index f584c2a036fd49e08e8c58f6e8878af04f987e2c..57dda88b0021b11a1602cf651f6a045bde5ac0dd 100644 (file)
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Dwarf.h"
+#include "llvm/Support/Endian.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
using namespace llvm;
#define DEBUG_TYPE "dwarfdebug"
clEnumVal(Disable, "Disabled"), clEnumValEnd),
cl::init(Default));
-static cl::opt<unsigned>
-DwarfVersionNumber("dwarf-version", cl::Hidden,
- cl::desc("Generate DWARF for dwarf version."), cl::init(0));
-
static const char *const DWARFGroupName = "DWARF Emission";
static const char *const DbgTimerName = "DWARF Debug Writer";
if (tag == dwarf::DW_TAG_pointer_type)
subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
- DIArray Elements = DICompositeType(subType).getTypeArray();
+ DIArray Elements = DICompositeType(subType).getElements();
for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
DIDerivedType DT(Elements.getElement(i));
if (getName() == DT.getName())
else
HasDwarfPubSections = DwarfPubSections == Enable;
+ unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
: MMI->getModule()->getDwarfVersion();
+ Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
+
{
NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
beginModule();
// scope then create and insert DIEs for these variables.
DIE &DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit &SPCU,
DISubprogram SP) {
- DIE *SPDie = SPCU.getDIE(SP);
-
- assert(SPDie && "Unable to find subprogram DIE!");
-
- // If we're updating an abstract DIE, then we will be adding the children and
- // object pointer later on. But what we don't want to do is process the
- // concrete DIE twice.
- if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
- assert(SPDie == AbsSPDIE);
- // Pick up abstract subprogram DIE.
- SPDie = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, SPCU.getUnitDie());
- SPCU.addDIEEntry(*SPDie, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
- } else if (!SP.getFunctionDeclaration()) {
- // There is not any need to generate specification DIE for a function
- // defined at compile unit level. If a function is defined inside another
- // function then gdb prefers the definition at top level and but does not
- // expect specification DIE in parent function. So avoid creating
- // specification DIE for a function defined inside a function.
- DIScope SPContext = resolve(SP.getContext());
- if (SP.isDefinition() && !SPContext.isCompileUnit() &&
- !SPContext.isFile() && !isSubprogramContext(SPContext)) {
- SPCU.addFlag(*SPDie, dwarf::DW_AT_declaration);
-
- // Add arguments.
- DICompositeType SPTy = SP.getType();
- DIArray Args = SPTy.getTypeArray();
- uint16_t SPTag = SPTy.getTag();
- if (SPTag == dwarf::DW_TAG_subroutine_type)
- SPCU.constructSubprogramArguments(*SPDie, Args);
- DIE *SPDeclDie = SPDie;
- SPDie =
- &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, SPCU.getUnitDie());
- SPCU.addDIEEntry(*SPDie, dwarf::DW_AT_specification, *SPDeclDie);
- }
- }
+ DIE *SPDie = SPCU.getOrCreateSubprogramDIE(SP);
attachLowHighPC(SPCU, *SPDie, FunctionBeginSym, FunctionEndSym);
- const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
+ const TargetRegisterInfo *RI = Asm->TM.getSubtargetImpl()->getRegisterInfo();
MachineLocation Location(RI->getFrameRegister(*Asm->MF));
SPCU.addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
assert(Scope->getScopeNode());
DIScope DS(Scope->getScopeNode());
DISubprogram InlinedSP = getDISubprogram(DS);
- DIE *OriginDIE = TheCU.getDIE(InlinedSP);
- // FIXME: This should be an assert (or possibly a
- // getOrCreateSubprogram(InlinedSP)) otherwise we're just failing to emit
- // inlining information.
- if (!OriginDIE) {
- DEBUG(dbgs() << "Unable to find original DIE for an inlined subprogram.");
- return nullptr;
- }
+ // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
+ // was inlined from another compile unit.
+ DIE *OriginDIE = AbstractSPDies[InlinedSP];
+ assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
DbgVariable &DV,
const LexicalScope &Scope,
DIE *&ObjectPointer) {
- AbstractOrInlined AOI = AOI_None;
- if (Scope.isAbstractScope())
- AOI = AOI_Abstract;
- else if (Scope.getInlinedAt())
- AOI = AOI_Inlined;
- auto Var = TheCU.constructVariableDIE(DV, AOI);
+ auto Var = TheCU.constructVariableDIE(DV, Scope.isAbstractScope());
if (DV.isObjectPointer())
ObjectPointer = Var.get();
return Var;
// If this is a variadic function, add an unspecified parameter.
