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Merge pull request #1468 from chriseth/sol_pullOutIndexaccess

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Refactor: Pull out array index access.
This commit is contained in:
Gav Wood 2015-03-31 11:19:42 +02:00
commit 4227be6e12
3 changed files with 117 additions and 100 deletions
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104
ArrayUtils.cpp
View File

@ -440,6 +440,110 @@ void ArrayUtils::retrieveLength(ArrayType const& _arrayType) const
}
}
void ArrayUtils::accessIndex(ArrayType const& _arrayType) const
{
ArrayType::Location location = _arrayType.getLocation();
eth::Instruction load =
location == ArrayType::Location::Storage ? eth::Instruction::SLOAD :
location == ArrayType::Location::Memory ? eth::Instruction::MLOAD :
eth::Instruction::CALLDATALOAD;
// retrieve length
if (!_arrayType.isDynamicallySized())
m_context << _arrayType.getLength();
else if (location == ArrayType::Location::CallData)
// length is stored on the stack
m_context << eth::Instruction::SWAP1;
else
m_context << eth::Instruction::DUP2 << load;
// stack: <base_ref> <index> <length>
// check out-of-bounds access
m_context << eth::Instruction::DUP2 << eth::Instruction::LT;
eth::AssemblyItem legalAccess = m_context.appendConditionalJump();
// out-of-bounds access throws exception (just STOP for now)
m_context << eth::Instruction::STOP;
m_context << legalAccess;
// stack: <base_ref> <index>
if (_arrayType.isByteArray())
switch (location)
{
case ArrayType::Location::Storage:
// byte array index storage lvalue on stack (goal):
// <ref> <byte_number> = <base_ref + index / 32> <index % 32>
m_context << u256(32) << eth::Instruction::SWAP2;
CompilerUtils(m_context).computeHashStatic();
// stack: 32 index data_ref
m_context
<< eth::Instruction::DUP3 << eth::Instruction::DUP3
<< eth::Instruction::DIV << eth::Instruction::ADD
// stack: 32 index (data_ref + index / 32)
<< eth::Instruction::SWAP2 << eth::Instruction::SWAP1
<< eth::Instruction::MOD;
break;
case ArrayType::Location::CallData:
// no lvalue, just retrieve the value
m_context
<< eth::Instruction::ADD << eth::Instruction::CALLDATALOAD
<< ((u256(0xff) << (256 - 8))) << eth::Instruction::AND;
break;
case ArrayType::Location::Memory:
solAssert(false, "Memory lvalues not yet implemented.");
}
else
{
// stack: <base_ref> <index>
m_context << eth::Instruction::SWAP1;
if (_arrayType.isDynamicallySized())
{
if (location == ArrayType::Location::Storage)
CompilerUtils(m_context).computeHashStatic();
else if (location == ArrayType::Location::Memory)
m_context << u256(32) << eth::Instruction::ADD;
}
// stack: <index> <data_ref>
switch (location)
{
case ArrayType::Location::CallData:
m_context
<< eth::Instruction::SWAP1 << _arrayType.getBaseType()->getCalldataEncodedSize()
<< eth::Instruction::MUL << eth::Instruction::ADD;
if (_arrayType.getBaseType()->isValueType())
CompilerUtils(m_context).loadFromMemoryDynamic(*_arrayType.getBaseType(), true, true, false);
break;
case ArrayType::Location::Storage:
m_context << eth::Instruction::SWAP1;
if (_arrayType.getBaseType()->getStorageBytes() <= 16)
{
// stack: <data_ref> <index>
// goal:
// <ref> <byte_number> = <base_ref + index / itemsPerSlot> <(index % itemsPerSlot) * byteSize>
unsigned byteSize = _arrayType.getBaseType()->getStorageBytes();
solAssert(byteSize != 0, "");
unsigned itemsPerSlot = 32 / byteSize;
m_context << u256(itemsPerSlot) << eth::Instruction::SWAP2;
// stack: itemsPerSlot index data_ref
m_context
<< eth::Instruction::DUP3 << eth::Instruction::DUP3
<< eth::Instruction::DIV << eth::Instruction::ADD
// stack: itemsPerSlot index (data_ref + index / itemsPerSlot)
<< eth::Instruction::SWAP2 << eth::Instruction::SWAP1
<< eth::Instruction::MOD
<< u256(byteSize) << eth::Instruction::MUL;
}
else
{
if (_arrayType.getBaseType()->getStorageSize() != 1)
m_context << _arrayType.getBaseType()->getStorageSize() << eth::Instruction::MUL;
m_context << eth::Instruction::ADD << u256(0);
}
break;
case ArrayType::Location::Memory:
solAssert(false, "Memory lvalues not yet implemented.");
}
}
}
void ArrayUtils::incrementByteOffset(unsigned _byteSize, unsigned _byteOffsetPosition, unsigned _storageOffsetPosition) const
{
solAssert(_byteSize < 32, "");

6
ArrayUtils.h
View File

@ -70,6 +70,12 @@ public:
/// Stack pre: reference (excludes byte offset for dynamic storage arrays)
/// Stack post: reference length
void retrieveLength(ArrayType const& _arrayType) const;
/// Retrieves the value at a specific index. If the location is storage, only retrieves the
/// position.
/// Stack pre: reference [length] index
/// Stack post for storage: slot byte_offset
/// Stack post for calldata: value
void accessIndex(ArrayType const& _arrayType) const;
private:
/// Adds the given number of bytes to a storage byte offset counter and also increments

