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codegen: add an option to CovertType so that it can truncate sign bits

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This commit is contained in:
Yoichi Hirai 2016-11-21 17:07:10 +01:00
parent 56d6641086
commit ea628001d5
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GPG Key ID: E7B75D080FCF7992
3 changed files with 22 additions and 10 deletions
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20
libsolidity/codegen/CompilerUtils.cpp
View File

@ -358,7 +358,7 @@ void CompilerUtils::pushCombinedFunctionEntryLabel(Declaration const& _function)
Instruction::OR;
}
void CompilerUtils::convertType(Type const& _typeOnStack, Type const& _targetType, bool _cleanupNeeded)
void CompilerUtils::convertType(Type const& _typeOnStack, Type const& _targetType, bool _cleanupNeeded, bool _chopSignBits)
{
// For a type extension, we need to remove all higher-order bits that we might have ignored in
// previous operations.
@ -370,6 +370,12 @@ void CompilerUtils::convertType(Type const& _typeOnStack, Type const& _targetTyp
Type::Category targetTypeCategory = _targetType.category();
bool enumOverflowCheckPending = (targetTypeCategory == Type::Category::Enum || stackTypeCategory == Type::Category::Enum);
bool chopSignBitsPending = _chopSignBits && targetTypeCategory == Type::Category::Integer;
if (chopSignBitsPending)
{
const IntegerType& targetIntegerType = dynamic_cast<const IntegerType &>(_targetType);
chopSignBitsPending = targetIntegerType.isSigned();
}
switch (stackTypeCategory)
{
@ -482,6 +488,17 @@ void CompilerUtils::convertType(Type const& _typeOnStack, Type const& _targetTyp
cleanHigherOrderBits(typeOnStack);
else if (_cleanupNeeded)
cleanHigherOrderBits(targetType);
if (chopSignBitsPending)
{
if (typeOnStack.numBits() < 256)
m_context
<< (u256(1) << (256 - typeOnStack.numBits()))
<< Instruction::SWAP1
<< Instruction::DUP2
<< Instruction::MUL
<< Instruction::DIV;
chopSignBitsPending = false;
}
}
}
break;
@ -728,6 +745,7 @@ void CompilerUtils::convertType(Type const& _typeOnStack, Type const& _targetTyp
}
solAssert(!enumOverflowCheckPending, "enum overflow checking missing.");
solAssert(!chopSignBitsPending, "forgot to chop the sign bits.");
}
void CompilerUtils::pushZeroValue(Type const& _type)

2
libsolidity/codegen/CompilerUtils.h
View File

@ -130,7 +130,7 @@ public:
/// if a reference type is converted from calldata or storage to memory.
/// If @a _cleanupNeeded, high order bits cleanup is also done if no type conversion would be
/// necessary.
void convertType(Type const& _typeOnStack, Type const& _targetType, bool _cleanupNeeded = false);
void convertType(Type const& _typeOnStack, Type const& _targetType, bool _cleanupNeeded = false, bool _chopSignBits = false);
/// Creates a zero-value for the given type and puts it onto the stack. This might allocate
/// memory for memory references.

10
libsolidity/codegen/LValue.cpp
View File

@ -234,7 +234,7 @@ void StorageItem::storeValue(Type const& _sourceType, SourceLocation const& _loc
m_context << Instruction::SWAP1;
utils.convertType(_sourceType, _sourceType, true);
utils.convertType(*m_dataType, *m_dataType, true);
utils.convertType(*m_dataType, *m_dataType, true, true);
m_context << Instruction::SWAP1;
m_context << Instruction::SSTORE;
@ -280,13 +280,7 @@ void StorageItem::storeValue(Type const& _sourceType, SourceLocation const& _loc
{
solAssert(m_dataType->sizeOnStack() == 1, "Invalid stack size for opaque type.");
// remove the higher order bits
utils.convertType(*m_dataType, *m_dataType, true);
m_context
<< (u256(1) << (8 * (32 - m_dataType->storageBytes())))
<< Instruction::SWAP1
<< Instruction::DUP2
<< Instruction::MUL
<< Instruction::DIV;
utils.convertType(*m_dataType, *m_dataType, true, true);
}
m_context << Instruction::MUL << Instruction::OR;
// stack: value storage_ref updated_value