DISubprogram SP(Scope->getScopeNode());
- DIArray FnArgs = SP.getType().getTypeArray();
- if (FnArgs.getElement(FnArgs.getNumElements() - 1)
- .isUnspecifiedParameter()) {
+ DITypeArray FnArgs = SP.getType().getTypeArray();
+ // If we have a single element of null, it is a function that returns void.
+ // If we have more than one elements and the last one is null, it is a
+ // variadic function.
+ if (FnArgs.getNumElements() > 1 &&
+ !FnArgs.getElement(FnArgs.getNumElements() - 1))
Children.push_back(
make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
- }
}
// Collect lexical scope children first.
assert(Scope->isAbstractScope());
assert(!Scope->getInlinedAt());
- DISubprogram Sub(Scope->getScopeNode());
+ DISubprogram SP(Scope->getScopeNode());
- if (!ProcessedSPNodes.insert(Sub))
+ ProcessedSPNodes.insert(SP);
+
+ DIE *&AbsDef = AbstractSPDies[SP];
+ if (AbsDef)
return;
- if (DIE *ScopeDIE = TheCU.getDIE(Sub)) {
- AbstractSPDies.insert(std::make_pair(Sub, ScopeDIE));
- TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
- createAndAddScopeChildren(TheCU, Scope, *ScopeDIE);
- }
+ // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
+ // was inlined from another compile unit.
+ DwarfCompileUnit &SPCU = *SPMap[SP];
+ DIE *ContextDIE;
+
+ // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
+ // the important distinction that the DIDescriptor is not associated with the
+ // DIE (since the DIDescriptor will be associated with the concrete DIE, if
+ // any). It could be refactored to some common utility function.
+ if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
+ ContextDIE = &SPCU.getUnitDie();
+ SPCU.getOrCreateSubprogramDIE(SPDecl);
+ } else
+ ContextDIE = SPCU.getOrCreateContextDIE(resolve(SP.getContext()));
+
+ // Passing null as the associated DIDescriptor because the abstract definition
+ // shouldn't be found by lookup.
+ AbsDef = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE,
+ DIDescriptor());
+ SPCU.applySubprogramAttributesToDefinition(SP, *AbsDef);
+
+ SPCU.addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
+ createAndAddScopeChildren(SPCU, Scope, *AbsDef);
}
DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
@@ -704,28 +685,6 @@ DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
return NewCU;
}
-// Construct subprogram DIE.
-void DwarfDebug::constructSubprogramDIE(DwarfCompileUnit &TheCU,
- const MDNode *N) {
- // FIXME: We should only call this routine once, however, during LTO if a
- // program is defined in multiple CUs we could end up calling it out of
- // beginModule as we walk the CUs.
-
- DwarfCompileUnit *&CURef = SPMap[N];
- if (CURef)
- return;
- CURef = &TheCU;
-
- DISubprogram SP(N);
- assert(SP.isSubprogram());
- assert(SP.isDefinition());
-
- DIE &SubprogramDie = *TheCU.getOrCreateSubprogramDIE(SP);
-
- // Expose as a global name.
- TheCU.addGlobalName(SP.getName(), SubprogramDie, resolve(SP.getContext()));
-}
-
void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
const MDNode *N) {
DIImportedEntity Module(N);
const Module *M = MMI->getModule();
+ FunctionDIs = makeSubprogramMap(*M);
+
// If module has named metadata anchors then use them, otherwise scan the
// module using debug info finder to collect debug info.
NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
DIArray SPs = CUNode.getSubprograms();
for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
- constructSubprogramDIE(CU, SPs.getElement(i));
+ SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
DIArray EnumTypes = CUNode.getEnumTypes();
- for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
- CU.getOrCreateTypeDIE(EnumTypes.getElement(i));
+ for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
+ DIType Ty(EnumTypes.getElement(i));
+ // The enum types array by design contains pointers to
+ // MDNodes rather than DIRefs. Unique them here.
