Changeset 188778 in webkit

Timestamp:

Aug 21, 2015 2:46:22 PM (9 years ago)

Author:

commit-queue@webkit.org

Message:

Implement WebAssembly function parser
​https://bugs.webkit.org/show_bug.cgi?id=147738

Patch by Sukolsak Sakshuwong <Sukolsak Sakshuwong> on 2015-08-21
Reviewed by Filip Pizlo.

Implement WebAssembly function parser for WebAssembly files produced by pack-asmjs
<​https://github.com/WebAssembly/polyfill-prototype-1>. This patch parses only
some instructions on statements and int32 expressions. Parsing of the rest
will be implemented in subsequent patches. The instruction lists in WASMConstants.h
are slightly modified from
<​https://github.com/WebAssembly/polyfill-prototype-1/blob/master/src/shared.h>.

• CMakeLists.txt:
• JavaScriptCore.vcxproj/JavaScriptCore.vcxproj:
• JavaScriptCore.vcxproj/JavaScriptCore.vcxproj.filters:
• JavaScriptCore.xcodeproj/project.pbxproj:
• wasm/WASMConstants.h: Added.
• wasm/WASMFormat.h:
• wasm/WASMFunctionParser.cpp: Added.

(JSC::WASMFunctionParser::checkSyntax):
(JSC::WASMFunctionParser::parseFunction):
(JSC::WASMFunctionParser::parseLocalVariables):
(JSC::WASMFunctionParser::parseStatement):
(JSC::WASMFunctionParser::parseSetLocalStatement):
(JSC::WASMFunctionParser::parseReturnStatement):
(JSC::WASMFunctionParser::parseBlockStatement):
(JSC::WASMFunctionParser::parseExpression):
(JSC::WASMFunctionParser::parseExpressionI32):
(JSC::WASMFunctionParser::parseImmediateExpressionI32):

• wasm/WASMFunctionParser.h: Added.

(JSC::WASMFunctionParser::WASMFunctionParser):

• wasm/WASMFunctionSyntaxChecker.h: Renamed from Source/JavaScriptCore/wasm/WASMMagicNumber.h.
• wasm/WASMModuleParser.cpp:

(JSC::WASMModuleParser::WASMModuleParser):
(JSC::WASMModuleParser::parseFunctionDefinitionSection):
(JSC::WASMModuleParser::parseFunctionDefinition):

• wasm/WASMModuleParser.h:
• wasm/WASMReader.cpp:

(JSC::WASMReader::readType):
(JSC::WASMReader::readExpressionType):
(JSC::WASMReader::readExportFormat):
(JSC::WASMReader::readOpStatement):
(JSC::WASMReader::readOpExpressionI32):
(JSC::WASMReader::readVariableTypes):
(JSC::WASMReader::readOp):

• wasm/WASMReader.h:

(JSC::WASMReader::offset):
(JSC::WASMReader::setOffset):

Location:

trunk/Source/JavaScriptCore

Files:

• CMakeLists.txt (modified) (1 diff)
• ChangeLog (modified) (1 diff)
• JavaScriptCore.vcxproj/JavaScriptCore.vcxproj (modified) (2 diffs)
• JavaScriptCore.vcxproj/JavaScriptCore.vcxproj.filters (modified) (2 diffs)
• JavaScriptCore.xcodeproj/project.pbxproj (modified) (8 diffs)
• wasm/WASMConstants.h (added)
• wasm/WASMFormat.h (modified) (1 diff)
• wasm/WASMFunctionParser.cpp (added)
• wasm/WASMFunctionParser.h (added)
• wasm/WASMFunctionSyntaxChecker.h (moved) (moved from trunk/Source/JavaScriptCore/wasm/WASMMagicNumber.h) (3 diffs)
• wasm/WASMModuleParser.cpp (modified) (3 diffs)
• wasm/WASMModuleParser.h (modified) (1 diff)
• wasm/WASMReader.cpp (modified) (3 diffs)
• wasm/WASMReader.h (modified) (4 diffs)

trunk/Source/JavaScriptCore/CMakeLists.txt

@@ -424 +424 @@
 
     wasm/JSWASMModule.cpp
+    wasm/WASMFunctionParser.cpp
     wasm/WASMModuleParser.cpp
     wasm/WASMReader.cpp

