feat: Add cwd option to use relative paths for compiler args

README.md

@@ -105,6 +105,8 @@ emcc-loader is configuable on webpack.config.js.
 
 - buildDir : string
 -- [Required] absolute path to temporary directory used by emcc.
+- cwd : string
+-- [default=undefined] working directory for compilers. If specified, all paths passed to compilers will be relative against cwd.
 - cc : string
 -- [default=emcc] c compiler path or command.
 - cxx : string

src/compiler.ts

@@ -114,7 +114,8 @@ export class Compiler {
 		const dependencies = await utility.getDependencies(
 			compiler,
 			srcPath,
-			flags
+			flags,
+			options.cwd
 		);
 		utility.addDependencies(context, dependencies);
 		const latestModifiedTime = await utility.getLatestModifiedTime(
@@ -128,9 +129,19 @@ export class Compiler {
 
 		await utility.mkdirs(path.dirname(outputPath), undefined);
 		const { stderr } = await utility
-			.execute(compiler, [...flags, '-c', '-o', outputPath, srcPath], {
-				shell: true,
-			})
+			.execute(
+				compiler,
+				[
+					...flags,
+					'-c',
+					'-o',
+					options.cwd
+						? path.relative(options.cwd, outputPath)
+						: outputPath,
+					options.cwd ? path.relative(options.cwd, srcPath) : srcPath,
+				],
+				{ cwd: options.cwd, shell: true }
+			)
 			.catch(err => {
 				if (err.err.code === 'ENOENT') {
 					throw new Error(
@@ -157,18 +168,28 @@ export class Compiler {
 			'-s',
 			'WASM=1',
 			'-o',
-			outputPath,
-			...objs,
+			options.cwd ? path.relative(options.cwd, outputPath) : outputPath,
+			...objs.map(o => (options.cwd ? path.relative(options.cwd, o) : o)),
 		];
 		if (options.preJs) {
-			flags.unshift('--pre-js', options.preJs);
+			flags.unshift(
+				'--pre-js',
+				options.cwd
+					? path.relative(options.cwd, options.preJs)
+					: options.preJs
+			);
 		}
 		if (options.postJs) {
-			flags.unshift('--post-js', options.postJs);
+			flags.unshift(
+				'--post-js',
+				options.cwd
+					? path.relative(options.cwd, options.postJs)
+					: options.postJs
+			);
 		}
 		await utility.mkdirs(path.dirname(outputPath), undefined);
 		const { stderr } = await utility
-			.execute(options.ld, flags, { shell: true })
+			.execute(options.ld, flags, { cwd: options.cwd, shell: true })
 			.catch(err => {
 				if (err.err.code === 'ENOENT') {
 					throw new Error(

src/option.ts

@@ -11,6 +11,11 @@ export type LoaderOption = {
 	 */
 	buildDir: string;
 
+	/**
+	 * A path to working directory for compiler.
+	 */
+	cwd?: string;
+
 	/**
 	 * Option for --pre-js
 	 */
@@ -74,6 +79,7 @@ export function parseOption(context: loader.LoaderContext): LoaderOption {
 		cc: <string>options.cc || 'emcc',
 		cxx: <string>options.cxx || 'em++',
 		ld: <string>options.ld || 'emcc',
+		cwd: <string | undefined>options.cwd,
 		/* eslint-disable @typescript-eslint/no-explicit-any */
 		commonFlags: <string[]>(<any>options.commonFlags) || [],
 		cFlags: <string[]>(<any>options.cFlags) || [],

src/utility.ts

@@ -19,11 +19,14 @@ export const readFile = promisify(fs.readFile);
 export async function getDependencies(
 	compiler: string,
 	absPath: string,
-	flags: string[]
+	flags: string[],
+	cwd?: string
 ) {
-	const { stdout } = await execute(compiler, [...flags, '-MM', absPath], {
-		shell: true,
-	}).catch(err => {
+	const { stdout } = await execute(
+		compiler,
+		[...flags, '-MM', cwd ? path.relative(cwd, absPath) : absPath],
+		{ cwd, shell: true }
+	).catch(err => {
 		throw err.err;
 	});
 	const dependencies = stdout