+ DIType UniqueTy(resolve(Ty.getRef()));
+ CU.getOrCreateTypeDIE(UniqueTy);
+ }
DIArray RetainedTypes = CUNode.getRetainedTypes();
for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
DIType Ty(RetainedTypes.getElement(i));
SectionMap[Asm->getObjFileLowering().getTextSection()];
}
+void DwarfDebug::finishVariableDefinitions() {
+ for (const auto &Var : ConcreteVariables) {
+ DIE *VariableDie = Var->getDIE();
+ // FIXME: There shouldn't be any variables without DIEs.
+ if (!VariableDie)
+ continue;
+ // FIXME: Consider the time-space tradeoff of just storing the unit pointer
+ // in the ConcreteVariables list, rather than looking it up again here.
+ // DIE::getUnit isn't simple - it walks parent pointers, etc.
+ DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
+ assert(Unit);
+ DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
+ if (AbsVar && AbsVar->getDIE()) {
+ Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
+ *AbsVar->getDIE());
+ } else
+ Unit->applyVariableAttributes(*Var, *VariableDie);
+ }
+}
+
+void DwarfDebug::finishSubprogramDefinitions() {
+ const Module *M = MMI->getModule();
+
+ NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
+ for (MDNode *N : CU_Nodes->operands()) {
+ DICompileUnit TheCU(N);
+ // Construct subprogram DIE and add variables DIEs.
+ DwarfCompileUnit *SPCU =
+ static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
+ DIArray Subprograms = TheCU.getSubprograms();
+ for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
+ DISubprogram SP(Subprograms.getElement(i));
+ // Perhaps the subprogram is in another CU (such as due to comdat
+ // folding, etc), in which case ignore it here.
+ if (SPMap[SP] != SPCU)
+ continue;
+ DIE *D = SPCU->getDIE(SP);
+ if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
+ if (D)
+ // If this subprogram has an abstract definition, reference that
+ SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
+ } else {
+ if (!D)
+ // Lazily construct the subprogram if we didn't see either concrete or
+ // inlined versions during codegen.
+ D = SPCU->getOrCreateSubprogramDIE(SP);
+ // And attach the attributes
+ SPCU->applySubprogramAttributesToDefinition(SP, *D);
+ }
+ }
+ }
+}
+
+
// Collect info for variables that were optimized out.
void DwarfDebug::collectDeadVariables() {
const Module *M = MMI->getModule();
if (Variables.getNumElements() == 0)
continue;
- // FIXME: See the comment in constructSubprogramDIE about duplicate
- // subprogram DIEs.
- constructSubprogramDIE(*SPCU, SP);
- DIE *SPDIE = SPCU->getDIE(SP);
+ DIE *SPDIE = AbstractSPDies.lookup(SP);
+ if (!SPDIE)
+ SPDIE = SPCU->getDIE(SP);
+ assert(SPDIE);
for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
DIVariable DV(Variables.getElement(vi));
assert(DV.isVariable());
- DbgVariable NewVar(DV, nullptr, this);
- SPDIE->addChild(SPCU->constructVariableDIE(NewVar));
+ DbgVariable NewVar(DV, this);
+ auto VariableDie = SPCU->constructVariableDIE(NewVar);
+ SPCU->applyVariableAttributes(NewVar, *VariableDie);
+ SPDIE->addChild(std::move(VariableDie));
}
}
}
}
void DwarfDebug::finalizeModuleInfo() {
+ finishSubprogramDefinitions();
+
+ finishVariableDefinitions();
+
// Collect info for variables that were optimized out.
collectDeadVariables();
emitDebugInfoDWO();
emitDebugAbbrevDWO();
emitDebugLineDWO();
+ emitDebugLocDWO();
// Emit DWO addresses.
AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
- emitDebugLocDWO();
} else
// Emit info into a debug loc section.
emitDebugLoc();
// clean up.
SPMap.clear();
+ AbstractVariables.clear();
// Reset these for the next Module if we have one.
FirstCU = nullptr;
}
// Find abstract variable, if any, associated with Var.
-DbgVariable *DwarfDebug::findAbstractVariable(DIVariable &DV,
- DebugLoc ScopeLoc) {
+DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
+ DIVariable &Cleansed) {
LLVMContext &Ctx = DV->getContext();
// More then one inlined variable corresponds to one abstract variable.
