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Use longjmp to return OutOfGas code from main function (WIP)

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[#80660432]
This commit is contained in:
Paweł Bylica 2014-10-14 20:49:48 +02:00
parent dbb3e81bdf
commit c57de781e4
2 changed files with 14 additions and 3 deletions
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15
evmcc/Compiler.cpp
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@ -6,7 +6,7 @@
#include <llvm/IR/IRBuilder.h> #include <llvm/IR/IRBuilder.h>
#include <llvm/IR/CFG.h> #include <llvm/IR/CFG.h>
#include <llvm/ADT/PostOrderIterator.h> #include <llvm/ADT/PostOrderIterator.h>
//#include <llvm/Transforms/Scalar.h> #include <llvm/IR/IntrinsicInst.h>
#include <libevmface/Instruction.h> #include <libevmface/Instruction.h>
@ -159,6 +159,7 @@ void Compiler::createBasicBlocks(const dev::bytes& bytecode)
m_finalBlock = std::make_unique<BasicBlock>("FinalBlock", m_mainFunc); m_finalBlock = std::make_unique<BasicBlock>("FinalBlock", m_mainFunc);
m_badJumpBlock = std::make_unique<BasicBlock>("BadJumpBlock", m_mainFunc); m_badJumpBlock = std::make_unique<BasicBlock>("BadJumpBlock", m_mainFunc);
m_jumpTableBlock = std::make_unique<BasicBlock>("JumpTableBlock", m_mainFunc); m_jumpTableBlock = std::make_unique<BasicBlock>("JumpTableBlock", m_mainFunc);
m_outOfGasBlock = std::make_unique<BasicBlock>("OutOfGas", m_mainFunc);
for (auto it = directJumpTargets.cbegin(); it != directJumpTargets.cend(); ++it) for (auto it = directJumpTargets.cbegin(); it != directJumpTargets.cend(); ++it)
{ {
@ -195,6 +196,7 @@ std::unique_ptr<llvm::Module> Compiler::compile(const dev::bytes& bytecode)
// Create the basic blocks. // Create the basic blocks.
auto entryBlock = llvm::BasicBlock::Create(context, "entry", m_mainFunc); auto entryBlock = llvm::BasicBlock::Create(context, "entry", m_mainFunc);
builder.SetInsertPoint(entryBlock); builder.SetInsertPoint(entryBlock);
createBasicBlocks(bytecode); createBasicBlocks(bytecode);
// Init runtime structures. // Init runtime structures.
@ -203,7 +205,12 @@ std::unique_ptr<llvm::Module> Compiler::compile(const dev::bytes& bytecode)
Ext ext(builder, module.get()); Ext ext(builder, module.get());
// Jump to first instruction // Jump to first instruction
builder.CreateBr(basicBlocks.begin()->second); auto setjmpFunc = llvm::Intrinsic::getDeclaration(module.get(), llvm::Intrinsic::eh_sjlj_setjmp);
auto jmpBufTy = llvm::ArrayType::get(builder.getInt64Ty(), 5);
auto jmpBuf = new llvm::GlobalVariable(*module, jmpBufTy, false, llvm::GlobalVariable::PrivateLinkage, llvm::UndefValue::get(jmpBufTy), "jmpBuf");
auto setjmpRet = builder.CreateCall(setjmpFunc, builder.CreateBitCast(jmpBuf, Type::BytePtr));
auto isNormalFlow = builder.CreateICmpEQ(setjmpRet, builder.getInt32(0));
builder.CreateCondBr(isNormalFlow, basicBlocks.begin()->second, m_outOfGasBlock->llvm());
for (auto basicBlockPairIt = basicBlocks.begin(); basicBlockPairIt != basicBlocks.end(); ++basicBlockPairIt) for (auto basicBlockPairIt = basicBlocks.begin(); basicBlockPairIt != basicBlocks.end(); ++basicBlockPairIt)
{ {
@ -921,10 +928,12 @@ std::unique_ptr<llvm::Module> Compiler::compile(const dev::bytes& bytecode)
builder.SetInsertPoint(m_finalBlock->llvm()); builder.SetInsertPoint(m_finalBlock->llvm());
builder.CreateRet(Constant::get(ReturnCode::Stop)); builder.CreateRet(Constant::get(ReturnCode::Stop));
// TODO: throw an exception or something
builder.SetInsertPoint(m_badJumpBlock->llvm()); builder.SetInsertPoint(m_badJumpBlock->llvm());
builder.CreateRet(Constant::get(ReturnCode::BadJumpDestination)); builder.CreateRet(Constant::get(ReturnCode::BadJumpDestination));
builder.SetInsertPoint(m_outOfGasBlock->llvm());
builder.CreateRet(Constant::get(ReturnCode::OutOfGas));
builder.SetInsertPoint(m_jumpTableBlock->llvm()); builder.SetInsertPoint(m_jumpTableBlock->llvm());
if (m_indirectJumpTargets.size() > 0) if (m_indirectJumpTargets.size() > 0)
{ {

2
evmcc/Compiler.h
View file

@ -59,6 +59,8 @@ private:
*/ */
std::unique_ptr<BasicBlock> m_badJumpBlock; std::unique_ptr<BasicBlock> m_badJumpBlock;
std::unique_ptr<BasicBlock> m_outOfGasBlock;
/// Main program function /// Main program function
llvm::Function* m_mainFunc = nullptr; llvm::Function* m_mainFunc = nullptr;
}; };