llvm-project/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h

649 lines
23 KiB
C++

//===-- llvm/CodeGen/DwarfDebug.h - Dwarf Debug Framework ------*- C++ -*--===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains support for writing dwarf debug info into asm files.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFDEBUG_H
#define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFDEBUG_H
#include "AsmPrinterHandler.h"
#include "DbgValueHistoryCalculator.h"
#include "DebugLocStream.h"
#include "DwarfAccelTable.h"
#include "DwarfFile.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/CodeGen/DIE.h"
#include "llvm/CodeGen/LexicalScopes.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MachineLocation.h"
#include "llvm/Support/Allocator.h"
#include <memory>
namespace llvm {
class AsmPrinter;
class ByteStreamer;
class ConstantInt;
class ConstantFP;
class DebugLocEntry;
class DwarfCompileUnit;
class DwarfDebug;
class DwarfTypeUnit;
class DwarfUnit;
class MachineModuleInfo;
//===----------------------------------------------------------------------===//
/// \brief This class is used to record source line correspondence.
class SrcLineInfo {
unsigned Line; // Source line number.
unsigned Column; // Source column.
unsigned SourceID; // Source ID number.
MCSymbol *Label; // Label in code ID number.
public:
SrcLineInfo(unsigned L, unsigned C, unsigned S, MCSymbol *label)
: Line(L), Column(C), SourceID(S), Label(label) {}
// Accessors
unsigned getLine() const { return Line; }
unsigned getColumn() const { return Column; }
unsigned getSourceID() const { return SourceID; }
MCSymbol *getLabel() const { return Label; }
};
//===----------------------------------------------------------------------===//
/// This class is used to track local variable information.
///
/// Variables can be created from allocas, in which case they're generated from
/// the MMI table. Such variables can have multiple expressions and frame
/// indices. The \a Expr and \a FrameIndices array must match.
///
/// Variables can be created from \c DBG_VALUE instructions. Those whose
/// location changes over time use \a DebugLocListIndex, while those with a
/// single instruction use \a MInsn and (optionally) a single entry of \a Expr.
///
/// Variables that have been optimized out use none of these fields.
class DbgVariable {
const DILocalVariable *Var; /// Variable Descriptor.
const DILocation *IA; /// Inlined at location.
SmallVector<const DIExpression *, 1> Expr; /// Complex address.
DIE *TheDIE = nullptr; /// Variable DIE.
unsigned DebugLocListIndex = ~0u; /// Offset in DebugLocs.
const MachineInstr *MInsn = nullptr; /// DBG_VALUE instruction.
SmallVector<int, 1> FrameIndex; /// Frame index.
DwarfDebug *DD;
public:
/// Construct a DbgVariable.
///
/// Creates a variable without any DW_AT_location. Call \a initializeMMI()
/// for MMI entries, or \a initializeDbgValue() for DBG_VALUE instructions.
DbgVariable(const DILocalVariable *V, const DILocation *IA, DwarfDebug *DD)
: Var(V), IA(IA), DD(DD) {}
/// Initialize from the MMI table.
void initializeMMI(const DIExpression *E, int FI) {
assert(Expr.empty() && "Already initialized?");
assert(FrameIndex.empty() && "Already initialized?");
assert(!MInsn && "Already initialized?");
assert((!E || E->isValid()) && "Expected valid expression");
assert(~FI && "Expected valid index");
Expr.push_back(E);
FrameIndex.push_back(FI);
}
/// Initialize from a DBG_VALUE instruction.
void initializeDbgValue(const MachineInstr *DbgValue) {
assert(Expr.empty() && "Already initialized?");
assert(FrameIndex.empty() && "Already initialized?");
assert(!MInsn && "Already initialized?");
assert(Var == DbgValue->getDebugVariable() && "Wrong variable");
assert(IA == DbgValue->getDebugLoc()->getInlinedAt() && "Wrong inlined-at");
MInsn = DbgValue;
if (auto *E = DbgValue->getDebugExpression())
if (E->getNumElements())
Expr.push_back(E);
}
// Accessors.