- DIVariable Var = cleanseInlinedVariable(DV, Ctx);
- DbgVariable *AbsDbgVariable = AbstractVariables.lookup(Var);
- if (AbsDbgVariable)
- return AbsDbgVariable;
+ // FIXME: This duplication of variables when inlining should probably be
+ // removed. It's done to allow each DIVariable to describe its location
+ // because the DebugLoc on the dbg.value/declare isn't accurate. We should
+ // make it accurate then remove this duplication/cleansing stuff.
+ Cleansed = cleanseInlinedVariable(DV, Ctx);
+ auto I = AbstractVariables.find(Cleansed);
+ if (I != AbstractVariables.end())
+ return I->second.get();
+ return nullptr;
+}
- LexicalScope *Scope = LScopes.findAbstractScope(ScopeLoc.getScope(Ctx));
- if (!Scope)
- return nullptr;
+DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
+ DIVariable Cleansed;
+ return getExistingAbstractVariable(DV, Cleansed);
+}
+
+void DwarfDebug::createAbstractVariable(const DIVariable &Var,
+ LexicalScope *Scope) {
+ auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
+ addScopeVariable(Scope, AbsDbgVariable.get());
+ AbstractVariables[Var] = std::move(AbsDbgVariable);
+}
+
+void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
+ const MDNode *ScopeNode) {
+ DIVariable Cleansed = DV;
+ if (getExistingAbstractVariable(DV, Cleansed))
+ return;
- AbsDbgVariable = new DbgVariable(Var, nullptr, this);
- addScopeVariable(Scope, AbsDbgVariable);
- AbstractVariables[Var] = AbsDbgVariable;
- return AbsDbgVariable;
+ createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
+}
+
+void
+DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
+ const MDNode *ScopeNode) {
+ DIVariable Cleansed = DV;
+ if (getExistingAbstractVariable(DV, Cleansed))
+ return;
+
+ if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
+ createAbstractVariable(Cleansed, Scope);
}
// If Var is a current function argument then add it to CurrentFnArguments list.
@@ -1089,6 +1144,7 @@ bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
// arguments does the function have at source level.
if (ArgNo > Size)
CurrentFnArguments.resize(ArgNo * 2);
+ assert(!CurrentFnArguments[ArgNo - 1]);
CurrentFnArguments[ArgNo - 1] = Var;
return true;
}
if (!Scope)
continue;
- DbgVariable *AbsDbgVariable = findAbstractVariable(DV, VI.Loc);
- DbgVariable *RegVar = new DbgVariable(DV, AbsDbgVariable, this);
+ ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
+ ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
+ DbgVariable *RegVar = ConcreteVariables.back().get();
RegVar->setFrameIndex(VI.Slot);
- if (!addCurrentFnArgument(RegVar, Scope))
- addScopeVariable(Scope, RegVar);
+ addScopeVariable(Scope, RegVar);
}
}
llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
}
+/// Determine whether two variable pieces overlap.
+static bool piecesOverlap(DIVariable P1, DIVariable P2) {
+ if (!P1.isVariablePiece() || !P2.isVariablePiece())
+ return true;
+ unsigned l1 = P1.getPieceOffset();
+ unsigned l2 = P2.getPieceOffset();
+ unsigned r1 = l1 + P1.getPieceSize();
+ unsigned r2 = l2 + P2.getPieceSize();
+ // True where [l1,r1[ and [r1,r2[ overlap.
+ return (l1 < r2) && (l2 < r1);
+}
+
+/// Build the location list for all DBG_VALUEs in the function that
+/// describe the same variable. If the ranges of several independent
+/// pieces of the same variable overlap partially, split them up and
+/// combine the ranges. The resulting DebugLocEntries are will have
+/// strict monotonically increasing begin addresses and will never
+/// overlap.
+//
+// Input:
+//
+// Ranges History [var, loc, piece ofs size]
+// 0 | [x, (reg0, piece 0, 32)]
+// 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
+// 2 | | ...
