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llvm-mirror/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
Adrian Prantl 803463121a Debug info: Fix PR22296 by omitting the DW_AT_location if we lost the 
physical register that is described in a DBG_VALUE.

In the testcase the DBG_VALUE describing "p5" becomes unavailable
because the register its address is in is clobbered and we (currently)
aren't smart enough to realize that the value is rematerialized immediately
after the DBG_VALUE and/or is actually a stack slot.

llvm-svn: 227056
2015-01-25 19:04:08 +00:00

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#include "DwarfCompileUnit.h"
#include "DwarfExpression.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Instruction.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetSubtargetInfo.h"
namespace llvm {
DwarfCompileUnit::DwarfCompileUnit(unsigned UID, DICompileUnit Node,
AsmPrinter *A, DwarfDebug *DW,
DwarfFile *DWU)
: DwarfUnit(UID, dwarf::DW_TAG_compile_unit, Node, A, DW, DWU),
Skeleton(nullptr), LabelBegin(nullptr), BaseAddress(nullptr) {
insertDIE(Node, &getUnitDie());
}
/// addLabelAddress - Add a dwarf label attribute data and value using
/// DW_FORM_addr or DW_FORM_GNU_addr_index.
///
void DwarfCompileUnit::addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
const MCSymbol *Label) {
// Don't use the address pool in non-fission or in the skeleton unit itself.
// FIXME: Once GDB supports this, it's probably worthwhile using the address
// pool from the skeleton - maybe even in non-fission (possibly fewer
// relocations by sharing them in the pool, but we have other ideas about how
// to reduce the number of relocations as well/instead).
if (!DD->useSplitDwarf() || !Skeleton)
return addLocalLabelAddress(Die, Attribute, Label);
if (Label)
DD->addArangeLabel(SymbolCU(this, Label));
unsigned idx = DD->getAddressPool().getIndex(Label);
DIEValue *Value = new (DIEValueAllocator) DIEInteger(idx);
Die.addValue(Attribute, dwarf::DW_FORM_GNU_addr_index, Value);
}
void DwarfCompileUnit::addLocalLabelAddress(DIE &Die,
dwarf::Attribute Attribute,
const MCSymbol *Label) {
if (Label)
DD->addArangeLabel(SymbolCU(this, Label));
Die.addValue(Attribute, dwarf::DW_FORM_addr,
Label ? (DIEValue *)new (DIEValueAllocator) DIELabel(Label)
: new (DIEValueAllocator) DIEInteger(0));
}
unsigned DwarfCompileUnit::getOrCreateSourceID(StringRef FileName,
StringRef DirName) {
// If we print assembly, we can't separate .file entries according to
// compile units. Thus all files will belong to the default compile unit.
// FIXME: add a better feature test than hasRawTextSupport. Even better,
// extend .file to support this.
return Asm->OutStreamer.EmitDwarfFileDirective(
0, DirName, FileName,
Asm->OutStreamer.hasRawTextSupport() ? 0 : getUniqueID());
}
// Return const expression if value is a GEP to access merged global
// constant. e.g.
// i8* getelementptr ({ i8, i8, i8, i8 }* @_MergedGlobals, i32 0, i32 0)
static const ConstantExpr *getMergedGlobalExpr(const Value *V) {
const ConstantExpr *CE = dyn_cast_or_null<ConstantExpr>(V);
if (!CE || CE->getNumOperands() != 3 ||
CE->getOpcode() != Instruction::GetElementPtr)
return nullptr;
// First operand points to a global struct.
Value *Ptr = CE->getOperand(0);
if (!isa<GlobalValue>(Ptr) ||
!isa<StructType>(cast<PointerType>(Ptr->getType())->getElementType()))
return nullptr;
// Second operand is zero.
const ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CE->getOperand(1));
if (!CI || !CI->isZero())
return nullptr;
// Third operand is offset.
if (!isa<ConstantInt>(CE->getOperand(2)))
return nullptr;
return CE;
}
/// getOrCreateGlobalVariableDIE - get or create global variable DIE.
DIE *DwarfCompileUnit::getOrCreateGlobalVariableDIE(DIGlobalVariable GV) {
// Check for pre-existence.
if (DIE *Die = getDIE(GV))
return Die;
assert(GV.isGlobalVariable());
DIScope GVContext = GV.getContext();
DIType GTy = DD->resolve(GV.getType());
// Construct the context before querying for the existence of the DIE in
// case such construction creates the DIE.
