src: add -r/--require flags for preloading modules

This patch adds a command line option (-r/--require) that allows one
to provide modules on the command line that will be 'required' during
node startup. This can be useful for debugging, tracing, memory leak
analysis etc. to be preloaded without explicit changes to the user
script. The option can be repeated to preload multiple modules.

PR-URL: https://github.com/iojs/io.js/pull/881
Reviewed-By: Trevor Norris <trev.norris@gmail.com>
Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>
Reviewed-By: Rod Vagg <rod@vagg.org>
This commit is contained in:
Ali Ijaz Sheikh 2015-02-17 14:37:37 -08:00 committed by Rod Vagg
parent f600111d82
commit 1514b82355
7 changed files with 199 additions and 71 deletions

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@ -52,6 +52,8 @@ and servers.
-i, --interactive always enter the REPL even if stdin
does not appear to be a terminal
-r, --require module to preload at startup
--no-deprecation silence deprecation warnings
--trace-deprecation show stack traces on deprecations

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@ -114,6 +114,8 @@ static bool trace_deprecation = false;
static bool throw_deprecation = false;
static bool abort_on_uncaught_exception = false;
static const char* eval_string = nullptr;
static unsigned int preload_module_count = 0;
static const char** preload_modules = nullptr;
static bool use_debug_agent = false;
static bool debug_wait_connect = false;
static int debug_port = 5858;
@ -2766,6 +2768,19 @@ void SetupProcessObject(Environment* env,
READONLY_PROPERTY(process, "_forceRepl", True(env->isolate()));
}
if (preload_module_count) {
CHECK(preload_modules);
Local<Array> array = Array::New(env->isolate());
for (unsigned int i = 0; i < preload_module_count; ++i) {
Local<String> module = String::NewFromUtf8(env->isolate(),
preload_modules[i]);
array->Set(i, module);
}
READONLY_PROPERTY(process,
"_preload_modules",
array);
}
// --no-deprecation
if (no_deprecation) {
READONLY_PROPERTY(process, "noDeprecation", True(env->isolate()));
@ -2990,6 +3005,7 @@ static void PrintHelp() {
" -p, --print evaluate script and print result\n"
" -i, --interactive always enter the REPL even if stdin\n"
" does not appear to be a terminal\n"
" -r, --require module to preload (option can be repeated)\n"
" --no-deprecation silence deprecation warnings\n"
" --throw-deprecation throw an exception anytime a deprecated "
"function is used\n"
@ -3045,11 +3061,13 @@ static void ParseArgs(int* argc,
const char** new_exec_argv = new const char*[nargs];
const char** new_v8_argv = new const char*[nargs];
const char** new_argv = new const char*[nargs];
const char** local_preload_modules = new const char*[nargs];
for (unsigned int i = 0; i < nargs; ++i) {
new_exec_argv[i] = nullptr;
new_v8_argv[i] = nullptr;
new_argv[i] = nullptr;
local_preload_modules[i] = nullptr;
}
// exec_argv starts with the first option, the other two start with argv[0].
@ -3098,6 +3116,15 @@ static void ParseArgs(int* argc,
eval_string += 1;
}
}
} else if (strcmp(arg, "--require") == 0 ||
strcmp(arg, "-r") == 0) {
const char* module = argv[index + 1];
if (module == nullptr) {
fprintf(stderr, "%s: %s requires an argument\n", argv[0], arg);
exit(9);
}
args_consumed += 1;
local_preload_modules[preload_module_count++] = module;
} else if (strcmp(arg, "--interactive") == 0 || strcmp(arg, "-i") == 0) {
force_repl = true;
} else if (strcmp(arg, "--no-deprecation") == 0) {
@ -3144,6 +3171,16 @@ static void ParseArgs(int* argc,
memcpy(argv, new_argv, new_argc * sizeof(*argv));
delete[] new_argv;
*argc = static_cast<int>(new_argc);
// Copy the preload_modules from the local array to an appropriately sized
// global array.
if (preload_module_count > 0) {
CHECK(!preload_modules);
preload_modules = new const char*[preload_module_count];
memcpy(preload_modules, local_preload_modules,
preload_module_count * sizeof(*preload_modules));
}
delete[] local_preload_modules;
}

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@ -68,7 +68,18 @@
var d = NativeModule.require('_debug_agent');
d.start();
} else if (process._eval != null) {
} else {
// There is user code to be run
// Load any preload modules
if (process._preload_modules) {
var Module = NativeModule.require('module');
process._preload_modules.forEach(function(module) {
Module._load(module);
});
}
if (process._eval != null) {
// User passed '-e' or '--eval' arguments to Node.
evalScript('[eval]');
} else if (process.argv[1]) {
@ -149,6 +160,7 @@
}
}
}
}
startup.globalVariables = function() {
global.process = process;

1
test/fixtures/printA.js vendored Normal file
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@ -0,0 +1 @@
console.log('A')

1
test/fixtures/printB.js vendored Normal file
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@ -0,0 +1 @@
console.log('B')

1
test/fixtures/printC.js vendored Normal file
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@ -0,0 +1 @@
console.log('C')

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@ -0,0 +1,74 @@
var common = require('../common'),
assert = require('assert'),
path = require('path'),
child_process = require('child_process');
var nodeBinary = process.argv[0];
var preloadOption = function(preloads) {
var option = '';
preloads.forEach(function(preload, index) {
// TODO: randomly pick -r or --require
option += '-r ' + preload + ' ';
});
return option;
}
var fixture = function(name) {
return path.join(__dirname, '../fixtures/' + name);
}
var fixtureA = fixture('printA.js');
var fixtureB = fixture('printB.js');
var fixtureC = fixture('printC.js')
var fixtureThrows = fixture('throws_error4.js');
// test preloading a single module works
child_process.exec(nodeBinary + ' '
+ preloadOption([fixtureA]) + ' '
+ fixtureB,
function(err, stdout, stderr) {
if (err) throw err;
assert.equal(stdout, 'A\nB\n');
});
// test preloading multiple modules works
child_process.exec(nodeBinary + ' '
+ preloadOption([fixtureA, fixtureB]) + ' '
+ fixtureC,
function(err, stdout, stderr) {
if (err) throw err;
assert.equal(stdout, 'A\nB\nC\n');
});
// test that preloading a throwing module aborts
child_process.exec(nodeBinary + ' '
+ preloadOption([fixtureA, fixtureThrows]) + ' '
+ fixtureB,
function(err, stdout, stderr) {
if (err) {
assert.equal(stdout, 'A\n');
} else {
throw new Error('Preload should have failed');
}
});
// test that preload can be used with --eval
child_process.exec(nodeBinary + ' '
+ preloadOption([fixtureA])
+ '-e "console.log(\'hello\');"',
function(err, stdout, stderr) {
if (err) throw err;
assert.equal(stdout, 'A\nhello\n');
});
// test that preload placement at other points in the cmdline
// also test that duplicated preload only gets loaded once
child_process.exec(nodeBinary + ' '
+ preloadOption([fixtureA])
+ '-e "console.log(\'hello\');" '
+ preloadOption([fixtureA, fixtureB]),
function(err, stdout, stderr) {
if (err) throw err;
assert.equal(stdout, 'A\nB\nhello\n');
});