| // Copyright 2012 the V8 project authors. All rights reserved. |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include <include/v8.h> |
| |
| #include <include/libplatform/libplatform.h> |
| |
| #include <assert.h> |
| #include <fcntl.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| /** |
| * This sample program shows how to implement a simple javascript shell |
| * based on V8. This includes initializing V8 with command line options, |
| * creating global functions, compiling and executing strings. |
| * |
| * For a more sophisticated shell, consider using the debug shell D8. |
| */ |
| |
| |
| v8::Local<v8::Context> CreateShellContext(v8::Isolate* isolate); |
| void RunShell(v8::Local<v8::Context> context, v8::Platform* platform); |
| int RunMain(v8::Isolate* isolate, v8::Platform* platform, int argc, |
| char* argv[]); |
| bool ExecuteString(v8::Isolate* isolate, v8::Local<v8::String> source, |
| v8::Local<v8::Value> name, bool print_result, |
| bool report_exceptions); |
| void Print(const v8::FunctionCallbackInfo<v8::Value>& args); |
| void Read(const v8::FunctionCallbackInfo<v8::Value>& args); |
| void Load(const v8::FunctionCallbackInfo<v8::Value>& args); |
| void Quit(const v8::FunctionCallbackInfo<v8::Value>& args); |
| void Version(const v8::FunctionCallbackInfo<v8::Value>& args); |
| v8::MaybeLocal<v8::String> ReadFile(v8::Isolate* isolate, const char* name); |
| void ReportException(v8::Isolate* isolate, v8::TryCatch* handler); |
| |
| |
| static bool run_shell; |
| |
| |
| int main(int argc, char* argv[]) { |
| v8::V8::InitializeICUDefaultLocation(argv[0]); |
| v8::V8::InitializeExternalStartupData(argv[0]); |
| std::unique_ptr<v8::Platform> platform = v8::platform::NewDefaultPlatform(); |
| v8::V8::InitializePlatform(platform.get()); |
| v8::V8::Initialize(); |
| v8::V8::SetFlagsFromCommandLine(&argc, argv, true); |
| v8::Isolate::CreateParams create_params; |
| create_params.array_buffer_allocator = |
| v8::ArrayBuffer::Allocator::NewDefaultAllocator(); |
| v8::Isolate* isolate = v8::Isolate::New(create_params); |
| run_shell = (argc == 1); |
| int result; |
| { |
| v8::Isolate::Scope isolate_scope(isolate); |
| v8::HandleScope handle_scope(isolate); |
| v8::Local<v8::Context> context = CreateShellContext(isolate); |
| if (context.IsEmpty()) { |
| fprintf(stderr, "Error creating context\n"); |
| return 1; |
| } |
| v8::Context::Scope context_scope(context); |
| result = RunMain(isolate, platform.get(), argc, argv); |
| if (run_shell) RunShell(context, platform.get()); |
| } |
| isolate->Dispose(); |
| v8::V8::Dispose(); |
| v8::V8::ShutdownPlatform(); |
| delete create_params.array_buffer_allocator; |
| return result; |
| } |
| |
| |
| // Extracts a C string from a V8 Utf8Value. |
| const char* ToCString(const v8::String::Utf8Value& value) { |
| return *value ? *value : "<string conversion failed>"; |
| } |
| |
| |
| // Creates a new execution environment containing the built-in |
| // functions. |
| v8::Local<v8::Context> CreateShellContext(v8::Isolate* isolate) { |
| // Create a template for the global object. |
| v8::Local<v8::ObjectTemplate> global = v8::ObjectTemplate::New(isolate); |
| // Bind the global 'print' function to the C++ Print callback. |
| global->Set( |
| v8::String::NewFromUtf8(isolate, "print", v8::NewStringType::kNormal) |
| .ToLocalChecked(), |
| v8::FunctionTemplate::New(isolate, Print)); |
| // Bind the global 'read' function to the C++ Read callback. |
| global->Set(v8::String::NewFromUtf8( |
| isolate, "read", v8::NewStringType::kNormal).ToLocalChecked(), |
