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/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* vim: set sts=2 sw=2 et tw=80: */
/* 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 file,
// FIXME: This file is currently not covered by TypeScript, there is no "@ts-check" comment.
// We should fix this once we know how to deal with the module imports below.
"use strict";
/* import-globals-from profiler_get_symbols.js */
importScripts(
);
/**
* @typedef {import("../@types/perf").SymbolicationWorkerInitialMessage} SymbolicationWorkerInitialMessage
* @typedef {import("../@types/perf").FileHandle} FileHandle
*/
// This worker uses the wasm module that was generated from https://github.com/mstange/profiler-get-symbols.
// See ProfilerGetSymbols.jsm for more information.
//
// The worker instantiates the module, reads the binary into wasm memory, runs
// the wasm code, and returns the symbol table or an error. Then it shuts down
// itself.
/* eslint camelcase: 0*/
const { getCompactSymbolTable, queryAPI } = wasm_bindgen;
// Returns a plain object that is Structured Cloneable and has name and
// message properties.
function createPlainErrorObject(e) {
// Regular errors: just rewrap the object.
const { name, message, fileName, lineNumber } = e;
return { name, message, fileName, lineNumber };
}
/**
* A FileAndPathHelper object is passed to getCompactSymbolTable, which calls
* the methods `getCandidatePathsForBinaryOrPdb` and `readFile` on it.
*/
class FileAndPathHelper {
constructor(libInfoMap, objdirs) {
this._libInfoMap = libInfoMap;
this._objdirs = objdirs;
}
/**
* Enumerate all paths at which we could find files with symbol information.
* This method is called by wasm code (via the bindings).
*
* @param {LibraryInfo} libraryInfo
* @returns {Array<string>}
*/
getCandidatePathsForDebugFile(libraryInfo) {
const { debugName, breakpadId } = libraryInfo;
const key = `${debugName}:${breakpadId}`;
const lib = this._libInfoMap.get(key);
if (!lib) {
throw new Error(
`Could not find the library for "${debugName}", "${breakpadId}".`
);
}
const { name, path, debugPath, arch } = lib;
const candidatePaths = [];
// First, try to find a binary with a matching file name and breakpadId
// in one of the manually specified objdirs.
// This is needed if the debuggee is a build running on a remote machine that
// was compiled by the developer on *this* machine (the "host machine"). In
// that case, the objdir will contain the compiled binary with full symbol and
// debug information, whereas the binary on the device may not exist in
// uncompressed form or may have been stripped of debug information and some
// symbol information.
// An objdir, or "object directory", is a directory on the host machine that's
// used to store build artifacts ("object files") from the compilation process.
// This only works if the binary is one of the Gecko binaries and not
// a system library.
for (const objdirPath of this._objdirs) {
try {
// Binaries are usually expected to exist at objdir/dist/bin/filename.
candidatePaths.push(PathUtils.join(objdirPath, "dist", "bin", name));
// Also search in the "objdir" directory itself (not just in dist/bin).
// If, for some unforeseen reason, the relevant binary is not inside the
// objdirs dist/bin/ directory, this provides a way out because it lets the
// user specify the actual location.
candidatePaths.push(PathUtils.join(objdirPath, name));
} catch (e) {
// PathUtils.join throws if objdirPath is not an absolute path.
// Ignore those invalid objdir paths.
}
}
// Check the absolute paths of the library last.
// We do this after the objdir search because the library's path may point
// to a stripped binary, which will have fewer symbols than the original
// binaries in the objdir.
if (debugPath !== path) {
// We're on Windows, and debugPath points to a PDB file.
// On non-Windows, path and debugPath are always the same.
// Check the PDB file before the binary because the PDB has the symbol
// information. The binary is only used as a last-ditch fallback
// for things like Windows system libraries (e.g. graphics drivers).
candidatePaths.push(debugPath);
}
// The location of the binary. If the profile was obtained on this machine
// (and not, for example, on an Android device), this file should always
// exist.
candidatePaths.push(path);
// On macOS, for system libraries, add a final fallback for the dyld shared
// cache. Starting with macOS 11, most system libraries are located in this
// system-wide cache file and not present as individual files.
if (arch && (path.startsWith("/usr/") || path.startsWith("/System/"))) {
// Use the special syntax `dyldcache:<dyldcachepath>:<librarypath>`.
