mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-22 18:54:02 +01:00
e695f6dc77
This doesn't help avoid any Dominator Tree recalculations just yet, there's one more pass to go..
99 lines
3.1 KiB
C++
99 lines
3.1 KiB
C++
//===- EscapeEnumerator.cpp -----------------------------------------------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Defines a helper class that enumerates all possible exits from a function,
|
|
// including exception handling.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/Transforms/Utils/EscapeEnumerator.h"
|
|
#include "llvm/ADT/Triple.h"
|
|
#include "llvm/Analysis/EHPersonalities.h"
|
|
#include "llvm/IR/Module.h"
|
|
#include "llvm/Transforms/Utils/Local.h"
|
|
|
|
using namespace llvm;
|
|
|
|
static FunctionCallee getDefaultPersonalityFn(Module *M) {
|
|
LLVMContext &C = M->getContext();
|
|
Triple T(M->getTargetTriple());
|
|
EHPersonality Pers = getDefaultEHPersonality(T);
|
|
return M->getOrInsertFunction(getEHPersonalityName(Pers),
|
|
FunctionType::get(Type::getInt32Ty(C), true));
|
|
}
|
|
|
|
IRBuilder<> *EscapeEnumerator::Next() {
|
|
if (Done)
|
|
return nullptr;
|
|
|
|
// Find all 'return', 'resume', and 'unwind' instructions.
|
|
while (StateBB != StateE) {
|
|
BasicBlock *CurBB = &*StateBB++;
|
|
|
|
// Branches and invokes do not escape, only unwind, resume, and return
|
|
// do.
|
|
Instruction *TI = CurBB->getTerminator();
|
|
if (!isa<ReturnInst>(TI) && !isa<ResumeInst>(TI))
|
|
continue;
|
|
|
|
if (CallInst *CI = CurBB->getTerminatingMustTailCall())
|
|
TI = CI;
|
|
Builder.SetInsertPoint(TI);
|
|
return &Builder;
|
|
}
|
|
|
|
Done = true;
|
|
|
|
if (!HandleExceptions)
|
|
return nullptr;
|
|
|
|
if (F.doesNotThrow())
|
|
return nullptr;
|
|
|
|
// Find all 'call' instructions that may throw.
|
|
// We cannot tranform calls with musttail tag.
|
|
SmallVector<Instruction *, 16> Calls;
|
|
for (BasicBlock &BB : F)
|
|
for (Instruction &II : BB)
|
|
if (CallInst *CI = dyn_cast<CallInst>(&II))
|
|
if (!CI->doesNotThrow() && !CI->isMustTailCall())
|
|
Calls.push_back(CI);
|
|
|
|
if (Calls.empty())
|
|
return nullptr;
|
|
|
|
// Create a cleanup block.
|
|
LLVMContext &C = F.getContext();
|
|
BasicBlock *CleanupBB = BasicBlock::Create(C, CleanupBBName, &F);
|
|
Type *ExnTy = StructType::get(Type::getInt8PtrTy(C), Type::getInt32Ty(C));
|
|
if (!F.hasPersonalityFn()) {
|
|
FunctionCallee PersFn = getDefaultPersonalityFn(F.getParent());
|
|
F.setPersonalityFn(cast<Constant>(PersFn.getCallee()));
|
|
}
|
|
|
|
if (isScopedEHPersonality(classifyEHPersonality(F.getPersonalityFn()))) {
|
|
report_fatal_error("Scoped EH not supported");
|
|
}
|
|
|
|
LandingPadInst *LPad =
|
|
LandingPadInst::Create(ExnTy, 1, "cleanup.lpad", CleanupBB);
|
|
LPad->setCleanup(true);
|
|
ResumeInst *RI = ResumeInst::Create(LPad, CleanupBB);
|
|
|
|
// Transform the 'call' instructions into 'invoke's branching to the
|
|
// cleanup block. Go in reverse order to make prettier BB names.
|
|
SmallVector<Value *, 16> Args;
|
|
for (unsigned I = Calls.size(); I != 0;) {
|
|
CallInst *CI = cast<CallInst>(Calls[--I]);
|
|
changeToInvokeAndSplitBasicBlock(CI, CleanupBB, DTU);
|
|
}
|
|
|
|
Builder.SetInsertPoint(RI);
|
|
return &Builder;
|
|
}
|