1//===- lib/CodeGen/DIE.h - DWARF Info Entries -------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Data structures for DWARF info entries.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CODEGEN_DIE_H
14#define LLVM_CODEGEN_DIE_H
15
16#include "llvm/ADT/FoldingSet.h"
17#include "llvm/ADT/PointerIntPair.h"
18#include "llvm/ADT/PointerUnion.h"
19#include "llvm/ADT/SmallVector.h"
20#include "llvm/ADT/StringRef.h"
21#include "llvm/ADT/iterator.h"
22#include "llvm/ADT/iterator_range.h"
23#include "llvm/BinaryFormat/Dwarf.h"
24#include "llvm/CodeGen/DwarfStringPoolEntry.h"
25#include "llvm/Support/AlignOf.h"
26#include "llvm/Support/Allocator.h"
27#include <cassert>
28#include <cstddef>
29#include <cstdint>
30#include <iterator>
31#include <new>
32#include <type_traits>
33#include <utility>
34#include <vector>
35
36namespace llvm {
37
38class AsmPrinter;
39class DIE;
40class DIEUnit;
41class DwarfCompileUnit;
42class MCExpr;
43class MCSection;
44class MCSymbol;
45class raw_ostream;
46
47//===--------------------------------------------------------------------===//
48/// Dwarf abbreviation data, describes one attribute of a Dwarf abbreviation.
49class DIEAbbrevData {
50 /// Dwarf attribute code.
51 dwarf::Attribute Attribute;
52
53 /// Dwarf form code.
54 dwarf::Form Form;
55
56 /// Dwarf attribute value for DW_FORM_implicit_const
57 int64_t Value = 0;
58
59public:
60 DIEAbbrevData(dwarf::Attribute A, dwarf::Form F)
61 : Attribute(A), Form(F) {}
62 DIEAbbrevData(dwarf::Attribute A, int64_t V)
63 : Attribute(A), Form(dwarf::DW_FORM_implicit_const), Value(V) {}
64
65 /// Accessors.
66 /// @{
67 dwarf::Attribute getAttribute() const { return Attribute; }
68 dwarf::Form getForm() const { return Form; }
69 int64_t getValue() const { return Value; }
70 /// @}
71
72 /// Used to gather unique data for the abbreviation folding set.
73 void Profile(FoldingSetNodeID &ID) const;
74};
75
76//===--------------------------------------------------------------------===//
77/// Dwarf abbreviation, describes the organization of a debug information
78/// object.
79class DIEAbbrev : public FoldingSetNode {
80 /// Unique number for node.
81 unsigned Number = 0;
82
83 /// Dwarf tag code.
84 dwarf::Tag Tag;
85
86 /// Whether or not this node has children.
87 ///
88 /// This cheats a bit in all of the uses since the values in the standard
89 /// are 0 and 1 for no children and children respectively.
90 bool Children;
91
92 /// Raw data bytes for abbreviation.
93 SmallVector<DIEAbbrevData, 12> Data;
94
95public:
96 DIEAbbrev(dwarf::Tag T, bool C) : Tag(T), Children(C) {}
97
98 /// Accessors.
99 /// @{
100 dwarf::Tag getTag() const { return Tag; }
101 unsigned getNumber() const { return Number; }
102 bool hasChildren() const { return Children; }
103 const SmallVectorImpl<DIEAbbrevData> &getData() const { return Data; }
104 void setChildrenFlag(bool hasChild) { Children = hasChild; }
105 void setNumber(unsigned N) { Number = N; }
106 /// @}
107
108 /// Adds another set of attribute information to the abbreviation.
109 void AddAttribute(dwarf::Attribute Attribute, dwarf::Form Form) {
110 Data.push_back(Elt: DIEAbbrevData(Attribute, Form));
111 }
112
113 /// Adds attribute with DW_FORM_implicit_const value
114 void AddImplicitConstAttribute(dwarf::Attribute Attribute, int64_t Value) {
115 Data.push_back(Elt: DIEAbbrevData(Attribute, Value));
116 }
117
118 /// Adds another set of attribute information to the abbreviation.
119 void AddAttribute(const DIEAbbrevData &AbbrevData) {
120 Data.push_back(Elt: AbbrevData);
121 }
122
123 /// Used to gather unique data for the abbreviation folding set.