| v8::FunctionTemplate::New(isolate, Read)); |
| // Bind the global 'load' function to the C++ Load callback. |
| global->Set(v8::String::NewFromUtf8( |
| isolate, "load", v8::NewStringType::kNormal).ToLocalChecked(), |
| v8::FunctionTemplate::New(isolate, Load)); |
| // Bind the 'quit' function |
| global->Set(v8::String::NewFromUtf8( |
| isolate, "quit", v8::NewStringType::kNormal).ToLocalChecked(), |
| v8::FunctionTemplate::New(isolate, Quit)); |
| // Bind the 'version' function |
| global->Set( |
| v8::String::NewFromUtf8(isolate, "version", v8::NewStringType::kNormal) |
| .ToLocalChecked(), |
| v8::FunctionTemplate::New(isolate, Version)); |
| |
| return v8::Context::New(isolate, NULL, global); |
| } |
| |
| |
| // The callback that is invoked by v8 whenever the JavaScript 'print' |
| // function is called. Prints its arguments on stdout separated by |
| // spaces and ending with a newline. |
| void Print(const v8::FunctionCallbackInfo<v8::Value>& args) { |
| bool first = true; |
| for (int i = 0; i < args.Length(); i++) { |
| v8::HandleScope handle_scope(args.GetIsolate()); |
| if (first) { |
| first = false; |
| } else { |
| printf(" "); |
| } |
| v8::String::Utf8Value str(args.GetIsolate(), args[i]); |
| const char* cstr = ToCString(str); |
| printf("%s", cstr); |
| } |
| printf("\n"); |
| fflush(stdout); |
| } |
| |
| |
| // The callback that is invoked by v8 whenever the JavaScript 'read' |
| // function is called. This function loads the content of the file named in |
| // the argument into a JavaScript string. |
| void Read(const v8::FunctionCallbackInfo<v8::Value>& args) { |
| if (args.Length() != 1) { |
| args.GetIsolate()->ThrowException( |
| v8::String::NewFromUtf8(args.GetIsolate(), "Bad parameters", |
| v8::NewStringType::kNormal).ToLocalChecked()); |
| return; |
| } |
| v8::String::Utf8Value file(args.GetIsolate(), args[0]); |
| if (*file == NULL) { |
| args.GetIsolate()->ThrowException( |
| v8::String::NewFromUtf8(args.GetIsolate(), "Error loading file", |
| v8::NewStringType::kNormal).ToLocalChecked()); |
| return; |
| } |
| v8::Local<v8::String> source; |
| if (!ReadFile(args.GetIsolate(), *file).ToLocal(&source)) { |
| args.GetIsolate()->ThrowException( |
| v8::String::NewFromUtf8(args.GetIsolate(), "Error loading file", |
| v8::NewStringType::kNormal).ToLocalChecked()); |
| return; |
| } |
| |
| args.GetReturnValue().Set(source); |
| } |
| |
| // The callback that is invoked by v8 whenever the JavaScript 'load' |
| // function is called. Loads, compiles and executes its argument |
| // JavaScript file. |
| void Load(const v8::FunctionCallbackInfo<v8::Value>& args) { |
| for (int i = 0; i < args.Length(); i++) { |
| v8::HandleScope handle_scope(args.GetIsolate()); |
| v8::String::Utf8Value file(args.GetIsolate(), args[i]); |
| if (*file == NULL) { |
| args.GetIsolate()->ThrowException( |
| v8::String::NewFromUtf8(args.GetIsolate(), "Error loading file", |
| v8::NewStringType::kNormal).ToLocalChecked()); |
| return; |
| } |
| v8::Local<v8::String> source; |
| if (!ReadFile(args.GetIsolate(), *file).ToLocal(&source)) { |
| args.GetIsolate()->ThrowException( |
| v8::String::NewFromUtf8(args.GetIsolate(), "Error loading file", |
| v8::NewStringType::kNormal).ToLocalChecked()); |
| return; |
| } |
| if (!ExecuteString(args.GetIsolate(), source, args[i], false, false)) { |
| args.GetIsolate()->ThrowException( |
| v8::String::NewFromUtf8(args.GetIsolate(), "Error executing file", |
| v8::NewStringType::kNormal).ToLocalChecked()); |
| return; |
| } |
| } |
| } |
| |
| |
| // The callback that is invoked by v8 whenever the JavaScript 'quit' |
