Duncan P. N. Exon Smith f1a894dcb2 TransformUtils: Fix metadata handling in CloneModule (and improve CloneFunctionInto)
This commit fixes how metadata is handled in CloneModule to be sound,
and improves how it's handled in CloneFunctionInto (although the latter
is still awkward when called within a module).

Ruiling Song pointed out in PR48841 that CloneModule was changed to
unsoundly use the RF_ReuseAndMutateDistinctMDs flag (renamed in
fa35c1f80f0ea080a7cbc581416929b0a654f25c for clarity). This flag papered
over a crash caused by other various changes made to CloneFunctionInto
over the past few years that made it unsound to use cloning between
different modules.

(This commit partially addresses PR48841, fixing the repro from
preprocessed source but not textual IR. MDNodeMapper::mapDistinctNode
became unsound in df763188c9a1ecb1e7e5c4d4ea53a99fbb755903 and this
commit does not address that regression.)

RF_ReuseAndMutateDistinctMDs is designed for the IRMover to use,
avoiding unnecessary clones of all referenced metadata when linking
between modules (with IRMover, the source module is discarded after
linking). It never makes sense to use when you're not discarding the
source. This commit drops its incorrect use in CloneModule.

Sadly, the right thing to do with metadata when cloning a function is
complicated, and this patch doesn't totally fix it.

The first problem is that there are two different types of referenceable
metadata and it's not obvious what to with one of them when remapping.

- `!0 = !{!1}` is metadata's version of a constant. Programatically it's
  called "uniqued" (probably a better term would be "constant") because,
  like `ConstantArray`, it's stored in uniquing tables. Once it's
  constructed, it's illegal to change its arguments.
- `!0 = distinct !{!1}` is a bit closer to a global variable. It's legal
  to change the operands after construction.

What should be done with distinct metadata when cloning functions within
the same module?

- Should new, cloned nodes be created?
- Should all references point to the same, old nodes?

The answer depends on whether that metadata is effectively owned by a
function.

And that's the second problem. Referenceable metadata's ownership model
is not clear or explicit. Technically, it's all stored on an
LLVMContext. However, any metadata that is `distinct`, that transitively
references a `distinct` node, or that transitively references a
GlobalValue is specific to a Module and is effectively owned by it. More
specifically, some metadata is effectively owned by a specific Function
within a module.

Effectively function-local metadata was introduced somewhere around
c10d0e5ccd12f049bddb24dcf8bbb7fbbc6c68f2, which made it illegal for two
functions to share a DISubprogram attachment.

When cloning a function within a module, you need to clone the
function-local debug info and suppress cloning of global debug info (the
status quo suppresses cloning some global debug info but not all). When
cloning a function to a new/different module, you need to clone all of
the debug info.

Here's what I think we should do (eventually? soon? not this patch
though):
- Distinguish explicitly (somehow) between pure constant metadata owned
  by the LLVMContext, global metadata owned by the Module, and local
  metadata owned by a GlobalValue (such as a function).
- Update CloneFunctionInto to trigger cloning of all "local" metadata
  (only), perhaps by adding a bit to RemapFlag. Alternatively, split
  out a separate function CloneFunctionMetadataInto to prime the
  metadata map that callers are updated to call ahead of time as
  appropriate.

Here's the somewhat more isolated fix in this patch:
- Converted the `ModuleLevelChanges` parameter to `CloneFunctionInto` to
  an enum called `CloneFunctionChangeType` that is one of
  LocalChangesOnly, GlobalChanges, DifferentModule, and ClonedModule.
- The code maintaining the "functions uniquely own subprograms"
  invariant is now only active in the first two cases, where a function
  is being cloned within a single module. That's necessary because this
  code inhibits cloning of (some) "global" metadata that's effectively
  owned by the module.
- The code maintaining the "all compile units must be explicitly
  referenced by !llvm.dbg.cu" invariant is now only active in the
  DifferentModule case, where a function is being cloned into a new
  module in isolation.
- CoroSplit.cpp's call to CloneFunctionInto in CoroCloner::create
  uses LocalChangeOnly, since fa635d730f74f3285b77cc1537f1692184b8bf5b
  only set `ModuleLevelChanges` to trigger cloning of local metadata.
- CloneModule drops its unsound use of RF_ReuseAndMutateDistinctMDs
  and special handling of !llvm.dbg.cu.
- Fixed some outdated header docs and left a couple of FIXMEs.

Differential Revision: https://reviews.llvm.org/D96531
2021-02-15 11:56:00 -08:00

