Changeset 293265 in webkit

Timestamp:

Apr 22, 2022, 4:21:38 PM (4 years ago)

Author:

dbezhetskov

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:

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• wasm/WasmSlowPaths.cpp (modified) (2 diffs)
• wasm/WasmTypeDefinition.h (modified) (2 diffs)
• wasm/WasmTypeDefinitionInlines.h (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2022-04-22  Dmitry Bezhetskov  <dbezhetskov@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  <glore@igalia.com>
 

trunk/Source/JavaScriptCore/wasm/WasmSlowPaths.cpp

@@ -501 +501 @@
 
     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);
 
@@ -542 +542 @@
         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);

trunk/Source/JavaScriptCore/wasm/WasmTypeDefinition.h

@@ -61 +61 @@
     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;
@@ -218 +226 @@
     static TypeIndex get(const TypeDefinition&);
 
-    static TypeIndex get(const FunctionSignature&);
     static const FunctionSignature& getFunctionSignature(TypeIndex);
 

trunk/Source/JavaScriptCore/wasm/WasmTypeDefinitionInlines.h

@@ -65 +65 @@
 }
 
-inline TypeIndex TypeInformation::get(const FunctionSignature& functionType)
-{
-    return get(*reinterpret_cast<TypeDefinition*>(const_cast<char*>(functionType.m_payload) - sizeof(TypeDefinition)));
-}
-
 } } // namespace JSC::Wasm