103
ExpressionCompiler.cpp
View File

@ -755,113 +755,20 @@ bool ExpressionCompiler::visit(IndexAccess const& _indexAccess)
{
ArrayType const& arrayType = dynamic_cast<ArrayType const&>(baseType);
solAssert(_indexAccess.getIndexExpression(), "Index expression expected.");
ArrayType::Location location = arrayType.getLocation();
eth::Instruction load =
location == ArrayType::Location::Storage ? eth::Instruction::SLOAD :
location == ArrayType::Location::Memory ? eth::Instruction::MLOAD :
eth::Instruction::CALLDATALOAD;
// remove storage byte offset
if (location == ArrayType::Location::Storage)
if (arrayType.getLocation() == ArrayType::Location::Storage)
m_context << eth::Instruction::POP;
// stack layout: <base_ref> [<length>] <index>
_indexAccess.getIndexExpression()->accept(*this);
// retrieve length
if (!arrayType.isDynamicallySized())
m_context << arrayType.getLength();
else if (location == ArrayType::Location::CallData)
// length is stored on the stack
m_context << eth::Instruction::SWAP1;
else
m_context << eth::Instruction::DUP2 << load;
// stack: <base_ref> <index> <length>
// check out-of-bounds access
m_context << eth::Instruction::DUP2 << eth::Instruction::LT;
eth::AssemblyItem legalAccess = m_context.appendConditionalJump();
// out-of-bounds access throws exception (just STOP for now)
m_context << eth::Instruction::STOP;
m_context << legalAccess;
// stack: <base_ref> <index>
// stack layout: <base_ref> [<length>] <index>
ArrayUtils(m_context).accessIndex(arrayType);
if (arrayType.getLocation() == ArrayType::Location::Storage)
{
if (arrayType.isByteArray())
switch (location)
{
case ArrayType::Location::Storage:
// byte array index storage lvalue on stack (goal):
// <ref> <byte_number> = <base_ref + index / 32> <index % 32>
m_context << u256(32) << eth::Instruction::SWAP2;
CompilerUtils(m_context).computeHashStatic();
// stack: 32 index data_ref
m_context
<< eth::Instruction::DUP3 << eth::Instruction::DUP3
<< eth::Instruction::DIV << eth::Instruction::ADD
// stack: 32 index (data_ref + index / 32)
<< eth::Instruction::SWAP2 << eth::Instruction::SWAP1
<< eth::Instruction::MOD;
setLValue<StorageByteArrayElement>(_indexAccess);
break;
case ArrayType::Location::CallData:
// no lvalue, just retrieve the value
m_context
<< eth::Instruction::ADD << eth::Instruction::CALLDATALOAD
<< ((u256(0xff) << (256 - 8))) << eth::Instruction::AND;
break;
case ArrayType::Location::Memory:
solAssert(false, "Memory lvalues not yet implemented.");
}
else
{
// stack: <base_ref> <index>
m_context << eth::Instruction::SWAP1;
if (arrayType.isDynamicallySized())
{
if (location == ArrayType::Location::Storage)
CompilerUtils(m_context).computeHashStatic();
else if (location == ArrayType::Location::Memory)
m_context << u256(32) << eth::Instruction::ADD;
}
// stack: <index> <data_ref>
switch (location)
{
case ArrayType::Location::CallData:
m_context
<< eth::Instruction::SWAP1 << arrayType.getBaseType()->getCalldataEncodedSize()
<< eth::Instruction::MUL << eth::Instruction::ADD;
if (arrayType.getBaseType()->isValueType())
CompilerUtils(m_context).loadFromMemoryDynamic(*arrayType.getBaseType(), true, true, false);
break;
case ArrayType::Location::Storage:
m_context << eth::Instruction::SWAP1;
if (arrayType.getBaseType()->getStorageBytes() <= 16)
{
// stack: <data_ref> <index>
// goal:
// <ref> <byte_number> = <base_ref + index / itemsPerSlot> <(index % itemsPerSlot) * byteSize>
unsigned byteSize = arrayType.getBaseType()->getStorageBytes();
solAssert(byteSize != 0, "");
unsigned itemsPerSlot = 32 / byteSize;
m_context << u256(itemsPerSlot) << eth::Instruction::SWAP2;
// stack: itemsPerSlot index data_ref
m_context
<< eth::Instruction::DUP3 << eth::Instruction::DUP3
<< eth::Instruction::DIV << eth::Instruction::ADD
// stack: itemsPerSlot index (data_ref + index / itemsPerSlot)
<< eth::Instruction::SWAP2 << eth::Instruction::SWAP1
<< eth::Instruction::MOD
<< u256(byteSize) << eth::Instruction::MUL;
}
else
{
if (arrayType.getBaseType()->getStorageSize() != 1)
m_context << arrayType.getBaseType()->getStorageSize() << eth::Instruction::MUL;
m_context << eth::Instruction::ADD << u256(0);
}
setLValueToStorageItem(_indexAccess);
break;
case ArrayType::Location::Memory:
solAssert(false, "Memory lvalues not yet implemented.");
}
}
}
else