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llvm-for-llvmta/include/llvm/CodeGen/DIE.h

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//===- lib/CodeGen/DIE.h - DWARF Info Entries -------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Data structures for DWARF info entries.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DIE_H
#define LLVM_LIB_CODEGEN_ASMPRINTER_DIE_H
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/PointerUnion.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/iterator.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/CodeGen/DwarfStringPoolEntry.h"
#include "llvm/Support/AlignOf.h"
#include "llvm/Support/Allocator.h"
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <iterator>
#include <new>
#include <type_traits>
#include <utility>
#include <vector>
namespace llvm {
class AsmPrinter;
class DIE;
class DIEUnit;
class DwarfCompileUnit;
class MCExpr;
class MCSection;
class MCSymbol;
class raw_ostream;
//===--------------------------------------------------------------------===//
/// Dwarf abbreviation data, describes one attribute of a Dwarf abbreviation.
class DIEAbbrevData {
/// Dwarf attribute code.
dwarf::Attribute Attribute;
/// Dwarf form code.
dwarf::Form Form;
/// Dwarf attribute value for DW_FORM_implicit_const
int64_t Value = 0;
public:
DIEAbbrevData(dwarf::Attribute A, dwarf::Form F)
: Attribute(A), Form(F) {}
DIEAbbrevData(dwarf::Attribute A, int64_t V)
: Attribute(A), Form(dwarf::DW_FORM_implicit_const), Value(V) {}
/// Accessors.
/// @{
dwarf::Attribute getAttribute() const { return Attribute; }
dwarf::Form getForm() const { return Form; }
int64_t getValue() const { return Value; }
/// @}
/// Used to gather unique data for the abbreviation folding set.
void Profile(FoldingSetNodeID &ID) const;
};
//===--------------------------------------------------------------------===//
/// Dwarf abbreviation, describes the organization of a debug information
/// object.
class DIEAbbrev : public FoldingSetNode {
/// Unique number for node.
unsigned Number = 0;
/// Dwarf tag code.
dwarf::Tag Tag;
/// Whether or not this node has children.
///
/// This cheats a bit in all of the uses since the values in the standard
/// are 0 and 1 for no children and children respectively.
bool Children;
/// Raw data bytes for abbreviation.
SmallVector<DIEAbbrevData, 12> Data;
public:
DIEAbbrev(dwarf::Tag T, bool C) : Tag(T), Children(C) {}
/// Accessors.
/// @{
dwarf::Tag getTag() const { return Tag; }
unsigned getNumber() const { return Number; }
bool hasChildren() const { return Children; }
const SmallVectorImpl<DIEAbbrevData> &getData() const { return Data; }
void setChildrenFlag(bool hasChild) { Children = hasChild; }
void setNumber(unsigned N) { Number = N; }
/// @}
/// Adds another set of attribute information to the abbreviation.
void AddAttribute(dwarf::Attribute Attribute, dwarf::Form Form) {
Data.push_back(DIEAbbrevData(Attribute, Form));
}
/// Adds attribute with DW_FORM_implicit_const value
void AddImplicitConstAttribute(dwarf::Attribute Attribute, int64_t Value) {
Data.push_back(DIEAbbrevData(Attribute, Value));
}
/// Used to gather unique data for the abbreviation folding set.
void Profile(FoldingSetNodeID &ID) const;
/// Print the abbreviation using the specified asm printer.
void Emit(const AsmPrinter *AP) const;
void print(raw_ostream &O) const;
void dump() const;
};
//===--------------------------------------------------------------------===//
/// Helps unique DIEAbbrev objects and assigns abbreviation numbers.
///
/// This class will unique the DIE abbreviations for a llvm::DIE object and
/// assign a unique abbreviation number to each unique DIEAbbrev object it
/// finds. The resulting collection of DIEAbbrev objects can then be emitted
/// into the .debug_abbrev section.
class DIEAbbrevSet {
/// The bump allocator to use when creating DIEAbbrev objects in the uniqued
/// storage container.
BumpPtrAllocator &Alloc;
/// FoldingSet that uniques the abbreviations.
FoldingSet<DIEAbbrev> AbbreviationsSet;
/// A list of all the unique abbreviations in use.
std::vector<DIEAbbrev *> Abbreviations;
public:
DIEAbbrevSet(BumpPtrAllocator &A) : Alloc(A) {}
~DIEAbbrevSet();
/// Generate the abbreviation declaration for a DIE and return a pointer to
/// the generated abbreviation.