DIE *ContextDIE = getOrCreateContextDIE(GVContext);
// Add to map.
DIE *VariableDIE = &createAndAddDIE(GV.getTag(), *ContextDIE, GV);
DIScope DeclContext;
if (DIDerivedType SDMDecl = GV.getStaticDataMemberDeclaration()) {
DeclContext = resolve(SDMDecl.getContext());
assert(SDMDecl.isStaticMember() && "Expected static member decl");
assert(GV.isDefinition());
// We need the declaration DIE that is in the static member's class.
DIE *VariableSpecDIE = getOrCreateStaticMemberDIE(SDMDecl);
addDIEEntry(*VariableDIE, dwarf::DW_AT_specification, *VariableSpecDIE);
} else {
DeclContext = GV.getContext();
// Add name and type.
addString(*VariableDIE, dwarf::DW_AT_name, GV.getDisplayName());
addType(*VariableDIE, GTy);
// Add scoping info.
if (!GV.isLocalToUnit())
addFlag(*VariableDIE, dwarf::DW_AT_external);
// Add line number info.
addSourceLine(*VariableDIE, GV);
}
if (!GV.isDefinition())
addFlag(*VariableDIE, dwarf::DW_AT_declaration);
// Add location.
bool addToAccelTable = false;
bool isGlobalVariable = GV.getGlobal() != nullptr;
if (isGlobalVariable) {
addToAccelTable = true;
DIELoc *Loc = new (DIEValueAllocator) DIELoc();
const MCSymbol *Sym = Asm->getSymbol(GV.getGlobal());
if (GV.getGlobal()->isThreadLocal()) {
// FIXME: Make this work with -gsplit-dwarf.
unsigned PointerSize = Asm->getDataLayout().getPointerSize();
assert((PointerSize == 4 || PointerSize == 8) &&
"Add support for other sizes if necessary");
// Based on GCC's support for TLS:
if (!DD->useSplitDwarf()) {
// 1) Start with a constNu of the appropriate pointer size
addUInt(*Loc, dwarf::DW_FORM_data1,
PointerSize == 4 ? dwarf::DW_OP_const4u : dwarf::DW_OP_const8u);
// 2) containing the (relocated) offset of the TLS variable
// within the module's TLS block.
addExpr(*Loc, dwarf::DW_FORM_udata,
Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
} else {
addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
addUInt(*Loc, dwarf::DW_FORM_udata,
DD->getAddressPool().getIndex(Sym, /* TLS */ true));
}
// 3) followed by a custom OP to make the debugger do a TLS lookup.
addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_push_tls_address);
} else {
DD->addArangeLabel(SymbolCU(this, Sym));
addOpAddress(*Loc, Sym);
}
addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
// Add the linkage name.
StringRef LinkageName = GV.getLinkageName();
if (!LinkageName.empty())
// From DWARF4: DIEs to which DW_AT_linkage_name may apply include:
// TAG_common_block, TAG_constant, TAG_entry_point, TAG_subprogram and
// TAG_variable.
addString(*VariableDIE,
DD->getDwarfVersion() >= 4 ? dwarf::DW_AT_linkage_name
: dwarf::DW_AT_MIPS_linkage_name,
GlobalValue::getRealLinkageName(LinkageName));
} else if (const ConstantInt *CI =
dyn_cast_or_null<ConstantInt>(GV.getConstant())) {
addConstantValue(*VariableDIE, CI, GTy);
} else if (const ConstantExpr *CE = getMergedGlobalExpr(GV.getConstant())) {
addToAccelTable = true;
// GV is a merged global.
DIELoc *Loc = new (DIEValueAllocator) DIELoc();
Value *Ptr = CE->getOperand(0);
MCSymbol *Sym = Asm->getSymbol(cast<GlobalValue>(Ptr));
DD->addArangeLabel(SymbolCU(this, Sym));
addOpAddress(*Loc, Sym);
addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
addUInt(*Loc, dwarf::DW_FORM_udata,
Asm->getDataLayout().getIndexedOffset(Ptr->getType(), Idx));
addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
}
if (addToAccelTable) {
DD->addAccelName(GV.getName(), *VariableDIE);
// If the linkage name is different than the name, go ahead and output
// that as well into the name table.