1029 lines
34 KiB
C++

//===- Cloning.cpp - Unit tests for the Cloner ----------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/DomTreeUpdater.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/Argument.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/DIBuilder.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Verifier.h"
#include "gtest/gtest.h"
using namespace llvm;
namespace {
class CloneInstruction : public ::testing::Test {
protected:
void SetUp() override { V = nullptr; }
template <typename T>
T *clone(T *V1) {
Value *V2 = V1->clone();
Orig.insert(V1);
Clones.insert(V2);
return cast<T>(V2);
}
void eraseClones() {
for (Value *V : Clones)
V->deleteValue();
Clones.clear();
}
void TearDown() override {
eraseClones();
for (Value *V : Orig)
V->deleteValue();
Orig.clear();
if (V)
V->deleteValue();
}
SmallPtrSet<Value *, 4> Orig; // Erase on exit
SmallPtrSet<Value *, 4> Clones; // Erase in eraseClones
LLVMContext context;
Value *V;
};
TEST_F(CloneInstruction, OverflowBits) {
V = new Argument(Type::getInt32Ty(context));
BinaryOperator *Add = BinaryOperator::Create(Instruction::Add, V, V);
BinaryOperator *Sub = BinaryOperator::Create(Instruction::Sub, V, V);
BinaryOperator *Mul = BinaryOperator::Create(Instruction::Mul, V, V);
BinaryOperator *AddClone = this->clone(Add);
BinaryOperator *SubClone = this->clone(Sub);
BinaryOperator *MulClone = this->clone(Mul);
EXPECT_FALSE(AddClone->hasNoUnsignedWrap());
EXPECT_FALSE(AddClone->hasNoSignedWrap());
EXPECT_FALSE(SubClone->hasNoUnsignedWrap());
EXPECT_FALSE(SubClone->hasNoSignedWrap());
EXPECT_FALSE(MulClone->hasNoUnsignedWrap());
EXPECT_FALSE(MulClone->hasNoSignedWrap());
eraseClones();
Add->setHasNoUnsignedWrap();
Sub->setHasNoUnsignedWrap();
Mul->setHasNoUnsignedWrap();
AddClone = this->clone(Add);
SubClone = this->clone(Sub);
MulClone = this->clone(Mul);
EXPECT_TRUE(AddClone->hasNoUnsignedWrap());
EXPECT_FALSE(AddClone->hasNoSignedWrap());
EXPECT_TRUE(SubClone->hasNoUnsignedWrap());
EXPECT_FALSE(SubClone->hasNoSignedWrap());
EXPECT_TRUE(MulClone->hasNoUnsignedWrap());
EXPECT_FALSE(MulClone->hasNoSignedWrap());
eraseClones();
Add->setHasNoSignedWrap();
Sub->setHasNoSignedWrap();
Mul->setHasNoSignedWrap();
AddClone = this->clone(Add);
SubClone = this->clone(Sub);
MulClone = this->clone(Mul);
EXPECT_TRUE(AddClone->hasNoUnsignedWrap());
EXPECT_TRUE(AddClone->hasNoSignedWrap());
EXPECT_TRUE(SubClone->hasNoUnsignedWrap());
EXPECT_TRUE(SubClone->hasNoSignedWrap());
EXPECT_TRUE(MulClone->hasNoUnsignedWrap());
EXPECT_TRUE(MulClone->hasNoSignedWrap());
eraseClones();
Add->setHasNoUnsignedWrap(false);
Sub->setHasNoUnsignedWrap(false);
Mul->setHasNoUnsignedWrap(false);
AddClone = this->clone(Add);
SubClone = this->clone(Sub);
MulClone = this->clone(Mul);
EXPECT_FALSE(AddClone->hasNoUnsignedWrap());
EXPECT_TRUE(AddClone->hasNoSignedWrap());
EXPECT_FALSE(SubClone->hasNoUnsignedWrap());
EXPECT_TRUE(SubClone->hasNoSignedWrap());
EXPECT_FALSE(MulClone->hasNoUnsignedWrap());
EXPECT_TRUE(MulClone->hasNoSignedWrap());
}
TEST_F(CloneInstruction, Inbounds) {
V = new Argument(Type::getInt32PtrTy(context));
Constant *Z = Constant::getNullValue(Type::getInt32Ty(context));
std::vector<Value *> ops;
ops.push_back(Z);
GetElementPtrInst *GEP =
GetElementPtrInst::Create(Type::getInt32Ty(context), V, ops);
EXPECT_FALSE(this->clone(GEP)->isInBounds());
GEP->setIsInBounds();
EXPECT_TRUE(this->clone(GEP)->isInBounds());
}
TEST_F(CloneInstruction, Exact) {
V = new Argument(Type::getInt32Ty(context));
BinaryOperator *SDiv = BinaryOperator::Create(Instruction::SDiv, V, V);
EXPECT_FALSE(this->clone(SDiv)->isExact());
SDiv->setIsExact(true);
EXPECT_TRUE(this->clone(SDiv)->isExact());
}
TEST_F(CloneInstruction, Attributes) {
Type *ArgTy1[] = { Type::getInt32PtrTy(context) };
FunctionType *FT1 = FunctionType::get(Type::getVoidTy(context), ArgTy1, false);
Function *F1 = Function::Create(FT1, Function::ExternalLinkage);
BasicBlock *BB = BasicBlock::Create(context, "", F1);
IRBuilder<> Builder(BB);
Builder.CreateRetVoid();
Function *F2 = Function::Create(FT1, Function::ExternalLinkage);
Argument *A = &*F1->arg_begin();
A->addAttr(Attribute::NoCapture);
SmallVector<ReturnInst*, 4> Returns;
ValueToValueMapTy VMap;
VMap[A] = UndefValue::get(A->getType());
CloneFunctionInto(F2, F1, VMap, CloneFunctionChangeType::LocalChangesOnly,
Returns);
EXPECT_FALSE(F2->arg_begin()->hasNoCaptureAttr());
delete F1;
delete F2;
}
TEST_F(CloneInstruction, CallingConvention) {