///
/// \param Die the debug info entry to generate the abbreviation for.
/// \returns A reference to the uniqued abbreviation declaration that is
/// owned by this class.
DIEAbbrev &uniqueAbbreviation(DIE &Die);
/// Print all abbreviations using the specified asm printer.
void Emit(const AsmPrinter *AP, MCSection *Section) const;
};
//===--------------------------------------------------------------------===//
/// An integer value DIE.
///
class DIEInteger {
uint64_t Integer;
public:
explicit DIEInteger(uint64_t I) : Integer(I) {}
/// Choose the best form for integer.
static dwarf::Form BestForm(bool IsSigned, uint64_t Int) {
if (IsSigned) {
const int64_t SignedInt = Int;
if ((char)Int == SignedInt)
return dwarf::DW_FORM_data1;
if ((short)Int == SignedInt)
return dwarf::DW_FORM_data2;
if ((int)Int == SignedInt)
return dwarf::DW_FORM_data4;
} else {
if ((unsigned char)Int == Int)
return dwarf::DW_FORM_data1;
if ((unsigned short)Int == Int)
return dwarf::DW_FORM_data2;
if ((unsigned int)Int == Int)
return dwarf::DW_FORM_data4;
}
return dwarf::DW_FORM_data8;
}
uint64_t getValue() const { return Integer; }
void setValue(uint64_t Val) { Integer = Val; }
void emitValue(const AsmPrinter *Asm, dwarf::Form Form) const;
unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
void print(raw_ostream &O) const;
};
//===--------------------------------------------------------------------===//
/// An expression DIE.
class DIEExpr {
const MCExpr *Expr;
public:
explicit DIEExpr(const MCExpr *E) : Expr(E) {}
/// Get MCExpr.
const MCExpr *getValue() const { return Expr; }
void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
void print(raw_ostream &O) const;
};
//===--------------------------------------------------------------------===//
/// A label DIE.
class DIELabel {
const MCSymbol *Label;
public:
explicit DIELabel(const MCSymbol *L) : Label(L) {}
/// Get MCSymbol.
const MCSymbol *getValue() const { return Label; }
void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
void print(raw_ostream &O) const;
};
//===--------------------------------------------------------------------===//
/// A BaseTypeRef DIE.
class DIEBaseTypeRef {
const DwarfCompileUnit *CU;
const uint64_t Index;
static constexpr unsigned ULEB128PadSize = 4;
public:
explicit DIEBaseTypeRef(const DwarfCompileUnit *TheCU, uint64_t Idx)
: CU(TheCU), Index(Idx) {}
/// EmitValue - Emit base type reference.
void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
/// SizeOf - Determine size of the base type reference in bytes.
unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
void print(raw_ostream &O) const;
uint64_t getIndex() const { return Index; }
};
//===--------------------------------------------------------------------===//
/// A simple label difference DIE.
///
class DIEDelta {
const MCSymbol *LabelHi;
const MCSymbol *LabelLo;
public:
DIEDelta(const MCSymbol *Hi, const MCSymbol *Lo) : LabelHi(Hi), LabelLo(Lo) {}
void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
void print(raw_ostream &O) const;
};
//===--------------------------------------------------------------------===//
/// A container for string pool string values.
///
/// This class is used with the DW_FORM_strp and DW_FORM_GNU_str_index forms.
class DIEString {
DwarfStringPoolEntryRef S;
public:
DIEString(DwarfStringPoolEntryRef S) : S(S) {}
/// Grab the string out of the object.
StringRef getString() const { return S.getString(); }
void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
void print(raw_ostream &O) const;
};
//===--------------------------------------------------------------------===//
/// A container for inline string values.
///
/// This class is used with the DW_FORM_string form.
class DIEInlineString {
StringRef S;
public:
template <typename Allocator>
explicit DIEInlineString(StringRef Str, Allocator &A) : S(Str.copy(A)) {}
~DIEInlineString() = default;
/// Grab the string out of the object.
