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Merged
merged 2 commits into from
May 15, 2025
+120 −102
Merged

Collect instruction location info for EOF assembly #16052

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287b66a
Add instruction location info to eof assembly
clonker Apr 9, 2025
a5e20d2
Refactor legacy assemble to also use RAII instruction location constr…
clonker Apr 10, 2025
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222 changes: 120 additions & 102 deletions libevmasm/Assembly.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -53,6 +53,54 @@ using namespace solidity::evmasm;
using namespace solidity::langutil;
using namespace solidity::util;

namespace
{

/// Produces instruction location info in RAII style. When an assembly instruction is added to the bytecode,
/// this class can be instantiated in that scope. It will record the current bytecode size (before addition)
/// and, at destruction time, record the new bytecode size. This information is then added to an external
/// instruction locations vector.
/// If the instruction decomposes into multiple individual evm instructions, `emit` can be
/// called for all but the last one (which will be emitted by the destructor).
class InstructionLocationEmitter
{
public:
InstructionLocationEmitter(
std::vector<LinkerObject::InstructionLocation>& _instructionLocations,
bytes const& _bytecode,
size_t const _assemblyItemIndex
):
m_instructionLocations(_instructionLocations),
m_bytecode(_bytecode),
m_assemblyItemIndex(_assemblyItemIndex),
m_instructionLocationStart(_bytecode.size())
{}

~InstructionLocationEmitter()
{
emit();
}

void emit()
{
auto const end = m_bytecode.size();
m_instructionLocations.push_back(LinkerObject::InstructionLocation{
.start = m_instructionLocationStart,
.end = end,
.assemblyItemIndex = m_assemblyItemIndex
});
m_instructionLocationStart = end;
}

private:
std::vector<LinkerObject::InstructionLocation>& m_instructionLocations;
bytes const& m_bytecode;
size_t const m_assemblyItemIndex{};
size_t m_instructionLocationStart{};
};

}

std::map<std::string, std::shared_ptr<std::string const>> Assembly::s_sharedSourceNames;

AssemblyItem const& Assembly::append(AssemblyItem _i)
Expand Down Expand Up @@ -1281,104 +1329,72 @@ LinkerObject const& Assembly::assembleLegacy() const
uint8_t dataRefPush = static_cast<uint8_t>(pushInstruction(bytesPerDataRef));

LinkerObject::CodeSectionLocation codeSectionLocation;
codeSectionLocation.instructionLocations.reserve(items.size());
codeSectionLocation.start = 0;
size_t assemblyItemIndex = 0;
auto assembleInstruction = [&](auto&& _addInstruction) {
size_t start = ret.bytecode.size();
_addInstruction();
size_t end = ret.bytecode.size();
codeSectionLocation.instructionLocations.emplace_back(
LinkerObject::InstructionLocation{
.start = start,
.end = end,
.assemblyItemIndex = assemblyItemIndex
}
);
};
for (AssemblyItem const& item: items)
for (auto const& [assemblyItemIndex, item]: items | ranges::views::enumerate)
{
// collect instruction locations via side effects
InstructionLocationEmitter instructionLocationEmitter(codeSectionLocation.instructionLocations, ret.bytecode, assemblyItemIndex);
// store position of the invalid jump destination
if (item.type() != Tag && m_tagPositionsInBytecode[0] == std::numeric_limits<size_t>::max())
m_tagPositionsInBytecode[0] = ret.bytecode.size();