const DILocalVariable *getVariable() const { return Var; }
const DILocation *getInlinedAt() const { return IA; }
const ArrayRef<const DIExpression *> getExpression() const { return Expr; }
void setDIE(DIE &D) { TheDIE = &D; }
DIE *getDIE() const { return TheDIE; }
void setDebugLocListIndex(unsigned O) { DebugLocListIndex = O; }
unsigned getDebugLocListIndex() const { return DebugLocListIndex; }
StringRef getName() const { return Var->getName(); }
const MachineInstr *getMInsn() const { return MInsn; }
const ArrayRef<int> getFrameIndex() const { return FrameIndex; }
void addMMIEntry(const DbgVariable &V) {
assert(DebugLocListIndex == ~0U && !MInsn && "not an MMI entry");
assert(V.DebugLocListIndex == ~0U && !V.MInsn && "not an MMI entry");
assert(V.Var == Var && "conflicting variable");
assert(V.IA == IA && "conflicting inlined-at location");
assert(!FrameIndex.empty() && "Expected an MMI entry");
assert(!V.FrameIndex.empty() && "Expected an MMI entry");
assert(Expr.size() == FrameIndex.size() && "Mismatched expressions");
assert(V.Expr.size() == V.FrameIndex.size() && "Mismatched expressions");
Expr.append(V.Expr.begin(), V.Expr.end());
FrameIndex.append(V.FrameIndex.begin(), V.FrameIndex.end());
assert(std::all_of(Expr.begin(), Expr.end(), [](const DIExpression *E) {
return E && E->isBitPiece();
}) && "conflicting locations for variable");
}
// Translate tag to proper Dwarf tag.
dwarf::Tag getTag() const {
if (Var->getTag() == dwarf::DW_TAG_arg_variable)
return dwarf::DW_TAG_formal_parameter;
return dwarf::DW_TAG_variable;
}
/// \brief Return true if DbgVariable is artificial.
bool isArtificial() const {
if (Var->isArtificial())
return true;
if (getType()->isArtificial())
return true;
return false;
}
bool isObjectPointer() const {
if (Var->isObjectPointer())
return true;
if (getType()->isObjectPointer())
return true;
return false;
}
bool hasComplexAddress() const {
assert(MInsn && "Expected DBG_VALUE, not MMI variable");
assert(FrameIndex.empty() && "Expected DBG_VALUE, not MMI variable");
assert(
(Expr.empty() || (Expr.size() == 1 && Expr.back()->getNumElements())) &&
"Invalid Expr for DBG_VALUE");
return !Expr.empty();
}
bool isBlockByrefVariable() const;
const DIType *getType() const;
private:
/// resolve - Look in the DwarfDebug map for the MDNode that
/// corresponds to the reference.
template <typename T> T *resolve(TypedDINodeRef<T> Ref) const;
};
/// \brief Helper used to pair up a symbol and its DWARF compile unit.
struct SymbolCU {
SymbolCU(DwarfCompileUnit *CU, const MCSymbol *Sym) : Sym(Sym), CU(CU) {}
const MCSymbol *Sym;
DwarfCompileUnit *CU;
};
/// \brief Collects and handles dwarf debug information.
class DwarfDebug : public AsmPrinterHandler {
// Target of Dwarf emission.
AsmPrinter *Asm;
// Collected machine module information.
MachineModuleInfo *MMI;
// All DIEValues are allocated through this allocator.
BumpPtrAllocator DIEValueAllocator;
// Maps MDNode with its corresponding DwarfCompileUnit.
MapVector<const MDNode *, DwarfCompileUnit *> CUMap;
// Maps subprogram MDNode with its corresponding DwarfCompileUnit.
MapVector<const MDNode *, DwarfCompileUnit *> SPMap;
// Maps a CU DIE with its corresponding DwarfCompileUnit.
DenseMap<const DIE *, DwarfCompileUnit *> CUDieMap;
// List of all labels used in aranges generation.
std::vector<SymbolCU> ArangeLabels;
// Size of each symbol emitted (for those symbols that have a specific size).
DenseMap<const MCSymbol *, uint64_t> SymSize;
LexicalScopes LScopes;
// Collection of abstract variables.
DenseMap<const MDNode *, std::unique_ptr<DbgVariable>> AbstractVariables;
SmallVector<std::unique_ptr<DbgVariable>, 64> ConcreteVariables;
// Collection of DebugLocEntry. Stored in a linked list so that DIELocLists
// can refer to them in spite of insertions into this list.
DebugLocStream DebugLocs;
// This is a collection of subprogram MDNodes that are processed to
// create DIEs.
SmallPtrSet<const MDNode *, 16> ProcessedSPNodes;
// Maps instruction with label emitted before instruction.
DenseMap<const MachineInstr *, MCSymbol *> LabelsBeforeInsn;
// Maps instruction with label emitted after instruction.
DenseMap<const MachineInstr *, MCSymbol *> LabelsAfterInsn;
// History of DBG_VALUE and clobber instructions for each user variable.
// Variables are listed in order of appearance.