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2015-08-21  Sukolsak Sakshuwong  <sukolsak@gmail.com>
+
+        Implement WebAssembly function parser
+        https://bugs.webkit.org/show_bug.cgi?id=147738
+
+        Reviewed by Filip Pizlo.
+
+        Implement WebAssembly function parser for WebAssembly files produced by pack-asmjs
+        <https://github.com/WebAssembly/polyfill-prototype-1>. This patch parses only
+        some instructions on statements and int32 expressions. Parsing of the rest
+        will be implemented in subsequent patches. The instruction lists in WASMConstants.h
+        are slightly modified from
+        <https://github.com/WebAssembly/polyfill-prototype-1/blob/master/src/shared.h>.
+
+        * CMakeLists.txt:
+        * JavaScriptCore.vcxproj/JavaScriptCore.vcxproj:
+        * JavaScriptCore.vcxproj/JavaScriptCore.vcxproj.filters:
+        * JavaScriptCore.xcodeproj/project.pbxproj:
+        * wasm/WASMConstants.h: Added.
+        * wasm/WASMFormat.h:
+        * wasm/WASMFunctionParser.cpp: Added.
+        (JSC::WASMFunctionParser::checkSyntax):
+        (JSC::WASMFunctionParser::parseFunction):
+        (JSC::WASMFunctionParser::parseLocalVariables):
+        (JSC::WASMFunctionParser::parseStatement):
+        (JSC::WASMFunctionParser::parseSetLocalStatement):
+        (JSC::WASMFunctionParser::parseReturnStatement):
+        (JSC::WASMFunctionParser::parseBlockStatement):
+        (JSC::WASMFunctionParser::parseExpression):
+        (JSC::WASMFunctionParser::parseExpressionI32):
+        (JSC::WASMFunctionParser::parseImmediateExpressionI32):
+        * wasm/WASMFunctionParser.h: Added.
+        (JSC::WASMFunctionParser::WASMFunctionParser):
+        * wasm/WASMFunctionSyntaxChecker.h: Renamed from Source/JavaScriptCore/wasm/WASMMagicNumber.h.
+        * wasm/WASMModuleParser.cpp:
+        (JSC::WASMModuleParser::WASMModuleParser):
+        (JSC::WASMModuleParser::parseFunctionDefinitionSection):
+        (JSC::WASMModuleParser::parseFunctionDefinition):
+        * wasm/WASMModuleParser.h:
+        * wasm/WASMReader.cpp:
+        (JSC::WASMReader::readType):
+        (JSC::WASMReader::readExpressionType):
+        (JSC::WASMReader::readExportFormat):
+        (JSC::WASMReader::readOpStatement):
+        (JSC::WASMReader::readOpExpressionI32):
+        (JSC::WASMReader::readVariableTypes):
+        (JSC::WASMReader::readOp):
+        * wasm/WASMReader.h:
+        (JSC::WASMReader::offset):
+        (JSC::WASMReader::setOffset):
+
 2015-08-21  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/JavaScriptCore/JavaScriptCore.vcxproj/JavaScriptCore.vcxproj

