[webkit-changes] [293265] trunk/Source/JavaScriptCore

[dbezhetskov]

Title: [293265] trunk/Source/_javascript_Core

Revision

293265

Author

dbezhets...@igalia.com

Date

2022-04-22 16:21:38 -0700 (Fri, 22 Apr 2022)

Log Message

[Refactoring] Reduce number of const and reinterpret casts
https://bugs.webkit.org/show_bug.cgi?id=239648

Reviewed by Yusuke Suzuki.

The statement
"reinterpret_cast<TypeDefinition*>(const_cast<char*>(functionType.m_payload)
- sizeof(TypeDefinition))"
is dangerous and it produces warning on some platfroms.
There is way to avoid it and this patch is doint that.

* wasm/WasmSlowPaths.cpp:
(JSC::LLInt::doWasmCallIndirect):
(JSC::LLInt::doWasmCallRef):
* wasm/WasmTypeDefinition.h:
(JSC::Wasm::FunctionSignature::operator== const):
* wasm/WasmTypeDefinitionInlines.h:

Modified Paths

• trunk/Source/_javascript_Core/ChangeLog
• trunk/Source/_javascript_Core/wasm/WasmSlowPaths.cpp
• trunk/Source/_javascript_Core/wasm/WasmTypeDefinition.h
• trunk/Source/_javascript_Core/wasm/WasmTypeDefinitionInlines.h

Diff

Modified: trunk/Source/_javascript_Core/ChangeLog (293264 => 293265)

--- trunk/Source/_javascript_Core/ChangeLog	2022-04-22 23:19:24 UTC (rev 293264)
+++ trunk/Source/_javascript_Core/ChangeLog	2022-04-22 23:21:38 UTC (rev 293265)
@@ -1,3 +1,23 @@
+2022-04-22  Dmitry Bezhetskov  <dbezhets...@igalia.com>
+
+        [Refactoring] Reduce number of const and reinterpret casts
+        https://bugs.webkit.org/show_bug.cgi?id=239648
+
+        Reviewed by Yusuke Suzuki.
+        
+        The statement
+        "reinterpret_cast<TypeDefinition*>(const_cast<char*>(functionType.m_payload)
+        - sizeof(TypeDefinition))"
+        is dangerous and it produces warning on some platfroms.
+        There is way to avoid it and this patch is doint that.
+
+        * wasm/WasmSlowPaths.cpp:
+        (JSC::LLInt::doWasmCallIndirect):
+        (JSC::LLInt::doWasmCallRef):
+        * wasm/WasmTypeDefinition.h:
+        (JSC::Wasm::FunctionSignature::operator== const):
+        * wasm/WasmTypeDefinitionInlines.h:
+
 2022-04-22  Geza Lore  <gl...@igalia.com>
 
         [JSC]Throw consistent exceptions for memory.init and memory.copy

Modified: trunk/Source/_javascript_Core/wasm/WasmSlowPaths.cpp (293264 => 293265)

--- trunk/Source/_javascript_Core/wasm/WasmSlowPaths.cpp	2022-04-22 23:19:24 UTC (rev 293264)
+++ trunk/Source/_javascript_Core/wasm/WasmSlowPaths.cpp	2022-04-22 23:21:38 UTC (rev 293265)
@@ -500,7 +500,7 @@
         WASM_THROW(Wasm::ExceptionType::NullTableEntry);
 
     const auto& callSignature = CALLEE()->signature(typeIndex);
-    if (function.typeIndex != Wasm::TypeInformation::get(callSignature))
+    if (callSignature != Wasm::TypeInformation::getFunctionSignature(function.typeIndex))
         WASM_THROW(Wasm::ExceptionType::BadSignature);
 
     if (targetInstance != instance)
@@ -541,7 +541,7 @@
     if (calleeInstance != callerInstance)
         calleeInstance->setCachedStackLimit(callerInstance->cachedStackLimit());
 
-    ASSERT(function.typeIndex == Wasm::TypeInformation::get(CALLEE()->signature(typeIndex)));
+    ASSERT(Wasm::TypeInformation::getFunctionSignature(function.typeIndex) == CALLEE()->signature(typeIndex));
     UNUSED_PARAM(typeIndex);
     WASM_CALL_RETURN(calleeInstance, function.entrypointLoadLocation->executableAddress(), WasmEntryPtrTag);
 }

Modified: trunk/Source/_javascript_Core/wasm/WasmTypeDefinition.h (293264 => 293265)

--- trunk/Source/_javascript_Core/wasm/WasmTypeDefinition.h	2022-04-22 23:19:24 UTC (rev 293264)
+++ trunk/Source/_javascript_Core/wasm/WasmTypeDefinition.h	2022-04-22 23:21:38 UTC (rev 293265)
@@ -60,6 +60,14 @@
     bool returnsVoid() const { return !returnCount(); }
     Type argumentType(FunctionArgCount i) const { return const_cast<FunctionSignature*>(this)->getArgumentType(i); }
 
+    bool operator==(const FunctionSignature& other) const
+    {
+        // Function signatures are unique because it is just an view class over TypeDefinition and
+        // so, we can compare two signatures with just payload pointers comparision.
+        // Other checks probably aren't necessary but it's good to be paranoid.
+        return m_payload == other.m_payload && m_argCount == other.m_argCount && m_retCount == other.m_retCount;
+    }
+
     WTF::String toString() const;
     void dump(WTF::PrintStream& out) const;
 
@@ -217,7 +225,6 @@
     static const TypeDefinition& get(TypeIndex);
     static TypeIndex get(const TypeDefinition&);
 
-    static TypeIndex get(const FunctionSignature&);
     static const FunctionSignature& getFunctionSignature(TypeIndex);
 
     static void tryCleanup();

Modified: trunk/Source/_javascript_Core/wasm/WasmTypeDefinitionInlines.h (293264 => 293265)

--- trunk/Source/_javascript_Core/wasm/WasmTypeDefinitionInlines.h	2022-04-22 23:19:24 UTC (rev 293264)
+++ trunk/Source/_javascript_Core/wasm/WasmTypeDefinitionInlines.h	2022-04-22 23:21:38 UTC (rev 293265)
@@ -64,11 +64,6 @@
     return bitwise_cast<TypeIndex>(&type);
 }
 
-inline TypeIndex TypeInformation::get(const FunctionSignature& functionType)
-{
-    return get(*reinterpret_cast<TypeDefinition*>(const_cast<char*>(functionType.m_payload) - sizeof(TypeDefinition)));
-}
-
 } } // namespace JSC::Wasm
 
 #endif // ENABLE(WEBASSEMBLY)

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