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-rw-r--r--libsolidity/ast/Types.h13
-rw-r--r--libsolidity/codegen/CompilerUtils.cpp36
-rw-r--r--libsolidity/codegen/ExpressionCompiler.cpp21
3 files changed, 45 insertions, 25 deletions
diff --git a/libsolidity/ast/Types.h b/libsolidity/ast/Types.h
index b7e64891..2c392705 100644
--- a/libsolidity/ast/Types.h
+++ b/libsolidity/ast/Types.h
@@ -229,6 +229,9 @@ public:
/// i.e. it behaves differently in lvalue context and in value context.
virtual bool isValueType() const { return false; }
virtual unsigned sizeOnStack() const { return 1; }
+ /// If it is possible to initialize such a value in memory by just writing zeros
+ /// of the size memoryHeadSize().
+ virtual bool hasSimpleZeroValueInMemory() const { return true; }
/// @returns the mobile (in contrast to static) type corresponding to the given type.
/// This returns the corresponding IntegerType or FixedPointType for RationalNumberType
/// and the pointer type for storage reference types.
@@ -568,6 +571,7 @@ public:
virtual TypePointer mobileType() const override { return copyForLocation(m_location, true); }
virtual bool dataStoredIn(DataLocation _location) const override { return m_location == _location; }
+ virtual bool hasSimpleZeroValueInMemory() const override { return false; }
/// Storage references can be pointers or bound references. In general, local variables are of
/// pointer type, state variables are bound references. Assignments to pointers or deleting
@@ -855,6 +859,7 @@ public:
virtual u256 storageSize() const override;
virtual bool canLiveOutsideStorage() const override { return false; }
virtual unsigned sizeOnStack() const override;
+ virtual bool hasSimpleZeroValueInMemory() const override { return false; }
virtual TypePointer mobileType() const override;
/// Converts components to their temporary types and performs some wildcard matching.
virtual TypePointer closestTemporaryType(TypePointer const& _targetType) const override;
@@ -999,6 +1004,7 @@ public:
virtual bool isValueType() const override { return true; }
virtual bool canLiveOutsideStorage() const override { return m_kind == Kind::Internal || m_kind == Kind::External; }
virtual unsigned sizeOnStack() const override;
+ virtual bool hasSimpleZeroValueInMemory() const override { return false; }
virtual MemberList::MemberMap nativeMembers(ContractDefinition const* _currentScope) const override;
virtual TypePointer encodingType() const override;
virtual TypePointer interfaceType(bool _inLibrary) const override;
@@ -1104,6 +1110,8 @@ public:
return _inLibrary ? shared_from_this() : TypePointer();
}
virtual bool dataStoredIn(DataLocation _location) const override { return _location == DataLocation::Storage; }
+ /// Cannot be stored in memory, but just in case.
+ virtual bool hasSimpleZeroValueInMemory() const override { solAssert(false, ""); }
TypePointer const& keyType() const { return m_keyType; }
TypePointer const& valueType() const { return m_valueType; }
@@ -1132,6 +1140,7 @@ public:
virtual u256 storageSize() const override;
virtual bool canLiveOutsideStorage() const override { return false; }
virtual unsigned sizeOnStack() const override;
+ virtual bool hasSimpleZeroValueInMemory() const override { solAssert(false, ""); }
virtual std::string toString(bool _short) const override { return "type(" + m_actualType->toString(_short) + ")"; }
virtual MemberList::MemberMap nativeMembers(ContractDefinition const* _currentScope) const override;
@@ -1154,6 +1163,7 @@ public:
virtual u256 storageSize() const override;
virtual bool canLiveOutsideStorage() const override { return false; }
virtual unsigned sizeOnStack() const override { return 0; }
+ virtual bool hasSimpleZeroValueInMemory() const override { solAssert(false, ""); }
virtual std::string richIdentifier() const override;
virtual bool operator==(Type const& _other) const override;
virtual std::string toString(bool _short) const override;
@@ -1179,6 +1189,7 @@ public:
virtual bool operator==(Type const& _other) const override;
virtual bool canBeStored() const override { return false; }
virtual bool canLiveOutsideStorage() const override { return true; }
+ virtual bool hasSimpleZeroValueInMemory() const override { solAssert(false, ""); }
virtual unsigned sizeOnStack() const override { return 0; }
virtual MemberList::MemberMap nativeMembers(ContractDefinition const*) const override;
@@ -1209,6 +1220,7 @@ public:
virtual bool operator==(Type const& _other) const override;
virtual bool canBeStored() const override { return false; }
