RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-10-22 12:33:33 +02:00
Code Issues Projects Releases Wiki Activity
659b3014e1
llvm-mirror/lib/IR/DebugInfo.cpp
Keno Fischer 474eb26f5c [StripDeadDebug/DIFinder] Track inlined SPs 
Summary:
In rL299692 I improved strip-dead-debug-info's ability to drop CUs that are not
referenced from the current module. However, in doing so I neglected to realize
that some SPs could be referenced entirely from inlined functions. It appears
I was not the only one to make this mistake, because DebugInfoFinder, doesn't
find those SPs either. Fix this in DebugInfoFinder and then use that to make
sure not to drop those CUs in strip-dead-debug-info.

Reviewers: aprantl

Reviewed By: aprantl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D31904

llvm-svn: 299936
2017-04-11 13:32:11 +00:00

662 lines
20 KiB
C++
Raw Blame History

//===--- DebugInfo.cpp - Debug Information Helper Classes -----------------===//
//
// 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 helper classes used to build and interpret debug
// information in LLVM IR form.
//
//===----------------------------------------------------------------------===//
#include "llvm/IR/DebugInfo.h"
#include "LLVMContextImpl.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DIBuilder.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/GVMaterializer.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
using namespace llvm::dwarf;
DISubprogram *llvm::getDISubprogram(const MDNode *Scope) {
if (auto *LocalScope = dyn_cast_or_null<DILocalScope>(Scope))
return LocalScope->getSubprogram();
return nullptr;
}
//===----------------------------------------------------------------------===//
// DebugInfoFinder implementations.
//===----------------------------------------------------------------------===//
void DebugInfoFinder::reset() {
CUs.clear();
SPs.clear();
GVs.clear();
TYs.clear();
Scopes.clear();
NodesSeen.clear();
}
void DebugInfoFinder::processModule(const Module &M) {
for (auto *CU : M.debug_compile_units()) {
addCompileUnit(CU);
for (auto DIG : CU->getGlobalVariables()) {
if (!addGlobalVariable(DIG))
continue;
auto *GV = DIG->getVariable();
processScope(GV->getScope());
processType(GV->getType().resolve());
}
for (auto *ET : CU->getEnumTypes())
processType(ET);
for (auto *RT : CU->getRetainedTypes())
if (auto *T = dyn_cast<DIType>(RT))
processType(T);
else
processSubprogram(cast<DISubprogram>(RT));
for (auto *Import : CU->getImportedEntities()) {
auto *Entity = Import->getEntity().resolve();
if (auto *T = dyn_cast<DIType>(Entity))
processType(T);
else if (auto *SP = dyn_cast<DISubprogram>(Entity))
processSubprogram(SP);
else if (auto *NS = dyn_cast<DINamespace>(Entity))
processScope(NS->getScope());
else if (auto *M = dyn_cast<DIModule>(Entity))
processScope(M->getScope());
}
}
for (auto &F : M.functions()) {
if (auto *SP = cast_or_null<DISubprogram>(F.getSubprogram()))
processSubprogram(SP);
// There could be subprograms from inlined functions referenced from
// instructions only. Walk the function to find them.
for (const BasicBlock &BB : F) {
for (const Instruction &I : BB) {
if (!I.getDebugLoc())
continue;
processLocation(M, I.getDebugLoc().get());
}
}
}
}
void DebugInfoFinder::processLocation(const Module &M, const DILocation *Loc) {
if (!Loc)
return;
processScope(Loc->getScope());
processLocation(M, Loc->getInlinedAt());
}
void DebugInfoFinder::processType(DIType *DT) {
if (!addType(DT))
return;
processScope(DT->getScope().resolve());
if (auto *ST = dyn_cast<DISubroutineType>(DT)) {
for (DITypeRef Ref : ST->getTypeArray())
processType(Ref.resolve());
return;
}
if (auto *DCT = dyn_cast<DICompositeType>(DT)) {
processType(DCT->getBaseType().resolve());
for (Metadata *D : DCT->getElements()) {