+// 3 | [clobber reg0]
+// 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
+//
+// Output:
+//
+// [0-1] [x, (reg0, piece 0, 32)]
+// [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
+// [3-4] [x, (reg1, piece 32, 32)]
+// [4- ] [x, (mem, piece 0, 64)]
+void
+DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
+ const DbgValueHistoryMap::InstrRanges &Ranges) {
+ SmallVector<DebugLocEntry::Value, 4> OpenRanges;
+
+ for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
+ const MachineInstr *Begin = I->first;
+ const MachineInstr *End = I->second;
+ assert(Begin->isDebugValue() && "Invalid History entry");
+
+ // Check if a variable is inaccessible in this range.
+ if (!Begin->isDebugValue() ||
+ (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
+ !Begin->getOperand(0).getReg())) {
+ OpenRanges.clear();
+ continue;
+ }
+
+ // If this piece overlaps with any open ranges, truncate them.
+ DIVariable DIVar = Begin->getDebugVariable();
+ auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
+ [&](DebugLocEntry::Value R) {
+ return piecesOverlap(DIVar, DIVariable(R.getVariable()));
+ });
+ OpenRanges.erase(Last, OpenRanges.end());
+
+ const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
+ assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
+
+ const MCSymbol *EndLabel;
+ if (End != nullptr)
+ EndLabel = getLabelAfterInsn(End);
+ else if (std::next(I) == Ranges.end())
+ EndLabel = FunctionEndSym;
+ else
+ EndLabel = getLabelBeforeInsn(std::next(I)->first);
+ assert(EndLabel && "Forgot label after instruction ending a range!");
+
+ DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
+
+ auto Value = getDebugLocValue(Begin);
+ DebugLocEntry Loc(StartLabel, EndLabel, Value);
+ bool couldMerge = false;
+
+ // If this is a piece, it may belong to the current DebugLocEntry.
+ if (DIVar.isVariablePiece()) {
+ // Add this value to the list of open ranges.
+ OpenRanges.push_back(Value);
+
+ // Attempt to add the piece to the last entry.
+ if (!DebugLoc.empty())
+ if (DebugLoc.back().MergeValues(Loc))
+ couldMerge = true;
+ }
+
+ if (!couldMerge) {
+ // Need to add a new DebugLocEntry. Add all values from still
+ // valid non-overlapping pieces.
+ for (auto Range : OpenRanges)
+ Loc.addValue(Range.second);
+ DebugLoc.push_back(std::move(Loc));
+ }
+
+ // Attempt to coalesce the ranges of two otherwise identical
+ // DebugLocEntries.
+ auto CurEntry = DebugLoc.rbegin();
+ auto PrevEntry = std::next(CurEntry);
+ if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
+ DebugLoc.pop_back();
+
+ DEBUG(dbgs() << "Values:\n";
+ for (auto Value : CurEntry->getValues())
+ Value.getVariable()->dump();
+ dbgs() << "-----\n");
+ }
+}
+
+
// Find variables for each lexical scope.
void
DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
@@ -1154,18 +1322,13 @@ DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
if (Processed.count(DV))
continue;
- // History contains relevant DBG_VALUE instructions for DV and instructions
- // clobbering it.
- const SmallVectorImpl<const MachineInstr *> &History = I.second;
- if (History.empty())
+ // Instruction ranges, specifying where DV is accessible.
+ const auto &Ranges = I.second;
+ if (Ranges.empty())
continue;
- const MachineInstr *MInsn = History.front();
LexicalScope *Scope = nullptr;
- if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
- DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
- Scope = LScopes.getCurrentFunctionScope();
- else if (MDNode *IA = DV.getInlinedAt()) {
+ if (MDNode *IA = DV.getInlinedAt()) {
DebugLoc DL = DebugLoc::getFromDILocation(IA);
Scope = LScopes.findInlinedScope(DebugLoc::get(
DL.getLine(), DL.getCol(), DV.getContext(), IA));
@@ -1175,69 +1338,29 @@ DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
if (!Scope)
continue;
- Processed.insert(DV);
+ Processed.insert(getEntireVariable(DV));
+ const MachineInstr *MInsn = Ranges.front().first;
assert(MInsn->isDebugValue() && "History must begin with debug value");
- DbgVariable *AbsVar = findAbstractVariable(DV, MInsn->getDebugLoc());
- DbgVariable *RegVar = new DbgVariable(DV, AbsVar, this);
- if (!addCurrentFnArgument(RegVar, Scope))
- addScopeVariable(Scope, RegVar);
- if (AbsVar)
- AbsVar->setMInsn(MInsn);
-
- // Simplify ranges that are fully coalesced.