@@ -893 +893 @@
     <ClCompile Include="..\tools\JSDollarVMPrototype.cpp" />
     <ClCompile Include="..\wasm\JSWASMModule.cpp" />
+    <ClCompile Include="..\wasm\WASMFunctionParser.cpp" />
     <ClCompile Include="..\wasm\WASMModuleParser.cpp" />
     <ClCompile Include="..\wasm\WASMReader.cpp" />
@@ -1787 +1788 @@
     <ClInclude Include="..\tools\TieredMMapArray.h" />
     <ClInclude Include="..\wasm\JSWASMModule.h" />
+    <ClInclude Include="..\wasm\WASMConstants.h" />
     <ClInclude Include="..\wasm\WASMFormat.h" />
-    <ClInclude Include="..\wasm\WASMMagicNumber.h" />
+    <ClInclude Include="..\wasm\WASMFunctionParser.h" />
+    <ClInclude Include="..\wasm\WASMFunctionSyntaxChecker.h" />
     <ClInclude Include="..\wasm\WASMModuleParser.h" />
     <ClInclude Include="..\wasm\WASMReader.h" />

trunk/Source/JavaScriptCore/JavaScriptCore.vcxproj/JavaScriptCore.vcxproj.filters

@@ -1842 +1842 @@
       <Filter>wasm</Filter>
     </ClCompile>
+    <ClCompile Include="..\wasm\WASMFunctionParser.cpp">
+      <Filter>wasm</Filter>
+    </ClCompile>
     <ClCompile Include="..\wasm\WASMModuleParser.cpp">
       <Filter>wasm</Filter>
@@ -4421 +4424 @@
       <Filter>wasm</Filter>
     </ClInclude>
+    <ClInclude Include="..\wasm\WASMConstants.h">
+      <Filter>wasm</Filter>
+    </ClInclude>
     <ClInclude Include="..\wasm\WASMFormat.h">
       <Filter>wasm</Filter>
     </ClInclude>
-    <ClInclude Include="..\wasm\WASMMagicNumber.h">
+    <ClInclude Include="..\wasm\WASMFunctionParser.h">
+      <Filter>wasm</Filter>
+    </ClInclude>
+    <ClInclude Include="..\wasm\WASMFunctionSyntaxChecker.h">
       <Filter>wasm</Filter>
     </ClInclude>