| // function is called. Quits. |
| void Quit(const v8::FunctionCallbackInfo<v8::Value>& args) { |
| // If not arguments are given args[0] will yield undefined which |
| // converts to the integer value 0. |
| int exit_code = |
| args[0]->Int32Value(args.GetIsolate()->GetCurrentContext()).FromMaybe(0); |
| fflush(stdout); |
| fflush(stderr); |
| exit(exit_code); |
| } |
| |
| |
| void Version(const v8::FunctionCallbackInfo<v8::Value>& args) { |
| args.GetReturnValue().Set( |
| v8::String::NewFromUtf8(args.GetIsolate(), v8::V8::GetVersion(), |
| v8::NewStringType::kNormal).ToLocalChecked()); |
| } |
| |
| |
| // Reads a file into a v8 string. |
| v8::MaybeLocal<v8::String> ReadFile(v8::Isolate* isolate, const char* name) { |
| FILE* file = fopen(name, "rb"); |
| if (file == NULL) return v8::MaybeLocal<v8::String>(); |
| |
| 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;) { |
| i += fread(&chars[i], 1, size - i, file); |
| if (ferror(file)) { |
| fclose(file); |
| return v8::MaybeLocal<v8::String>(); |
| } |
| } |
| fclose(file); |
| v8::MaybeLocal<v8::String> result = v8::String::NewFromUtf8( |
| isolate, chars, v8::NewStringType::kNormal, static_cast<int>(size)); |
| delete[] chars; |
| return result; |
| } |
| |
| |
| // Process remaining command line arguments and execute files |
| int RunMain(v8::Isolate* isolate, v8::Platform* platform, int argc, |
| char* argv[]) { |
| for (int i = 1; i < argc; i++) { |
| const char* str = argv[i]; |
| if (strcmp(str, "--shell") == 0) { |
| run_shell = true; |
| } else if (strcmp(str, "-f") == 0) { |
| // Ignore any -f flags for compatibility with the other stand- |
| // alone JavaScript engines. |
| continue; |
| } else if (strncmp(str, "--", 2) == 0) { |
| fprintf(stderr, |
| "Warning: unknown flag %s.\nTry --help for options\n", str); |
| } else if (strcmp(str, "-e") == 0 && i + 1 < argc) { |
| // Execute argument given to -e option directly. |
| v8::Local<v8::String> file_name = |
| v8::String::NewFromUtf8(isolate, "unnamed", |
| v8::NewStringType::kNormal).ToLocalChecked(); |
| v8::Local<v8::String> source; |
| if (!v8::String::NewFromUtf8(isolate, argv[++i], |
| v8::NewStringType::kNormal) |
| .ToLocal(&source)) { |
| return 1; |
| } |
| bool success = ExecuteString(isolate, source, file_name, false, true); |
| while (v8::platform::PumpMessageLoop(platform, isolate)) continue; |
| if (!success) return 1; |
| } else { |
| // Use all other arguments as names of files to load and run. |
| v8::Local<v8::String> file_name = |
| v8::String::NewFromUtf8(isolate, str, v8::NewStringType::kNormal) |
| .ToLocalChecked(); |
| v8::Local<v8::String> source; |
| if (!ReadFile(isolate, str).ToLocal(&source)) { |
| fprintf(stderr, "Error reading '%s'\n", str); |
| continue; |
| } |
| bool success = ExecuteString(isolate, source, file_name, false, true); |
| while (v8::platform::PumpMessageLoop(platform, isolate)) continue; |
| if (!success) return 1; |
| } |
| } |
| return 0; |
| } |
| |
| |
| // The read-eval-execute loop of the shell. |
| void RunShell(v8::Local<v8::Context> context, v8::Platform* platform) { |
| fprintf(stderr, "V8 version %s [sample shell]\n", v8::V8::GetVersion()); |
| static const int kBufferSize = 256; |
| // Enter the execution environment before evaluating any code. |
| v8::Context::Scope context_scope(context); |
| v8::Local<v8::String> name( |
| v8::String::NewFromUtf8(context->GetIsolate(), "(shell)", |
| v8::NewStringType::kNormal).ToLocalChecked()); |
| while (true) { |
| char buffer[kBufferSize]; |
| fprintf(stderr, "> "); |
