let JSDCE clean up objects and arrays without side effects (emscripte…

…n-core#5989)
curiousdannii · Jan 12, 2018 · 50b0e6a · 50b0e6a
1 parent 73046c4
commit 50b0e6a
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Showing 4 changed files with 25 additions and 7 deletions.
diff --git a/tests/optimizer/JSDCE-output.js b/tests/optimizer/JSDCE-output.js
@@ -1,6 +1,10 @@
 
 var z = fleefl();
 var zz = fleefl();
+var keeperObj = {
+ x: fleefl()
+};
+var keeperArray = [ 1, 2, "3", four() ];
 function g(a) {
  return a + 1;
 }

diff --git a/tests/optimizer/JSDCE.js b/tests/optimizer/JSDCE.js
@@ -4,7 +4,10 @@ var x;
 var y = 1;
 var z = fleefl();
 var xx, yy = 1, zz = fleefl(); // but zz must remain due to the side effects in the value
-var obj = {};
+var obj = { x: 5 };
+var keeperObj = { x: fleefl() };
+var array = [1, 2, '3', function() { ignoreInsideIt() }];
+var keeperArray = [1, 2, '3', four()];
 function f(x, y, z) {
   // shadow the x,y,z
   x = y;

diff --git a/tests/optimizer/eliminator-test-output.js b/tests/optimizer/eliminator-test-output.js
@@ -121,11 +121,7 @@ function g(a1, a2) {
  a = c;
  foo(c);
  foo(2);
- for (var i = 0; i < 5; i++) {
-  {
-   a: 1
-  } + [ 2, 3 ];
- }
+ for (var i = 0; i < 5; i++) {}
  for (var iterator in SOME_GLOBAL) {
   quux(iterator);
  }

diff --git a/tools/js-optimizer.js b/tools/js-optimizer.js
@@ -1410,7 +1410,22 @@ function hasSideEffects(node) { // this is 99% incomplete!
     }
     case 'conditional': return hasSideEffects(node[1]) || hasSideEffects(node[2]) || hasSideEffects(node[3]);
     case 'function': case 'defun': return false;
-    case 'object': return false;
+    case 'object': {
+      var children = node[1];
+      if (!Array.isArray(children)) return false;
+      for (var i = 0; i < children.length; i++) {
+        if (hasSideEffects(children[i][1])) return true;
+      }
+      return false;
+    }
+    case 'array': {
+      var children = node[1];
+      if (!Array.isArray(children)) return false;
+      for (var i = 0; i < children.length; i++) {
+        if (hasSideEffects(children[i])) return true;
+      }
+      return false;
+    }
     default: return true;
   }
 }