switch (item.type())
{
case Operation:
assembleInstruction([&](){
ret.bytecode += assembleOperation(item);
});
ret.bytecode += assembleOperation(item);
break;
case Push:
assembleInstruction([&](){
ret.bytecode += assemblePush(item);
});
ret.bytecode += assemblePush(item);
break;
case PushTag:
{
assembleInstruction([&](){
ret.bytecode.push_back(tagPush);
tagRefs[ret.bytecode.size()] = item.splitForeignPushTag();
ret.bytecode.resize(ret.bytecode.size() + bytesPerTag);
});
ret.bytecode.push_back(tagPush);
tagRefs[ret.bytecode.size()] = item.splitForeignPushTag();
ret.bytecode.resize(ret.bytecode.size() + bytesPerTag);
break;
}
case PushData:
assembleInstruction([&]() {
ret.bytecode.push_back(dataRefPush);
dataRefs.insert(std::make_pair(h256(item.data()), ret.bytecode.size()));
ret.bytecode.resize(ret.bytecode.size() + bytesPerDataRef);
});
ret.bytecode.push_back(dataRefPush);
dataRefs.insert(std::make_pair(h256(item.data()), ret.bytecode.size()));
ret.bytecode.resize(ret.bytecode.size() + bytesPerDataRef);
break;
case PushSub:
assembleInstruction([&]() {
assertThrow(item.data() <= std::numeric_limits<size_t>::max(), AssemblyException, "");
ret.bytecode.push_back(dataRefPush);
subRefs.insert(std::make_pair(static_cast<size_t>(item.data()), ret.bytecode.size()));
ret.bytecode.resize(ret.bytecode.size() + bytesPerDataRef);
});
assertThrow(item.data() <= std::numeric_limits<size_t>::max(), AssemblyException, "");
ret.bytecode.push_back(dataRefPush);
subRefs.insert(std::make_pair(static_cast<size_t>(item.data()), ret.bytecode.size()));
ret.bytecode.resize(ret.bytecode.size() + bytesPerDataRef);
break;
case PushSubSize:
{
assembleInstruction([&](){
assertThrow(item.data() <= std::numeric_limits<size_t>::max(), AssemblyException, "");
auto s = subAssemblyById(static_cast<size_t>(item.data()))->assemble().bytecode.size();
item.setPushedValue(u256(s));
unsigned b = std::max<unsigned>(1, numberEncodingSize(s));
ret.bytecode.push_back(static_cast<uint8_t>(pushInstruction(b)));
ret.bytecode.resize(ret.bytecode.size() + b);
bytesRef byr(&ret.bytecode.back() + 1 - b, b);
toBigEndian(s, byr);
});
assertThrow(item.data() <= std::numeric_limits<size_t>::max(), AssemblyException, "");
auto s = subAssemblyById(static_cast<size_t>(item.data()))->assemble().bytecode.size();
item.setPushedValue(u256(s));
unsigned b = std::max<unsigned>(1, numberEncodingSize(s));
ret.bytecode.push_back(static_cast<uint8_t>(pushInstruction(b)));
ret.bytecode.resize(ret.bytecode.size() + b);
bytesRef byr(&ret.bytecode.back() + 1 - b, b);
toBigEndian(s, byr);
break;
}
case PushProgramSize:
{
assembleInstruction([&](){
ret.bytecode.push_back(dataRefPush);
sizeRefs.push_back(static_cast<unsigned>(ret.bytecode.size()));
ret.bytecode.resize(ret.bytecode.size() + bytesPerDataRef);
});
ret.bytecode.push_back(dataRefPush);
sizeRefs.push_back(static_cast<unsigned>(ret.bytecode.size()));
ret.bytecode.resize(ret.bytecode.size() + bytesPerDataRef);
break;
}
case PushLibraryAddress:
{
assembleInstruction([&]() {
auto const [bytecode, linkRef] = assemblePushLibraryAddress(item, ret.bytecode.size());
ret.bytecode += bytecode;
ret.linkReferences.insert(linkRef);
});
auto const [bytecode, linkRef] = assemblePushLibraryAddress(item, ret.bytecode.size());
ret.bytecode += bytecode;
ret.linkReferences.insert(linkRef);
break;
}
case PushImmutable:
assembleInstruction([&]() {
ret.bytecode.push_back(static_cast<uint8_t>(Instruction::PUSH32));
// Maps keccak back to the "identifier" std::string of that immutable.
ret.immutableReferences[item.data()].first = m_immutables.at(item.data());
// Record the bytecode offset of the PUSH32 argument.
ret.immutableReferences[item.data()].second.emplace_back(ret.bytecode.size());
// Advance bytecode by 32 bytes (default initialized).
ret.bytecode.resize(ret.bytecode.size() + 32);
});
ret.bytecode.push_back(static_cast<uint8_t>(Instruction::PUSH32));
// Maps keccak back to the "identifier" std::string of that immutable.
ret.immutableReferences[item.data()].first = m_immutables.at(item.data());
// Record the bytecode offset of the PUSH32 argument.
ret.immutableReferences[item.data()].second.emplace_back(ret.bytecode.size());
// Advance bytecode by 32 bytes (default initialized).
ret.bytecode.resize(ret.bytecode.size() + 32);
break;
case VerbatimBytecode:
ret.bytecode += assembleVerbatimBytecode(item);
Expand All @@ -1391,53 +1407,41 @@ LinkerObject const& Assembly::assembleLegacy() const
{
if (i != offsets.size() - 1)
{
assembleInstruction([&]() {
ret.bytecode.push_back(uint8_t(Instruction::DUP2));
});
assembleInstruction([&]() {
ret.bytecode.push_back(uint8_t(Instruction::DUP2));
});
ret.bytecode.push_back(static_cast<uint8_t>(Instruction::DUP2));
// This item type decomposes into multiple evm instructions, so we manually call emit()
instructionLocationEmitter.emit();
ret.bytecode.push_back(static_cast<uint8_t>(Instruction::DUP2));
instructionLocationEmitter.emit();
}
assembleInstruction([&]() {
// TODO: should we make use of the constant optimizer methods for pushing the offsets?
bytes offsetBytes = toCompactBigEndian(u256(offsets[i]));
ret.bytecode.push_back(static_cast<uint8_t>(pushInstruction(static_cast<unsigned>(offsetBytes.size()))));
ret.bytecode += offsetBytes;
});
assembleInstruction([&]() {
ret.bytecode.push_back(uint8_t(Instruction::ADD));
});
assembleInstruction([&]() {
ret.bytecode.push_back(uint8_t(Instruction::MSTORE));
});
// TODO: should we make use of the constant optimizer methods for pushing the offsets?
bytes offsetBytes = toCompactBigEndian(u256(offsets[i]));
ret.bytecode.push_back(static_cast<uint8_t>(pushInstruction(static_cast<unsigned>(offsetBytes.size()))));
ret.bytecode += offsetBytes;
instructionLocationEmitter.emit();
ret.bytecode.push_back(static_cast<uint8_t>(Instruction::ADD));
instructionLocationEmitter.emit();
ret.bytecode.push_back(static_cast<uint8_t>(Instruction::MSTORE));
// No emit needed here, it's taken care of by the destructor of instructionLocationEmitter.
}
if (offsets.empty())
{
assembleInstruction([&]() {
ret.bytecode.push_back(uint8_t(Instruction::POP));
});
assembleInstruction([&]() {
ret.bytecode.push_back(uint8_t(Instruction::POP));
});
ret.bytecode.push_back(static_cast<uint8_t>(Instruction::POP));
instructionLocationEmitter.emit();
ret.bytecode.push_back(static_cast<uint8_t>(Instruction::POP));
// no emit needed here, it's taken care of by the destructor of instructionLocationEmitter
}
immutableReferencesBySub.erase(item.data());
break;
}
case PushDeployTimeAddress:
assembleInstruction([&]() {
ret.bytecode += assemblePushDeployTimeAddress();
});
ret.bytecode += assemblePushDeployTimeAddress();
break;
case Tag:
assembleInstruction([&](){
ret.bytecode += assembleTag(item, ret.bytecode.size(), true);
});
ret.bytecode += assembleTag(item, ret.bytecode.size(), true);
break;
default:
solAssert(false, "Unexpected opcode while assembling.");
}