124 void Profile(FoldingSetNodeID &ID) const;
125
126 /// Print the abbreviation using the specified asm printer.
127 void Emit(const AsmPrinter *AP) const;
128
129 void print(raw_ostream &O) const;
130 void dump() const;
131};
132
133//===--------------------------------------------------------------------===//
134/// Helps unique DIEAbbrev objects and assigns abbreviation numbers.
135///
136/// This class will unique the DIE abbreviations for a llvm::DIE object and
137/// assign a unique abbreviation number to each unique DIEAbbrev object it
138/// finds. The resulting collection of DIEAbbrev objects can then be emitted
139/// into the .debug_abbrev section.
140class DIEAbbrevSet {
141 /// The bump allocator to use when creating DIEAbbrev objects in the uniqued
142 /// storage container.
143 BumpPtrAllocator &Alloc;
144 /// FoldingSet that uniques the abbreviations.
145 FoldingSet<DIEAbbrev> AbbreviationsSet;
146 /// A list of all the unique abbreviations in use.
147 std::vector<DIEAbbrev *> Abbreviations;
148
149public:
150 DIEAbbrevSet(BumpPtrAllocator &A) : Alloc(A) {}
151 ~DIEAbbrevSet();
152
153 /// Generate the abbreviation declaration for a DIE and return a pointer to
154 /// the generated abbreviation.
155 ///
156 /// \param Die the debug info entry to generate the abbreviation for.
157 /// \returns A reference to the uniqued abbreviation declaration that is
158 /// owned by this class.
159 DIEAbbrev &uniqueAbbreviation(DIE &Die);
160
161 /// Print all abbreviations using the specified asm printer.
162 void Emit(const AsmPrinter *AP, MCSection *Section) const;
163};
164
165//===--------------------------------------------------------------------===//
166/// An integer value DIE.
167///
168class DIEInteger {
169 uint64_t Integer;
170
171public:
172 explicit DIEInteger(uint64_t I) : Integer(I) {}
173
174 /// Choose the best form for integer.
175 static dwarf::Form BestForm(bool IsSigned, uint64_t Int) {
176 if (IsSigned) {
177 const int64_t SignedInt = Int;
178 if ((char)Int == SignedInt)
179 return dwarf::DW_FORM_data1;
180 if ((short)Int == SignedInt)
181 return dwarf::DW_FORM_data2;
182 if ((int)Int == SignedInt)
183 return dwarf::DW_FORM_data4;
184 } else {
185 if ((unsigned char)Int == Int)
186 return dwarf::DW_FORM_data1;
187 if ((unsigned short)Int == Int)
188 return dwarf::DW_FORM_data2;
189 if ((unsigned int)Int == Int)
190 return dwarf::DW_FORM_data4;
191 }
192 return dwarf::DW_FORM_data8;
193 }
194
195 uint64_t getValue() const { return Integer; }
196 void setValue(uint64_t Val) { Integer = Val; }
197
198 void emitValue(const AsmPrinter *Asm, dwarf::Form Form) const;
199 unsigned sizeOf(const dwarf::FormParams &FormParams, dwarf::Form Form) const;
200
201 void print(raw_ostream &O) const;
202};
203
204//===--------------------------------------------------------------------===//
205/// An expression DIE.
206class DIEExpr {
207 const MCExpr *Expr;
208
209public:
210 explicit DIEExpr(const MCExpr *E) : Expr(E) {}
211
212 /// Get MCExpr.
213 const MCExpr *getValue() const { return Expr; }
214
215 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
216 unsigned sizeOf(const dwarf::FormParams &FormParams, dwarf::Form Form) const;
217
218 void print(raw_ostream &O) const;
219};
220
221//===--------------------------------------------------------------------===//
222/// A label DIE.
223class DIELabel {
224 const MCSymbol *Label;
225
226public:
227 explicit DIELabel(const MCSymbol *L) : Label(L) {}
228
229 /// Get MCSymbol.
230 const MCSymbol *getValue() const { return Label; }
231
232 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
233 unsigned sizeOf(const dwarf::FormParams &FormParams, dwarf::Form Form) const;
234
235 void print(raw_ostream &O) const;
236};
237
238//===--------------------------------------------------------------------===//
239/// A BaseTypeRef DIE.
