llvm-6502/lib/IR/LLVMContextImpl.cpp
Duncan P. N. Exon Smith 0294f639d2 IR: Drop metadata references more aggressively during teardown
Sometimes teardown happens before the debug info graph is complete
(e.g., when clang throws an error).  In that case, `MDNode`s will still
have RAUW, so deleting constants that the `MDNode`s point at will be
relatively expensive -- it'll cause re-uniquing all up the chain (what
I've been referring to as "teardown madness").

So, drop references *before* deleting constants.  We need to drop a few
more references now: the metadata side of the metadata/value bridges
needs to be dropped off the cliff along with the rest of it (previously,
the bridges were cleaned before we did anything with the `MDNode`s).

There's no real functionality change here -- state before and after
`LLVMContextImpl::~LLVMContextImpl()` is unchanged -- so no testcase.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226044 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-14 21:58:17 +00:00

185 lines
5.5 KiB
C++

//===-- LLVMContextImpl.cpp - Implement LLVMContextImpl -------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the opaque LLVMContextImpl.
//
//===----------------------------------------------------------------------===//
#include "LLVMContextImpl.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/Module.h"
#include <algorithm>
using namespace llvm;
LLVMContextImpl::LLVMContextImpl(LLVMContext &C)
: TheTrueVal(nullptr), TheFalseVal(nullptr),
VoidTy(C, Type::VoidTyID),
LabelTy(C, Type::LabelTyID),
HalfTy(C, Type::HalfTyID),
FloatTy(C, Type::FloatTyID),
DoubleTy(C, Type::DoubleTyID),
MetadataTy(C, Type::MetadataTyID),
X86_FP80Ty(C, Type::X86_FP80TyID),
FP128Ty(C, Type::FP128TyID),
PPC_FP128Ty(C, Type::PPC_FP128TyID),
X86_MMXTy(C, Type::X86_MMXTyID),
Int1Ty(C, 1),
Int8Ty(C, 8),
Int16Ty(C, 16),
Int32Ty(C, 32),
Int64Ty(C, 64) {
InlineAsmDiagHandler = nullptr;
InlineAsmDiagContext = nullptr;
DiagnosticHandler = nullptr;
DiagnosticContext = nullptr;
RespectDiagnosticFilters = false;
YieldCallback = nullptr;
YieldOpaqueHandle = nullptr;
NamedStructTypesUniqueID = 0;
}
namespace {
struct DropReferences {
// Takes the value_type of a ConstantUniqueMap's internal map, whose 'second'
// is a Constant*.
template <typename PairT> void operator()(const PairT &P) {
P.second->dropAllReferences();
}
};
// Temporary - drops pair.first instead of second.
struct DropFirst {
// Takes the value_type of a ConstantUniqueMap's internal map, whose 'second'
// is a Constant*.
template<typename PairT>
void operator()(const PairT &P) {
P.first->dropAllReferences();
}
};
}
LLVMContextImpl::~LLVMContextImpl() {
// NOTE: We need to delete the contents of OwnedModules, but Module's dtor
// will call LLVMContextImpl::removeModule, thus invalidating iterators into
// the container. Avoid iterators during this operation:
while (!OwnedModules.empty())
delete *OwnedModules.begin();
// Drop references for MDNodes. Do this before Values get deleted to avoid
// unnecessary RAUW when nodes are still unresolved.
for (auto *I : DistinctMDNodes)
I->dropAllReferences();
for (auto *I : MDTuples)
I->dropAllReferences();
for (auto *I : MDLocations)
I->dropAllReferences();
// Also drop references that come from the Value bridges.
for (auto &Pair : ValuesAsMetadata)
Pair.second->dropUsers();
for (auto &Pair : MetadataAsValues)
Pair.second->dropUse();
// Destroy MDNodes.
for (UniquableMDNode *I : DistinctMDNodes)
I->deleteAsSubclass();
for (MDTuple *I : MDTuples)
delete I;
for (MDLocation *I : MDLocations)
delete I;
// Free the constants. This is important to do here to ensure that they are
// freed before the LeakDetector is torn down.
std::for_each(ExprConstants.map_begin(), ExprConstants.map_end(),
DropFirst());
std::for_each(ArrayConstants.map_begin(), ArrayConstants.map_end(),
DropFirst());
std::for_each(StructConstants.map_begin(), StructConstants.map_end(),
DropFirst());
std::for_each(VectorConstants.map_begin(), VectorConstants.map_end(),
DropFirst());
ExprConstants.freeConstants();
ArrayConstants.freeConstants();
StructConstants.freeConstants();
VectorConstants.freeConstants();
DeleteContainerSeconds(CAZConstants);
DeleteContainerSeconds(CPNConstants);
DeleteContainerSeconds(UVConstants);
InlineAsms.freeConstants();
DeleteContainerSeconds(IntConstants);
DeleteContainerSeconds(FPConstants);
for (StringMap<ConstantDataSequential*>::iterator I = CDSConstants.begin(),
E = CDSConstants.end(); I != E; ++I)
delete I->second;
CDSConstants.clear();
// Destroy attributes.
for (FoldingSetIterator<AttributeImpl> I = AttrsSet.begin(),
E = AttrsSet.end(); I != E; ) {
FoldingSetIterator<AttributeImpl> Elem = I++;
delete &*Elem;
}
// Destroy attribute lists.
for (FoldingSetIterator<AttributeSetImpl> I = AttrsLists.begin(),
E = AttrsLists.end(); I != E; ) {
FoldingSetIterator<AttributeSetImpl> Elem = I++;
delete &*Elem;
}
// Destroy attribute node lists.
for (FoldingSetIterator<AttributeSetNode> I = AttrsSetNodes.begin(),
E = AttrsSetNodes.end(); I != E; ) {
FoldingSetIterator<AttributeSetNode> Elem = I++;
delete &*Elem;
}
// Destroy MetadataAsValues.
{
SmallVector<MetadataAsValue *, 8> MDVs;
MDVs.reserve(MetadataAsValues.size());
for (auto &Pair : MetadataAsValues)
MDVs.push_back(Pair.second);
MetadataAsValues.clear();
for (auto *V : MDVs)
delete V;
}
// Destroy ValuesAsMetadata.
for (auto &Pair : ValuesAsMetadata)
delete Pair.second;
// Destroy MDStrings.
MDStringCache.clear();
}
// ConstantsContext anchors
void UnaryConstantExpr::anchor() { }
void BinaryConstantExpr::anchor() { }
void SelectConstantExpr::anchor() { }
void ExtractElementConstantExpr::anchor() { }
void InsertElementConstantExpr::anchor() { }
void ShuffleVectorConstantExpr::anchor() { }
void ExtractValueConstantExpr::anchor() { }
void InsertValueConstantExpr::anchor() { }
void GetElementPtrConstantExpr::anchor() { }
void CompareConstantExpr::anchor() { }