DbgValueHistoryMap DbgValues;
// Previous instruction's location information. This is used to determine
// label location to indicate scope boundries in dwarf debug info.
DebugLoc PrevInstLoc;
MCSymbol *PrevLabel;
// This location indicates end of function prologue and beginning of function
// body.
DebugLoc PrologEndLoc;
// If nonnull, stores the current machine function we're processing.
const MachineFunction *CurFn;
// If nonnull, stores the current machine instruction we're processing.
const MachineInstr *CurMI;
// If nonnull, stores the CU in which the previous subprogram was contained.
const DwarfCompileUnit *PrevCU;
// As an optimization, there is no need to emit an entry in the directory
// table for the same directory as DW_AT_comp_dir.
StringRef CompilationDir;
// Holder for the file specific debug information.
DwarfFile InfoHolder;
// Holders for the various debug information flags that we might need to
// have exposed. See accessor functions below for description.
// Holder for imported entities.
typedef SmallVector<std::pair<const MDNode *, const MDNode *>, 32>
ImportedEntityMap;
ImportedEntityMap ScopesWithImportedEntities;
// Map from MDNodes for user-defined types to the type units that describe
// them.
DenseMap<const MDNode *, const DwarfTypeUnit *> DwarfTypeUnits;
SmallVector<
std::pair<std::unique_ptr<DwarfTypeUnit>, const DICompositeType *>, 1>
TypeUnitsUnderConstruction;
// Whether to emit the pubnames/pubtypes sections.
bool HasDwarfPubSections;
// Whether or not to use AT_ranges for compilation units.
bool HasCURanges;
// Whether we emitted a function into a section other than the default
// text.
bool UsedNonDefaultText;
// Whether to use the GNU TLS opcode (instead of the standard opcode).
bool UseGNUTLSOpcode;
// Version of dwarf we're emitting.
unsigned DwarfVersion;
// Maps from a type identifier to the actual MDNode.
DITypeIdentifierMap TypeIdentifierMap;
// DWARF5 Experimental Options
bool HasDwarfAccelTables;
bool HasSplitDwarf;
// Separated Dwarf Variables
// In general these will all be for bits that are left in the
// original object file, rather than things that are meant
// to be in the .dwo sections.
// Holder for the skeleton information.
DwarfFile SkeletonHolder;
/// Store file names for type units under fission in a line table header that
/// will be emitted into debug_line.dwo.
// FIXME: replace this with a map from comp_dir to table so that we can emit
// multiple tables during LTO each of which uses directory 0, referencing the
// comp_dir of all the type units that use it.
MCDwarfDwoLineTable SplitTypeUnitFileTable;
// True iff there are multiple CUs in this module.
bool SingleCU;
bool IsDarwin;
bool IsPS4;
AddressPool AddrPool;
DwarfAccelTable AccelNames;
DwarfAccelTable AccelObjC;
DwarfAccelTable AccelNamespace;
DwarfAccelTable AccelTypes;
DenseMap<const Function *, DISubprogram *> FunctionDIs;
MCDwarfDwoLineTable *getDwoLineTable(const DwarfCompileUnit &);
const SmallVectorImpl<std::unique_ptr<DwarfUnit>> &getUnits() {
return InfoHolder.getUnits();
}
typedef DbgValueHistoryMap::InlinedVariable InlinedVariable;
/// \brief Find abstract variable associated with Var.
DbgVariable *getExistingAbstractVariable(InlinedVariable IV,
const DILocalVariable *&Cleansed);
DbgVariable *getExistingAbstractVariable(InlinedVariable IV);
void createAbstractVariable(const DILocalVariable *DV, LexicalScope *Scope);
void ensureAbstractVariableIsCreated(InlinedVariable Var,
const MDNode *Scope);
void ensureAbstractVariableIsCreatedIfScoped(InlinedVariable Var,
const MDNode *Scope);
DbgVariable *createConcreteVariable(LexicalScope &Scope, InlinedVariable IV);
/// \brief Construct a DIE for this abstract scope.
void constructAbstractSubprogramScopeDIE(LexicalScope *Scope);
/// \brief Compute the size and offset of a DIE given an incoming Offset.
unsigned computeSizeAndOffset(DIE *Die, unsigned Offset);
/// \brief Compute the size and offset of all the DIEs.
void computeSizeAndOffsets();
/// \brief Collect info for variables that were optimized out.
void collectDeadVariables();
void finishVariableDefinitions();
void finishSubprogramDefinitions();
/// \brief Finish off debug information after all functions have been
/// processed.
void finalizeModuleInfo();
/// \brief Emit the debug info section.