StringRef getString() const { return S; }
void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
void print(raw_ostream &O) const;
};
//===--------------------------------------------------------------------===//
/// A pointer to another debug information entry. An instance of this class can
/// also be used as a proxy for a debug information entry not yet defined
/// (ie. types.)
class DIEEntry {
DIE *Entry;
public:
DIEEntry() = delete;
explicit DIEEntry(DIE &E) : Entry(&E) {}
DIE &getEntry() const { return *Entry; }
void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
void print(raw_ostream &O) const;
};
//===--------------------------------------------------------------------===//
/// Represents a pointer to a location list in the debug_loc
/// section.
class DIELocList {
/// Index into the .debug_loc vector.
size_t Index;
public:
DIELocList(size_t I) : Index(I) {}
/// Grab the current index out.
size_t getValue() const { return Index; }
void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
void print(raw_ostream &O) const;
};
//===--------------------------------------------------------------------===//
/// A debug information entry value. Some of these roughly correlate
/// to DWARF attribute classes.
class DIEBlock;
class DIELoc;
class DIEValue {
public:
enum Type {
isNone,
#define HANDLE_DIEVALUE(T) is##T,
#include "llvm/CodeGen/DIEValue.def"
};
private:
/// Type of data stored in the value.
Type Ty = isNone;
dwarf::Attribute Attribute = (dwarf::Attribute)0;
dwarf::Form Form = (dwarf::Form)0;
/// Storage for the value.
///
/// All values that aren't standard layout (or are larger than 8 bytes)
/// should be stored by reference instead of by value.
using ValTy = AlignedCharArrayUnion<DIEInteger, DIEString, DIEExpr, DIELabel,
DIEDelta *, DIEEntry, DIEBlock *,
DIELoc *, DIELocList, DIEBaseTypeRef *>;
static_assert(sizeof(ValTy) <= sizeof(uint64_t) ||
sizeof(ValTy) <= sizeof(void *),
"Expected all large types to be stored via pointer");
/// Underlying stored value.
ValTy Val;
template <class T> void construct(T V) {
static_assert(std::is_standard_layout<T>::value ||
std::is_pointer<T>::value,
"Expected standard layout or pointer");
new (reinterpret_cast<void *>(&Val)) T(V);
}
template <class T> T *get() { return reinterpret_cast<T *>(&Val); }
template <class T> const T *get() const {
return reinterpret_cast<const T *>(&Val);
}
template <class T> void destruct() { get<T>()->~T(); }
/// Destroy the underlying value.
///
/// This should get optimized down to a no-op. We could skip it if we could
/// add a static assert on \a std::is_trivially_copyable(), but we currently
/// support versions of GCC that don't understand that.
void destroyVal() {
switch (Ty) {
case isNone:
return;
#define HANDLE_DIEVALUE_SMALL(T) \
case is##T: \
destruct<DIE##T>(); \
return;
#define HANDLE_DIEVALUE_LARGE(T) \
case is##T: \
destruct<const DIE##T *>(); \
return;
#include "llvm/CodeGen/DIEValue.def"
}
}
/// Copy the underlying value.
///
/// This should get optimized down to a simple copy. We need to actually
/// construct the value, rather than calling memcpy, to satisfy strict
/// aliasing rules.
void copyVal(const DIEValue &X) {
switch (Ty) {
case isNone:
return;
#define HANDLE_DIEVALUE_SMALL(T) \
case is##T: \
construct<DIE##T>(*X.get<DIE##T>()); \
return;
#define HANDLE_DIEVALUE_LARGE(T) \
case is##T: \
construct<const DIE##T *>(*X.get<const DIE##T *>()); \
return;
#include "llvm/CodeGen/DIEValue.def"
}
}
public:
DIEValue() = default;
DIEValue(const DIEValue &X) : Ty(X.Ty), Attribute(X.Attribute), Form(X.Form) {
copyVal(X);
}
DIEValue &operator=(const DIEValue &X) {
destroyVal();
Ty = X.Ty;
Attribute = X.Attribute;
Form = X.Form;
copyVal(X);
return *this;
}
~DIEValue() { destroyVal(); }
#define HANDLE_DIEVALUE_SMALL(T) \
DIEValue(dwarf::Attribute Attribute, dwarf::Form Form, const DIE##T &V) \
: Ty(is##T), Attribute(Attribute), Form(Form) { \
construct<DIE##T>(V); \
}
#define HANDLE_DIEVALUE_LARGE(T) \
DIEValue(dwarf::Attribute Attribute, dwarf::Form Form, const DIE##T *V) \
: Ty(is##T), Attribute(Attribute), Form(Form) { \
assert(V && "Expected valid value"); \
construct<const DIE##T *>(V); \
}
#include "llvm/CodeGen/DIEValue.def"
/// Accessors.