240class DIEBaseTypeRef {
241 const DwarfCompileUnit *CU;
242 const uint64_t Index;
243 static constexpr unsigned ULEB128PadSize = 4;
244
245public:
246 explicit DIEBaseTypeRef(const DwarfCompileUnit *TheCU, uint64_t Idx)
247 : CU(TheCU), Index(Idx) {}
248
249 /// EmitValue - Emit base type reference.
250 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
251 /// sizeOf - Determine size of the base type reference in bytes.
252 unsigned sizeOf(const dwarf::FormParams &, dwarf::Form) const;
253
254 void print(raw_ostream &O) const;
255 uint64_t getIndex() const { return Index; }
256};
257
258//===--------------------------------------------------------------------===//
259/// A simple label difference DIE.
260///
261class DIEDelta {
262 const MCSymbol *LabelHi;
263 const MCSymbol *LabelLo;
264
265public:
266 DIEDelta(const MCSymbol *Hi, const MCSymbol *Lo) : LabelHi(Hi), LabelLo(Lo) {}
267
268 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
269 unsigned sizeOf(const dwarf::FormParams &FormParams, dwarf::Form Form) const;
270
271 void print(raw_ostream &O) const;
272};
273
274//===--------------------------------------------------------------------===//
275/// A container for string pool string values.
276///
277/// This class is used with the DW_FORM_strp and DW_FORM_GNU_str_index forms.
278class DIEString {
279 DwarfStringPoolEntryRef S;
280
281public:
282 DIEString(DwarfStringPoolEntryRef S) : S(S) {}
283
284 /// Grab the string out of the object.
285 StringRef getString() const { return S.getString(); }
286
287 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
288 unsigned sizeOf(const dwarf::FormParams &FormParams, dwarf::Form Form) const;
289
290 void print(raw_ostream &O) const;
291};
292
293//===--------------------------------------------------------------------===//
294/// A container for inline string values.
295///
296/// This class is used with the DW_FORM_string form.
297class DIEInlineString {
298 StringRef S;
299
300public:
301 template <typename Allocator>
302 explicit DIEInlineString(StringRef Str, Allocator &A) : S(Str.copy(A)) {}
303
304 ~DIEInlineString() = default;
305
306 /// Grab the string out of the object.
307 StringRef getString() const { return S; }
308
309 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
310 unsigned sizeOf(const dwarf::FormParams &, dwarf::Form) const;
311
312 void print(raw_ostream &O) const;
313};
314
315//===--------------------------------------------------------------------===//
316/// A pointer to another debug information entry. An instance of this class can
317/// also be used as a proxy for a debug information entry not yet defined
318/// (ie. types.)
319class DIEEntry {
320 DIE *Entry;
321
322public:
323 DIEEntry() = delete;
324 explicit DIEEntry(DIE &E) : Entry(&E) {}
325
326 DIE &getEntry() const { return *Entry; }
327
328 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
329 unsigned sizeOf(const dwarf::FormParams &FormParams, dwarf::Form Form) const;
330
331 void print(raw_ostream &O) const;
332};
333
334//===--------------------------------------------------------------------===//
335/// Represents a pointer to a location list in the debug_loc
336/// section.
337class DIELocList {
338 /// Index into the .debug_loc vector.
339 size_t Index;
340
341public:
342 DIELocList(size_t I) : Index(I) {}
343
344 /// Grab the current index out.
345 size_t getValue() const { return Index; }
346
347 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
348 unsigned sizeOf(const dwarf::FormParams &FormParams, dwarf::Form Form) const;
349
350 void print(raw_ostream &O) const;
351};
352
353//===--------------------------------------------------------------------===//
354/// A BaseTypeRef DIE.
355class DIEAddrOffset {
356 DIEInteger Addr;
357 DIEDelta Offset;
358
359public:
360 explicit DIEAddrOffset(uint64_t Idx, const MCSymbol *Hi, const MCSymbol *Lo)
361 : Addr(Idx), Offset(Hi, Lo) {}
362
363 void emitValue(const AsmPrinter *AP, dwarf::Form Form) const;
364 unsigned sizeOf(const dwarf::FormParams &FormParams, dwarf::Form Form) const;
365
366 void print(raw_ostream &O) const;
367};
368
369//===--------------------------------------------------------------------===//
370/// A debug information entry value. Some of these roughly correlate
371/// to DWARF attribute classes.