if (auto *T = dyn_cast<DIType>(D))
processType(T);
else if (auto *SP = dyn_cast<DISubprogram>(D))
processSubprogram(SP);
}
return;
}
if (auto *DDT = dyn_cast<DIDerivedType>(DT)) {
processType(DDT->getBaseType().resolve());
}
}
void DebugInfoFinder::processScope(DIScope *Scope) {
if (!Scope)
return;
if (auto *Ty = dyn_cast<DIType>(Scope)) {
processType(Ty);
return;
}
if (auto *CU = dyn_cast<DICompileUnit>(Scope)) {
addCompileUnit(CU);
return;
}
if (auto *SP = dyn_cast<DISubprogram>(Scope)) {
processSubprogram(SP);
return;
}
if (!addScope(Scope))
return;
if (auto *LB = dyn_cast<DILexicalBlockBase>(Scope)) {
processScope(LB->getScope());
} else if (auto *NS = dyn_cast<DINamespace>(Scope)) {
processScope(NS->getScope());
} else if (auto *M = dyn_cast<DIModule>(Scope)) {
processScope(M->getScope());
}
}
void DebugInfoFinder::processSubprogram(DISubprogram *SP) {
if (!addSubprogram(SP))
return;
processScope(SP->getScope().resolve());
processType(SP->getType());
for (auto *Element : SP->getTemplateParams()) {
if (auto *TType = dyn_cast<DITemplateTypeParameter>(Element)) {
processType(TType->getType().resolve());
} else if (auto *TVal = dyn_cast<DITemplateValueParameter>(Element)) {
processType(TVal->getType().resolve());
}
}
}
void DebugInfoFinder::processDeclare(const Module &M,
const DbgDeclareInst *DDI) {
auto *N = dyn_cast<MDNode>(DDI->getVariable());
if (!N)
return;
auto *DV = dyn_cast<DILocalVariable>(N);
if (!DV)
return;
if (!NodesSeen.insert(DV).second)
return;
processScope(DV->getScope());
processType(DV->getType().resolve());
}
void DebugInfoFinder::processValue(const Module &M, const DbgValueInst *DVI) {
auto *N = dyn_cast<MDNode>(DVI->getVariable());
if (!N)
return;
auto *DV = dyn_cast<DILocalVariable>(N);
if (!DV)
return;
if (!NodesSeen.insert(DV).second)
return;
processScope(DV->getScope());
processType(DV->getType().resolve());
}
bool DebugInfoFinder::addType(DIType *DT) {
if (!DT)
return false;
if (!NodesSeen.insert(DT).second)
return false;
TYs.push_back(const_cast<DIType *>(DT));
return true;
}
bool DebugInfoFinder::addCompileUnit(DICompileUnit *CU) {
if (!CU)
return false;
if (!NodesSeen.insert(CU).second)
return false;
CUs.push_back(CU);
return true;
}
bool DebugInfoFinder::addGlobalVariable(DIGlobalVariableExpression *DIG) {
if (!NodesSeen.insert(DIG).second)
return false;
GVs.push_back(DIG);
return true;
}
bool DebugInfoFinder::addSubprogram(DISubprogram *SP) {
if (!SP)
return false;
if (!NodesSeen.insert(SP).second)
return false;
SPs.push_back(SP);
return true;
}
bool DebugInfoFinder::addScope(DIScope *Scope) {
if (!Scope)
return false;
// FIXME: Ocaml binding generates a scope with no content, we treat it
// as null for now.
if (Scope->getNumOperands() == 0)
return false;
if (!NodesSeen.insert(Scope).second)
return false;
Scopes.push_back(Scope);
return true;
}
static llvm::MDNode *stripDebugLocFromLoopID(llvm::MDNode *N) {
assert(N->op_begin() != N->op_end() && "Missing self reference?");
// if there is no debug location, we do not have to rewrite this MDNode.
if (std::none_of(N->op_begin() + 1, N->op_end(), [](const MDOperand &Op) {
return isa<DILocation>(Op.get());
}))
return N;
// If there is only the debug location without any actual loop metadata, we
// can remove the metadata.
if (std::none_of(N->op_begin() + 1, N->op_end(), [](const MDOperand &Op) {
return !isa<DILocation>(Op.get());
}))
return nullptr;
SmallVector<Metadata *, 4> Args;
// Reserve operand 0 for loop id self reference.
auto TempNode = MDNode::getTemporary(N->getContext(), None);
Args.push_back(TempNode.get());
// Add all non-debug location operands back.
for (auto Op = N->op_begin() + 1; Op != N->op_end(); Op++) {
if (!isa<DILocation>(*Op))
Args.push_back(*Op);
}
// Set the first operand to itself.