++assemblyItemIndex;
}

codeSectionLocation.end = ret.bytecode.size();
Expand Down Expand Up @@ -1606,9 +1610,17 @@ LinkerObject const& Assembly::assembleEOF() const
for (auto&& [codeSectionIndex, codeSection]: m_codeSections | ranges::views::enumerate)
{
auto const sectionStart = ret.bytecode.size();

std::vector<LinkerObject::InstructionLocation> instructionLocations;
instructionLocations.reserve(codeSection.items.size());

solAssert(!codeSection.items.empty(), "Empty code section.");
for (AssemblyItem const& item: codeSection.items)

for (auto const& [assemblyItemIndex, item]: codeSection.items | ranges::views::enumerate)
{
// collect instruction locations via side effects
InstructionLocationEmitter instructionLocationEmitter {instructionLocations, ret.bytecode, assemblyItemIndex};
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Suggested change
InstructionLocationEmitter instructionLocationEmitter {instructionLocations, ret.bytecode, assemblyItemIndex};
InstructionLocationEmitter instructionLocationEmitter{instructionLocations, ret.bytecode, assemblyItemIndex};


// store position of the invalid jump destination
if (item.type() != Tag && m_tagPositionsInBytecode[0] == std::numeric_limits<size_t>::max())
m_tagPositionsInBytecode[0] = ret.bytecode.size();
Expand Down Expand Up @@ -1724,6 +1736,12 @@ LinkerObject const& Assembly::assembleEOF() const
"Code section too large for EOF."
);
setBigEndianUint16(ret.bytecode, codeSectionSizePositions[codeSectionIndex], ret.bytecode.size() - sectionStart);

ret.codeSectionLocations.push_back(LinkerObject::CodeSectionLocation{
.start = sectionStart,
.end = ret.bytecode.size(),
.instructionLocations = std::move(instructionLocations)
});
}

for (auto const& [refPos, tagId]: tagRef)
Expand Down