Changeset 189846 in webkit

Timestamp:

Sep 15, 2015 10:49:11 PM (9 years ago)

Author:

commit-queue@webkit.org

Message:

Implement imported global variables in WebAssembly
​https://bugs.webkit.org/show_bug.cgi?id=149206

Patch by Sukolsak Sakshuwong <Sukolsak Sakshuwong> on 2015-09-15
Reviewed by Filip Pizlo.

Values can now be imported to a WebAssembly module through properties of
the imports object that is passed to loadWebAssembly(). In order to
avoid any side effect when accessing the imports object, we check that
the properties are data properties. We also check that each value is a
primitive and is not a Symbol. According to the ECMA262 6.0 spec,
calling ToNumber() on a primitive that is not a Symbol should not cause
any side effect.[1]

[1]: ​http://www.ecma-international.org/ecma-262/6.0/#sec-tonumber

• tests/stress/wasm-globals.js:
• tests/stress/wasm/globals.wasm:
• wasm/WASMModuleParser.cpp:

(JSC::WASMModuleParser::parseModule):
(JSC::WASMModuleParser::parseGlobalSection):

• wasm/WASMModuleParser.h:

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• tests/stress/wasm-globals.js (modified) (3 diffs)
• tests/stress/wasm/globals.wasm (modified) (previous)
• wasm/WASMModuleParser.cpp (modified) (5 diffs)
• wasm/WASMModuleParser.h (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2015-09-15  Sukolsak Sakshuwong  <sukolsak@gmail.com>
+
+        Implement imported global variables in WebAssembly
+        https://bugs.webkit.org/show_bug.cgi?id=149206
+
+        Reviewed by Filip Pizlo.
+
+        Values can now be imported to a WebAssembly module through properties of
+        the imports object that is passed to loadWebAssembly(). In order to
+        avoid any side effect when accessing the imports object, we check that
+        the properties are data properties. We also check that each value is a
+        primitive and is not a Symbol. According to the ECMA262 6.0 spec,
+        calling ToNumber() on a primitive that is not a Symbol should not cause
+        any side effect.[1]
+
+        [1]: http://www.ecma-international.org/ecma-262/6.0/#sec-tonumber
+
+        * tests/stress/wasm-globals.js:
+        * tests/stress/wasm/globals.wasm:
+        * wasm/WASMModuleParser.cpp:
+        (JSC::WASMModuleParser::parseModule):
+        (JSC::WASMModuleParser::parseGlobalSection):
+        * wasm/WASMModuleParser.h:
+
 2015-09-15  Sukolsak Sakshuwong  <sukolsak@gmail.com>
 

trunk/Source/JavaScriptCore/tests/stress/wasm-globals.js

@@ -9 +9 @@
 wasm/globals.wasm is generated by pack-asmjs <https://github.com/WebAssembly/polyfill-prototype-1> from the following script:
 
-function asmModule(global, env, buffer) {
+function asmModule(global, imports, buffer) {
     "use asm";
 
     var fround = global.Math.fround;
+    var a = imports.a | 0;
+    var b = fround(imports.b);
+    var c = +imports.c;
     var x = 0;
     var y = fround(0);
     var z = 0.0;
+
+    function getA() {
+        return a | 0;
+    }
+
+    function getB() {
+        return b;
+    }
+
+    function getC() {
+        return c;
+    }
 
     function getX() {
@@ -45 +60 @@
 
     return {
+        getA: getA,
+        getB: getB,
+        getC: getC,
         getX: getX,
         getY: getY,
@@ -55 +73 @@
 */
 
-var module = loadWebAssembly("wasm/globals.wasm");
+var imports = {
+    a: 42,
+    b: 4.2,
+    c: 4.2,
+};
+var module = loadWebAssembly("wasm/globals.wasm", imports);
+
+shouldBe(module.getA(), 42);
+shouldBe(module.getB(), 4.199999809265137);
+shouldBe(module.getC(), 4.2);
 
 shouldBe(module.getX(), 0);

trunk/Source/JavaScriptCore/wasm/WASMModuleParser.cpp

@@ -85 +85 @@
     parseFunctionImportSection(exec);
     PROPAGATE_ERROR();
-    parseGlobalSection();
+    parseGlobalSection(exec);
     PROPAGATE_ERROR();
     parseFunctionDeclarationSection();
@@ -182 +182 @@
 }
 
-void WASMModuleParser::parseGlobalSection()
+void WASMModuleParser::parseGlobalSection(ExecState* exec)
 {
     uint32_t numberOfInternalI32GlobalVariables;
@@ -219 +219 @@
         READ_STRING_OR_FAIL(importName, "Cannot read the import name of an int32 global variable.");
         globalVariableTypes.uncheckedAppend(WASMType::I32);
-        globalVariables.uncheckedAppend(JSWASMModule::GlobalVariable(0)); // FIXME: Import the value.
+        JSValue value;
+        getImportedValue(exec, importName, value);
+        PROPAGATE_ERROR();
+        FAIL_IF_FALSE(value.isPrimitive() && !value.isSymbol(), "\"" + importName + "\" is not a primitive or is a Symbol.");
+        globalVariables.uncheckedAppend(JSWASMModule::GlobalVariable(value.toInt32(exec)));
     }
     for (uint32_t i = 0; i < numberOfImportedF32GlobalVariables; ++i) {
@@ -225 +229 @@
         READ_STRING_OR_FAIL(importName, "Cannot read the import name of a float32 global variable.");
         globalVariableTypes.uncheckedAppend(WASMType::F32);
-        globalVariables.uncheckedAppend(JSWASMModule::GlobalVariable(0.0f)); // FIXME: Import the value.
+        JSValue value;
+        getImportedValue(exec, importName, value);
+        PROPAGATE_ERROR();
+        FAIL_IF_FALSE(value.isPrimitive() && !value.isSymbol(), "\"" + importName + "\" is not a primitive or is a Symbol.");
+        globalVariables.uncheckedAppend(JSWASMModule::GlobalVariable(static_cast<float>(value.toNumber(exec))));
     }
     for (uint32_t i = 0; i < numberOfImportedF64GlobalVariables; ++i) {
@@ -231 +239 @@
         READ_STRING_OR_FAIL(importName, "Cannot read the import name of a float64 global variable.");
         globalVariableTypes.uncheckedAppend(WASMType::F64);
-        globalVariables.uncheckedAppend(JSWASMModule::GlobalVariable(0.0)); // FIXME: Import the value.
+        JSValue value;
+        getImportedValue(exec, importName, value);
+        PROPAGATE_ERROR();
+        FAIL_IF_FALSE(value.isPrimitive() && !value.isSymbol(), "\"" + importName + "\" is not a primitive or is a Symbol.");
+        globalVariables.uncheckedAppend(JSWASMModule::GlobalVariable(value.toNumber(exec)));
     }
 }

trunk/Source/JavaScriptCore/wasm/WASMModuleParser.h

@@ -51 +51 @@
     void parseSignatureSection();
     void parseFunctionImportSection(ExecState*);
-    void parseGlobalSection();
+    void parseGlobalSection(ExecState*);
     void parseFunctionDeclarationSection();
     void parseFunctionPointerTableSection();