if (GV.getLinkageName() != "" && GV.getName() != GV.getLinkageName())
DD->addAccelName(GV.getLinkageName(), *VariableDIE);
}
addGlobalName(GV.getName(), *VariableDIE, DeclContext);
return VariableDIE;
}
void DwarfCompileUnit::addRange(RangeSpan Range) {
bool SameAsPrevCU = this == DD->getPrevCU();
DD->setPrevCU(this);
// If we have no current ranges just add the range and return, otherwise,
// check the current section and CU against the previous section and CU we
// emitted into and the subprogram was contained within. If these are the
// same then extend our current range, otherwise add this as a new range.
if (CURanges.empty() || !SameAsPrevCU ||
(&CURanges.back().getEnd()->getSection() !=
&Range.getEnd()->getSection())) {
CURanges.push_back(Range);
return;
}
CURanges.back().setEnd(Range.getEnd());
}
void DwarfCompileUnit::addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
const MCSymbol *Label,
const MCSymbol *Sec) {
if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
addLabel(Die, Attribute,
DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
: dwarf::DW_FORM_data4,
Label);
else
addSectionDelta(Die, Attribute, Label, Sec);
}
void DwarfCompileUnit::initStmtList(MCSymbol *DwarfLineSectionSym) {
// Define start line table label for each Compile Unit.
MCSymbol *LineTableStartSym =
Asm->OutStreamer.getDwarfLineTableSymbol(getUniqueID());
stmtListIndex = UnitDie.getValues().size();
// DW_AT_stmt_list is a offset of line number information for this
// compile unit in debug_line section. For split dwarf this is
// left in the skeleton CU and so not included.
// The line table entries are not always emitted in assembly, so it
// is not okay to use line_table_start here.
addSectionLabel(UnitDie, dwarf::DW_AT_stmt_list, LineTableStartSym,
DwarfLineSectionSym);
}
void DwarfCompileUnit::applyStmtList(DIE &D) {
D.addValue(dwarf::DW_AT_stmt_list,
UnitDie.getAbbrev().getData()[stmtListIndex].getForm(),
UnitDie.getValues()[stmtListIndex]);
}
void DwarfCompileUnit::attachLowHighPC(DIE &D, const MCSymbol *Begin,
const MCSymbol *End) {
assert(Begin && "Begin label should not be null!");
assert(End && "End label should not be null!");
assert(Begin->isDefined() && "Invalid starting label");
assert(End->isDefined() && "Invalid end label");
addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
if (DD->getDwarfVersion() < 4)
addLabelAddress(D, dwarf::DW_AT_high_pc, End);
else
addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
}
// Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
// and DW_AT_high_pc attributes. If there are global variables in this
// scope then create and insert DIEs for these variables.
DIE &DwarfCompileUnit::updateSubprogramScopeDIE(DISubprogram SP) {
DIE *SPDie = getOrCreateSubprogramDIE(SP, includeMinimalInlineScopes());
attachLowHighPC(*SPDie, DD->getFunctionBeginSym(), DD->getFunctionEndSym());
if (!DD->getCurrentFunction()->getTarget().Options.DisableFramePointerElim(
*DD->getCurrentFunction()))
addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
// Only include DW_AT_frame_base in full debug info
if (!includeMinimalInlineScopes()) {
const TargetRegisterInfo *RI =
Asm->TM.getSubtargetImpl()->getRegisterInfo();
MachineLocation Location(RI->getFrameRegister(*Asm->MF));
if (RI->isPhysicalRegister(Location.getReg()))
addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
}
// Add name to the name table, we do this here because we're guaranteed
// to have concrete versions of our DW_TAG_subprogram nodes.
DD->addSubprogramNames(SP, *SPDie);
return *SPDie;
}
// Construct a DIE for this scope.
void DwarfCompileUnit::constructScopeDIE(
LexicalScope *Scope, SmallVectorImpl<std::unique_ptr<DIE>> &FinalChildren) {
if (!Scope || !Scope->getScopeNode())
return;
DIScope DS(Scope->getScopeNode());
assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
"Only handle inlined subprograms here, use "
"constructSubprogramScopeDIE for non-inlined "
"subprograms");
SmallVector<std::unique_ptr<DIE>, 8> Children;
// We try to create the scope DIE first, then the children DIEs. This will
// avoid creating un-used children then removing them later when we find out
// the scope DIE is null.