MDNode *LoopID = MDNode::get(N->getContext(), Args);
LoopID->replaceOperandWith(0, LoopID);
return LoopID;
}
bool llvm::stripDebugInfo(Function &F) {
bool Changed = false;
if (F.getSubprogram()) {
Changed = true;
F.setSubprogram(nullptr);
}
llvm::DenseMap<llvm::MDNode*, llvm::MDNode*> LoopIDsMap;
for (BasicBlock &BB : F) {
for (auto II = BB.begin(), End = BB.end(); II != End;) {
Instruction &I = *II++; // We may delete the instruction, increment now.
if (isa<DbgInfoIntrinsic>(&I)) {
I.eraseFromParent();
Changed = true;
continue;
}
if (I.getDebugLoc()) {
Changed = true;
I.setDebugLoc(DebugLoc());
}
}
auto *TermInst = BB.getTerminator();
if (auto *LoopID = TermInst->getMetadata(LLVMContext::MD_loop)) {
auto *NewLoopID = LoopIDsMap.lookup(LoopID);
if (!NewLoopID)
NewLoopID = LoopIDsMap[LoopID] = stripDebugLocFromLoopID(LoopID);
if (NewLoopID != LoopID)
TermInst->setMetadata(LLVMContext::MD_loop, NewLoopID);
}
}
return Changed;
}
bool llvm::StripDebugInfo(Module &M) {
bool Changed = false;
for (Module::named_metadata_iterator NMI = M.named_metadata_begin(),
NME = M.named_metadata_end(); NMI != NME;) {
NamedMDNode *NMD = &*NMI;
++NMI;
// We're stripping debug info, and without them, coverage information
// doesn't quite make sense.
if (NMD->getName().startswith("llvm.dbg.") ||
NMD->getName() == "llvm.gcov") {
NMD->eraseFromParent();
Changed = true;
}
}
for (Function &F : M)
Changed |= stripDebugInfo(F);
for (auto &GV : M.globals()) {
SmallVector<MDNode *, 1> MDs;
GV.getMetadata(LLVMContext::MD_dbg, MDs);
if (!MDs.empty()) {
GV.eraseMetadata(LLVMContext::MD_dbg);
Changed = true;
}
}
if (GVMaterializer *Materializer = M.getMaterializer())
Materializer->setStripDebugInfo();
return Changed;
}
namespace {
/// Helper class to downgrade -g metadata to -gline-tables-only metadata.
class DebugTypeInfoRemoval {
DenseMap<Metadata *, Metadata *> Replacements;
public:
/// The (void)() type.
MDNode *EmptySubroutineType;
private:
/// Remember what linkage name we originally had before stripping. If we end
/// up making two subprograms identical who originally had different linkage
/// names, then we need to make one of them distinct, to avoid them getting
/// uniqued. Maps the new node to the old linkage name.
DenseMap<DISubprogram *, StringRef> NewToLinkageName;
// TODO: Remember the distinct subprogram we created for a given linkage name,
// so that we can continue to unique whenever possible. Map <newly created
// node, old linkage name> to the first (possibly distinct) mdsubprogram
// created for that combination. This is not strictly needed for correctness,
// but can cut down on the number of MDNodes and let us diff cleanly with the
// output of -gline-tables-only.
public:
DebugTypeInfoRemoval(LLVMContext &C)
: EmptySubroutineType(DISubroutineType::get(C, DINode::FlagZero, 0,
MDNode::get(C, {}))) {}
Metadata *map(Metadata *M) {
if (!M)
return nullptr;
auto Replacement = Replacements.find(M);
if (Replacement != Replacements.end())
return Replacement->second;
return M;
}
MDNode *mapNode(Metadata *N) { return dyn_cast_or_null<MDNode>(map(N)); }
/// Recursively remap N and all its referenced children. Does a DF post-order
/// traversal, so as to remap bottoms up.
void traverseAndRemap(MDNode *N) { traverse(N); }
private:
// Create a new DISubprogram, to replace the one given.
DISubprogram *getReplacementSubprogram(DISubprogram *MDS) {
auto *FileAndScope = cast_or_null<DIFile>(map(MDS->getFile()));
StringRef LinkageName = MDS->getName().empty() ? MDS->getLinkageName() : "";
DISubprogram *Declaration = nullptr;
auto *Type = cast_or_null<DISubroutineType>(map(MDS->getType()));
DITypeRef ContainingType(map(MDS->getContainingType()));
auto *Unit = cast_or_null<DICompileUnit>(map(MDS->getUnit()));
auto Variables = nullptr;
auto TemplateParams = nullptr;
// Make a distinct DISubprogram, for situations that warrent it.
