Bug 1412238 - WebAssembly.Global semantics adjustments. r=luke

Track some spec changes: WebAssembly.Global has valueOf, not
toPrimitive, and the value accessor is enumerable.

Also fix two moz.build files that did not get fixed when we allowed
the experiment with WebAssembly.Global to continue on early beta.

--HG--
extra : rebase_source : 3aee04ce3bb4de8cbcb7b7d37727547bf1d5f16b

js/src/jit-test/tests/wasm/globals.js

@@ -317,36 +317,67 @@ if (typeof WebAssembly.Global === "function") {
     assertEq((new WebAssembly.Global({type: "i32", value: 3.14})).value, 3);
     assertEq((new WebAssembly.Global({type: "f32", value: { valueOf: () => 33.5 }})).value, 33.5);
 
-    // Misc internal conversions
-    let g = new WebAssembly.Global({type: "i32", value: 42});
+    // Nothing special about NaN, it coerces just fine
+    assertEq((new WebAssembly.Global({type: "i32", value: NaN})).value, 0);
 
-    // @@toPrimitive
-    assertEq(g - 5, 37);
-    assertEq(String(g), "42");
+    {
+	// "value" is enumerable
+	let x = new WebAssembly.Global({type: "i32"});
+	let s = "";
+	for ( let i in x )
+	    s = s + i + ",";
+	assertEq(s, "value,");
+    }
 
-    // @@toStringTag
-    assertEq(g.toString(), "[object WebAssembly.Global]");
+    // "value" is defined on the prototype, not on the object
+    assertEq("value" in WebAssembly.Global.prototype, true);
 
-    // An exported global should appear as a WebAssembly.Global instance:
-    let i =
-	new WebAssembly.Instance(
-	    new WebAssembly.Module(
-		wasmTextToBinary(`(module (global (export "g") i32 (i32.const 42)))`)));
+    // Can't set the value of an immutable global
+    assertErrorMessage(() => (new WebAssembly.Global({type: "i32"})).value = 10,
+		       TypeError,
+		       /can't set value of immutable global/);
 
-    assertEq(typeof i.exports.g, "object");
-    assertEq(i.exports.g instanceof WebAssembly.Global, true);
+    {
+	// Misc internal conversions
+	let g = new WebAssembly.Global({type: "i32", value: 42});
 
-    // An exported global can be imported into another instance even if
-    // it is an object:
-    let j =
-	new WebAssembly.Instance(
-	    new WebAssembly.Module(
-		wasmTextToBinary(`(module
-				   (global (import "" "g") i32)
-				   (func (export "f") (result i32)
-				    (get_global 0)))`)),
-	    { "": { "g": i.exports.g }});
+	// valueOf
+	assertEq(g - 5, 37);
 
-    // And when it is then accessed it has the right value:
-    assertEq(j.exports.f(), 42);
+	// @@toStringTag
+	assertEq(g.toString(), "[object WebAssembly.Global]");
+    }
+
+    {
+	// An exported global should appear as a WebAssembly.Global instance:
+	let i =
+	    new WebAssembly.Instance(
+		new WebAssembly.Module(
+		    wasmTextToBinary(`(module (global (export "g") i32 (i32.const 42)))`)));
+
+	assertEq(typeof i.exports.g, "object");
+	assertEq(i.exports.g instanceof WebAssembly.Global, true);
+
+	// An exported global can be imported into another instance even if
+	// it is an object:
+	let j =
+	    new WebAssembly.Instance(
+		new WebAssembly.Module(
+		    wasmTextToBinary(`(module
+				       (global (import "" "g") i32)
+				       (func (export "f") (result i32)
+					(get_global 0)))`)),
+		{ "": { "g": i.exports.g }});
+
+	// And when it is then accessed it has the right value:
+	assertEq(j.exports.f(), 42);
+    }
+
+    // TEST THIS LAST
+
+    // "value" is deletable
+    assertEq(delete WebAssembly.Global.prototype.value, true);
+    assertEq("value" in WebAssembly.Global.prototype, false);
+
+    // ADD NO MORE TESTS HERE!
 }

js/src/jsapi-tests/moz.build

@@ -156,6 +156,7 @@ if CONFIG['JS_BUILD_BINAST'] and CONFIG['JS_STANDALONE']:
 
 
 DEFINES['EXPORT_JS_API'] = True
+DEFINES['ENABLE_WASM_GLOBAL'] = True
 
 LOCAL_INCLUDES += [
     '!..',

js/src/shell/moz.build

@@ -18,6 +18,7 @@ UNIFIED_SOURCES += [
 ]
 
 DEFINES['EXPORT_JS_API'] = True
+DEFINES['ENABLE_WASM_GLOBAL'] = True
 
 # Also set in ../moz.build
 DEFINES['ENABLE_SHARED_ARRAY_BUFFER'] = True

js/src/wasm/WasmJS.cpp

@@ -2154,13 +2154,14 @@ WasmGlobalObject::valueSetter(JSContext* cx, unsigned argc, Value* vp)
 
 const JSPropertySpec WasmGlobalObject::properties[] =
 {
-    JS_PSGS("value", WasmGlobalObject::valueGetter, WasmGlobalObject::valueSetter, 0),
+    JS_PSGS("value", WasmGlobalObject::valueGetter, WasmGlobalObject::valueSetter,
+            JSPROP_ENUMERATE),
     JS_PS_END
 };
 
 const JSFunctionSpec WasmGlobalObject::methods[] =
 {
-    JS_SYM_FN(toPrimitive, WasmGlobalObject::valueGetter, 1, JSPROP_READONLY),
+    JS_FN(js_valueOf_str, WasmGlobalObject::valueGetter, 0, 0),
     JS_FS_END
 };