// Dyld cache location used on macOS 13+:
candidatePaths.push(
`dyldcache:/System/Volumes/Preboot/Cryptexes/OS/System/Library/dyld/dyld_shared_cache_${arch}:${path}`
);
// Dyld cache location used on macOS 11 and 12:
candidatePaths.push(
`dyldcache:/System/Library/dyld/dyld_shared_cache_${arch}:${path}`
);
}
return candidatePaths;
}
/**
* Enumerate all paths at which we could find the binary which matches the
* given libraryInfo, in order to disassemble machine code.
* This method is called by wasm code (via the bindings).
*
* @param {LibraryInfo} libraryInfo
* @returns {Array<string>}
*/
getCandidatePathsForBinary(libraryInfo) {
const { debugName, breakpadId } = libraryInfo;
const key = `${debugName}:${breakpadId}`;
const lib = this._libInfoMap.get(key);
if (!lib) {
throw new Error(
`Could not find the library for "${debugName}", "${breakpadId}".`
);
}
const { name, path, arch } = lib;
const candidatePaths = [];
// The location of the binary. If the profile was obtained on this machine
// (and not, for example, on an Android device), this file should always
// exist.
candidatePaths.push(path);
// Fall back to searching in the manually specified objdirs.
// This is needed if the debuggee is a build running on a remote machine that
// was compiled by the developer on *this* machine (the "host machine"). In
// that case, the objdir will contain the compiled binary.
for (const objdirPath of this._objdirs) {
try {
// Binaries are usually expected to exist at objdir/dist/bin/filename.
candidatePaths.push(PathUtils.join(objdirPath, "dist", "bin", name));
// Also search in the "objdir" directory itself (not just in dist/bin).
// If, for some unforeseen reason, the relevant binary is not inside the
// objdirs dist/bin/ directory, this provides a way out because it lets the
// user specify the actual location.
candidatePaths.push(PathUtils.join(objdirPath, name));
} catch (e) {
// PathUtils.join throws if objdirPath is not an absolute path.
// Ignore those invalid objdir paths.
}
}
// On macOS, for system libraries, add a final fallback for the dyld shared
// cache. Starting with macOS 11, most system libraries are located in this
// system-wide cache file and not present as individual files.
if (arch && (path.startsWith("/usr/") || path.startsWith("/System/"))) {
// Use the special syntax `dyldcache:<dyldcachepath>:<librarypath>`.
// Dyld cache location used on macOS 13+:
candidatePaths.push(
`dyldcache:/System/Volumes/Preboot/Cryptexes/OS/System/Library/dyld/dyld_shared_cache_${arch}:${path}`
);
// Dyld cache location used on macOS 11 and 12:
candidatePaths.push(
`dyldcache:/System/Library/dyld/dyld_shared_cache_${arch}:${path}`
);
}
return candidatePaths;
}
/**
* Asynchronously prepare the file at `path` for synchronous reading.
* This method is called by wasm code (via the bindings).
*
* @param {string} path
* @returns {FileHandle}
*/
async readFile(path) {
const info = await IOUtils.stat(path);
if (info.type === "directory") {
throw new Error(`Path "${path}" is a directory.`);
}
return IOUtils.openFileForSyncReading(path);
}
}
/** @param {MessageEvent<SymbolicationWorkerInitialMessage>} e */
onmessage = async e => {
try {
const { request, libInfoMap, objdirs, module } = e.data;
if (!(module instanceof WebAssembly.Module)) {
throw new Error("invalid WebAssembly module");
}
// Instantiate the WASM module.
await wasm_bindgen(module);
const helper = new FileAndPathHelper(libInfoMap, objdirs);
switch (request.type) {
case "GET_SYMBOL_TABLE": {
const { debugName, breakpadId } = request;
const result = await getCompactSymbolTable(
debugName,
breakpadId,
helper
);
postMessage(
{ result },
result.map(r => r.buffer)
);
break;
}
case "QUERY_SYMBOLICATION_API": {
const { path, requestJson } = request;
const result = await queryAPI(path, requestJson, helper);
postMessage({ result });
break;
}
default:
throw new Error(`Unexpected request type ${request.type}`);
}
} catch (error) {
postMessage({ error: createPlainErrorObject(error) });
}
close();
};
onunhandledrejection = e => {
// Unhandled rejections can happen if the WASM code throws a
// "RuntimeError: unreachable executed" exception, which can happen
// if the Rust code panics or runs out of memory.
// These panics currently are not propagated to the promise reject
// Ideally, the Rust code should never panic and handle all error
// cases gracefully.
e.preventDefault();
postMessage({ error: createPlainErrorObject(e.reason) });
};
// Catch any other unhandled errors, just to be sure.
onerror = e => {
postMessage({ error: createPlainErrorObject(e) });
};