/// @{
Type getType() const { return Ty; }
dwarf::Attribute getAttribute() const { return Attribute; }
dwarf::Form getForm() const { return Form; }
explicit operator bool() const { return Ty; }
/// @}
#define HANDLE_DIEVALUE_SMALL(T) \
const DIE##T &getDIE##T() const { \
assert(getType() == is##T && "Expected " #T); \
return *get<DIE##T>(); \
}
#define HANDLE_DIEVALUE_LARGE(T) \
const DIE##T &getDIE##T() const { \
assert(getType() == is##T && "Expected " #T); \
return **get<const DIE##T *>(); \
}
#include "llvm/CodeGen/DIEValue.def"
/// Emit value via the Dwarf writer.
void emitValue(const AsmPrinter *AP) const;
/// Return the size of a value in bytes.
unsigned SizeOf(const AsmPrinter *AP) const;
void print(raw_ostream &O) const;
void dump() const;
};
struct IntrusiveBackListNode {
PointerIntPair<IntrusiveBackListNode *, 1> Next;
IntrusiveBackListNode() : Next(this, true) {}
IntrusiveBackListNode *getNext() const {
return Next.getInt() ? nullptr : Next.getPointer();
}
};
struct IntrusiveBackListBase {
using Node = IntrusiveBackListNode;
Node *Last = nullptr;
bool empty() const { return !Last; }
void push_back(Node &N) {
assert(N.Next.getPointer() == &N && "Expected unlinked node");
assert(N.Next.getInt() == true && "Expected unlinked node");
if (Last) {
N.Next = Last->Next;
Last->Next.setPointerAndInt(&N, false);
}
Last = &N;
}
void push_front(Node &N) {
assert(N.Next.getPointer() == &N && "Expected unlinked node");
assert(N.Next.getInt() == true && "Expected unlinked node");
if (Last) {
N.Next.setPointerAndInt(Last->Next.getPointer(), false);
Last->Next.setPointerAndInt(&N, true);
} else {
Last = &N;
}
}
};
template <class T> class IntrusiveBackList : IntrusiveBackListBase {
public:
using IntrusiveBackListBase::empty;
void push_back(T &N) { IntrusiveBackListBase::push_back(N); }
void push_front(T &N) { IntrusiveBackListBase::push_front(N); }
T &back() { return *static_cast<T *>(Last); }
const T &back() const { return *static_cast<T *>(Last); }
T &front() {
return *static_cast<T *>(Last ? Last->Next.getPointer() : nullptr);
}
const T &front() const {
return *static_cast<T *>(Last ? Last->Next.getPointer() : nullptr);
}
void takeNodes(IntrusiveBackList<T> &Other) {
if (Other.empty())
return;
T *FirstNode = static_cast<T *>(Other.Last->Next.getPointer());
T *IterNode = FirstNode;
do {
// Keep a pointer to the node and increment the iterator.
T *TmpNode = IterNode;
IterNode = static_cast<T *>(IterNode->Next.getPointer());
// Unlink the node and push it back to this list.
TmpNode->Next.setPointerAndInt(TmpNode, true);
push_back(*TmpNode);
} while (IterNode != FirstNode);
Other.Last = nullptr;
}
class const_iterator;
class iterator
: public iterator_facade_base<iterator, std::forward_iterator_tag, T> {
friend class const_iterator;
Node *N = nullptr;
public:
iterator() = default;
explicit iterator(T *N) : N(N) {}
iterator &operator++() {
N = N->getNext();
return *this;
}
explicit operator bool() const { return N; }
T &operator*() const { return *static_cast<T *>(N); }
bool operator==(const iterator &X) const { return N == X.N; }
};
class const_iterator
: public iterator_facade_base<const_iterator, std::forward_iterator_tag,
const T> {
const Node *N = nullptr;
public:
const_iterator() = default;
// Placate MSVC by explicitly scoping 'iterator'.
const_iterator(typename IntrusiveBackList<T>::iterator X) : N(X.N) {}
explicit const_iterator(const T *N) : N(N) {}
const_iterator &operator++() {
N = N->getNext();
return *this;
}
explicit operator bool() const { return N; }
const T &operator*() const { return *static_cast<const T *>(N); }
bool operator==(const const_iterator &X) const { return N == X.N; }
};
iterator begin() {
return Last ? iterator(static_cast<T *>(Last->Next.getPointer())) : end();
}
const_iterator begin() const {
return const_cast<IntrusiveBackList *>(this)->begin();
}
iterator end() { return iterator(); }
const_iterator end() const { return const_iterator(); }
static iterator toIterator(T &N) { return iterator(&N); }
static const_iterator toIterator(const T &N) { return const_iterator(&N); }
};
/// A list of DIE values.