std::unique_ptr<DIE> ScopeDIE;
if (Scope->getParent() && DS.isSubprogram()) {
ScopeDIE = constructInlinedScopeDIE(Scope);
if (!ScopeDIE)
return;
// We create children when the scope DIE is not null.
createScopeChildrenDIE(Scope, Children);
} else {
// Early exit when we know the scope DIE is going to be null.
if (DD->isLexicalScopeDIENull(Scope))
return;
unsigned ChildScopeCount;
// We create children here when we know the scope DIE is not going to be
// null and the children will be added to the scope DIE.
createScopeChildrenDIE(Scope, Children, &ChildScopeCount);
// Skip imported directives in gmlt-like data.
if (!includeMinimalInlineScopes()) {
// There is no need to emit empty lexical block DIE.
for (const auto &E : DD->findImportedEntitiesForScope(DS))
Children.push_back(
constructImportedEntityDIE(DIImportedEntity(E.second)));
}
// If there are only other scopes as children, put them directly in the
// parent instead, as this scope would serve no purpose.
if (Children.size() == ChildScopeCount) {
FinalChildren.insert(FinalChildren.end(),
std::make_move_iterator(Children.begin()),
std::make_move_iterator(Children.end()));
return;
}
ScopeDIE = constructLexicalScopeDIE(Scope);
assert(ScopeDIE && "Scope DIE should not be null.");
}
// Add children
for (auto &I : Children)
ScopeDIE->addChild(std::move(I));
FinalChildren.push_back(std::move(ScopeDIE));
}
void DwarfCompileUnit::addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
const MCSymbol *Hi, const MCSymbol *Lo) {
DIEValue *Value = new (DIEValueAllocator) DIEDelta(Hi, Lo);
Die.addValue(Attribute, DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
: dwarf::DW_FORM_data4,
Value);
}
void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
SmallVector<RangeSpan, 2> Range) {
// Emit offset in .debug_range as a relocatable label. emitDIE will handle
// emitting it appropriately.
auto *RangeSectionSym = DD->getRangeSectionSym();
RangeSpanList List(
Asm->GetTempSymbol("debug_ranges", DD->getNextRangeNumber()),
std::move(Range));
// Under fission, ranges are specified by constant offsets relative to the
// CU's DW_AT_GNU_ranges_base.
if (isDwoUnit())
addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
RangeSectionSym);
else
addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
RangeSectionSym);
// Add the range list to the set of ranges to be emitted.
(Skeleton ? Skeleton : this)->CURangeLists.push_back(std::move(List));
}
void DwarfCompileUnit::attachRangesOrLowHighPC(
DIE &Die, SmallVector<RangeSpan, 2> Ranges) {
if (Ranges.size() == 1) {
const auto &single = Ranges.front();
attachLowHighPC(Die, single.getStart(), single.getEnd());
} else
addScopeRangeList(Die, std::move(Ranges));
}
void DwarfCompileUnit::attachRangesOrLowHighPC(
DIE &Die, const SmallVectorImpl<InsnRange> &Ranges) {
SmallVector<RangeSpan, 2> List;
List.reserve(Ranges.size());
for (const InsnRange &R : Ranges)
List.push_back(RangeSpan(DD->getLabelBeforeInsn(R.first),
DD->getLabelAfterInsn(R.second)));
attachRangesOrLowHighPC(Die, std::move(List));
}
// This scope represents inlined body of a function. Construct DIE to
// represent this concrete inlined copy of the function.
std::unique_ptr<DIE>
DwarfCompileUnit::constructInlinedScopeDIE(LexicalScope *Scope) {
assert(Scope->getScopeNode());
DIScope DS(Scope->getScopeNode());
DISubprogram InlinedSP = getDISubprogram(DS);
// Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
// was inlined from another compile unit.
DIE *OriginDIE = DU->getAbstractSPDies()[InlinedSP];
assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
// Add the call site information to the DIE.
DILocation DL(Scope->getInlinedAt());
addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
// Add name to the name table, we do this here because we're guaranteed
// to have concrete versions of our DW_TAG_inlined_subprogram nodes.