auto distinctMDSubprogram = [&]() {
return DISubprogram::getDistinct(
MDS->getContext(), FileAndScope, MDS->getName(), LinkageName,
FileAndScope, MDS->getLine(), Type, MDS->isLocalToUnit(),
MDS->isDefinition(), MDS->getScopeLine(), ContainingType,
MDS->getVirtuality(), MDS->getVirtualIndex(),
MDS->getThisAdjustment(), MDS->getFlags(), MDS->isOptimized(), Unit,
TemplateParams, Declaration, Variables);
};
if (MDS->isDistinct())
return distinctMDSubprogram();
auto *NewMDS = DISubprogram::get(
MDS->getContext(), FileAndScope, MDS->getName(), LinkageName,
FileAndScope, MDS->getLine(), Type, MDS->isLocalToUnit(),
MDS->isDefinition(), MDS->getScopeLine(), ContainingType,
MDS->getVirtuality(), MDS->getVirtualIndex(), MDS->getThisAdjustment(),
MDS->getFlags(), MDS->isOptimized(), Unit, TemplateParams, Declaration,
Variables);
StringRef OldLinkageName = MDS->getLinkageName();
// See if we need to make a distinct one.
auto OrigLinkage = NewToLinkageName.find(NewMDS);
if (OrigLinkage != NewToLinkageName.end()) {
if (OrigLinkage->second == OldLinkageName)
// We're good.
return NewMDS;
// Otherwise, need to make a distinct one.
// TODO: Query the map to see if we already have one.
return distinctMDSubprogram();
}
NewToLinkageName.insert({NewMDS, MDS->getLinkageName()});
return NewMDS;
}
/// Create a new compile unit, to replace the one given
DICompileUnit *getReplacementCU(DICompileUnit *CU) {
// Drop skeleton CUs.
if (CU->getDWOId())
return nullptr;
auto *File = cast_or_null<DIFile>(map(CU->getFile()));
MDTuple *EnumTypes = nullptr;
MDTuple *RetainedTypes = nullptr;
MDTuple *GlobalVariables = nullptr;
MDTuple *ImportedEntities = nullptr;
return DICompileUnit::getDistinct(
CU->getContext(), CU->getSourceLanguage(), File, CU->getProducer(),
CU->isOptimized(), CU->getFlags(), CU->getRuntimeVersion(),
CU->getSplitDebugFilename(), DICompileUnit::LineTablesOnly, EnumTypes,
RetainedTypes, GlobalVariables, ImportedEntities, CU->getMacros(),
CU->getDWOId(), CU->getSplitDebugInlining(),
CU->getDebugInfoForProfiling());
}
DILocation *getReplacementMDLocation(DILocation *MLD) {
auto *Scope = map(MLD->getScope());
auto *InlinedAt = map(MLD->getInlinedAt());
if (MLD->isDistinct())
return DILocation::getDistinct(MLD->getContext(), MLD->getLine(),
MLD->getColumn(), Scope, InlinedAt);
return DILocation::get(MLD->getContext(), MLD->getLine(), MLD->getColumn(),
Scope, InlinedAt);
}
/// Create a new generic MDNode, to replace the one given
MDNode *getReplacementMDNode(MDNode *N) {
SmallVector<Metadata *, 8> Ops;
Ops.reserve(N->getNumOperands());
for (auto &I : N->operands())
if (I)
Ops.push_back(map(I));
auto *Ret = MDNode::get(N->getContext(), Ops);
return Ret;
}
/// Attempt to re-map N to a newly created node.
void remap(MDNode *N) {
if (Replacements.count(N))
return;
auto doRemap = [&](MDNode *N) -> MDNode * {
if (!N)
return nullptr;
if (auto *MDSub = dyn_cast<DISubprogram>(N)) {
remap(MDSub->getUnit());
return getReplacementSubprogram(MDSub);
}
if (isa<DISubroutineType>(N))
return EmptySubroutineType;
if (auto *CU = dyn_cast<DICompileUnit>(N))
return getReplacementCU(CU);
if (isa<DIFile>(N))
return N;
if (auto *MDLB = dyn_cast<DILexicalBlockBase>(N))
// Remap to our referenced scope (recursively).
return mapNode(MDLB->getScope());
if (auto *MLD = dyn_cast<DILocation>(N))
return getReplacementMDLocation(MLD);
// Otherwise, if we see these, just drop them now. Not strictly necessary,
// but this speeds things up a little.
if (isa<DINode>(N))
return nullptr;
return getReplacementMDNode(N);
};
Replacements[N] = doRemap(N);
}
/// Do the remapping traversal.
void traverse(MDNode *);
};
} // Anonymous namespace.
void DebugTypeInfoRemoval::traverse(MDNode *N) {
if (!N || Replacements.count(N))
return;
// To avoid cycles, as well as for efficiency sake, we will sometimes prune
// parts of the graph.
auto prune = [](MDNode *Parent, MDNode *Child) {
if (auto *MDS = dyn_cast<DISubprogram>(Parent))
return Child == MDS->getVariables().get();
return false;
};
SmallVector<MDNode *, 16> ToVisit;
DenseSet<MDNode *> Opened;
// Visit each node starting at N in post order, and map them.
