Merge pull request webpack#7490 from xtuc/feat-wasm-some-cleanups

wasm some cleanups

Author: sokra

declarations.d.ts

@@ -139,6 +139,12 @@ declare module "@webassemblyjs/ast" {
 		args: string[];
 		result: string[];
 	}
+
+	// Node matcher
+	export function isGlobalType(n: Node): boolean;
+	export function isTable(n: Node): boolean;
+	export function isMemory(n: Node): boolean;
+	export function isFuncImportDescr(n: Node): boolean;
 }
 
 /**

lib/wasm/WebAssemblyGenerator.js

@@ -13,6 +13,9 @@ const { shrinkPaddedLEB128 } = require("@webassemblyjs/wasm-opt");
 const { editWithAST, addWithAST } = require("@webassemblyjs/wasm-edit");
 const { decode } = require("@webassemblyjs/wasm-parser");
 const t = require("@webassemblyjs/ast");
+const {
+	moduleContextFromModuleAST
+} = require("@webassemblyjs/helper-module-context");
 
 const WebAssemblyExportImportedDependency = require("../dependencies/WebAssemblyExportImportedDependency");
 
@@ -45,20 +48,6 @@ function compose(...fns) {
 	}, value => value);
 }
 
-// Utility functions
-
-/**
- * @param {t.ModuleImport} n the import
- * @returns {boolean} true, if a global was imported
- */
-const isGlobalImport = n => n.descr.type === "GlobalType";
-
-/**
- * @param {t.ModuleImport} n the import
- * @returns {boolean} true, if a func was imported
- */
-const isFuncImport = n => n.descr.type === "FuncImportDescr";
-
 // TODO replace with @callback
 
 /**
@@ -75,24 +64,6 @@ const removeStartFunc = state => bin => {
 	});
 };
 
-/**
- * Retrieve the start function
- *
- * @param {Object} ast - Module's AST
- * @returns {t.Identifier | undefined} - node if any
- */
-function getStartFuncIndex(ast) {
-	let startAtFuncIndex;
-
-	t.traverse(ast, {
-		Start({ node }) {
-			startAtFuncIndex = node.index;
-		}
-	});
-
-	return startAtFuncIndex;
-}
-
 /**
  * Get imported globals
  *
@@ -104,7 +75,7 @@ function getImportedGlobals(ast) {
 
 	t.traverse(ast, {
 		ModuleImport({ node }) {
-			if (isGlobalImport(node) === true) {
+			if (t.isGlobalType(node.descr) === true) {
 				importedGlobals.push(node);
 			}
 		}
@@ -118,7 +89,7 @@ function getCountImportedFunc(ast) {
 
 	t.traverse(ast, {
 		ModuleImport({ node }) {
-			if (isFuncImport(node) === true) {
+			if (t.isFuncImportDescr(node.descr) === true) {
 				count++;
 			}
 		}
@@ -206,7 +177,7 @@ const rewriteImportedGlobals = state => bin => {
 
 	bin = editWithAST(state.ast, bin, {
 		ModuleImport(path) {
-			if (isGlobalImport(path.node) === true) {
+			if (t.isGlobalType(path.node.descr) === true) {
 				const globalType = path.node.descr;
 
 				globalType.mutability = "var";
@@ -309,7 +280,7 @@ const rewriteImports = ({ ast, usedDependencyMap }) => bin => {
  * @param {Object} state transformation state
  * @param {Object} state.ast - Module's ast
  * @param {t.Identifier} state.initFuncId identifier of the init function
- * @param {t.Index} state.startAtFuncIndex index of the start function
+ * @param {t.Index} state.startAtFuncOffset index of the start function
  * @param {t.ModuleImport[]} state.importedGlobals list of imported globals
  * @param {t.Instruction[]} state.additionalInitCode list of addition instructions for the init function
  * @param {t.Index} state.nextFuncIndex index of the next function
@@ -319,7 +290,7 @@ const rewriteImports = ({ ast, usedDependencyMap }) => bin => {
 const addInitFunction = ({
 	ast,
 	initFuncId,
-	startAtFuncIndex,
+	startAtFuncOffset,
 	importedGlobals,
 	additionalInitCode,
 	nextFuncIndex,
@@ -342,8 +313,8 @@ const addInitFunction = ({
 		return [...acc, ...body];
 	}, []);
 