DD->addSubprogramNames(InlinedSP, *ScopeDIE);
return ScopeDIE;
}
// Construct new DW_TAG_lexical_block for this scope and attach
// DW_AT_low_pc/DW_AT_high_pc labels.
std::unique_ptr<DIE>
DwarfCompileUnit::constructLexicalScopeDIE(LexicalScope *Scope) {
if (DD->isLexicalScopeDIENull(Scope))
return nullptr;
auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
if (Scope->isAbstractScope())
return ScopeDIE;
attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
return ScopeDIE;
}
/// constructVariableDIE - Construct a DIE for the given DbgVariable.
std::unique_ptr<DIE> DwarfCompileUnit::constructVariableDIE(DbgVariable &DV,
bool Abstract) {
auto D = constructVariableDIEImpl(DV, Abstract);
DV.setDIE(*D);
return D;
}
std::unique_ptr<DIE>
DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
bool Abstract) {
// Define variable debug information entry.
auto VariableDie = make_unique<DIE>(DV.getTag());
if (Abstract) {
applyVariableAttributes(DV, *VariableDie);
return VariableDie;
}
// Add variable address.
unsigned Offset = DV.getDotDebugLocOffset();
if (Offset != ~0U) {
addLocationList(*VariableDie, dwarf::DW_AT_location, Offset);
return VariableDie;
}
// Check if variable is described by a DBG_VALUE instruction.
if (const MachineInstr *DVInsn = DV.getMInsn()) {
assert(DVInsn->getNumOperands() == 4);
if (DVInsn->getOperand(0).isReg()) {
const MachineOperand RegOp = DVInsn->getOperand(0);
// If the second operand is an immediate, this is an indirect value.
if (DVInsn->getOperand(1).isImm()) {
MachineLocation Location(RegOp.getReg(),
DVInsn->getOperand(1).getImm());
addVariableAddress(DV, *VariableDie, Location);
} else if (RegOp.getReg())
addVariableAddress(DV, *VariableDie, MachineLocation(RegOp.getReg()));
} else if (DVInsn->getOperand(0).isImm())
addConstantValue(*VariableDie, DVInsn->getOperand(0), DV.getType());
else if (DVInsn->getOperand(0).isFPImm())
addConstantFPValue(*VariableDie, DVInsn->getOperand(0));
else if (DVInsn->getOperand(0).isCImm())
addConstantValue(*VariableDie, DVInsn->getOperand(0).getCImm(),
DV.getType());
return VariableDie;
}
// .. else use frame index.
int FI = DV.getFrameIndex();
if (FI != ~0) {
unsigned FrameReg = 0;
const TargetFrameLowering *TFI =
Asm->TM.getSubtargetImpl()->getFrameLowering();
int Offset = TFI->getFrameIndexReference(*Asm->MF, FI, FrameReg);
MachineLocation Location(FrameReg, Offset);
addVariableAddress(DV, *VariableDie, Location);
}
return VariableDie;
}
std::unique_ptr<DIE> DwarfCompileUnit::constructVariableDIE(
DbgVariable &DV, const LexicalScope &Scope, DIE *&ObjectPointer) {
auto Var = constructVariableDIE(DV, Scope.isAbstractScope());
if (DV.isObjectPointer())
ObjectPointer = Var.get();
return Var;
}
DIE *DwarfCompileUnit::createScopeChildrenDIE(
LexicalScope *Scope, SmallVectorImpl<std::unique_ptr<DIE>> &Children,
unsigned *ChildScopeCount) {
DIE *ObjectPointer = nullptr;
for (DbgVariable *DV : DU->getScopeVariables().lookup(Scope))
Children.push_back(constructVariableDIE(*DV, *Scope, ObjectPointer));
unsigned ChildCountWithoutScopes = Children.size();
for (LexicalScope *LS : Scope->getChildren())
constructScopeDIE(LS, Children);
if (ChildScopeCount)
*ChildScopeCount = Children.size() - ChildCountWithoutScopes;
return ObjectPointer;
}
void DwarfCompileUnit::constructSubprogramScopeDIE(LexicalScope *Scope) {
assert(Scope && Scope->getScopeNode());
assert(!Scope->getInlinedAt());
assert(!Scope->isAbstractScope());
DISubprogram Sub(Scope->getScopeNode());
assert(Sub.isSubprogram());
DD->getProcessedSPNodes().insert(Sub);
DIE &ScopeDIE = updateSubprogramScopeDIE(Sub);
// If this is a variadic function, add an unspecified parameter.
DITypeArray FnArgs = Sub.getType().getTypeArray();
// Collect lexical scope children first.