virtual bool canLiveOutsideStorage() const override { return true; }
+ virtual bool hasSimpleZeroValueInMemory() const override { solAssert(false, ""); }
virtual unsigned sizeOnStack() const override { return 0; }
virtual MemberList::MemberMap nativeMembers(ContractDefinition const*) const override;
@@ -1238,6 +1250,7 @@ public:
virtual bool canLiveOutsideStorage() const override { return false; }
virtual bool isValueType() const override { return true; }
virtual unsigned sizeOnStack() const override { return 1; }
+ virtual bool hasSimpleZeroValueInMemory() const override { solAssert(false, ""); }
virtual std::string toString(bool) const override { return "inaccessible dynamic type"; }
virtual TypePointer decodingType() const override { return std::make_shared<IntegerType>(256); }
};
diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp
index 676d5d4e..deaef017 100644
--- a/libsolidity/codegen/CompilerUtils.cpp
+++ b/libsolidity/codegen/CompilerUtils.cpp
@@ -495,14 +495,34 @@ void CompilerUtils::abiDecodeV2(TypePointers const& _parameterTypes, bool _fromM
void CompilerUtils::zeroInitialiseMemoryArray(ArrayType const& _type)
{
- auto repeat = m_context.newTag();
- m_context << repeat;
- pushZeroValue(*_type.baseType());
- storeInMemoryDynamic(*_type.baseType());
- m_context << Instruction::SWAP1 << u256(1) << Instruction::SWAP1;
- m_context << Instruction::SUB << Instruction::SWAP1;
- m_context << Instruction::DUP2;
- m_context.appendConditionalJumpTo(repeat);
+ if (_type.baseType()->hasSimpleZeroValueInMemory())
+ {
+ solAssert(_type.baseType()->isValueType(), "");
+ Whiskers templ(R"({
+ let size := mul(length, <element_size>)
+ // cheap way of zero-initializing a memory range
+ codecopy(memptr, codesize(), size)
+ memptr := add(memptr, size)
+ })");
+ templ("element_size", to_string(_type.baseType()->memoryHeadSize()));
+ m_context.appendInlineAssembly(templ.render(), {"length", "memptr"});
+ }
+ else
+ {
+ // TODO: Potential optimization:
+ // When we create a new multi-dimensional dynamic array, each element
+ // is initialized to an empty array. It actually does not hurt
+ // to re-use exactly the same empty array for all elements. Currently,
+ // a new one is created each time.
+ auto repeat = m_context.newTag();
+ m_context << repeat;
+ pushZeroValue(*_type.baseType());
+ storeInMemoryDynamic(*_type.baseType());
+ m_context << Instruction::SWAP1 << u256(1) << Instruction::SWAP1;
+ m_context << Instruction::SUB << Instruction::SWAP1;
+ m_context << Instruction::DUP2;
+ m_context.appendConditionalJumpTo(repeat);
+ }
m_context << Instruction::SWAP1 << Instruction::POP;
}
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index 9e2d30d5..76aa6843 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -850,8 +850,6 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
}
case FunctionType::Kind::ObjectCreation:
{
- // Will allocate at the end of memory (MSIZE) and not write at all unless the base
- // type is dynamically sized.
ArrayType const& arrayType = dynamic_cast<ArrayType const&>(*_functionCall.annotation().type);
_functionCall.expression().accept(*this);
solAssert(arguments.size() == 1, "");
@@ -861,15 +859,7 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
utils().convertType(*arguments[0]->annotation().type, IntegerType(256));
// Stack: requested_length
- // Allocate at max(MSIZE, freeMemoryPointer)
utils().fetchFreeMemoryPointer();
- m_context << Instruction::DUP1 << Instruction::MSIZE;
- m_context << Instruction::LT;
- auto initialise = m_context.appendConditionalJump();
- // Free memory pointer does not point to empty memory, use MSIZE.
- m_context << Instruction::POP;
- m_context << Instruction::MSIZE;
- m_context << initialise;
// Stack: requested_length memptr
m_context << Instruction::SWAP1;
@@ -894,13 +884,10 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
// Check if length is zero
m_context << Instruction::DUP1 << Instruction::ISZERO;
auto skipInit = m_context.appendConditionalJump();
-
- // We only have to initialise if the base type is a not a value type.
- if (dynamic_cast<ReferenceType const*>(arrayType.baseType().get()))
- {
- m_context << Instruction::DUP2 << u256(32) << Instruction::ADD;
- utils().zeroInitialiseMemoryArray(arrayType);
- }
+ // Always initialize because the free memory pointer might point at
+ // a dirty memory area.
+ m_context << Instruction::DUP2 << u256(32) << Instruction::ADD;
+ utils().zeroInitialiseMemoryArray(arrayType);
m_context << skipInit;
m_context << Instruction::POP;
break;
generated by cgit (git 2.34.1) at 2024-11-18 15:59:41 +0800