Fix parsing of nested object patterns in acorn-optimizer.js

Fixes: emscripten-core#20818
sbc100 · Dec 4, 2023 · e5253dc · e5253dc
1 parent 1dd30e1
commit e5253dc
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Showing 3 changed files with 16 additions and 17 deletions.
diff --git a/test/optimizer/JSDCE-objectPattern-output.js b/test/optimizer/JSDCE-objectPattern-output.js
@@ -5,6 +5,7 @@ let z = 50;
 globalThis.f = function(r) {
  let {a: a, b: b} = r;
  let {z: c} = r;
+ let [i, {foo: p, bar: q}] = r;
  return g(a, b, c, d, z);
 };
 

diff --git a/test/optimizer/JSDCE-objectPattern.js b/test/optimizer/JSDCE-objectPattern.js
@@ -13,6 +13,7 @@ let z = 50;
 globalThis.f = function(r) {
   let { a, b } = r;
   let { z: c } = r;
+  let [i, {foo : p, bar : q}] = r;
   return g(a, b, c, d, z);
 };
 

diff --git a/tools/acorn-optimizer.js b/tools/acorn-optimizer.js
@@ -424,25 +424,22 @@ function runJSDCE(ast, aggressive) {
 
     recursiveWalk(ast, {
       VariableDeclarator(node, c) {
-        const id = node.id;
-        if (id.type === 'ObjectPattern') {
-          id.properties.forEach((node) => {
-            const value = node.value;
-            assert(value.type === 'Identifier');
-            const name = value.name;
-            ensureData(scopes[scopes.length - 1], name).def = 1;
-          });
-        } else if (id.type === 'ArrayPattern') {
-          id.elements.forEach((node) => {
-            assertAt(node.type === 'Identifier', node.start, "expected Indentifier but found " + node.type);
-            const name = node.name;
+        function traverse(id) {
+          if (id.type === 'ObjectPattern') {
+            for (const prop of id.properties) {
+              traverse(prop.value);
+            }
+          } else if (id.type === 'ArrayPattern') {
+            for (const elem of id.elements) {
+              traverse(elem)
+            }
+          } else {
+            assertAt(id.type === 'Identifier', id.start);
+            const name = id.name;
             ensureData(scopes[scopes.length - 1], name).def = 1;
-          });
-        } else {
-          assertAt(id.type === 'Identifier', id.start);
-          const name = id.name;
-          ensureData(scopes[scopes.length - 1], name).def = 1;
+          }
         }
+        traverse(node.id);
         if (node.init) c(node.init);
       },
       ObjectExpression(node, c) {