// ObjectPointer might be a local (non-argument) local variable if it's a
// block's synthetic this pointer.
if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, ScopeDIE))
addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
// 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) &&
!includeMinimalInlineScopes())
ScopeDIE.addChild(make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
}
DIE *DwarfCompileUnit::createAndAddScopeChildren(LexicalScope *Scope,
DIE &ScopeDIE) {
// We create children when the scope DIE is not null.
SmallVector<std::unique_ptr<DIE>, 8> Children;
DIE *ObjectPointer = createScopeChildrenDIE(Scope, Children);
// Add children
for (auto &I : Children)
ScopeDIE.addChild(std::move(I));
return ObjectPointer;
}
void
DwarfCompileUnit::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
DIE *&AbsDef = DU->getAbstractSPDies()[Scope->getScopeNode()];
if (AbsDef)
return;
DISubprogram SP(Scope->getScopeNode());
DIE *ContextDIE;
if (includeMinimalInlineScopes())
ContextDIE = &getUnitDie();
// 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.
else if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
ContextDIE = &getUnitDie();
getOrCreateSubprogramDIE(SPDecl);
} else
ContextDIE = getOrCreateContextDIE(resolve(SP.getContext()));
// Passing null as the associated DIDescriptor because the abstract definition
// shouldn't be found by lookup.
AbsDef =
&createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, DIDescriptor());
applySubprogramAttributesToDefinition(SP, *AbsDef);
if (!includeMinimalInlineScopes())
addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, *AbsDef))
addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
}
std::unique_ptr<DIE>
DwarfCompileUnit::constructImportedEntityDIE(const DIImportedEntity &Module) {
assert(Module.Verify() &&
"Use one of the MDNode * overloads to handle invalid metadata");
std::unique_ptr<DIE> IMDie = make_unique<DIE>((dwarf::Tag)Module.getTag());
insertDIE(Module, IMDie.get());
DIE *EntityDie;
DIDescriptor Entity = resolve(Module.getEntity());
if (Entity.isNameSpace())
EntityDie = getOrCreateNameSpace(DINameSpace(Entity));
else if (Entity.isSubprogram())
EntityDie = getOrCreateSubprogramDIE(DISubprogram(Entity));
else if (Entity.isType())
EntityDie = getOrCreateTypeDIE(DIType(Entity));
else if (Entity.isGlobalVariable())
EntityDie = getOrCreateGlobalVariableDIE(DIGlobalVariable(Entity));
else
EntityDie = getDIE(Entity);
assert(EntityDie);
addSourceLine(*IMDie, Module.getLineNumber(),
Module.getContext().getFilename(),
Module.getContext().getDirectory());
addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
StringRef Name = Module.getName();
if (!Name.empty())
addString(*IMDie, dwarf::DW_AT_name, Name);
return IMDie;
}
void DwarfCompileUnit::finishSubprogramDefinition(DISubprogram SP) {
DIE *D = getDIE(SP);
if (DIE *AbsSPDIE = DU->getAbstractSPDies().lookup(SP)) {
if (D)
// If this subprogram has an abstract definition, reference that
addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
} else {
if (!D && !includeMinimalInlineScopes())
// Lazily construct the subprogram if we didn't see either concrete or
// inlined versions during codegen. (except in -gmlt ^ where we want
// to omit these entirely)
D = getOrCreateSubprogramDIE(SP);
if (D)
// And attach the attributes
applySubprogramAttributesToDefinition(SP, *D);
}
}
void DwarfCompileUnit::collectDeadVariables(DISubprogram SP) {
assert(SP.isSubprogram() && "CU's subprogram list contains a non-subprogram");
assert(SP.isDefinition() &&
"CU's subprogram list contains a subprogram declaration");
DIArray Variables = SP.getVariables();
if (Variables.getNumElements() == 0)
return;
DIE *SPDIE = DU->getAbstractSPDies().lookup(SP);
if (!SPDIE)
SPDIE = 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, DIExpression(nullptr), DD);
auto VariableDie = constructVariableDIE(NewVar);
applyVariableAttributes(NewVar, *VariableDie);
SPDIE->addChild(std::move(VariableDie));
}
}
void DwarfCompileUnit::emitHeader(const MCSymbol *ASectionSym) const {
// Don't bother labeling the .dwo unit, as its offset isn't used.