| char* str = fgets(buffer, kBufferSize, stdin); |
| if (str == NULL) break; |
| v8::HandleScope handle_scope(context->GetIsolate()); |
| ExecuteString( |
| context->GetIsolate(), |
| v8::String::NewFromUtf8(context->GetIsolate(), str, |
| v8::NewStringType::kNormal).ToLocalChecked(), |
| name, true, true); |
| while (v8::platform::PumpMessageLoop(platform, context->GetIsolate())) |
| continue; |
| } |
| fprintf(stderr, "\n"); |
| } |
| |
| |
| // Executes a string within the current v8 context. |
| bool ExecuteString(v8::Isolate* isolate, v8::Local<v8::String> source, |
| v8::Local<v8::Value> name, bool print_result, |
| bool report_exceptions) { |
| v8::HandleScope handle_scope(isolate); |
| v8::TryCatch try_catch(isolate); |
| v8::ScriptOrigin origin(name); |
| v8::Local<v8::Context> context(isolate->GetCurrentContext()); |
| v8::Local<v8::Script> script; |
| if (!v8::Script::Compile(context, source, &origin).ToLocal(&script)) { |
| // Print errors that happened during compilation. |
| if (report_exceptions) |
| ReportException(isolate, &try_catch); |
| return false; |
| } else { |
| v8::Local<v8::Value> result; |
| if (!script->Run(context).ToLocal(&result)) { |
| assert(try_catch.HasCaught()); |
| // Print errors that happened during execution. |
| if (report_exceptions) |
| ReportException(isolate, &try_catch); |
| return false; |
| } else { |
| assert(!try_catch.HasCaught()); |
| if (print_result && !result->IsUndefined()) { |
| // If all went well and the result wasn't undefined then print |
| // the returned value. |
| v8::String::Utf8Value str(isolate, result); |
| const char* cstr = ToCString(str); |
| printf("%s\n", cstr); |
| } |
| return true; |
| } |
| } |
| } |
| |
| |
| void ReportException(v8::Isolate* isolate, v8::TryCatch* try_catch) { |
| v8::HandleScope handle_scope(isolate); |
| v8::String::Utf8Value exception(isolate, try_catch->Exception()); |
| const char* exception_string = ToCString(exception); |
| v8::Local<v8::Message> message = try_catch->Message(); |
| if (message.IsEmpty()) { |
| // V8 didn't provide any extra information about this error; just |
| // print the exception. |
| fprintf(stderr, "%s\n", exception_string); |
| } else { |
| // Print (filename):(line number): (message). |
| v8::String::Utf8Value filename(isolate, |
| message->GetScriptOrigin().ResourceName()); |
| v8::Local<v8::Context> context(isolate->GetCurrentContext()); |
| const char* filename_string = ToCString(filename); |
| int linenum = message->GetLineNumber(context).FromJust(); |
| fprintf(stderr, "%s:%i: %s\n", filename_string, linenum, exception_string); |
| // Print line of source code. |
| v8::String::Utf8Value sourceline( |
| isolate, message->GetSourceLine(context).ToLocalChecked()); |
| const char* sourceline_string = ToCString(sourceline); |
| fprintf(stderr, "%s\n", sourceline_string); |
| // Print wavy underline (GetUnderline is deprecated). |
| int start = message->GetStartColumn(context).FromJust(); |
| for (int i = 0; i < start; i++) { |
| fprintf(stderr, " "); |
| } |
| int end = message->GetEndColumn(context).FromJust(); |
| for (int i = start; i < end; i++) { |
| fprintf(stderr, "^"); |
| } |
| fprintf(stderr, "\n"); |
| v8::Local<v8::Value> stack_trace_string; |
| if (try_catch->StackTrace(context).ToLocal(&stack_trace_string) && |
| stack_trace_string->IsString() && |
| v8::Local<v8::String>::Cast(stack_trace_string)->Length() > 0) { |
| v8::String::Utf8Value stack_trace(isolate, stack_trace_string); |
| const char* stack_trace_string = ToCString(stack_trace); |
| fprintf(stderr, "%s\n", stack_trace_string); |
| } |
| } |
| } |