trunk/Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj

@@ -1033 +1033 @@
                 79EE0BFF1B4AFB85000385C9 /* VariableEnvironment.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 79EE0BFD1B4AFB85000385C9 /* VariableEnvironment.cpp */; };
                 79EE0C001B4AFB85000385C9 /* VariableEnvironment.h in Headers */ = {isa = PBXBuildFile; fileRef = 79EE0BFE1B4AFB85000385C9 /* VariableEnvironment.h */; settings = {ATTRIBUTES = (Private, ); }; };
+                7B0247551B8682DD00542440 /* WASMConstants.h in Headers */ = {isa = PBXBuildFile; fileRef = 7B0247521B8682D500542440 /* WASMConstants.h */; settings = {ATTRIBUTES = (Private, ); }; };
+                7B0247561B8682E100542440 /* WASMFunctionParser.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 7B0247531B8682D500542440 /* WASMFunctionParser.cpp */; };
+                7B0247571B8682E400542440 /* WASMFunctionParser.h in Headers */ = {isa = PBXBuildFile; fileRef = 7B0247541B8682D500542440 /* WASMFunctionParser.h */; settings = {ATTRIBUTES = (Private, ); }; };
+                7B0247591B868EB700542440 /* WASMFunctionSyntaxChecker.h in Headers */ = {isa = PBXBuildFile; fileRef = 7B0247581B868EAE00542440 /* WASMFunctionSyntaxChecker.h */; settings = {ATTRIBUTES = (Private, ); }; };
                 7B39F76D1B62DE2E00360FB4 /* WASMModuleParser.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 7B39F7691B62DE2200360FB4 /* WASMModuleParser.cpp */; };
                 7B39F76E1B62DE3200360FB4 /* WASMModuleParser.h in Headers */ = {isa = PBXBuildFile; fileRef = 7B39F76A1B62DE2200360FB4 /* WASMModuleParser.h */; settings = {ATTRIBUTES = (Private, ); }; };
                 7B39F7701B62DE3200360FB4 /* WASMReader.h in Headers */ = {isa = PBXBuildFile; fileRef = 7B39F76C1B62DE2200360FB4 /* WASMReader.h */; settings = {ATTRIBUTES = (Private, ); }; };
                 7B39F7721B63574D00360FB4 /* WASMReader.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 7B39F7711B63574B00360FB4 /* WASMReader.cpp */; };
-                7B7A5E271B68288C0027CAD0 /* WASMMagicNumber.h in Headers */ = {isa = PBXBuildFile; fileRef = 7B7A5E261B6828840027CAD0 /* WASMMagicNumber.h */; settings = {ATTRIBUTES = (Private, ); }; };
                 7B98D1361B60CD5F0023B1A4 /* JSWASMModule.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 7B98D1341B60CD5A0023B1A4 /* JSWASMModule.cpp */; };
                 7B98D1371B60CD620023B1A4 /* JSWASMModule.h in Headers */ = {isa = PBXBuildFile; fileRef = 7B98D1351B60CD5A0023B1A4 /* JSWASMModule.h */; settings = {ATTRIBUTES = (Private, ); }; };
@@ -2843 +2846 @@
                 79EE0BFD1B4AFB85000385C9 /* VariableEnvironment.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = VariableEnvironment.cpp; sourceTree = "<group>"; };
                 79EE0BFE1B4AFB85000385C9 /* VariableEnvironment.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = VariableEnvironment.h; sourceTree = "<group>"; };
+                7B0247521B8682D500542440 /* WASMConstants.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WASMConstants.h; sourceTree = "<group>"; };
+                7B0247531B8682D500542440 /* WASMFunctionParser.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = WASMFunctionParser.cpp; sourceTree = "<group>"; };
+                7B0247541B8682D500542440 /* WASMFunctionParser.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WASMFunctionParser.h; sourceTree = "<group>"; };
+                7B0247581B868EAE00542440 /* WASMFunctionSyntaxChecker.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WASMFunctionSyntaxChecker.h; sourceTree = "<group>"; };
                 7B39F7691B62DE2200360FB4 /* WASMModuleParser.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = WASMModuleParser.cpp; sourceTree = "<group>"; };
                 7B39F76A1B62DE2200360FB4 /* WASMModuleParser.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WASMModuleParser.h; sourceTree = "<group>"; };
                 7B39F76C1B62DE2200360FB4 /* WASMReader.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WASMReader.h; sourceTree = "<group>"; };
                 7B39F7711B63574B00360FB4 /* WASMReader.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = WASMReader.cpp; sourceTree = "<group>"; };
-                7B7A5E261B6828840027CAD0 /* WASMMagicNumber.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WASMMagicNumber.h; sourceTree = "<group>"; };
                 7B98D1341B60CD5A0023B1A4 /* JSWASMModule.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = JSWASMModule.cpp; sourceTree = "<group>"; };
                 7B98D1351B60CD5A0023B1A4 /* JSWASMModule.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = JSWASMModule.h; sourceTree = "<group>"; };
@@ -4445 +4451 @@
                                 7B98D1341B60CD5A0023B1A4 /* JSWASMModule.cpp */,
                                 7B98D1351B60CD5A0023B1A4 /* JSWASMModule.h */,
+                                7B0247521B8682D500542440 /* WASMConstants.h */,
                                 7BC547D21B69599B00959B58 /* WASMFormat.h */,
-                                7B7A5E261B6828840027CAD0 /* WASMMagicNumber.h */,
+                                7B0247531B8682D500542440 /* WASMFunctionParser.cpp */,
+                                7B0247541B8682D500542440 /* WASMFunctionParser.h */,
+                                7B0247581B868EAE00542440 /* WASMFunctionSyntaxChecker.h */,
                                 7B39F7691B62DE2200360FB4 /* WASMModuleParser.cpp */,
                                 7B39F76A1B62DE2200360FB4 /* WASMModuleParser.h */,
@@ -5972 +5981 @@
                                 86E116B10FE75AC800B512BC /* CodeLocation.h in Headers */,
                                 0FBD7E691447999600481315 /* CodeOrigin.h in Headers */,
+                                7B0247591B868EB700542440 /* WASMFunctionSyntaxChecker.h in Headers */,
                                 0F21C27D14BE727A00ADC64B /* CodeSpecializationKind.h in Headers */,
                                 0F0B83A714BCF50700885B4F /* CodeType.h in Headers */,
@@ -6231 +6241 @@
                                 0FCEFAE0180738C000472CE4 /* FTLLocation.h in Headers */,
                                 A1587D701B4DC14100D69849 /* IntlDateTimeFormatConstructor.h in Headers */,
+                                7B0247571B8682E400542440 /* WASMFunctionParser.h in Headers */,
                                 0FEA0A10170513DB00BB722C /* FTLLowerDFGToLLVM.h in Headers */,
                                 A7D89D0217A0B90400773AD8 /* FTLLoweredNodeValue.h in Headers */,
@@ -6619 +6630 @@
                                 BC18C4510E16F5CD00B34460 /* ProfileNode.h in Headers */,
                                 0FF729A5166AD351000F5BA3 /* ProfilerBytecode.h in Headers */,
+                                7B0247551B8682DD00542440 /* WASMConstants.h in Headers */,
                                 0FF729B9166AD360000F5BA3 /* ProfilerBytecodes.h in Headers */,
                                 0F13912A16771C36009CCB07 /* ProfilerBytecodeSequence.h in Headers */,
@@ -6642 +6654 @@
                                 0FF7168C15A3B235008F5DAA /* PropertyOffset.h in Headers */,
                                 A785F6BC18C553FE00F10626 /* SpillRegistersMode.h in Headers */,
-                                7B7A5E271B68288C0027CAD0 /* WASMMagicNumber.h in Headers */,
                                 BC18C4550E16F5CD00B34460 /* PropertySlot.h in Headers */,
                                 0FB7F39C15ED8E4600F167B2 /* PropertyStorage.h in Headers */,
@@ -7576 +7587 @@
                                 E33637A51B63220200EE0840 /* ReflectObject.cpp in Sources */,
                                 147F39CB107EC37600427A48 /* FunctionConstructor.cpp in Sources */,
+                                7B0247561B8682E100542440 /* WASMFunctionParser.cpp in Sources */,
                                 0FF0F19F16B72A17005DF95B /* FunctionExecutableDump.cpp in Sources */,
                                 52B310FD1974AE870080857C /* FunctionHasExecutedCache.cpp in Sources */,

