forked from nodejs/node
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathshell.cc
More file actions
397 lines (376 loc) · 15.5 KB
/
shell.cc
File metadata and controls
397 lines (376 loc) · 15.5 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
// 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 <assert.h>
#include <fcntl.h>
#include <include/libplatform/libplatform.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "include/v8-context.h"
#include "include/v8-exception.h"
#include "include/v8-initialization.h"
#include "include/v8-isolate.h"
#include "include/v8-local-handle.h"
#include "include/v8-script.h"
#include "include/v8-template.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::Global<v8::Context> CreateShellContext(v8::Isolate* isolate);
void RunShell(v8::Isolate* isolate, const v8::Global<v8::Context>& context,
v8::Platform* platform);
int RunMain(v8::Isolate* isolate, const v8::Global<v8::Context>& context,
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>& info);
void Read(const v8::FunctionCallbackInfo<v8::Value>& info);
void Load(const v8::FunctionCallbackInfo<v8::Value>& info);
void Quit(const v8::FunctionCallbackInfo<v8::Value>& info);
void Version(const v8::FunctionCallbackInfo<v8::Value>& info);
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::SetFlagsFromCommandLine(&argc, argv, true);
v8::V8::Initialize();
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::Global<v8::Context> context = CreateShellContext(isolate);
if (context.IsEmpty()) {
fprintf(stderr, "Error creating context\n");
return 1;
}
result = RunMain(isolate, context, platform.get(), argc, argv);
if (run_shell) RunShell(isolate, context, platform.get());
}
isolate->Dispose();
v8::V8::Dispose();
v8::V8::DisposePlatform();
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::Global<v8::Context> CreateShellContext(v8::Isolate* isolate) {
v8::HandleScope handle_scope(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(isolate, "print", v8::FunctionTemplate::New(isolate, Print));
// Bind the global 'read' function to the C++ Read callback.
global->Set(isolate, "read", v8::FunctionTemplate::New(isolate, Read));
// Bind the global 'load' function to the C++ Load callback.
global->Set(isolate, "load", v8::FunctionTemplate::New(isolate, Load));
// Bind the 'quit' function
global->Set(isolate, "quit", v8::FunctionTemplate::New(isolate, Quit));
// Bind the 'version' function
global->Set(isolate, "version", v8::FunctionTemplate::New(isolate, Version));
// Return the context.
v8::Local<v8::Context> context = v8::Context::New(isolate, nullptr, global);
return v8::Global<v8::Context>(isolate, context);
}
// 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>& info) {
bool first = true;
for (int i = 0; i < info.Length(); i++) {
v8::HandleScope handle_scope(info.GetIsolate());
if (first) {
first = false;
} else {
printf(" ");
}
v8::String::Utf8Value str(info.GetIsolate(), info[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>& info) {
if (info.Length() != 1) {
info.GetIsolate()->ThrowError("Bad parameters");
return;
}
v8::String::Utf8Value file(info.GetIsolate(), info[0]);
if (*file == nullptr) {
info.GetIsolate()->ThrowError("Error loading file");
return;
}
v8::Local<v8::String> source;
if (!ReadFile(info.GetIsolate(), *file).ToLocal(&source)) {
info.GetIsolate()->ThrowError("Error loading file");
return;
}
info.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>& info) {
for (int i = 0; i < info.Length(); i++) {
v8::HandleScope handle_scope(info.GetIsolate());
v8::String::Utf8Value file(info.GetIsolate(), info[i]);
if (*file == nullptr) {
info.GetIsolate()->ThrowError("Error loading file");
return;
}
v8::Local<v8::String> source;
if (!ReadFile(info.GetIsolate(), *file).ToLocal(&source)) {
info.GetIsolate()->ThrowError("Error loading file");
return;
}
if (!ExecuteString(info.GetIsolate(), source, info[i], false, false)) {
info.GetIsolate()->ThrowError("Error executing file");
return;
}
}
}
// The callback that is invoked by v8 whenever the JavaScript 'quit'
// function is called. Quits.
void Quit(const v8::FunctionCallbackInfo<v8::Value>& info) {
// If not arguments are given info[0] will yield undefined which
// converts to the integer value 0.
int exit_code =
info[0]->Int32Value(info.GetIsolate()->GetCurrentContext()).FromMaybe(0);
fflush(stdout);
fflush(stderr);
exit(exit_code);
}
// The callback that is invoked by v8 whenever the JavaScript 'version'
// function is called. Returns a string containing the current V8 version.
void Version(const v8::FunctionCallbackInfo<v8::Value>& info) {
info.GetReturnValue().Set(
v8::String::NewFromUtf8(info.GetIsolate(), v8::V8::GetVersion())
.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 == nullptr) return {};
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 {};
}
}
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, const v8::Global<v8::Context>& context,
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.
bool success;
{
// Enter the execution environment before evaluating any code.
v8::HandleScope handle_scope(isolate);
v8::Context::Scope context_scope(context.Get(isolate));
v8::Local<v8::String> file_name =
v8::String::NewFromUtf8Literal(isolate, "unnamed");
v8::Local<v8::String> source;
if (!v8::String::NewFromUtf8(isolate, argv[++i]).ToLocal(&source)) {
return 1;
}
success = ExecuteString(isolate, source, file_name, false, true);
}
// It is important not to pump the message loop when there are v8::Local
// handles on the stack, as this may trigger a stackless GC.
while (v8::platform::PumpMessageLoop(platform, isolate)) continue;
if (!success) return 1;
} else {
// Use all other arguments as names of files to load and run.
bool success;
{
// Enter the execution environment before evaluating any code.
v8::HandleScope handle_scope(isolate);
v8::Context::Scope context_scope(context.Get(isolate));
v8::Local<v8::String> file_name =
v8::String::NewFromUtf8(isolate, str).ToLocalChecked();
v8::Local<v8::String> source;
if (!ReadFile(isolate, str).ToLocal(&source)) {
fprintf(stderr, "Error reading '%s'\n", str);
continue;
}
success = ExecuteString(isolate, source, file_name, false, true);
}
// It is important not to pump the message loop when there are v8::Local
// handles on the stack, as this may trigger a stackless GC.
while (v8::platform::PumpMessageLoop(platform, isolate)) continue;
if (!success) return 1;
}
}
return 0;
}
// The read-eval-execute loop of the shell.
void RunShell(v8::Isolate* isolate, const v8::Global<v8::Context>& context,
v8::Platform* platform) {
fprintf(stderr, "V8 version %s [sample shell]\n", v8::V8::GetVersion());
static const int kBufferSize = 256;
while (true) {
char buffer[kBufferSize];
fprintf(stderr, "> ");
char* str = fgets(buffer, kBufferSize, stdin);
if (str == nullptr) break;
{
// Enter the execution environment before evaluating any code.
v8::HandleScope handle_scope(isolate);
v8::Context::Scope context_scope(context.Get(isolate));
v8::Local<v8::String> name(
v8::String::NewFromUtf8Literal(isolate, "(shell)"));
ExecuteString(isolate,
v8::String::NewFromUtf8(isolate, str).ToLocalChecked(),
name, true, true);
}
// It is important not to pump the message loop when there are v8::Local
// handles on the stack, as this may trigger a stackless GC.
while (v8::platform::PumpMessageLoop(platform, isolate)) 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() &&
stack_trace_string.As<v8::String>()->Length() > 0) {
v8::String::Utf8Value stack_trace(isolate, stack_trace_string);
const char* err = ToCString(stack_trace);
fprintf(stderr, "%s\n", err);
}
}
}