if (!Skeleton)
Asm->OutStreamer.EmitLabel(LabelBegin);
DwarfUnit::emitHeader(ASectionSym);
}
/// addGlobalName - Add a new global name to the compile unit.
void DwarfCompileUnit::addGlobalName(StringRef Name, DIE &Die,
DIScope Context) {
if (includeMinimalInlineScopes())
return;
std::string FullName = getParentContextString(Context) + Name.str();
GlobalNames[FullName] = &Die;
}
/// Add a new global type to the unit.
void DwarfCompileUnit::addGlobalType(DIType Ty, const DIE &Die,
DIScope Context) {
if (includeMinimalInlineScopes())
return;
std::string FullName = getParentContextString(Context) + Ty.getName().str();
GlobalTypes[FullName] = &Die;
}
/// addVariableAddress - Add DW_AT_location attribute for a
/// DbgVariable based on provided MachineLocation.
void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
MachineLocation Location) {
if (DV.variableHasComplexAddress())
addComplexAddress(DV, Die, dwarf::DW_AT_location, Location);
else if (DV.isBlockByrefVariable())
addBlockByrefAddress(DV, Die, dwarf::DW_AT_location, Location);
else
addAddress(Die, dwarf::DW_AT_location, Location);
}
/// Add an address attribute to a die based on the location provided.
void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
const MachineLocation &Location) {
DIELoc *Loc = new (DIEValueAllocator) DIELoc();
bool validReg;
if (Location.isReg())
validReg = addRegisterOpPiece(*Loc, Location.getReg());
else
validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
if (!validReg)
return;
// Now attach the location information to the DIE.
addBlock(Die, Attribute, Loc);
}
/// Start with the address based on the location provided, and generate the
/// DWARF information necessary to find the actual variable given the extra
/// address information encoded in the DbgVariable, starting from the starting
/// location. Add the DWARF information to the die.
void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
dwarf::Attribute Attribute,
const MachineLocation &Location) {
DIELoc *Loc = new (DIEValueAllocator) DIELoc();
DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
DIExpression Expr = DV.getExpression();
bool ValidReg;
if (Location.getOffset()) {
ValidReg = DwarfExpr.AddMachineRegIndirect(Location.getReg(),
Location.getOffset());
if (ValidReg)
DwarfExpr.AddExpression(Expr);
} else
ValidReg = DwarfExpr.AddMachineRegExpression(Expr, Location.getReg());
// Now attach the location information to the DIE.
if (ValidReg)
addBlock(Die, Attribute, Loc);
}
/// Add a Dwarf loclistptr attribute data and value.
void DwarfCompileUnit::addLocationList(DIE &Die, dwarf::Attribute Attribute,
unsigned Index) {
DIEValue *Value = new (DIEValueAllocator) DIELocList(Index);
dwarf::Form Form = DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
: dwarf::DW_FORM_data4;
Die.addValue(Attribute, Form, Value);
}
void DwarfCompileUnit::applyVariableAttributes(const DbgVariable &Var,
DIE &VariableDie) {
StringRef Name = Var.getName();
if (!Name.empty())
addString(VariableDie, dwarf::DW_AT_name, Name);
addSourceLine(VariableDie, Var.getVariable());
addType(VariableDie, Var.getType());
if (Var.isArtificial())
addFlag(VariableDie, dwarf::DW_AT_artificial);
}
/// Add a Dwarf expression attribute data and value.
void DwarfCompileUnit::addExpr(DIELoc &Die, dwarf::Form Form,
const MCExpr *Expr) {
DIEValue *Value = new (DIEValueAllocator) DIEExpr(Expr);
Die.addValue((dwarf::Attribute)0, Form, Value);
}
void DwarfCompileUnit::applySubprogramAttributesToDefinition(DISubprogram SP,
DIE &SPDie) {
DISubprogram SPDecl = SP.getFunctionDeclaration();
DIScope Context = resolve(SPDecl ? SPDecl.getContext() : SP.getContext());
applySubprogramAttributes(SP, SPDie, includeMinimalInlineScopes());
addGlobalName(SP.getName(), SPDie, Context);
}
bool DwarfCompileUnit::isDwoUnit() const {
return DD->useSplitDwarf() && Skeleton;
}
bool DwarfCompileUnit::includeMinimalInlineScopes() const {
return getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly ||
(DD->useSplitDwarf() && !Skeleton);
}
} // end llvm namespace
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