Type *ArgTy1[] = { Type::getInt32PtrTy(context) };
FunctionType *FT1 = FunctionType::get(Type::getVoidTy(context), ArgTy1, false);
Function *F1 = Function::Create(FT1, Function::ExternalLinkage);
F1->setCallingConv(CallingConv::Cold);
BasicBlock *BB = BasicBlock::Create(context, "", F1);
IRBuilder<> Builder(BB);
Builder.CreateRetVoid();
Function *F2 = Function::Create(FT1, Function::ExternalLinkage);
SmallVector<ReturnInst*, 4> Returns;
ValueToValueMapTy VMap;
VMap[&*F1->arg_begin()] = &*F2->arg_begin();
CloneFunctionInto(F2, F1, VMap, CloneFunctionChangeType::LocalChangesOnly,
Returns);
EXPECT_EQ(CallingConv::Cold, F2->getCallingConv());
delete F1;
delete F2;
}
TEST_F(CloneInstruction, DuplicateInstructionsToSplit) {
Type *ArgTy1[] = {Type::getInt32PtrTy(context)};
FunctionType *FT = FunctionType::get(Type::getVoidTy(context), ArgTy1, false);
V = new Argument(Type::getInt32Ty(context));
Function *F = Function::Create(FT, Function::ExternalLinkage);
BasicBlock *BB1 = BasicBlock::Create(context, "", F);
IRBuilder<> Builder1(BB1);
BasicBlock *BB2 = BasicBlock::Create(context, "", F);
IRBuilder<> Builder2(BB2);
Builder1.CreateBr(BB2);
Instruction *AddInst = cast<Instruction>(Builder2.CreateAdd(V, V));
Instruction *MulInst = cast<Instruction>(Builder2.CreateMul(AddInst, V));
Instruction *SubInst = cast<Instruction>(Builder2.CreateSub(MulInst, V));
Builder2.CreateRetVoid();
// Dummy DTU.
ValueToValueMapTy Mapping;
DomTreeUpdater DTU(DomTreeUpdater::UpdateStrategy::Lazy);
auto Split =
DuplicateInstructionsInSplitBetween(BB2, BB1, SubInst, Mapping, DTU);
EXPECT_TRUE(Split);
EXPECT_EQ(Mapping.size(), 2u);
EXPECT_TRUE(Mapping.find(AddInst) != Mapping.end());
EXPECT_TRUE(Mapping.find(MulInst) != Mapping.end());
auto AddSplit = dyn_cast<Instruction>(Mapping[AddInst]);
EXPECT_TRUE(AddSplit);
EXPECT_EQ(AddSplit->getOperand(0), V);
EXPECT_EQ(AddSplit->getOperand(1), V);
EXPECT_EQ(AddSplit->getParent(), Split);
auto MulSplit = dyn_cast<Instruction>(Mapping[MulInst]);
EXPECT_TRUE(MulSplit);
EXPECT_EQ(MulSplit->getOperand(0), AddSplit);
EXPECT_EQ(MulSplit->getOperand(1), V);
EXPECT_EQ(MulSplit->getParent(), Split);
EXPECT_EQ(AddSplit->getNextNode(), MulSplit);
EXPECT_EQ(MulSplit->getNextNode(), Split->getTerminator());
delete F;
}
TEST_F(CloneInstruction, DuplicateInstructionsToSplitBlocksEq1) {
Type *ArgTy1[] = {Type::getInt32PtrTy(context)};
FunctionType *FT = FunctionType::get(Type::getVoidTy(context), ArgTy1, false);
V = new Argument(Type::getInt32Ty(context));
Function *F = Function::Create(FT, Function::ExternalLinkage);
BasicBlock *BB1 = BasicBlock::Create(context, "", F);
IRBuilder<> Builder1(BB1);
BasicBlock *BB2 = BasicBlock::Create(context, "", F);
IRBuilder<> Builder2(BB2);
Builder1.CreateBr(BB2);
Instruction *AddInst = cast<Instruction>(Builder2.CreateAdd(V, V));
Instruction *MulInst = cast<Instruction>(Builder2.CreateMul(AddInst, V));
Instruction *SubInst = cast<Instruction>(Builder2.CreateSub(MulInst, V));
Builder2.CreateBr(BB2);
// Dummy DTU.
DomTreeUpdater DTU(DomTreeUpdater::UpdateStrategy::Lazy);
ValueToValueMapTy Mapping;
auto Split = DuplicateInstructionsInSplitBetween(
BB2, BB2, BB2->getTerminator(), Mapping, DTU);
EXPECT_TRUE(Split);
EXPECT_EQ(Mapping.size(), 3u);
EXPECT_TRUE(Mapping.find(AddInst) != Mapping.end());
EXPECT_TRUE(Mapping.find(MulInst) != Mapping.end());
EXPECT_TRUE(Mapping.find(SubInst) != Mapping.end());
auto AddSplit = dyn_cast<Instruction>(Mapping[AddInst]);
EXPECT_TRUE(AddSplit);
EXPECT_EQ(AddSplit->getOperand(0), V);
EXPECT_EQ(AddSplit->getOperand(1), V);
EXPECT_EQ(AddSplit->getParent(), Split);
auto MulSplit = dyn_cast<Instruction>(Mapping[MulInst]);
EXPECT_TRUE(MulSplit);
EXPECT_EQ(MulSplit->getOperand(0), AddSplit);
EXPECT_EQ(MulSplit->getOperand(1), V);
EXPECT_EQ(MulSplit->getParent(), Split);
auto SubSplit = dyn_cast<Instruction>(Mapping[SubInst]);
EXPECT_EQ(MulSplit->getNextNode(), SubSplit);
EXPECT_EQ(SubSplit->getNextNode(), Split->getTerminator());
EXPECT_EQ(Split->getSingleSuccessor(), BB2);
EXPECT_EQ(BB2->getSingleSuccessor(), Split);
delete F;
}
TEST_F(CloneInstruction, DuplicateInstructionsToSplitBlocksEq2) {
Type *ArgTy1[] = {Type::getInt32PtrTy(context)};
FunctionType *FT = FunctionType::get(Type::getVoidTy(context), ArgTy1, false);
V = new Argument(Type::getInt32Ty(context));
Function *F = Function::Create(FT, Function::ExternalLinkage);
BasicBlock *BB1 = BasicBlock::Create(context, "", F);
IRBuilder<> Builder1(BB1);
BasicBlock *BB2 = BasicBlock::Create(context, "", F);