372class DIEBlock;
373class DIELoc;
374class DIEValue {
375public:
376 enum Type {
377 isNone,
378#define HANDLE_DIEVALUE(T) is##T,
379#include "llvm/CodeGen/DIEValue.def"
380 };
381
382private:
383 /// Type of data stored in the value.
384 Type Ty = isNone;
385 dwarf::Attribute Attribute = (dwarf::Attribute)0;
386 dwarf::Form Form = (dwarf::Form)0;
387
388 /// Storage for the value.
389 ///
390 /// All values that aren't standard layout (or are larger than 8 bytes)
391 /// should be stored by reference instead of by value.
392 using ValTy =
393 AlignedCharArrayUnion<DIEInteger, DIEString, DIEExpr, DIELabel,
394 DIEDelta *, DIEEntry, DIEBlock *, DIELoc *,
395 DIELocList, DIEBaseTypeRef *, DIEAddrOffset *>;
396
397 static_assert(sizeof(ValTy) <= sizeof(uint64_t) ||
398 sizeof(ValTy) <= sizeof(void *),
399 "Expected all large types to be stored via pointer");
400
401 /// Underlying stored value.
402 ValTy Val;
403
404 template <class T> void construct(T V) {
405 static_assert(std::is_standard_layout<T>::value ||
406 std::is_pointer<T>::value,
407 "Expected standard layout or pointer");
408 new (reinterpret_cast<void *>(&Val)) T(V);
409 }
410
411 template <class T> T *get() { return reinterpret_cast<T *>(&Val); }
412 template <class T> const T *get() const {
413 return reinterpret_cast<const T *>(&Val);
414 }
415 template <class T> void destruct() { get<T>()->~T(); }
416
417 /// Destroy the underlying value.
418 ///
419 /// This should get optimized down to a no-op. We could skip it if we could
420 /// add a static assert on \a std::is_trivially_copyable(), but we currently
421 /// support versions of GCC that don't understand that.
422 void destroyVal() {
423 switch (Ty) {
424 case isNone:
425 return;
426#define HANDLE_DIEVALUE_SMALL(T) \
427 case is##T: \
428 destruct<DIE##T>(); \
429 return;
430#define HANDLE_DIEVALUE_LARGE(T) \
431 case is##T: \
432 destruct<const DIE##T *>(); \
433 return;
434#include "llvm/CodeGen/DIEValue.def"
435 }
436 }
437
438 /// Copy the underlying value.
439 ///
440 /// This should get optimized down to a simple copy. We need to actually
441 /// construct the value, rather than calling memcpy, to satisfy strict
442 /// aliasing rules.
443 void copyVal(const DIEValue &X) {
444 switch (Ty) {
445 case isNone:
446 return;
447#define HANDLE_DIEVALUE_SMALL(T) \
448 case is##T: \
449 construct<DIE##T>(*X.get<DIE##T>()); \
450 return;
451#define HANDLE_DIEVALUE_LARGE(T) \
452 case is##T: \
453 construct<const DIE##T *>(*X.get<const DIE##T *>()); \
454 return;
455#include "llvm/CodeGen/DIEValue.def"
456 }
457 }
458
459public:
460 DIEValue() = default;
461
462 DIEValue(const DIEValue &X) : Ty(X.Ty), Attribute(X.Attribute), Form(X.Form) {
463 copyVal(X);
464 }
465
466 DIEValue &operator=(const DIEValue &X) {
467 if (this == &X)
468 return *this;
469 destroyVal();
470 Ty = X.Ty;
471 Attribute = X.Attribute;
472 Form = X.Form;
473 copyVal(X);
474 return *this;
475 }
476
477 ~DIEValue() { destroyVal(); }
478
479#define HANDLE_DIEVALUE_SMALL(T) \
480 DIEValue(dwarf::Attribute Attribute, dwarf::Form Form, const DIE##T &V) \
481 : Ty(is##T), Attribute(Attribute), Form(Form) { \
482 construct<DIE##T>(V); \
483 }
484#define HANDLE_DIEVALUE_LARGE(T) \
485 DIEValue(dwarf::Attribute Attribute, dwarf::Form Form, const DIE##T *V) \
486 : Ty(is##T), Attribute(Attribute), Form(Form) { \
487 assert(V && "Expected valid value"); \
488 construct<const DIE##T *>(V); \
489 }
490#include "llvm/CodeGen/DIEValue.def"
491
492 /// Accessors.