void emitDebugInfo();
/// \brief Emit the abbreviation section.
void emitAbbreviations();
/// \brief Emit a specified accelerator table.
void emitAccel(DwarfAccelTable &Accel, MCSection *Section,
StringRef TableName);
/// \brief Emit visible names into a hashed accelerator table section.
void emitAccelNames();
/// \brief Emit objective C classes and categories into a hashed
/// accelerator table section.
void emitAccelObjC();
/// \brief Emit namespace dies into a hashed accelerator table.
void emitAccelNamespaces();
/// \brief Emit type dies into a hashed accelerator table.
void emitAccelTypes();
/// \brief Emit visible names into a debug pubnames section.
/// \param GnuStyle determines whether or not we want to emit
/// additional information into the table ala newer gcc for gdb
/// index.
void emitDebugPubNames(bool GnuStyle = false);
/// \brief Emit visible types into a debug pubtypes section.
/// \param GnuStyle determines whether or not we want to emit
/// additional information into the table ala newer gcc for gdb
/// index.
void emitDebugPubTypes(bool GnuStyle = false);
void emitDebugPubSection(
bool GnuStyle, MCSection *PSec, StringRef Name,
const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const);
/// \brief Emit visible names into a debug str section.
void emitDebugStr();
/// \brief Emit visible names into a debug loc section.
void emitDebugLoc();
/// \brief Emit visible names into a debug loc dwo section.
void emitDebugLocDWO();
/// \brief Emit visible names into a debug aranges section.
void emitDebugARanges();
/// \brief Emit visible names into a debug ranges section.
void emitDebugRanges();
/// \brief Emit inline info using custom format.
void emitDebugInlineInfo();
/// DWARF 5 Experimental Split Dwarf Emitters
/// \brief Initialize common features of skeleton units.
void initSkeletonUnit(const DwarfUnit &U, DIE &Die,
std::unique_ptr<DwarfUnit> NewU);
/// \brief Construct the split debug info compile unit for the debug info
/// section.
DwarfCompileUnit &constructSkeletonCU(const DwarfCompileUnit &CU);
/// \brief Construct the split debug info compile unit for the debug info
/// section.
DwarfTypeUnit &constructSkeletonTU(DwarfTypeUnit &TU);
/// \brief Emit the debug info dwo section.
void emitDebugInfoDWO();
/// \brief Emit the debug abbrev dwo section.
void emitDebugAbbrevDWO();
/// \brief Emit the debug line dwo section.
void emitDebugLineDWO();
/// \brief Emit the debug str dwo section.
void emitDebugStrDWO();
/// Flags to let the linker know we have emitted new style pubnames. Only
/// emit it here if we don't have a skeleton CU for split dwarf.
void addGnuPubAttributes(DwarfUnit &U, DIE &D) const;
/// \brief Create new DwarfCompileUnit for the given metadata node with tag
/// DW_TAG_compile_unit.
DwarfCompileUnit &constructDwarfCompileUnit(const DICompileUnit *DIUnit);
/// \brief Construct imported_module or imported_declaration DIE.
void constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
const DIImportedEntity *N);
/// \brief Register a source line with debug info. Returns the unique
/// label that was emitted and which provides correspondence to the
/// source line list.
void recordSourceLine(unsigned Line, unsigned Col, const MDNode *Scope,
unsigned Flags);
/// \brief Indentify instructions that are marking the beginning of or
/// ending of a scope.
void identifyScopeMarkers();
/// \brief Populate LexicalScope entries with variables' info.
void collectVariableInfo(DwarfCompileUnit &TheCU, const DISubprogram *SP,
DenseSet<InlinedVariable> &ProcessedVars);
/// \brief Build the location list for all DBG_VALUEs in the
/// function that describe the same variable.
void buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
const DbgValueHistoryMap::InstrRanges &Ranges);
/// \brief Collect variable information from the side table maintained
/// by MMI.
void collectVariableInfoFromMMITable(DenseSet<InlinedVariable> &P);
/// \brief Ensure that a label will be emitted before MI.
void requestLabelBeforeInsn(const MachineInstr *MI) {
LabelsBeforeInsn.insert(std::make_pair(MI, nullptr));
}
/// \brief Ensure that a label will be emitted after MI.
void requestLabelAfterInsn(const MachineInstr *MI) {
LabelsAfterInsn.insert(std::make_pair(MI, nullptr));
}
public:
//===--------------------------------------------------------------------===//
// Main entry points.