///
/// This is a singly-linked list, but instead of reversing the order of
/// insertion, we keep a pointer to the back of the list so we can push in
/// order.
///
/// There are two main reasons to choose a linked list over a customized
/// vector-like data structure.
///
/// 1. For teardown efficiency, we want DIEs to be BumpPtrAllocated. Using a
/// linked list here makes this way easier to accomplish.
/// 2. Carrying an extra pointer per \a DIEValue isn't expensive. 45% of DIEs
/// have 2 or fewer values, and 90% have 5 or fewer. A vector would be
/// over-allocated by 50% on average anyway, the same cost as the
/// linked-list node.
class DIEValueList {
struct Node : IntrusiveBackListNode {
DIEValue V;
explicit Node(DIEValue V) : V(V) {}
};
using ListTy = IntrusiveBackList<Node>;
ListTy List;
public:
class const_value_iterator;
class value_iterator
: public iterator_adaptor_base<value_iterator, ListTy::iterator,
std::forward_iterator_tag, DIEValue> {
friend class const_value_iterator;
using iterator_adaptor =
iterator_adaptor_base<value_iterator, ListTy::iterator,
std::forward_iterator_tag, DIEValue>;
public:
value_iterator() = default;
explicit value_iterator(ListTy::iterator X) : iterator_adaptor(X) {}
explicit operator bool() const { return bool(wrapped()); }
DIEValue &operator*() const { return wrapped()->V; }
};
class const_value_iterator : public iterator_adaptor_base<
const_value_iterator, ListTy::const_iterator,
std::forward_iterator_tag, const DIEValue> {
using iterator_adaptor =
iterator_adaptor_base<const_value_iterator, ListTy::const_iterator,
std::forward_iterator_tag, const DIEValue>;
public:
const_value_iterator() = default;
const_value_iterator(DIEValueList::value_iterator X)
: iterator_adaptor(X.wrapped()) {}
explicit const_value_iterator(ListTy::const_iterator X)
: iterator_adaptor(X) {}
explicit operator bool() const { return bool(wrapped()); }
const DIEValue &operator*() const { return wrapped()->V; }
};
using value_range = iterator_range<value_iterator>;
using const_value_range = iterator_range<const_value_iterator>;
value_iterator addValue(BumpPtrAllocator &Alloc, const DIEValue &V) {
List.push_back(*new (Alloc) Node(V));
return value_iterator(ListTy::toIterator(List.back()));
}
template <class T>
value_iterator addValue(BumpPtrAllocator &Alloc, dwarf::Attribute Attribute,
dwarf::Form Form, T &&Value) {
return addValue(Alloc, DIEValue(Attribute, Form, std::forward<T>(Value)));
}
/// Take ownership of the nodes in \p Other, and append them to the back of
/// the list.
void takeValues(DIEValueList &Other) { List.takeNodes(Other.List); }
value_range values() {
return make_range(value_iterator(List.begin()), value_iterator(List.end()));
}
const_value_range values() const {
return make_range(const_value_iterator(List.begin()),
const_value_iterator(List.end()));
}
};
//===--------------------------------------------------------------------===//
/// A structured debug information entry. Has an abbreviation which
/// describes its organization.
class DIE : IntrusiveBackListNode, public DIEValueList {
friend class IntrusiveBackList<DIE>;
friend class DIEUnit;
/// Dwarf unit relative offset.
unsigned Offset = 0;
/// Size of instance + children.
unsigned Size = 0;
unsigned AbbrevNumber = ~0u;
/// Dwarf tag code.
dwarf::Tag Tag = (dwarf::Tag)0;
/// Set to true to force a DIE to emit an abbreviation that says it has
/// children even when it doesn't. This is used for unit testing purposes.
bool ForceChildren = false;
/// Children DIEs.
