Merge pull request #7413 from xtuc/feat-wasm-global-in-global-initilizer2

wasm global with global as initializer

lib/wasm/WebAssemblyGenerator.js

@@ -178,6 +178,7 @@ function getNextFuncIndex(ast, countImportedFunc) {
  * @returns {ArrayBufferTransform} transform
  */
 const rewriteImportedGlobals = state => bin => {
+	const additionalInitCode = state.additionalInitCode;
 	const newGlobals = [];
 
 	bin = editWithAST(state.ast, bin, {
@@ -212,7 +213,34 @@ const rewriteImportedGlobals = state => bin => {
 		// in order to preserve non-imported global's order we need to re-inject
 		// those as well
 		Global(path) {
-			newGlobals.push(path.node);
+			const { node } = path;
+			const [init] = node.init;
+
+			if (init.id === "get_global") {
+				node.globalType.mutability = "var";
+
+				const initialGlobalidx = init.args[0];
+
+				const valtype = node.globalType.valtype;
+
+				node.init = [
+					// Poisong globals, they are meant to be rewritten
+					t.objectInstruction("const", valtype, [t.numberLiteralFromRaw(666)])
+				];
+
+				additionalInitCode.push(
+					/**
+					 * get_global in global initilizer only work for imported globals.
+					 * They have the same indices than the init params, so use the
+					 * same index.
+					 */
+					t.instruction("get_local", [initialGlobalidx]),
+					t.instruction("set_global", [t.indexLiteral(newGlobals.length)])
+				);
+			}
+
+			newGlobals.push(node);
+
 			path.remove();
 		}
 	});
@@ -274,6 +302,7 @@ const rewriteImports = ({ ast, usedDependencyMap }) => bin => {
  * @param {t.Identifier} state.initFuncId identifier of the init function
  * @param {t.IndexLiteral} state.startAtFuncIndex 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.IndexLiteral} state.nextFuncIndex index of the next function
  * @param {t.IndexLiteral} state.nextTypeIndex index of the next type
  * @returns {ArrayBufferTransform} transform
@@ -283,6 +312,7 @@ const addInitFunction = ({
 	initFuncId,
 	startAtFuncIndex,
 	importedGlobals,
+	additionalInitCode,
 	nextFuncIndex,
 	nextTypeIndex
 }) => bin => {
@@ -307,6 +337,10 @@ const addInitFunction = ({
 		funcBody.push(t.callInstruction(startAtFuncIndex));
 	}
 
+	for (const instr of additionalInitCode) {
+		funcBody.push(instr);
+	}
+
 	const funcResults = [];
 
 	// Code section
@@ -370,6 +404,9 @@ class WebAssemblyGenerator extends Generator {
 
 		const usedDependencyMap = getUsedDependencyMap(module);
 
+		/** @type {t.Instruction[]} */
+		const additionalInitCode = [];
+
 		const transform = compose(
 			rewriteExportNames({
 				ast,
@@ -378,7 +415,7 @@ class WebAssemblyGenerator extends Generator {
 
 			removeStartFunc({ ast }),
 
-			rewriteImportedGlobals({ ast }),
+			rewriteImportedGlobals({ ast, additionalInitCode }),
 
 			rewriteImports({
 				ast,
@@ -389,6 +426,7 @@ class WebAssemblyGenerator extends Generator {
 				ast,
 				initFuncId,
 				importedGlobals,
+				additionalInitCode,
 				startAtFuncIndex,
 				nextFuncIndex,
 				nextTypeIndex

test/cases/wasm/global-refs-imported-global/env.js

@@ -0,0 +1 @@
+export const n = 33;

test/cases/wasm/global-refs-imported-global/index.js

@@ -0,0 +1,5 @@
+it("should allow global with imported global as initilizer", function() {
+	return import("./module.wat").then(function({get}) {
+		expect(get()).toEqual(33);
+	});
+});

test/cases/wasm/global-refs-imported-global/module.wat

@@ -0,0 +1,9 @@
+(module
+  (import "./env.js" "n" (global i32))
+  (global i32 (get_global 0))
+
+  (func (export "get") (result i32)
+    (get_global 1)
+  )
+)
+

test/cases/wasm/global-refs-imported-global/test.filter.js

@@ -0,0 +1,5 @@
+var supportsWebAssembly = require("../../../helpers/supportsWebAssembly");
+
+module.exports = function(config) {
+	return supportsWebAssembly();
+};

yarn.lock

@@ -6187,8 +6187,8 @@ walker@~1.0.5:
     makeerror "1.0.x"
 
 wast-loader@^1.5.5:
-  version "1.5.5"
-  resolved "https://registry.yarnpkg.com/wast-loader/-/wast-loader-1.5.5.tgz#a1d6cdc468b6963a6e479de683dc74755f09b81a"
+  version "1.5.7"
+  resolved "https://registry.yarnpkg.com/wast-loader/-/wast-loader-1.5.7.tgz#1b165cef7225c70a7e82a50e4f8bf0bc1ec9f2fd"
   dependencies:
     wabt "^1.0.0"