trunk/Source/JavaScriptCore/wasm/WASMFormat.h

@@ -66 +66 @@
 };
 
-enum class WASMExportFormat : uint8_t {
-    Default,
-    Record,
-    NumberOfExportFormats
-};
-
 struct WASMSignature {
     WASMExpressionType returnType;

trunk/Source/JavaScriptCore/wasm/WASMFunctionSyntaxChecker.h

@@ -24 +24 @@
  */
 
-#ifndef WASMMagicNumber_h
-#define WASMMagicNumber_h
+#ifndef WASMFunctionSyntaxChecker_h
+#define WASMFunctionSyntaxChecker_h
 
 #if ENABLE(WEBASSEMBLY)
@@ -31 +31 @@
 namespace JSC {
 
-static const uint32_t wasmMagicNumber = 0x6d736177;
+class WASMFunctionSyntaxChecker {
+public:
+    typedef int Expression;
+    typedef int Statement;
+};
 
 } // namespace JSC
@@ -37 +41 @@
 #endif // ENABLE(WEBASSEMBLY)
 
-#endif // WASMMagicNumber_h
+#endif // WASMFunctionSyntaxChecker_h

trunk/Source/JavaScriptCore/wasm/WASMModuleParser.cpp

@@ -32 +32 @@
 #include "JSWASMModule.h"
 #include "StrongInlines.h"
-#include "WASMMagicNumber.h"
+#include "WASMConstants.h"
+#include "WASMFunctionParser.h"
 #include <wtf/MathExtras.h>
 
