diff options
Diffstat (limited to 'libsolidity/codegen/CompilerUtils.cpp')
| -rw-r--r-- | libsolidity/codegen/CompilerUtils.cpp | 30 |
1 files changed, 22 insertions, 8 deletions
diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp index deaef017..79aef7b0 100644 --- a/libsolidity/codegen/CompilerUtils.cpp +++ b/libsolidity/codegen/CompilerUtils.cpp @@ -21,6 +21,7 @@ */ #include <libsolidity/codegen/CompilerUtils.h> + #include <libsolidity/ast/AST.h> #include <libsolidity/codegen/ArrayUtils.h> #include <libsolidity/codegen/LValue.h> @@ -39,11 +40,17 @@ namespace solidity const unsigned CompilerUtils::dataStartOffset = 4; const size_t CompilerUtils::freeMemoryPointer = 64; +const size_t CompilerUtils::zeroPointer = CompilerUtils::freeMemoryPointer + 32; +const size_t CompilerUtils::generalPurposeMemoryStart = CompilerUtils::zeroPointer + 32; const unsigned CompilerUtils::identityContractAddress = 4; +static_assert(CompilerUtils::freeMemoryPointer >= 64, "Free memory pointer must not overlap with scratch area."); +static_assert(CompilerUtils::zeroPointer >= CompilerUtils::freeMemoryPointer + 32, "Zero pointer must not overlap with free memory pointer."); +static_assert(CompilerUtils::generalPurposeMemoryStart >= CompilerUtils::zeroPointer + 32, "General purpose memory must not overlap with zero area."); + void CompilerUtils::initialiseFreeMemoryPointer() { - m_context << u256(freeMemoryPointer + 32); + m_context << u256(generalPurposeMemoryStart); storeFreeMemoryPointer(); } @@ -1051,6 +1058,13 @@ void CompilerUtils::pushZeroValue(Type const& _type) return; } solAssert(referenceType->location() == DataLocation::Memory, ""); + if (auto arrayType = dynamic_cast<ArrayType const*>(&_type)) + if (arrayType->isDynamicallySized()) + { + // Push a memory location that is (hopefully) always zero. + pushZeroPointer(); + return; + } TypePointer type = _type.shared_from_this(); m_context.callLowLevelFunction( @@ -1071,13 +1085,8 @@ void CompilerUtils::pushZeroValue(Type const& _type) } else if (auto arrayType = dynamic_cast<ArrayType const*>(type.get())) { - if (arrayType->isDynamicallySized()) - { - // zero length - _context << u256(0); - utils.storeInMemoryDynamic(IntegerType(256)); - } - else if (arrayType->length() > 0) + solAssert(!arrayType->isDynamicallySized(), ""); + if (arrayType->length() > 0) { _context << arrayType->length() << Instruction::SWAP1; // stack: items_to_do memory_pos @@ -1094,6 +1103,11 @@ void CompilerUtils::pushZeroValue(Type const& _type) ); } +void CompilerUtils::pushZeroPointer() +{ + m_context << u256(zeroPointer); +} + void CompilerUtils::moveToStackVariable(VariableDeclaration const& _variable) { unsigned const stackPosition = m_context.baseToCurrentStackOffset(m_context.baseStackOffsetOfVariable(_variable)); |