- if (History.size() <= 1 ||
- (History.size() == 2 && MInsn->isIdenticalTo(History.back()))) {
- RegVar->setMInsn(MInsn);
+ ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
+ ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
+ DbgVariable *RegVar = ConcreteVariables.back().get();
+ addScopeVariable(Scope, RegVar);
+
+ // Check if the first DBG_VALUE is valid for the rest of the function.
+ if (Ranges.size() == 1 && Ranges.front().second == nullptr)
continue;
- }
// Handle multiple DBG_VALUE instructions describing one variable.
RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
DebugLocList &LocList = DotDebugLocEntries.back();
+ LocList.CU = TheCU;
LocList.Label =
Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
- SmallVector<DebugLocEntry, 4> &DebugLoc = LocList.List;
- for (SmallVectorImpl<const MachineInstr *>::const_iterator
- HI = History.begin(),
- HE = History.end();
- HI != HE; ++HI) {
- const MachineInstr *Begin = *HI;
- assert(Begin->isDebugValue() && "Invalid History entry");
-
- // Check if DBG_VALUE is truncating a range.
- if (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
- !Begin->getOperand(0).getReg())
- continue;
-
- // Compute the range for a register location.
- const MCSymbol *FLabel = getLabelBeforeInsn(Begin);
- const MCSymbol *SLabel = nullptr;
- if (HI + 1 == HE)
- // If Begin is the last instruction in History then its value is valid
- // until the end of the function.
- SLabel = FunctionEndSym;
- else {
- const MachineInstr *End = HI[1];
- DEBUG(dbgs() << "DotDebugLoc Pair:\n"
- << "\t" << *Begin << "\t" << *End << "\n");
- if (End->isDebugValue())
- SLabel = getLabelBeforeInsn(End);
- else {
- // End is a normal instruction clobbering the range.
- SLabel = getLabelAfterInsn(End);
- assert(SLabel && "Forgot label after clobber instruction");
- ++HI;
- }
- }
-
- // The value is valid until the next DBG_VALUE or clobber.
- DebugLocEntry Loc(FLabel, SLabel, getDebugLocValue(Begin), TheCU);
- if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc))
- DebugLoc.push_back(std::move(Loc));
- }
+ // Build the location list for this variable.
+ buildLocationList(LocList.List, Ranges);
}
// Collect info for variables that were optimized out.
@@ -1247,8 +1370,11 @@ DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
assert(DV.isVariable());
if (!Processed.insert(DV))
continue;
- if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext()))
- addScopeVariable(Scope, new DbgVariable(DV, nullptr, this));
+ if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
+ ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
+ ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
+ addScopeVariable(Scope, ConcreteVariables.back().get());
+ }
}
}
}
}
+static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
+ // First known non-DBG_VALUE and non-frame setup location marks
+ // the beginning of the function body.
+ for (const auto &MBB : *MF)
+ for (const auto &MI : MBB)
+ if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
+ !MI.getDebugLoc().isUnknown())
+ return MI.getDebugLoc();
+ return DebugLoc();
+}
+
// Gather pre-function debug information. Assumes being called immediately
// after the function entry point has been emitted.
void DwarfDebug::beginFunction(const MachineFunction *MF) {
if (!MMI->hasDebugInfo())
return;
+ auto DI = FunctionDIs.find(MF->getFunction());
+ if (DI == FunctionDIs.end())
+ return;
+
// Grab the lexical scopes for the function, if we don't have any of those
// then we're not going to be able to do anything.
LScopes.initialize(*MF);
// belongs to so that we add to the correct per-cu line table in the
// non-asm case.
LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
+ // FnScope->getScopeNode() and DI->second should represent the same function,
+ // though they may not be the same MDNode due to inline functions merged in
+ // LTO where the debug info metadata still differs (either due to distinct
+ // written differences - two versions of a linkonce_odr function
+ // written/copied into two separate files, or some sub-optimal metadata that
+ // isn't structurally identical (see: file path/name info from clang, which
+ // includes the directory of the cpp file being built, even when the file name
+ // is absolute (such as an <> lookup header)))
DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
assert(TheCU && "Unable to find compile unit!");
if (Asm->OutStreamer.hasRawTextSupport())
// Assumes in correct section after the entry point.