@@ -50 +51 @@
 
 WASMModuleParser::WASMModuleParser(const SourceCode& source)
-    : m_reader(static_cast<WebAssemblySourceProvider*>(source.provider())->data())
+    : m_source(source)
+    , m_reader(static_cast<WebAssemblySourceProvider*>(source.provider())->data())
 {
 }
@@ -248 +250 @@
 void WASMModuleParser::parseFunctionDefinitionSection()
 {
-    for (size_t i = 0; i < m_module->functionDeclarations().size(); ++i) {
-        parseFunctionDefinition();
+    for (size_t functionIndex = 0; functionIndex < m_module->functionDeclarations().size(); ++functionIndex) {
+        parseFunctionDefinition(functionIndex);
         PROPAGATE_ERROR();
     }
 }
 
-void WASMModuleParser::parseFunctionDefinition()
-{
-    // FIXME: Support any functions. https://bugs.webkit.org/show_bug.cgi?id=147738
-    // Currently, we only support functions that have "return 0;" as their only statement.
-    // These functions consist of exactly 4 bytes, i.e.
-    // 1. The number of local variables (0) [0x80]
-    // 2. The number of statements (1) [0x01]
-    // 3. The return statement [0x0f]
-    // 4. The immediate expression (0) [0xa0]
-    uint32_t functionDefinitionBytes;
-    READ_UINT32_OR_FAIL(functionDefinitionBytes, "Cannot read the function definition.");
-    FAIL_IF_FALSE(functionDefinitionBytes == 0xa00f0180, "Only functions that have \"return 0;\" "
-        "as their only statement are supported at the moment.");
+void WASMModuleParser::parseFunctionDefinition(size_t functionIndex)
+{
+    unsigned startOffsetInSource = m_reader.offset();
+    unsigned endOffsetInSource;
+    String errorMessage;
+    if (!WASMFunctionParser::checkSyntax(m_module.get(), m_source, functionIndex, startOffsetInSource, endOffsetInSource, errorMessage)) {
+        m_errorMessage = errorMessage;
+        return;
+    }
+    m_reader.setOffset(endOffsetInSource);
 }
 

trunk/Source/JavaScriptCore/wasm/WASMModuleParser.h

@@ -55 +55 @@
     void parseFunctionPointerTableSection();
     void parseFunctionDefinitionSection();
-    void parseFunctionDefinition();
+    void parseFunctionDefinition(size_t functionIndex);
     void parseExportSection();
 
+    const SourceCode& m_source;
     WASMReader m_reader;
     Strong<JSWASMModule> m_module;

trunk/Source/JavaScriptCore/wasm/WASMReader.cpp

@@ -22 +22 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * =========================================================================
+ *
+ * Copyright (c) 2015 by the repository authors of
+ * WebAssembly/polyfill-prototype-1.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  */
 
@@ -114 +131 @@
 bool WASMReader::readType(WASMType& result)
 {
-    return readByte<WASMType>(result, (uint8_t)WASMType::NumberOfTypes);
+    return readByte<WASMType>(result, static_cast<uint8_t>(WASMType::NumberOfTypes));
 }
 
 bool WASMReader::readExpressionType(WASMExpressionType& result)
 {
-    return readByte<WASMExpressionType>(result, (uint8_t)WASMExpressionType::NumberOfExpressionTypes);
+    return readByte<WASMExpressionType>(result, static_cast<uint8_t>(WASMExpressionType::NumberOfExpressionTypes));
 }
 
 bool WASMReader::readExportFormat(WASMExportFormat& result)
 {
-    return readByte<WASMExportFormat>(result, (uint8_t)WASMExportFormat::NumberOfExportFormats);
+    return readByte<WASMExportFormat>(result, static_cast<uint8_t>(WASMExportFormat::NumberOfExportFormats));
 }
 