IntrusiveBackList<DIE> Children;
/// The owner is either the parent DIE for children of other DIEs, or a
/// DIEUnit which contains this DIE as its unit DIE.
PointerUnion<DIE *, DIEUnit *> Owner;
explicit DIE(dwarf::Tag Tag) : Tag(Tag) {}
public:
DIE() = delete;
DIE(const DIE &RHS) = delete;
DIE(DIE &&RHS) = delete;
DIE &operator=(const DIE &RHS) = delete;
DIE &operator=(const DIE &&RHS) = delete;
static DIE *get(BumpPtrAllocator &Alloc, dwarf::Tag Tag) {
return new (Alloc) DIE(Tag);
}
// Accessors.
unsigned getAbbrevNumber() const { return AbbrevNumber; }
dwarf::Tag getTag() const { return Tag; }
/// Get the compile/type unit relative offset of this DIE.
unsigned getOffset() const { return Offset; }
unsigned getSize() const { return Size; }
bool hasChildren() const { return ForceChildren || !Children.empty(); }
void setForceChildren(bool B) { ForceChildren = B; }
using child_iterator = IntrusiveBackList<DIE>::iterator;
using const_child_iterator = IntrusiveBackList<DIE>::const_iterator;
using child_range = iterator_range<child_iterator>;
using const_child_range = iterator_range<const_child_iterator>;
child_range children() {
return make_range(Children.begin(), Children.end());
}
const_child_range children() const {
return make_range(Children.begin(), Children.end());
}
DIE *getParent() const;
/// Generate the abbreviation for this DIE.
///
/// Calculate the abbreviation for this, which should be uniqued and
/// eventually used to call \a setAbbrevNumber().
DIEAbbrev generateAbbrev() const;
/// Set the abbreviation number for this DIE.
void setAbbrevNumber(unsigned I) { AbbrevNumber = I; }
/// Get the absolute offset within the .debug_info or .debug_types section
/// for this DIE.
uint64_t getDebugSectionOffset() const;
/// Compute the offset of this DIE and all its children.
///
/// This function gets called just before we are going to generate the debug
/// information and gives each DIE a chance to figure out its CU relative DIE
/// offset, unique its abbreviation and fill in the abbreviation code, and
/// return the unit offset that points to where the next DIE will be emitted
/// within the debug unit section. After this function has been called for all
/// DIE objects, the DWARF can be generated since all DIEs will be able to
/// properly refer to other DIE objects since all DIEs have calculated their
/// offsets.
///
/// \param AP AsmPrinter to use when calculating sizes.
/// \param AbbrevSet the abbreviation used to unique DIE abbreviations.
/// \param CUOffset the compile/type unit relative offset in bytes.
/// \returns the offset for the DIE that follows this DIE within the
/// current compile/type unit.
unsigned computeOffsetsAndAbbrevs(const AsmPrinter *AP,
DIEAbbrevSet &AbbrevSet, unsigned CUOffset);
/// Climb up the parent chain to get the compile unit or type unit DIE that
/// this DIE belongs to.
///
/// \returns the compile or type unit DIE that owns this DIE, or NULL if
/// this DIE hasn't been added to a unit DIE.
const DIE *getUnitDie() const;
/// Climb up the parent chain to get the compile unit or type unit that this
/// DIE belongs to.
///
/// \returns the DIEUnit that represents the compile or type unit that owns
/// this DIE, or NULL if this DIE hasn't been added to a unit DIE.
DIEUnit *getUnit() const;
void setOffset(unsigned O) { Offset = O; }
void setSize(unsigned S) { Size = S; }
/// Add a child to the DIE.
DIE &addChild(DIE *Child) {
assert(!Child->getParent() && "Child should be orphaned");
Child->Owner = this;
Children.push_back(*Child);
return Children.back();
}
DIE &addChildFront(DIE *Child) {
assert(!Child->getParent() && "Child should be orphaned");
Child->Owner = this;
Children.push_front(*Child);
return Children.front();
}
/// Find a value in the DIE with the attribute given.
///
/// Returns a default-constructed DIEValue (where \a DIEValue::getType()
/// gives \a DIEValue::isNone) if no such attribute exists.