IRBuilder<> Builder2(BB2);
Builder1.CreateBr(BB2);
Instruction *AddInst = cast<Instruction>(Builder2.CreateAdd(V, V));
Instruction *MulInst = cast<Instruction>(Builder2.CreateMul(AddInst, V));
Instruction *SubInst = cast<Instruction>(Builder2.CreateSub(MulInst, V));
Builder2.CreateBr(BB2);
// Dummy DTU.
DomTreeUpdater DTU(DomTreeUpdater::UpdateStrategy::Lazy);
ValueToValueMapTy Mapping;
auto Split =
DuplicateInstructionsInSplitBetween(BB2, BB2, SubInst, Mapping, DTU);
EXPECT_TRUE(Split);
EXPECT_EQ(Mapping.size(), 2u);
EXPECT_TRUE(Mapping.find(AddInst) != Mapping.end());
EXPECT_TRUE(Mapping.find(MulInst) != Mapping.end());
auto AddSplit = dyn_cast<Instruction>(Mapping[AddInst]);
EXPECT_TRUE(AddSplit);
EXPECT_EQ(AddSplit->getOperand(0), V);
EXPECT_EQ(AddSplit->getOperand(1), V);
EXPECT_EQ(AddSplit->getParent(), Split);
auto MulSplit = dyn_cast<Instruction>(Mapping[MulInst]);
EXPECT_TRUE(MulSplit);
EXPECT_EQ(MulSplit->getOperand(0), AddSplit);
EXPECT_EQ(MulSplit->getOperand(1), V);
EXPECT_EQ(MulSplit->getParent(), Split);
EXPECT_EQ(MulSplit->getNextNode(), Split->getTerminator());
EXPECT_EQ(Split->getSingleSuccessor(), BB2);
EXPECT_EQ(BB2->getSingleSuccessor(), Split);
delete F;
}
static void runWithLoopInfoAndDominatorTree(
Module &M, StringRef FuncName,
function_ref<void(Function &F, LoopInfo &LI, DominatorTree &DT)> Test) {
auto *F = M.getFunction(FuncName);
ASSERT_NE(F, nullptr) << "Could not find " << FuncName;
DominatorTree DT(*F);
LoopInfo LI(DT);
Test(*F, LI, DT);
}
static std::unique_ptr<Module> parseIR(LLVMContext &C, const char *IR) {
SMDiagnostic Err;
std::unique_ptr<Module> Mod = parseAssemblyString(IR, Err, C);
if (!Mod)
Err.print("CloneLoop", errs());
return Mod;
}
TEST(CloneLoop, CloneLoopNest) {
// Parse the module.
LLVMContext Context;
std::unique_ptr<Module> M = parseIR(
Context,
R"(define void @foo(i32* %A, i32 %ub) {
entry:
%guardcmp = icmp slt i32 0, %ub
br i1 %guardcmp, label %for.outer.preheader, label %for.end
for.outer.preheader:
br label %for.outer
for.outer:
%j = phi i32 [ 0, %for.outer.preheader ], [ %inc.outer, %for.outer.latch ]
br i1 %guardcmp, label %for.inner.preheader, label %for.outer.latch
for.inner.preheader:
br label %for.inner
for.inner:
%i = phi i32 [ 0, %for.inner.preheader ], [ %inc, %for.inner ]
%idxprom = sext i32 %i to i64
%arrayidx = getelementptr inbounds i32, i32* %A, i64 %idxprom
store i32 %i, i32* %arrayidx, align 4
%inc = add nsw i32 %i, 1
%cmp = icmp slt i32 %inc, %ub
br i1 %cmp, label %for.inner, label %for.inner.exit
for.inner.exit:
br label %for.outer.latch
for.outer.latch:
%inc.outer = add nsw i32 %j, 1
%cmp.outer = icmp slt i32 %inc.outer, %ub
br i1 %cmp.outer, label %for.outer, label %for.outer.exit
for.outer.exit:
br label %for.end
for.end:
ret void
})"
);
runWithLoopInfoAndDominatorTree(
*M, "foo", [&](Function &F, LoopInfo &LI, DominatorTree &DT) {
Function::iterator FI = F.begin();
// First basic block is entry - skip it.
BasicBlock *Preheader = &*(++FI);
BasicBlock *Header = &*(++FI);
assert(Header->getName() == "for.outer");
Loop *L = LI.getLoopFor(Header);
EXPECT_NE(L, nullptr);
EXPECT_EQ(Header, L->getHeader());
EXPECT_EQ(Preheader, L->getLoopPreheader());
ValueToValueMapTy VMap;
SmallVector<BasicBlock *, 4> ClonedLoopBlocks;
Loop *NewLoop = cloneLoopWithPreheader(Preheader, Preheader, L, VMap,
"", &LI, &DT, ClonedLoopBlocks);
EXPECT_NE(NewLoop, nullptr);
EXPECT_EQ(NewLoop->getSubLoops().size(), 1u);
Loop::block_iterator BI = NewLoop->block_begin();
EXPECT_TRUE((*BI)->getName().startswith("for.outer"));
EXPECT_TRUE((*(++BI))->getName().startswith("for.inner.preheader"));
EXPECT_TRUE((*(++BI))->getName().startswith("for.inner"));
EXPECT_TRUE((*(++BI))->getName().startswith("for.inner.exit"));
EXPECT_TRUE((*(++BI))->getName().startswith("for.outer.latch"));
});
}
class CloneFunc : public ::testing::Test {
protected:
void SetUp() override {
SetupModule();
CreateOldFunc();
CreateNewFunc();
SetupFinder();
}
void TearDown() override { delete Finder; }
void SetupModule() {
M = new Module("", C);
}
void CreateOldFunc() {
FunctionType* FuncType = FunctionType::get(Type::getVoidTy(C), false);
OldFunc = Function::Create(FuncType, GlobalValue::PrivateLinkage, "f", M);
CreateOldFunctionBodyAndDI();
}
void CreateOldFunctionBodyAndDI() {
DIBuilder DBuilder(*M);
IRBuilder<> IBuilder(C);
// Function DI
auto *File = DBuilder.createFile("filename.c", "/file/dir/");
DITypeRefArray ParamTypes = DBuilder.getOrCreateTypeArray(None);
DISubroutineType *FuncType =