@@ -137 +154 @@
 }
 
+bool WASMReader::readOpStatement(bool& hasImmediate, WASMOpStatement& op, WASMOpStatementWithImmediate& opWithImmediate, uint8_t& immediate)
+{
+    return readOp(hasImmediate, op, opWithImmediate, immediate,
+        static_cast<uint8_t>(WASMOpStatement::NumberOfWASMOpStatements),
+        static_cast<uint8_t>(WASMOpStatementWithImmediate::NumberOfWASMOpStatementWithImmediates));
+}
+
+bool WASMReader::readOpExpressionI32(bool& hasImmediate, WASMOpExpressionI32& op, WASMOpExpressionI32WithImmediate& opWithImmediate, uint8_t& immediate)
+{
+    return readOp(hasImmediate, op, opWithImmediate, immediate,
+        static_cast<uint8_t>(WASMOpExpressionI32::NumberOfWASMOpExpressionI32s),
+        static_cast<uint8_t>(WASMOpExpressionI32WithImmediate::NumberOfWASMOpExpressionI32WithImmediates));
+}
+
+bool WASMReader::readVariableTypes(bool& hasImmediate, WASMVariableTypes& variableTypes, WASMVariableTypesWithImmediate& variableTypesWithImmediate, uint8_t& immediate)
+{
+    return readOp(hasImmediate, variableTypes, variableTypesWithImmediate, immediate,
+        static_cast<uint8_t>(WASMVariableTypes::NumberOfVariableTypes),
+        static_cast<uint8_t>(WASMVariableTypesWithImmediate::NumberOfVariableTypesWithImmediates));
+}
+
+template <class T, class TWithImmediate>
+bool WASMReader::readOp(bool& hasImmediate, T& op, TWithImmediate& opWithImmediate, uint8_t& immediate, uint8_t numberOfValues, uint8_t numberOfValuesWithImmediate)
+{
+    CHECK_READ(1);
+    uint8_t byte = *m_cursor++;
+
+    if (!(byte & hasImmediateInOpFlag)) {
+        if (byte >= numberOfValues)
+            return false;
+        hasImmediate = false;
+        op = T(byte);
+        return true;
+    }
+
+    uint8_t byteWithoutImmediate = (byte >> immediateBits) & (opWithImmediateLimit - 1);
+    if (byteWithoutImmediate >= numberOfValuesWithImmediate)
+        return false;
+    hasImmediate = true;
+    opWithImmediate = TWithImmediate(byteWithoutImmediate);
+    immediate = byte & (immediateLimit - 1);
+    return true;
+}
+
 } // namespace JSC
 

trunk/Source/JavaScriptCore/wasm/WASMReader.h

@@ -29 +29 @@
 #if ENABLE(WEBASSEMBLY)
 
+#include "WASMConstants.h"
 #include "WASMFormat.h"
 #include <wtf/Vector.h>
@@ -42 +43 @@
     }
 
+    unsigned offset() const { return m_cursor - m_buffer.data(); }
+    void setOffset(unsigned offset) { m_cursor = m_buffer.data() + offset; }
+
     bool readUInt32(uint32_t& result);
     bool readFloat(float& result);
@@ -50 +54 @@
     bool readExpressionType(WASMExpressionType& result);
     bool readExportFormat(WASMExportFormat& result);
+    bool readOpStatement(bool& hasImmediate, WASMOpStatement&, WASMOpStatementWithImmediate&, uint8_t& immediate);
+    bool readOpExpressionI32(bool& hasImmediate, WASMOpExpressionI32&, WASMOpExpressionI32WithImmediate&, uint8_t& immediate);
+    bool readVariableTypes(bool& hasImmediate, WASMVariableTypes&, WASMVariableTypesWithImmediate&, uint8_t& immediate);
 
 private:
@@ -55 +62 @@
 
     template <class T> bool readByte(T& result, uint8_t numberOfValues);
+    template <class T, class TWithImmediate> bool readOp(bool& hasImmediate, T&, TWithImmediate&, uint8_t& immediate, uint8_t numberOfValues, uint8_t numberOfValuesWithImmediate);
 
     const Vector<uint8_t>& m_buffer;