Asm->OutStreamer.EmitLabel(FunctionBeginSym);
- // Collect user variables, find the end of the prologue.
- for (const auto &MBB : *MF) {
- for (const auto &MI : MBB) {
- if (MI.isDebugValue()) {
- assert(MI.getNumOperands() > 1 && "Invalid machine instruction!");
- // Keep track of user variables in order of appearance. Create the
- // empty history for each variable so that the order of keys in
- // DbgValues is correct. Actual history will be populated in
- // calculateDbgValueHistory() function.
- const MDNode *Var = MI.getDebugVariable();
- DbgValues.insert(
- std::make_pair(Var, SmallVector<const MachineInstr *, 4>()));
- } else if (!MI.getFlag(MachineInstr::FrameSetup) &&
- PrologEndLoc.isUnknown() && !MI.getDebugLoc().isUnknown()) {
- // First known non-DBG_VALUE and non-frame setup location marks
- // the beginning of the function body.
- PrologEndLoc = MI.getDebugLoc();
- }
- }
- }
-
// Calculate history for local variables.
- calculateDbgValueHistory(MF, Asm->TM.getRegisterInfo(), DbgValues);
+ calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
+ DbgValues);
// Request labels for the full history.
- for (auto &I : DbgValues) {
- const SmallVectorImpl<const MachineInstr *> &History = I.second;
- if (History.empty())
+ for (const auto &I : DbgValues) {
+ const auto &Ranges = I.second;
+ if (Ranges.empty())
continue;
// The first mention of a function argument gets the FunctionBeginSym
// label, so arguments are visible when breaking at function entry.
- DIVariable DV(I.first);
+ DIVariable DV(Ranges.front().first->getDebugVariable());
if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
- getDISubprogram(DV.getContext()).describes(MF->getFunction()))
- LabelsBeforeInsn[History.front()] = FunctionBeginSym;
-
- for (const MachineInstr *MI : History) {
- if (MI->isDebugValue())
- requestLabelBeforeInsn(MI);
- else
- requestLabelAfterInsn(MI);
+ getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
+ if (!DV.isVariablePiece())
+ LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
+ else {
+ // Mark all non-overlapping initial pieces.
+ for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
+ DIVariable Piece = I->first->getDebugVariable();
+ if (std::all_of(Ranges.begin(), I,
+ [&](DbgValueHistoryMap::InstrRange Pred){
+ return !piecesOverlap(Piece, Pred.first->getDebugVariable());
+ }))
+ LabelsBeforeInsn[I->first] = FunctionBeginSym;
+ else
+ break;
+ }
+ }
+ }
+
+ for (const auto &Range : Ranges) {
+ requestLabelBeforeInsn(Range.first);
+ if (Range.second)
+ requestLabelAfterInsn(Range.second);
}
}
PrevLabel = FunctionBeginSym;
// Record beginning of function.
+ PrologEndLoc = findPrologueEndLoc(MF);
if (!PrologEndLoc.isUnknown()) {
DebugLoc FnStartDL =
PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
}
void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
+ if (addCurrentFnArgument(Var, LS))
+ return;
SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
DIVariable DV = Var->getVariable();
// Variables with positive arg numbers are parameters.
assert(CurFn == MF);
assert(CurFn != nullptr);
- if (!MMI->hasDebugInfo() || LScopes.empty()) {
+ if (!MMI->hasDebugInfo() || LScopes.empty() ||
+ !FunctionDIs.count(MF->getFunction())) {
// If we don't have a lexical scope for this function then there will
// be a hole in the range information. Keep note of this by setting the
// previously used section to nullptr.
// Construct abstract scopes.
for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
DISubprogram SP(AScope->getScopeNode());
- if (!SP.isSubprogram())
- continue;
+ assert(SP.isSubprogram());
// Collect info for variables that were optimized out.
DIArray Variables = SP.getVariables();
for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
assert(DV && DV.isVariable());
if (!ProcessedVars.insert(DV))
continue;
- // Check that DbgVariable for DV wasn't created earlier, when
- // findAbstractVariable() was called for inlined instance of DV.
