Fix bitcasted functions. More...
#include "WebAssembly.h"#include "llvm/IR/CallSite.h"#include "llvm/IR/Constants.h"#include "llvm/IR/Instructions.h"#include "llvm/IR/Module.h"#include "llvm/IR/Operator.h"#include "llvm/Pass.h"#include "llvm/Support/Debug.h"#include "llvm/Support/raw_ostream.h"
Go to the source code of this file.
Macros | |
| #define | DEBUG_TYPE "wasm-fix-function-bitcasts" |
Functions | |
| INITIALIZE_PASS (FixFunctionBitcasts, DEBUG_TYPE, "Fix mismatching bitcasts for WebAssembly", false, false) ModulePass *llvm | |
| static void | FindUses (Value *V, Function &F, SmallVectorImpl< std::pair< Use *, Function *>> &Uses, SmallPtrSetImpl< Constant *> &ConstantBCs) |
| static Function * | CreateWrapper (Function *F, FunctionType *Ty) |
| bool | shouldFixMainFunction (FunctionType *FuncTy, FunctionType *MainTy) |
Detailed Description
Fix bitcasted functions.
WebAssembly requires caller and callee signatures to match, however in LLVM, some amount of slop is vaguely permitted. Detect mismatch by looking for bitcasts of functions and rewrite them to use wrapper functions instead.
This doesn't catch all cases, such as when a function's address is taken in one place and casted in another, but it works for many common cases.
Note that LLVM already optimizes away function bitcasts in common cases by dropping arguments as needed, so this pass only ends up getting used in less common cases.
Definition in file WebAssemblyFixFunctionBitcasts.cpp.
Macro Definition Documentation
◆ DEBUG_TYPE
Definition at line 37 of file WebAssemblyFixFunctionBitcasts.cpp.
Function Documentation
◆ CreateWrapper()
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static |
Definition at line 117 of file WebAssemblyFixFunctionBitcasts.cpp.
References llvm::Function::arg_begin(), llvm::Function::arg_end(), llvm::AMDGPU::HSAMD::Kernel::Key::Args, llvm::BasicBlock::Create(), llvm::Function::Create(), llvm::CallInst::Create(), llvm::ReturnInst::Create(), llvm::CastInst::CreateBitOrPointerCast(), llvm::dbgs(), llvm::Function::eraseFromParent(), llvm::UndefValue::get(), llvm::Module::getContext(), llvm::Function::getFunctionType(), llvm::Value::getName(), llvm::FunctionType::getNumParams(), llvm::GlobalValue::getParent(), llvm::FunctionType::getReturnType(), llvm::Value::getType(), llvm::CastInst::isBitOrNoopPointerCastable(), llvm::Type::isStructTy(), llvm::FunctionType::isVarArg(), llvm::Function::isVarArg(), llvm::Type::isVoidTy(), LLVM_DEBUG, llvm::FunctionType::param_begin(), llvm::FunctionType::param_end(), llvm::GlobalValue::PrivateLinkage, llvm::SmallVectorTemplateBase< T >::push_back(), llvm::Value::setName(), llvm::SmallVectorBase::size(), and Wrapper.
Referenced by shouldFixMainFunction().
◆ FindUses()
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static |
Definition at line 68 of file WebAssemblyFixFunctionBitcasts.cpp.
References Callee, llvm::GlobalValue::getType(), llvm::SmallPtrSetImpl< PtrType >::insert(), and llvm::Value::uses().
Referenced by shouldFixMainFunction().
◆ INITIALIZE_PASS()
| INITIALIZE_PASS | ( | FixFunctionBitcasts | , |
| DEBUG_TYPE | , | ||
| "Fix mismatching bitcasts for WebAssembly" | , | ||
| false | , | ||
| false | |||
| ) |
Definition at line 59 of file WebAssemblyFixFunctionBitcasts.cpp.
◆ shouldFixMainFunction()
| bool shouldFixMainFunction | ( | FunctionType * | FuncTy, |
| FunctionType * | MainTy | ||
| ) |
Definition at line 227 of file WebAssemblyFixFunctionBitcasts.cpp.
References llvm::AMDGPU::HSAMD::Kernel::Key::Args, C, llvm::CallInst::Create(), CreateWrapper(), llvm::dbgs(), llvm::dyn_cast(), llvm::Function::eraseFromParent(), F(), FindUses(), llvm::FunctionType::get(), llvm::PointerType::get(), llvm::UndefValue::get(), llvm::ConstantExpr::getBitCast(), llvm::CallBase::getCalledValue(), llvm::Value::getContext(), llvm::PointerType::getElementType(), llvm::Type::getInt32Ty(), llvm::Type::getInt8PtrTy(), llvm::GlobalValue::getLinkage(), llvm::FunctionType::getNumParams(), llvm::User::getOperandUse(), llvm::FunctionType::getReturnType(), llvm::Value::getType(), llvm::GlobalValue::getVisibility(), llvm::DenseMapBase< DenseMap< KeyT, ValueT, KeyInfoT, BucketT >, KeyT, ValueT, KeyInfoT, BucketT >::insert(), llvm::GlobalValue::isDeclaration(), llvm::FunctionType::isVarArg(), LLVM_DEBUG, llvm::SmallVectorTemplateBase< T >::push_back(), llvm::Value::replaceAllUsesWith(), llvm::GlobalValue::setLinkage(), llvm::Value::setName(), llvm::GlobalValue::setVisibility(), llvm::Value::stripPointerCasts(), and Wrapper.