//
DwarfDebug(AsmPrinter *A, Module *M);
~DwarfDebug() override;
/// \brief Emit all Dwarf sections that should come prior to the
/// content.
void beginModule();
/// \brief Emit all Dwarf sections that should come after the content.
void endModule() override;
/// \brief Gather pre-function debug information.
void beginFunction(const MachineFunction *MF) override;
/// \brief Gather and emit post-function debug information.
void endFunction(const MachineFunction *MF) override;
/// \brief Process beginning of an instruction.
void beginInstruction(const MachineInstr *MI) override;
/// \brief Process end of an instruction.
void endInstruction() override;
/// \brief Add a DIE to the set of types that we're going to pull into
/// type units.
void addDwarfTypeUnitType(DwarfCompileUnit &CU, StringRef Identifier,
DIE &Die, const DICompositeType *CTy);
/// \brief Add a label so that arange data can be generated for it.
void addArangeLabel(SymbolCU SCU) { ArangeLabels.push_back(SCU); }
/// \brief For symbols that have a size designated (e.g. common symbols),
/// this tracks that size.
void setSymbolSize(const MCSymbol *Sym, uint64_t Size) override {
SymSize[Sym] = Size;
}
/// \brief Returns whether to use DW_OP_GNU_push_tls_address, instead of the
/// standard DW_OP_form_tls_address opcode
bool useGNUTLSOpcode() const { return UseGNUTLSOpcode; }
// Experimental DWARF5 features.
/// \brief Returns whether or not to emit tables that dwarf consumers can
/// use to accelerate lookup.
bool useDwarfAccelTables() const { return HasDwarfAccelTables; }
/// \brief Returns whether or not to change the current debug info for the
/// split dwarf proposal support.
bool useSplitDwarf() const { return HasSplitDwarf; }
/// Returns the Dwarf Version.
unsigned getDwarfVersion() const { return DwarfVersion; }
/// Returns the previous CU that was being updated
const DwarfCompileUnit *getPrevCU() const { return PrevCU; }
void setPrevCU(const DwarfCompileUnit *PrevCU) { this->PrevCU = PrevCU; }
/// Returns the entries for the .debug_loc section.
const DebugLocStream &getDebugLocs() const { return DebugLocs; }
/// \brief Emit an entry for the debug loc section. This can be used to
/// handle an entry that's going to be emitted into the debug loc section.
void emitDebugLocEntry(ByteStreamer &Streamer,
const DebugLocStream::Entry &Entry);
/// Emit the location for a debug loc entry, including the size header.
void emitDebugLocEntryLocation(const DebugLocStream::Entry &Entry);
/// Find the MDNode for the given reference.
template <typename T> T *resolve(TypedDINodeRef<T> Ref) const {
return Ref.resolve(TypeIdentifierMap);
}
/// \brief Return the TypeIdentifierMap.
const DITypeIdentifierMap &getTypeIdentifierMap() const {
return TypeIdentifierMap;
}
/// Find the DwarfCompileUnit for the given CU Die.
DwarfCompileUnit *lookupUnit(const DIE *CU) const {
return CUDieMap.lookup(CU);
}
/// isSubprogramContext - Return true if Context is either a subprogram
/// or another context nested inside a subprogram.
bool isSubprogramContext(const MDNode *Context);
void addSubprogramNames(const DISubprogram *SP, DIE &Die);
AddressPool &getAddressPool() { return AddrPool; }
void addAccelName(StringRef Name, const DIE &Die);
void addAccelObjC(StringRef Name, const DIE &Die);
void addAccelNamespace(StringRef Name, const DIE &Die);
void addAccelType(StringRef Name, const DIE &Die, char Flags);
const MachineFunction *getCurrentFunction() const { return CurFn; }
iterator_range<ImportedEntityMap::const_iterator>
findImportedEntitiesForScope(const MDNode *Scope) const {
return make_range(std::equal_range(
ScopesWithImportedEntities.begin(), ScopesWithImportedEntities.end(),
std::pair<const MDNode *, const MDNode *>(Scope, nullptr),
less_first()));
}
/// \brief A helper function to check whether the DIE for a given Scope is
/// going to be null.
bool isLexicalScopeDIENull(LexicalScope *Scope);
/// \brief Return Label preceding the instruction.
MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
/// \brief Return Label immediately following the instruction.
MCSymbol *getLabelAfterInsn(const MachineInstr *MI);
// FIXME: Sink these functions down into DwarfFile/Dwarf*Unit.
SmallPtrSet<const MDNode *, 16> &getProcessedSPNodes() {
return ProcessedSPNodes;
}
};
} // End of namespace llvm
#endif