DBuilder.createSubroutineType(ParamTypes);
auto *CU = DBuilder.createCompileUnit(dwarf::DW_LANG_C99,
DBuilder.createFile("filename.c",
"/file/dir"),
"CloneFunc", false, "", 0);
auto *Subprogram = DBuilder.createFunction(
CU, "f", "f", File, 4, FuncType, 3, DINode::FlagZero,
DISubprogram::SPFlagLocalToUnit | DISubprogram::SPFlagDefinition);
OldFunc->setSubprogram(Subprogram);
// Function body
BasicBlock* Entry = BasicBlock::Create(C, "", OldFunc);
IBuilder.SetInsertPoint(Entry);
DebugLoc Loc = DILocation::get(Subprogram->getContext(), 3, 2, Subprogram);
IBuilder.SetCurrentDebugLocation(Loc);
AllocaInst* Alloca = IBuilder.CreateAlloca(IntegerType::getInt32Ty(C));
IBuilder.SetCurrentDebugLocation(
DILocation::get(Subprogram->getContext(), 4, 2, Subprogram));
Value* AllocaContent = IBuilder.getInt32(1);
Instruction* Store = IBuilder.CreateStore(AllocaContent, Alloca);
IBuilder.SetCurrentDebugLocation(
DILocation::get(Subprogram->getContext(), 5, 2, Subprogram));
// Create a local variable around the alloca
auto *IntType = DBuilder.createBasicType("int", 32, dwarf::DW_ATE_signed);
auto *E = DBuilder.createExpression();
auto *Variable =
DBuilder.createAutoVariable(Subprogram, "x", File, 5, IntType, true);
auto *DL = DILocation::get(Subprogram->getContext(), 5, 0, Subprogram);
DBuilder.insertDeclare(Alloca, Variable, E, DL, Store);
DBuilder.insertDbgValueIntrinsic(AllocaContent, Variable, E, DL, Entry);
// Also create an inlined variable.
// Create a distinct struct type that we should not duplicate during
// cloning).
auto *StructType = DICompositeType::getDistinct(
C, dwarf::DW_TAG_structure_type, "some_struct", nullptr, 0, nullptr,
nullptr, 32, 32, 0, DINode::FlagZero, nullptr, 0, nullptr, nullptr);
auto *InlinedSP = DBuilder.createFunction(
CU, "inlined", "inlined", File, 8, FuncType, 9, DINode::FlagZero,
DISubprogram::SPFlagLocalToUnit | DISubprogram::SPFlagDefinition);
auto *InlinedVar =
DBuilder.createAutoVariable(InlinedSP, "inlined", File, 5, StructType, true);
auto *Scope = DBuilder.createLexicalBlock(
DBuilder.createLexicalBlockFile(InlinedSP, File), File, 1, 1);
auto InlinedDL = DILocation::get(
Subprogram->getContext(), 9, 4, Scope,
DILocation::get(Subprogram->getContext(), 5, 2, Subprogram));
IBuilder.SetCurrentDebugLocation(InlinedDL);
DBuilder.insertDeclare(Alloca, InlinedVar, E, InlinedDL, Store);
IBuilder.CreateStore(IBuilder.getInt32(2), Alloca);
// Finalize the debug info.
DBuilder.finalize();
IBuilder.CreateRetVoid();
// Create another, empty, compile unit.
DIBuilder DBuilder2(*M);
DBuilder2.createCompileUnit(dwarf::DW_LANG_C99,
DBuilder.createFile("extra.c", "/file/dir"),
"CloneFunc", false, "", 0);
DBuilder2.finalize();
}
void CreateNewFunc() {
ValueToValueMapTy VMap;
NewFunc = CloneFunction(OldFunc, VMap, nullptr);
}
void SetupFinder() {
Finder = new DebugInfoFinder();
Finder->processModule(*M);
}
LLVMContext C;
Function* OldFunc;
Function* NewFunc;
Module* M;
DebugInfoFinder* Finder;
};
// Test that a new, distinct function was created.
TEST_F(CloneFunc, NewFunctionCreated) {
EXPECT_NE(OldFunc, NewFunc);
}
// Test that a new subprogram entry was added and is pointing to the new
// function, while the original subprogram still points to the old one.
TEST_F(CloneFunc, Subprogram) {
EXPECT_FALSE(verifyModule(*M, &errs()));
EXPECT_EQ(3U, Finder->subprogram_count());
EXPECT_NE(NewFunc->getSubprogram(), OldFunc->getSubprogram());
}
// Test that instructions in the old function still belong to it in the
// metadata, while instruction in the new function belong to the new one.
TEST_F(CloneFunc, InstructionOwnership) {
EXPECT_FALSE(verifyModule(*M));
inst_iterator OldIter = inst_begin(OldFunc);
inst_iterator OldEnd = inst_end(OldFunc);
inst_iterator NewIter = inst_begin(NewFunc);
inst_iterator NewEnd = inst_end(NewFunc);
while (OldIter != OldEnd && NewIter != NewEnd) {
Instruction& OldI = *OldIter;
Instruction& NewI = *NewIter;
EXPECT_NE(&OldI, &NewI);
EXPECT_EQ(OldI.hasMetadata(), NewI.hasMetadata());
if (OldI.hasMetadata()) {
const DebugLoc& OldDL = OldI.getDebugLoc();
const DebugLoc& NewDL = NewI.getDebugLoc();
// Verify that the debug location data is the same
EXPECT_EQ(OldDL.getLine(), NewDL.getLine());
EXPECT_EQ(OldDL.getCol(), NewDL.getCol());
// But that they belong to different functions
auto *OldSubprogram = cast<DISubprogram>(OldDL.getInlinedAtScope());
auto *NewSubprogram = cast<DISubprogram>(NewDL.getInlinedAtScope());
EXPECT_EQ(OldFunc->getSubprogram(), OldSubprogram);