- LLVMContext &Ctx = DV->getContext();
- DIVariable CleanDV = cleanseInlinedVariable(DV, Ctx);
- if (AbstractVariables.lookup(CleanDV))
- continue;
- if (LexicalScope *Scope = LScopes.findAbstractScope(DV.getContext()))
- addScopeVariable(Scope, new DbgVariable(DV, nullptr, this));
+ ensureAbstractVariableIsCreated(DV, DV.getContext());
}
constructAbstractSubprogramScopeDIE(TheCU, AScope);
}
PrevCU = &TheCU;
// Clear debug info
- for (auto &I : ScopeVariables)
- DeleteContainerPointers(I.second);
+ // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
+ // DbgVariables except those that are also in AbstractVariables (since they
+ // can be used cross-function)
ScopeVariables.clear();
- DeleteContainerPointers(CurrentFnArguments);
+ CurrentFnArguments.clear();
DbgValues.clear();
- AbstractVariables.clear();
LabelsBeforeInsn.clear();
LabelsAfterInsn.clear();
PrevLabel = nullptr;
Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
}
+/// Emits an optimal (=sorted) sequence of DW_OP_pieces.
+void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
+ const DITypeIdentifierMap &Map,
+ ArrayRef<DebugLocEntry::Value> Values) {
+ assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
+ return DIVariable(P.getVariable()).isVariablePiece();
+ }) && "all values are expected to be pieces");
+ assert(std::is_sorted(Values.begin(), Values.end()) &&
+ "pieces are expected to be sorted");
+
+ unsigned Offset = 0;
+ for (auto Piece : Values) {
+ DIVariable Var(Piece.getVariable());
+ unsigned PieceOffset = Var.getPieceOffset();
+ unsigned PieceSize = Var.getPieceSize();
+ assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
+ if (Offset < PieceOffset) {
+ // The DWARF spec seriously mandates pieces with no locations for gaps.
+ Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
+ Offset += PieceOffset-Offset;
+ }
+
+ Offset += PieceSize;
+
+ const unsigned SizeOfByte = 8;
+ assert(!Var.isIndirect() && "indirect address for piece");
+#ifndef NDEBUG
+ unsigned VarSize = Var.getSizeInBits(Map);
+ assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
+ && "piece is larger than or outside of variable");
+ assert(PieceSize*SizeOfByte != VarSize
+ && "piece covers entire variable");
+#endif
+ if (Piece.isLocation() && Piece.getLoc().isReg())
+ Asm->EmitDwarfRegOpPiece(Streamer,
+ Piece.getLoc(),
+ PieceSize*SizeOfByte);
+ else {
+ emitDebugLocValue(Streamer, Piece);
+ Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
+ }
+ }
+}
+
+
void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
const DebugLocEntry &Entry) {
- assert(Entry.getValues().size() == 1 &&
- "multi-value entries are not supported yet.");
const DebugLocEntry::Value Value = Entry.getValues()[0];
DIVariable DV(Value.getVariable());
+ if (DV.isVariablePiece())
+ // Emit all pieces that belong to the same variable and range.
+ return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
+
+ assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
+ emitDebugLocValue(Streamer, Value);
+}
+
+void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
+ const DebugLocEntry::Value &Value) {
+ DIVariable DV(Value.getVariable());
+ // Regular entry.
if (Value.isInt()) {
DIBasicType BTy(resolve(DV.getType()));
if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
} else if (Element == DIBuilder::OpDeref) {
if (!Loc.isReg())
Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
+ } else if (Element == DIBuilder::OpPiece) {
+ i += 3;
+ // handled in emitDebugLocEntry.
} else
llvm_unreachable("unknown Opcode found in complex address");
}
unsigned char Size = Asm->getDataLayout().getPointerSize();
for (const auto &DebugLoc : DotDebugLocEntries) {
Asm->OutStreamer.EmitLabel(DebugLoc.Label);
+ const DwarfCompileUnit *CU = DebugLoc.CU;
+ assert(!CU->getRanges().empty());
for (const auto &Entry : DebugLoc.List) {
// Set up the range. This range is relative to the entry point of the
// compile unit. This is a hard coded 0 for low_pc when we're emitting
// ranges, or the DW_AT_low_pc on the compile unit otherwise.
- const DwarfCompileUnit *CU = Entry.getCU();
if (CU->getRanges().size() == 1) {
// Grab the begin symbol from the first range as our base.
const MCSymbol *Base = CU->getRanges()[0].getStart();