493 /// @{
494 Type getType() const { return Ty; }
495 dwarf::Attribute getAttribute() const { return Attribute; }
496 dwarf::Form getForm() const { return Form; }
497 explicit operator bool() const { return Ty; }
498 /// @}
499
500#define HANDLE_DIEVALUE_SMALL(T) \
501 const DIE##T &getDIE##T() const { \
502 assert(getType() == is##T && "Expected " #T); \
503 return *get<DIE##T>(); \
504 }
505#define HANDLE_DIEVALUE_LARGE(T) \
506 const DIE##T &getDIE##T() const { \
507 assert(getType() == is##T && "Expected " #T); \
508 return **get<const DIE##T *>(); \
509 }
510#include "llvm/CodeGen/DIEValue.def"
511
512 /// Emit value via the Dwarf writer.
513 void emitValue(const AsmPrinter *AP) const;
514
515 /// Return the size of a value in bytes.
516 unsigned sizeOf(const dwarf::FormParams &FormParams) const;
517
518 void print(raw_ostream &O) const;
519 void dump() const;
520};
521
522struct IntrusiveBackListNode {
523 PointerIntPair<IntrusiveBackListNode *, 1> Next;
524
525 IntrusiveBackListNode() : Next(this, true) {}
526
527 IntrusiveBackListNode *getNext() const {
528 return Next.getInt() ? nullptr : Next.getPointer();
529 }
530};
531
532struct IntrusiveBackListBase {
533 using Node = IntrusiveBackListNode;
534
535 Node *Last = nullptr;
536
537 bool empty() const { return !Last; }
538
539 void push_back(Node &N) {
540 assert(N.Next.getPointer() == &N && "Expected unlinked node");
541 assert(N.Next.getInt() == true && "Expected unlinked node");
542
543 if (Last) {
544 N.Next = Last->Next;
545 Last->Next.setPointerAndInt(PtrVal: &N, IntVal: false);
546 }
547 Last = &N;
548 }
549
550 void push_front(Node &N) {
551 assert(N.Next.getPointer() == &N && "Expected unlinked node");
552 assert(N.Next.getInt() == true && "Expected unlinked node");
553
554 if (Last) {
555 N.Next.setPointerAndInt(PtrVal: Last->Next.getPointer(), IntVal: false);
556 Last->Next.setPointerAndInt(PtrVal: &N, IntVal: true);
557 } else {
558 Last = &N;
559 }
560 }
561};
562
563template <class T> class IntrusiveBackList : IntrusiveBackListBase {
564public:
565 using IntrusiveBackListBase::empty;
566
567 void push_back(T &N) { IntrusiveBackListBase::push_back(N); }
568 void push_front(T &N) { IntrusiveBackListBase::push_front(N); }
569
570 T &back() { return *static_cast<T *>(Last); }
571 const T &back() const { return *static_cast<T *>(Last); }
572 T &front() {
573 return *static_cast<T *>(Last ? Last->Next.getPointer() : nullptr);
574 }
575 const T &front() const {
576 return *static_cast<T *>(Last ? Last->Next.getPointer() : nullptr);
577 }
578
579 void takeNodes(IntrusiveBackList<T> &Other) {
580 if (Other.empty())
581 return;
582
583 T *FirstNode = static_cast<T *>(Other.Last->Next.getPointer());
584 T *IterNode = FirstNode;
585 do {
586 // Keep a pointer to the node and increment the iterator.
587 T *TmpNode = IterNode;
588 IterNode = static_cast<T *>(IterNode->Next.getPointer());
589
590 // Unlink the node and push it back to this list.