EXPECT_EQ(NewFunc->getSubprogram(), NewSubprogram);
}
++OldIter;
++NewIter;
}
EXPECT_EQ(OldEnd, OldIter);
EXPECT_EQ(NewEnd, NewIter);
}
// Test that the arguments for debug intrinsics in the new function were
// properly cloned
TEST_F(CloneFunc, DebugIntrinsics) {
EXPECT_FALSE(verifyModule(*M));
inst_iterator OldIter = inst_begin(OldFunc);
inst_iterator OldEnd = inst_end(OldFunc);
inst_iterator NewIter = inst_begin(NewFunc);
inst_iterator NewEnd = inst_end(NewFunc);
while (OldIter != OldEnd && NewIter != NewEnd) {
Instruction& OldI = *OldIter;
Instruction& NewI = *NewIter;
if (DbgDeclareInst* OldIntrin = dyn_cast<DbgDeclareInst>(&OldI)) {
DbgDeclareInst* NewIntrin = dyn_cast<DbgDeclareInst>(&NewI);
EXPECT_TRUE(NewIntrin);
// Old address must belong to the old function
EXPECT_EQ(OldFunc, cast<AllocaInst>(OldIntrin->getAddress())->
getParent()->getParent());
// New address must belong to the new function
EXPECT_EQ(NewFunc, cast<AllocaInst>(NewIntrin->getAddress())->
getParent()->getParent());
if (OldIntrin->getDebugLoc()->getInlinedAt()) {
// Inlined variable should refer to the same DILocalVariable as in the
// Old Function
EXPECT_EQ(OldIntrin->getVariable(), NewIntrin->getVariable());
} else {
// Old variable must belong to the old function.
EXPECT_EQ(OldFunc->getSubprogram(),
cast<DISubprogram>(OldIntrin->getVariable()->getScope()));
// New variable must belong to the new function.
EXPECT_EQ(NewFunc->getSubprogram(),
cast<DISubprogram>(NewIntrin->getVariable()->getScope()));
}
} else if (DbgValueInst* OldIntrin = dyn_cast<DbgValueInst>(&OldI)) {
DbgValueInst* NewIntrin = dyn_cast<DbgValueInst>(&NewI);
EXPECT_TRUE(NewIntrin);
if (!OldIntrin->getDebugLoc()->getInlinedAt()) {
// Old variable must belong to the old function.
EXPECT_EQ(OldFunc->getSubprogram(),
cast<DISubprogram>(OldIntrin->getVariable()->getScope()));
// New variable must belong to the new function.
EXPECT_EQ(NewFunc->getSubprogram(),
cast<DISubprogram>(NewIntrin->getVariable()->getScope()));
}
}
++OldIter;
++NewIter;
}
}
static int GetDICompileUnitCount(const Module& M) {
if (const auto* LLVM_DBG_CU = M.getNamedMetadata("llvm.dbg.cu")) {
return LLVM_DBG_CU->getNumOperands();
}
return 0;
}
static bool haveCompileUnitsInCommon(const Module &LHS, const Module &RHS) {
const NamedMDNode *LHSCUs = LHS.getNamedMetadata("llvm.dbg.cu");
if (!LHSCUs)
return false;
const NamedMDNode *RHSCUs = RHS.getNamedMetadata("llvm.dbg.cu");
if (!RHSCUs)
return false;
SmallPtrSet<const MDNode *, 8> Found;
for (int I = 0, E = LHSCUs->getNumOperands(); I != E; ++I)
if (const MDNode *N = LHSCUs->getOperand(I))
Found.insert(N);
for (int I = 0, E = RHSCUs->getNumOperands(); I != E; ++I)
if (const MDNode *N = RHSCUs->getOperand(I))
if (Found.count(N))
return true;
return false;
}
TEST(CloneFunction, CloneEmptyFunction) {
StringRef ImplAssembly = R"(
define void @foo() {
ret void
}
declare void @bar()
)";
LLVMContext Context;
SMDiagnostic Error;
auto ImplModule = parseAssemblyString(ImplAssembly, Error, Context);
EXPECT_TRUE(ImplModule != nullptr);
auto *ImplFunction = ImplModule->getFunction("foo");
EXPECT_TRUE(ImplFunction != nullptr);
auto *DeclFunction = ImplModule->getFunction("bar");
EXPECT_TRUE(DeclFunction != nullptr);
ValueToValueMapTy VMap;
SmallVector<ReturnInst *, 8> Returns;
ClonedCodeInfo CCI;
CloneFunctionInto(ImplFunction, DeclFunction, VMap,
CloneFunctionChangeType::GlobalChanges, Returns, "", &CCI);
EXPECT_FALSE(verifyModule(*ImplModule, &errs()));
EXPECT_FALSE(CCI.ContainsCalls);
EXPECT_FALSE(CCI.ContainsDynamicAllocas);
}
TEST(CloneFunction, CloneFunctionWithInalloca) {
StringRef ImplAssembly = R"(
declare void @a(i32* inalloca)
define void @foo() {
%a = alloca inalloca i32
call void @a(i32* inalloca %a)
ret void
}
declare void @bar()
)";
LLVMContext Context;
SMDiagnostic Error;
auto ImplModule = parseAssemblyString(ImplAssembly, Error, Context);
EXPECT_TRUE(ImplModule != nullptr);
auto *ImplFunction = ImplModule->getFunction("foo");
EXPECT_TRUE(ImplFunction != nullptr);
auto *DeclFunction = ImplModule->getFunction("bar");
EXPECT_TRUE(DeclFunction != nullptr);
ValueToValueMapTy VMap;
SmallVector<ReturnInst *, 8> Returns;
ClonedCodeInfo CCI;
CloneFunctionInto(DeclFunction, ImplFunction, VMap,
CloneFunctionChangeType::GlobalChanges, Returns, "", &CCI);
EXPECT_FALSE(verifyModule(*ImplModule, &errs()));
EXPECT_TRUE(CCI.ContainsCalls);
EXPECT_TRUE(CCI.ContainsDynamicAllocas);
}
TEST(CloneFunction, CloneFunctionWithSubprograms) {
