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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
"use strict";
const Debugger = require("Debugger");
const {
reportException,
/**
* Multiple actors that use a |Debugger| instance come in a few versions, each
* with a different set of debuggees. One version for content tabs (globals
* within a tab), one version for chrome debugging (all globals), and sometimes
* a third version for addon debugging (chrome globals the addon is loaded in
* and content globals the addon injects scripts into). The |makeDebugger|
* function helps us avoid repeating the logic for finding and maintaining the
* correct set of globals for a given |Debugger| instance across each version of
* all of our actors.
*
* The |makeDebugger| function expects a single object parameter with the
* following properties:
*
* @param Function findDebuggees
* Called with one argument: a |Debugger| instance. This function should
* return an iterable of globals to be added to the |Debugger|
* instance. The globals are the actual global objects and aren't wrapped
* in in a |Debugger.Object|.
*
* @param Function shouldAddNewGlobalAsDebuggee
* Called with one argument: a |Debugger.Object| wrapping a global
* object. This function must return |true| if the global object should
* be added as debuggee, and |false| otherwise.
*
* @returns Debugger
* Returns a |Debugger| instance that can manage its set of debuggee
* globals itself and is decorated with the |EventEmitter| class.
*
* Existing |Debugger| properties set on the returned |Debugger|
* instance:
*
* - onNewGlobalObject: The |Debugger| will automatically add new
* globals as debuggees if calling |shouldAddNewGlobalAsDebuggee|
* with the global returns true.
*
* - uncaughtExceptionHook: The |Debugger| already has an error
* reporter attached to |uncaughtExceptionHook|, so if any
* |Debugger| hooks fail, the error will be reported.
*
* New properties set on the returned |Debugger| instance:
*
* - addDebuggees: A function which takes no arguments. It adds all
* current globals that should be debuggees (as determined by
* |findDebuggees|) to the |Debugger| instance.
*/
module.exports = function makeDebugger({
findDebuggees,
shouldAddNewGlobalAsDebuggee,
} = {}) {
const dbg = new Debugger();
EventEmitter.decorate(dbg);
// By default, we disable asm.js and WASM debugging because of performance reason.
// Enabling asm.js debugging (allowUnobservedAsmJS=false) will make asm.js fallback to JS compiler
// and be debugging as a regular JS script.
dbg.allowUnobservedAsmJS = true;
// Enabling WASM debugging (allowUnobservedWasm=false) will make the engine compile WASM scripts
// into different machine code with debugging instructions. This significantly increase the memory usage of it.
dbg.allowUnobservedWasm = true;
dbg.uncaughtExceptionHook = reportDebuggerHookException;
const onNewGlobalObject = function (global) {
if (shouldAddNewGlobalAsDebuggee(global)) {
safeAddDebuggee(this, global);
}
};
dbg.onNewGlobalObject = onNewGlobalObject;
dbg.addDebuggees = function () {
for (const global of findDebuggees(this)) {
safeAddDebuggee(this, global);
}
};
dbg.disable = function () {
dbg.removeAllDebuggees();
dbg.onNewGlobalObject = undefined;
};
dbg.enable = function () {
dbg.addDebuggees();
dbg.onNewGlobalObject = onNewGlobalObject;
};
dbg.findDebuggees = function () {
return findDebuggees(dbg);
};
return dbg;
};
const reportDebuggerHookException = e => reportException("DBG-SERVER", e);
/**
* Add |global| as a debuggee to |dbg|, handling error cases.
*/
function safeAddDebuggee(dbg, global) {
let globalDO;
try {
globalDO = dbg.addDebuggee(global);
} catch (e) {
// Ignoring attempt to add the debugger's compartment as a debuggee.
return;
}
if (dbg.onNewDebuggee) {
dbg.onNewDebuggee(globalDO);
}
}