-	if (typeof startAtFuncIndex !== "undefined") {
-		funcBody.push(t.callInstruction(startAtFuncIndex));
+	if (typeof startAtFuncOffset === "number") {
+		funcBody.push(t.callInstruction(t.numberLiteralFromRaw(startAtFuncOffset)));
 	}
 
 	for (const instr of additionalInitCode) {
@@ -405,15 +376,18 @@ class WebAssemblyGenerator extends Generator {
 				: "__webpack_init__"
 		);
 
+		// parse it
 		const ast = decode(bin, {
 			ignoreDataSection: true,
 			ignoreCodeSection: true,
 			ignoreCustomNameSection: true
 		});
 
+		const moduleContext = moduleContextFromModuleAST(ast.body[0]);
+
 		const importedGlobals = getImportedGlobals(ast);
 		const countImportedFunc = getCountImportedFunc(ast);
-		const startAtFuncIndex = getStartFuncIndex(ast);
+		const startAtFuncOffset = moduleContext.getStart();
 		const nextFuncIndex = getNextFuncIndex(ast, countImportedFunc);
 		const nextTypeIndex = getNextTypeIndex(ast);
 
@@ -451,7 +425,7 @@ class WebAssemblyGenerator extends Generator {
 				initFuncId,
 				importedGlobals,
 				additionalInitCode,
-				startAtFuncIndex,
+				startAtFuncOffset,
 				nextFuncIndex,
 				nextTypeIndex
 			})

lib/wasm/WebAssemblyParser.js

@@ -16,30 +16,6 @@ const WebAssemblyExportImportedDependency = require("../dependencies/WebAssembly
 
 /** @typedef {import("../Module")} Module */
 
-/**
- * @param {t.ModuleImport} n the import
- * @returns {boolean} true, if a memory was imported
- */
-const isMemoryImport = n => n.descr.type === "Memory";
-
-/**
- * @param {t.ModuleImport} n the import
- * @returns {boolean} true, if a table was imported
- */
-const isTableImport = n => n.descr.type === "Table";
-
-/**
- * @param {t.ModuleImport} n the import
- * @returns {boolean} true, if a func was imported
- */
-const isFuncImport = n => n.descr.type === "FuncImportDescr";
-
-/**
- * @param {t.ModuleImport} n the import
- * @returns {boolean} true, if a global was imported
- */
-const isGlobalImport = n => n.descr.type === "GlobalType";
-
 const JS_COMPAT_TYPES = new Set(["i32", "f32", "f64"]);
 
 /**
@@ -160,16 +136,16 @@ class WebAssemblyParser extends Tapable {
 				/** @type {false | string} */
 				let onlyDirectImport = false;
 
-				if (isMemoryImport(node) === true) {
+				if (t.isMemory(node.descr) === true) {
 					onlyDirectImport = "Memory";
-				} else if (isTableImport(node) === true) {
+				} else if (t.isTable(node.descr) === true) {
 					onlyDirectImport = "Table";
-				} else if (isFuncImport(node) === true) {
+				} else if (t.isFuncImportDescr(node.descr) === true) {
 					const incompatibleType = getJsIncompatibleType(node.descr.signature);
 					if (incompatibleType) {
 						onlyDirectImport = `Non-JS-compatible Func Sigurature (${incompatibleType})`;
 					}
-				} else if (isGlobalImport(node) === true) {
+				} else if (t.isGlobalType(node.descr) === true) {
 					const type = node.descr.valtype;
 					if (!JS_COMPAT_TYPES.has(type)) {
 						onlyDirectImport = `Non-JS-compatible Global Type (${type})`;
@@ -185,7 +161,7 @@ class WebAssemblyParser extends Tapable {
 
 				state.module.addDependency(dep);
 
-				if (isGlobalImport(node)) {
+				if (t.isGlobalType(node.descr)) {
 					importedGlobals.push(node);
 				}
 			}

package.json

@@ -5,11 +5,11 @@
   "description": "Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.",
   "license": "MIT",
   "dependencies": {
-    "@webassemblyjs/ast": "1.5.10",
-    "@webassemblyjs/helper-module-context": "1.5.10",
-    "@webassemblyjs/wasm-edit": "1.5.10",
-    "@webassemblyjs/wasm-opt": "1.5.10",
-    "@webassemblyjs/wasm-parser": "1.5.10",
+    "@webassemblyjs/ast": "1.5.11",
+    "@webassemblyjs/helper-module-context": "1.5.11",
+    "@webassemblyjs/wasm-edit": "1.5.11",
+    "@webassemblyjs/wasm-opt": "1.5.11",
+    "@webassemblyjs/wasm-parser": "1.5.11",
     "acorn": "^5.0.0",
     "acorn-dynamic-import": "^3.0.0",
     "ajv": "^6.1.0",