DIEValue findAttribute(dwarf::Attribute Attribute) const;
void print(raw_ostream &O, unsigned IndentCount = 0) const;
void dump() const;
};
//===--------------------------------------------------------------------===//
/// Represents a compile or type unit.
class DIEUnit {
/// The compile unit or type unit DIE. This variable must be an instance of
/// DIE so that we can calculate the DIEUnit from any DIE by traversing the
/// parent backchain and getting the Unit DIE, and then casting itself to a
/// DIEUnit. This allows us to be able to find the DIEUnit for any DIE without
/// having to store a pointer to the DIEUnit in each DIE instance.
DIE Die;
/// The section this unit will be emitted in. This may or may not be set to
/// a valid section depending on the client that is emitting DWARF.
MCSection *Section;
uint64_t Offset; /// .debug_info or .debug_types absolute section offset.
protected:
virtual ~DIEUnit() = default;
public:
explicit DIEUnit(dwarf::Tag UnitTag);
DIEUnit(const DIEUnit &RHS) = delete;
DIEUnit(DIEUnit &&RHS) = delete;
void operator=(const DIEUnit &RHS) = delete;
void operator=(const DIEUnit &&RHS) = delete;
/// Set the section that this DIEUnit will be emitted into.
///
/// This function is used by some clients to set the section. Not all clients
/// that emit DWARF use this section variable.
void setSection(MCSection *Section) {
assert(!this->Section);
this->Section = Section;
}
virtual const MCSymbol *getCrossSectionRelativeBaseAddress() const {
return nullptr;
}
/// Return the section that this DIEUnit will be emitted into.
///
/// \returns Section pointer which can be NULL.
MCSection *getSection() const { return Section; }
void setDebugSectionOffset(uint64_t O) { Offset = O; }
uint64_t getDebugSectionOffset() const { return Offset; }
DIE &getUnitDie() { return Die; }
const DIE &getUnitDie() const { return Die; }
};
struct BasicDIEUnit final : DIEUnit {
explicit BasicDIEUnit(dwarf::Tag UnitTag) : DIEUnit(UnitTag) {}
};
//===--------------------------------------------------------------------===//
/// DIELoc - Represents an expression location.
//
class DIELoc : public DIEValueList {
mutable unsigned Size = 0; // Size in bytes excluding size header.
public:
DIELoc() = default;
/// ComputeSize - Calculate the size of the location expression.
///
unsigned ComputeSize(const AsmPrinter *AP) const;
// TODO: move setSize() and Size to DIEValueList.
void setSize(unsigned size) { Size = size; }
/// BestForm - Choose the best form for data.
///
dwarf::Form BestForm(unsigned DwarfVersion) const {
if (DwarfVersion > 3)
return dwarf::DW_FORM_exprloc;
// Pre-DWARF4 location expressions were blocks and not exprloc.
if ((unsigned char)Size == Size)
return dwarf::DW_FORM_block1;
if ((unsigned short)Size == Size)
return dwarf::DW_FORM_block2;
if ((unsigned int)Size == Size)
return dwarf::DW_FORM_block4;
return dwarf::DW_FORM_block;
}
void emitValue(const AsmPrinter *Asm, dwarf::Form Form) const;
unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
void print(raw_ostream &O) const;
};
//===--------------------------------------------------------------------===//
/// DIEBlock - Represents a block of values.
//
class DIEBlock : public DIEValueList {
mutable unsigned Size = 0; // Size in bytes excluding size header.
public:
DIEBlock() = default;
/// ComputeSize - Calculate the size of the location expression.
///
unsigned ComputeSize(const AsmPrinter *AP) const;
// TODO: move setSize() and Size to DIEValueList.
void setSize(unsigned size) { Size = size; }
/// BestForm - Choose the best form for data.
///
dwarf::Form BestForm() const {
if ((unsigned char)Size == Size)
return dwarf::DW_FORM_block1;
if ((unsigned short)Size == Size)
return dwarf::DW_FORM_block2;
if ((unsigned int)Size == Size)
return dwarf::DW_FORM_block4;
return dwarf::DW_FORM_block;
}
void emitValue(const AsmPrinter *Asm, dwarf::Form Form) const;
unsigned SizeOf(const AsmPrinter *AP, dwarf::Form Form) const;
void print(raw_ostream &O) const;
};
} // end namespace llvm
#endif // LLVM_LIB_CODEGEN_ASMPRINTER_DIE_H
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