remove _ast variable, add WeakMap

sokra · sokra · commit 85ef6343894e · 2018-05-10T20:19:30.000+02:00
diff --git a/lib/wasm/WebAssemblyGenerator.js b/lib/wasm/WebAssemblyGenerator.js
@@ -6,6 +6,7 @@
 
 const Generator = require("../Generator");
 const { RawSource } = require("webpack-sources");
+const WebAssemblyParser = require("./WebAssemblyParser");
 
 const { editWithAST, addWithAST } = require("@webassemblyjs/wasm-edit");
 const t = require("@webassemblyjs/ast");
@@ -243,7 +244,7 @@ const addInitFunction = ({
 
 class WebAssemblyGenerator extends Generator {
 	generate(module) {
-		const ast = module._ast;
+		const ast = WebAssemblyParser.getAst(module);
 		const bin = module.originalSource().source();
 
 		const importedGlobals = getImportedGlobals(ast);
diff --git a/lib/wasm/WebAssemblyParser.js b/lib/wasm/WebAssemblyParser.js
@@ -10,6 +10,8 @@ const { decode } = require("@webassemblyjs/wasm-parser");
 const { Tapable } = require("tapable");
 const WebAssemblyImportDependency = require("../dependencies/WebAssemblyImportDependency");
 
+/** @typedef {import("../Module")} Module */
+
 /**
  * @param {t.ModuleImport} n the import
  * @returns {boolean} true, if a memory was imported
@@ -27,20 +29,30 @@ const decoderOpts = {
 	ignoreDataSection: true
 };
 
+/** @type {WeakMap<Module, TODO>} */
+const astStore = new WeakMap();
+
 class WebAssemblyParser extends Tapable {
 	constructor(options) {
 		super();
 		this.hooks = {};
 		this.options = options;
 	}
 
+	static getAst(module) {
+		return astStore.get(module);
+	}
+
 	parse(binary, state) {
 		// flag it as ESM
 		state.module.buildMeta.exportsType = "namespace";
 
 		// parse it
 		const ast = decode(binary, decoderOpts);
 
+		// cache it to be available for generators
+		astStore.set(state.module, ast);
+
 		// extract imports and exports
 		const exports = (state.module.buildMeta.providedExports = []);
 		t.traverse(ast, {
@@ -70,8 +82,6 @@ class WebAssemblyParser extends Tapable {
 			}
 		});
 
-		state.module._ast = ast;
-
 		return state;
 	}
 }