// Tests that the debug info is duplicated correctly when a DISubprogram
// happens to be one of the operands of the DISubprogram that is being cloned.
// In general, operands of "test" that are distinct should be duplicated,
// but in this case "my_operator" should not be duplicated. If it is
// duplicated, the metadata in the llvm.dbg.declare could end up with
// different duplicates.
StringRef ImplAssembly = R"(
declare void @llvm.dbg.declare(metadata, metadata, metadata)
define void @test() !dbg !5 {
call void @llvm.dbg.declare(metadata i8* undef, metadata !4, metadata !DIExpression()), !dbg !6
ret void
}
declare void @cloned()
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!2}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1)
!1 = !DIFile(filename: "test.cpp", directory: "")
!2 = !{i32 1, !"Debug Info Version", i32 3}
!3 = distinct !DISubprogram(name: "my_operator", scope: !1, unit: !0, retainedNodes: !{!4})
!4 = !DILocalVariable(name: "awaitables", scope: !3)
!5 = distinct !DISubprogram(name: "test", scope: !3, unit: !0)
!6 = !DILocation(line: 55, column: 15, scope: !3, inlinedAt: !7)
!7 = distinct !DILocation(line: 73, column: 14, scope: !5)
)";
LLVMContext Context;
SMDiagnostic Error;
auto ImplModule = parseAssemblyString(ImplAssembly, Error, Context);
EXPECT_TRUE(ImplModule != nullptr);
auto *OldFunc = ImplModule->getFunction("test");
EXPECT_TRUE(OldFunc != nullptr);
auto *NewFunc = ImplModule->getFunction("cloned");
EXPECT_TRUE(NewFunc != nullptr);
ValueToValueMapTy VMap;
SmallVector<ReturnInst *, 8> Returns;
ClonedCodeInfo CCI;
CloneFunctionInto(NewFunc, OldFunc, VMap,
CloneFunctionChangeType::GlobalChanges, Returns, "", &CCI);
// This fails if the scopes in the llvm.dbg.declare variable and location
// aren't the same.
EXPECT_FALSE(verifyModule(*ImplModule, &errs()));
}
TEST(CloneFunction, CloneFunctionToDifferentModule) {
StringRef ImplAssembly = R"(
define void @foo() {
ret void, !dbg !5
}
!llvm.module.flags = !{!0}
!llvm.dbg.cu = !{!2, !6}
!0 = !{i32 1, !"Debug Info Version", i32 3}
!1 = distinct !DISubprogram(unit: !2)
!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3)
!3 = !DIFile(filename: "foo.c", directory: "/tmp")
!4 = distinct !DISubprogram(unit: !2)
!5 = !DILocation(line: 4, scope: !1)
!6 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3)
)";
StringRef DeclAssembly = R"(
declare void @foo()
)";
LLVMContext Context;
SMDiagnostic Error;
auto ImplModule = parseAssemblyString(ImplAssembly, Error, Context);
EXPECT_TRUE(ImplModule != nullptr);
// DICompileUnits: !2, !6. Only !2 is reachable from @foo().
EXPECT_TRUE(GetDICompileUnitCount(*ImplModule) == 2);
auto* ImplFunction = ImplModule->getFunction("foo");
EXPECT_TRUE(ImplFunction != nullptr);
auto DeclModule = parseAssemblyString(DeclAssembly, Error, Context);
EXPECT_TRUE(DeclModule != nullptr);
// No DICompileUnits defined here.
EXPECT_TRUE(GetDICompileUnitCount(*DeclModule) == 0);
auto* DeclFunction = DeclModule->getFunction("foo");
EXPECT_TRUE(DeclFunction != nullptr);
ValueToValueMapTy VMap;
VMap[ImplFunction] = DeclFunction;
// No args to map
SmallVector<ReturnInst*, 8> Returns;
CloneFunctionInto(DeclFunction, ImplFunction, VMap,
CloneFunctionChangeType::DifferentModule, Returns);
EXPECT_FALSE(verifyModule(*ImplModule, &errs()));
EXPECT_FALSE(verifyModule(*DeclModule, &errs()));
// DICompileUnit !2 shall be cloned into DeclModule.
EXPECT_TRUE(GetDICompileUnitCount(*DeclModule) == 1);
EXPECT_FALSE(haveCompileUnitsInCommon(*ImplModule, *DeclModule));
}
class CloneModule : public ::testing::Test {
protected:
void SetUp() override {
SetupModule();
CreateOldModule();
CreateNewModule();
}
void SetupModule() { OldM = new Module("", C); }
void CreateOldModule() {
auto *CD = OldM->getOrInsertComdat("comdat");
CD->setSelectionKind(Comdat::ExactMatch);
auto GV = new GlobalVariable(
*OldM, Type::getInt32Ty(C), false, GlobalValue::ExternalLinkage,
ConstantInt::get(Type::getInt32Ty(C), 1), "gv");
GV->addMetadata(LLVMContext::MD_type, *MDNode::get(C, {}));
GV->setComdat(CD);
{
// Add an empty compile unit first that isn't otherwise referenced, to
// confirm that compile units get cloned in the correct order.
DIBuilder EmptyBuilder(*OldM);
auto *File = EmptyBuilder.createFile("empty.c", "/file/dir/");
(void)EmptyBuilder.createCompileUnit(dwarf::DW_LANG_C99, File,
"EmptyUnit", false, "", 0);
EmptyBuilder.finalize();
}
DIBuilder DBuilder(*OldM);
IRBuilder<> IBuilder(C);
auto *FuncType = FunctionType::get(Type::getVoidTy(C), false);
