolate();
{
v8::HandleScope scope(isolate);
v8::Local<v8::Context> context = v8::Context::New(isolate);
if (!RunExtraCode(isolate, context, warmup_source, "<warm-up>")) {
return result;
}
}
{
v8::HandleScope handle_scope(isolate);
isolate->ContextDisposedNotification(false);
v8::Local<v8::Context> context = v8::Context::New(isolate);
snapshot_creator->SetDefaultContext(context);
}
result = snapshot_creator->CreateBlob(
v8::SnapshotCreator::FunctionCodeHandling::kKeep);
}
if (i::FLAG_profile_deserialization) {
i::PrintF("Warming up snapshot took %0.3f ms\n",
timer.Elapsed().InMillisecondsF());
}
timer.Stop();
return result;
}
void WriteEmbeddedFile(v8::SnapshotCreator* creator, SnapshotWriter* writer) {
i::Isolate* isolate = reinterpret_cast<i::Isolate*>(creator->GetIsolate());
isolate->PrepareEmbeddedBlobForSerialization();
i::EmbeddedData embedded_blob = i::EmbeddedData::FromBlob();
writer->WriteEmbedded(&embedded_blob);
}
} // namespace
int main(int argc, char** argv) {
v8::base::EnsureConsoleOutput();
// Make mksnapshot runs predictable to create reproducible snapshots.
i::FLAG_predictable = true;
// Print the usage if an error occurs when parsing the command line
// flags or if the help flag is set.
int result = i::FlagList::SetFlagsFromCommandLine(&argc, argv, true);
if (result > 0 || (argc > 3) || i::FLAG_help) {
::printf("Usage: %s --startup_src=... --startup_blob=... [extras]\n",
argv[0]);
i::FlagList::PrintHelp();
return !i::FLAG_help;
}
i::CpuFeatures::Probe(true);
v8::V8::InitializeICUDefaultLocation(argv[0]);
std::unique_ptr<v8::Platform> platform = v8::platform::NewDefaultPlatform();
v8::V8::InitializePlatform(platform.get());
v8::V8::Initialize();
{
SnapshotWriter writer;
if (i::FLAG_startup_src) writer.SetSnapshotFile(i::FLAG_startup_src);
if (i::FLAG_startup_blob) writer.SetStartupBlobFile(i::FLAG_startup_blob);
if (i::FLAG_embedded_builtins) {
if (i::FLAG_embedded_src) writer.SetEmbeddedFile(i::FLAG_embedded_src);
if (i::FLAG_embedded_variant)
writer.SetEmbeddedVariant(i::FLAG_embedded_variant);
}
std::unique_ptr<char> embed_script(
GetExtraCode(argc >= 2 ? argv[1] : nullptr, "embedding"));
std::unique_ptr<char> warmup_script(
GetExtraCode(argc >= 3 ? argv[2] : nullptr, "warm up"));
v8::StartupData blob;
{
v8::Isolate* isolate = v8::Isolate::Allocate();
if (i::FLAG_embedded_builtins) {
// Set code range such that relative jumps for builtins to
// builtin calls in the snapshot are possible.
i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
size_t code_range_size =
i::kMaximalCodeRangeSize == 0
? i::kMaxPCRelativeCodeRangeInMB
: std::min(i::kMaximalCodeRangeSize / i::MB,
i::kMaxPCRelativeCodeRangeInMB);
i_isolate->heap()->ConfigureHeap(0, 0, code_range_size);
}
v8::SnapshotCreator snapshot_creator(isolate);
if (i::FLAG_embedded_builtins) {
// This process is a bit tricky since we might go on to make a second
// snapshot if a warmup script is passed. In that case, create the first
// snapshot without off-heap trampolines and only move code off-heap for
// the warmed-up snapshot.
if (!warmup_script) WriteEmbeddedFile(&snapshot_creator, &writer);
}
blob = CreateSnapshotDataBlob(&snapshot_creator, embed_script.get());
}
if (warmup_script) {
CHECK(blob.raw_size > 0 && blob.data != nullptr);
v8::StartupData cold = blob;
v8::SnapshotCreator snapshot_creator(nullptr, &cold);
if (i::FLAG_embedded_builtins) {
WriteEmbeddedFile(&snapshot_creator, &writer);
}
blob = WarmUpSnapshotDataBlob(&snapshot_creator, warmup_script.get());
delete[] cold.data;
}
CHECK(blob.data);
writer.WriteSnapshot(blob);
delete[] blob.data;
}
v8::V8::Dispose();
v8::V8::ShutdownPlatform();
return 0;
}