ToVisit.push_back(N);
while (!ToVisit.empty()) {
auto *N = ToVisit.back();
if (!Opened.insert(N).second) {
// Close it.
remap(N);
ToVisit.pop_back();
continue;
}
for (auto &I : N->operands())
if (auto *MDN = dyn_cast_or_null<MDNode>(I))
if (!Opened.count(MDN) && !Replacements.count(MDN) && !prune(N, MDN) &&
!isa<DICompileUnit>(MDN))
ToVisit.push_back(MDN);
}
}
bool llvm::stripNonLineTableDebugInfo(Module &M) {
bool Changed = false;
// First off, delete the debug intrinsics.
auto RemoveUses = [&](StringRef Name) {
if (auto *DbgVal = M.getFunction(Name)) {
while (!DbgVal->use_empty())
cast<Instruction>(DbgVal->user_back())->eraseFromParent();
DbgVal->eraseFromParent();
Changed = true;
}
};
RemoveUses("llvm.dbg.declare");
RemoveUses("llvm.dbg.value");
// Delete non-CU debug info named metadata nodes.
for (auto NMI = M.named_metadata_begin(), NME = M.named_metadata_end();
NMI != NME;) {
NamedMDNode *NMD = &*NMI;
++NMI;
// Specifically keep dbg.cu around.
if (NMD->getName() == "llvm.dbg.cu")
continue;
}
// Drop all dbg attachments from global variables.
for (auto &GV : M.globals())
GV.eraseMetadata(LLVMContext::MD_dbg);
DebugTypeInfoRemoval Mapper(M.getContext());
auto remap = [&](llvm::MDNode *Node) -> llvm::MDNode * {
if (!Node)
return nullptr;
Mapper.traverseAndRemap(Node);
auto *NewNode = Mapper.mapNode(Node);
Changed |= Node != NewNode;
Node = NewNode;
return NewNode;
};
// Rewrite the DebugLocs to be equivalent to what
// -gline-tables-only would have created.
for (auto &F : M) {
if (auto *SP = F.getSubprogram()) {
Mapper.traverseAndRemap(SP);
auto *NewSP = cast<DISubprogram>(Mapper.mapNode(SP));
Changed |= SP != NewSP;
F.setSubprogram(NewSP);
}
for (auto &BB : F) {
for (auto &I : BB) {
auto remapDebugLoc = [&](DebugLoc DL) -> DebugLoc {
auto *Scope = DL.getScope();
MDNode *InlinedAt = DL.getInlinedAt();
Scope = remap(Scope);
InlinedAt = remap(InlinedAt);
return DebugLoc::get(DL.getLine(), DL.getCol(), Scope, InlinedAt);
};
if (I.getDebugLoc() != DebugLoc())
I.setDebugLoc(remapDebugLoc(I.getDebugLoc()));
// Remap DILocations in untyped MDNodes (e.g., llvm.loop).
SmallVector<std::pair<unsigned, MDNode *>, 2> MDs;
I.getAllMetadata(MDs);
for (auto Attachment : MDs)
if (auto *T = dyn_cast_or_null<MDTuple>(Attachment.second))
for (unsigned N = 0; N < T->getNumOperands(); ++N)
if (auto *Loc = dyn_cast_or_null<DILocation>(T->getOperand(N)))
if (Loc != DebugLoc())
T->replaceOperandWith(N, remapDebugLoc(Loc));
}
}
}
// Create a new llvm.dbg.cu, which is equivalent to the one
// -gline-tables-only would have created.
for (auto &NMD : M.getNamedMDList()) {
SmallVector<MDNode *, 8> Ops;
for (MDNode *Op : NMD.operands())
Ops.push_back(remap(Op));
if (!Changed)
continue;
NMD.clearOperands();
for (auto *Op : Ops)
if (Op)
NMD.addOperand(Op);
}
return Changed;
}
unsigned llvm::getDebugMetadataVersionFromModule(const Module &M) {
if (auto *Val = mdconst::dyn_extract_or_null<ConstantInt>(
M.getModuleFlag("Debug Info Version")))
return Val->getZExtValue();
return 0;
}
Reference in New Issue View Git Blame Copy Permalink