auto *PersFn = Function::Create(FuncType, GlobalValue::ExternalLinkage,
"persfn", OldM);
auto *F =
Function::Create(FuncType, GlobalValue::PrivateLinkage, "f", OldM);
F->setPersonalityFn(PersFn);
F->setComdat(CD);
// Create debug info
auto *File = DBuilder.createFile("filename.c", "/file/dir/");
DITypeRefArray ParamTypes = DBuilder.getOrCreateTypeArray(None);
DISubroutineType *DFuncType = DBuilder.createSubroutineType(ParamTypes);
auto *CU = DBuilder.createCompileUnit(dwarf::DW_LANG_C99,
DBuilder.createFile("filename.c",
"/file/dir"),
"CloneModule", false, "", 0);
// Function DI
auto *Subprogram = DBuilder.createFunction(
CU, "f", "f", File, 4, DFuncType, 3, DINode::FlagZero,
DISubprogram::SPFlagLocalToUnit | DISubprogram::SPFlagDefinition);
F->setSubprogram(Subprogram);
// Create and assign DIGlobalVariableExpression to gv
auto GVExpression = DBuilder.createGlobalVariableExpression(
Subprogram, "gv", "gv", File, 1, DBuilder.createNullPtrType(), false);
GV->addDebugInfo(GVExpression);
// DIGlobalVariableExpression not attached to any global variable
auto Expr = DBuilder.createExpression(
ArrayRef<uint64_t>{dwarf::DW_OP_constu, 42U, dwarf::DW_OP_stack_value});
DBuilder.createGlobalVariableExpression(
Subprogram, "unattached", "unattached", File, 1,
DBuilder.createNullPtrType(), false, true, Expr);
auto *Entry = BasicBlock::Create(C, "", F);
IBuilder.SetInsertPoint(Entry);
IBuilder.CreateRetVoid();
// Finalize the debug info
DBuilder.finalize();
}
void CreateNewModule() { NewM = llvm::CloneModule(*OldM).release(); }
LLVMContext C;
Module *OldM;
Module *NewM;
};
TEST_F(CloneModule, Verify) {
// Confirm the old module is (still) valid.
EXPECT_FALSE(verifyModule(*OldM));
// Check the new module.
EXPECT_FALSE(verifyModule(*NewM));
}
TEST_F(CloneModule, OldModuleUnchanged) {
DebugInfoFinder Finder;
Finder.processModule(*OldM);
EXPECT_EQ(1U, Finder.subprogram_count());
}
TEST_F(CloneModule, Subprogram) {
Function *NewF = NewM->getFunction("f");
DISubprogram *SP = NewF->getSubprogram();
EXPECT_TRUE(SP != nullptr);
EXPECT_EQ(SP->getName(), "f");
EXPECT_EQ(SP->getFile()->getFilename(), "filename.c");
EXPECT_EQ(SP->getLine(), (unsigned)4);
}
TEST_F(CloneModule, GlobalMetadata) {
GlobalVariable *NewGV = NewM->getGlobalVariable("gv");
EXPECT_NE(nullptr, NewGV->getMetadata(LLVMContext::MD_type));
}
TEST_F(CloneModule, GlobalDebugInfo) {
GlobalVariable *NewGV = NewM->getGlobalVariable("gv");
EXPECT_TRUE(NewGV != nullptr);
// Find debug info expression assigned to global
SmallVector<DIGlobalVariableExpression *, 1> GVs;
NewGV->getDebugInfo(GVs);
EXPECT_EQ(GVs.size(), 1U);
DIGlobalVariableExpression *GVExpr = GVs[0];
DIGlobalVariable *GV = GVExpr->getVariable();
EXPECT_TRUE(GV != nullptr);
EXPECT_EQ(GV->getName(), "gv");
EXPECT_EQ(GV->getLine(), 1U);
// Assert that the scope of the debug info attached to
// global variable matches the cloned function.
DISubprogram *SP = NewM->getFunction("f")->getSubprogram();
EXPECT_TRUE(SP != nullptr);
EXPECT_EQ(GV->getScope(), SP);
}
TEST_F(CloneModule, CompileUnit) {
// Find DICompileUnit listed in llvm.dbg.cu
auto *NMD = NewM->getNamedMetadata("llvm.dbg.cu");
EXPECT_TRUE(NMD != nullptr);
EXPECT_EQ(NMD->getNumOperands(), 2U);
EXPECT_FALSE(haveCompileUnitsInCommon(*OldM, *NewM));
// Check that the empty CU is first, even though it's not referenced except
// from named metadata.
DICompileUnit *EmptyCU = dyn_cast<llvm::DICompileUnit>(NMD->getOperand(0));
EXPECT_TRUE(EmptyCU != nullptr);
EXPECT_EQ("EmptyUnit", EmptyCU->getProducer());
// Get the interesting CU.
DICompileUnit *CU = dyn_cast<llvm::DICompileUnit>(NMD->getOperand(1));
EXPECT_TRUE(CU != nullptr);
EXPECT_EQ("CloneModule", CU->getProducer());
// Assert this CU is consistent with the cloned function debug info
DISubprogram *SP = NewM->getFunction("f")->getSubprogram();
EXPECT_TRUE(SP != nullptr);
EXPECT_EQ(SP->getUnit(), CU);
// Check globals listed in CU have the correct scope
DIGlobalVariableExpressionArray GlobalArray = CU->getGlobalVariables();
EXPECT_EQ(GlobalArray.size(), 2U);
for (DIGlobalVariableExpression *GVExpr : GlobalArray) {
DIGlobalVariable *GV = GVExpr->getVariable();
EXPECT_EQ(GV->getScope(), SP);
}
}
TEST_F(CloneModule, Comdat) {
GlobalVariable *NewGV = NewM->getGlobalVariable("gv");
auto *CD = NewGV->getComdat();
ASSERT_NE(nullptr, CD);
EXPECT_EQ("comdat", CD->getName());
EXPECT_EQ(Comdat::ExactMatch, CD->getSelectionKind());
Function *NewF = NewM->getFunction("f");
EXPECT_EQ(CD, NewF->getComdat());
}
}