591 TmpNode->Next.setPointerAndInt(TmpNode, true);
592 push_back(N&: *TmpNode);
593 } while (IterNode != FirstNode);
594
595 Other.Last = nullptr;
596 }
597
598 bool deleteNode(T &N) {
599 if (Last == &N) {
600 Last = Last->Next.getPointer();
601 Last->Next.setInt(true);
602 return true;
603 }
604
605 Node *cur = Last;
606 while (cur && cur->Next.getPointer()) {
607 if (cur->Next.getPointer() == &N) {
608 cur->Next.setPointer(cur->Next.getPointer()->Next.getPointer());
609 return true;
610 }
611 cur = cur->Next.getPointer();
612 }
613
614 return false;
615 }
616
617 class const_iterator;
618 class iterator
619 : public iterator_facade_base<iterator, std::forward_iterator_tag, T> {
620 friend class const_iterator;
621
622 Node *N = nullptr;
623
624 public:
625 iterator() = default;
626 explicit iterator(T *N) : N(N) {}
627
628 iterator &operator++() {
629 N = N->getNext();
630 return *this;
631 }
632
633 explicit operator bool() const { return N; }
634 T &operator*() const { return *static_cast<T *>(N); }
635
636 bool operator==(const iterator &X) const { return N == X.N; }
637 };
638
639 class const_iterator
640 : public iterator_facade_base<const_iterator, std::forward_iterator_tag,
641 const T> {
642 const Node *N = nullptr;
643
644 public:
645 const_iterator() = default;
646 // Placate MSVC by explicitly scoping 'iterator'.
647 const_iterator(typename IntrusiveBackList<T>::iterator X) : N(X.N) {}
648 explicit const_iterator(const T *N) : N(N) {}
649
650 const_iterator &operator++() {
651 N = N->getNext();
652 return *this;
653 }
654
655 explicit operator bool() const { return N; }
656 const T &operator*() const { return *static_cast<const T *>(N); }
657
658 bool operator==(const const_iterator &X) const { return N == X.N; }
659 };
660
661 iterator begin() {
662 return Last ? iterator(static_cast<T *>(Last->Next.getPointer())) : end();
663 }
664 const_iterator begin() const {
665 return const_cast<IntrusiveBackList *>(this)->begin();
666 }
667 iterator end() { return iterator(); }
668 const_iterator end() const { return const_iterator(); }
669
670 static iterator toIterator(T &N) { return iterator(&N); }
671 static const_iterator toIterator(const T &N) { return const_iterator(&N); }
672};
673
674/// A list of DIE values.
675///
676/// This is a singly-linked list, but instead of reversing the order of
677/// insertion, we keep a pointer to the back of the list so we can push in
678/// order.
679///
680/// There are two main reasons to choose a linked list over a customized
681/// vector-like data structure.
682///
683/// 1. For teardown efficiency, we want DIEs to be BumpPtrAllocated. Using a
684/// linked list here makes this way easier to accomplish.
685/// 2. Carrying an extra pointer per \a DIEValue isn't expensive. 45% of DIEs
686/// have 2 or fewer values, and 90% have 5 or fewer. A vector would be
687/// over-allocated by 50% on average anyway, the same cost as the
688/// linked-list node.
689class DIEValueList {
690 struct Node : IntrusiveBackListNode {
691 DIEValue V;
692
693 explicit Node(DIEValue V) : V(V) {}
694 };
695
696 using ListTy = IntrusiveBackList<Node>;
697
698 ListTy List;
699
700public:
701 class const_value_iterator;
702 class value_iterator
703 : public iterator_adaptor_base<value_iterator, ListTy::iterator,
704 std::forward_iterator_tag, DIEValue> {
705 friend class const_value_iterator;
706
707 using iterator_adaptor =
708 iterator_adaptor_base<value_iterator, ListTy::iterator,
709 std::forward_iterator_tag, DIEValue>;
710
711 public:
712 value_iterator() = default;
713 explicit value_iterator(ListTy::iterator X) : iterator_adaptor(X) {}
714
715 explicit operator bool() const { return bool(wrapped()); }
716 DIEValue &operator*() const { return wrapped()->V; }
717 };
718
719 class const_value_iterator : public iterator_adaptor_base<
720 const_value_iterator, ListTy::const_iterator,
721 std::forward_iterator_tag, const DIEValue> {
722 using iterator_adaptor =
723 iterator_adaptor_base<const_value_iterator, ListTy::const_iterator,
724 std::forward_iterator_tag, const DIEValue>;
725
726 public:
727 const_value_iterator() = default;
728 const_value_iterator(DIEValueList::value_iterator X)
729 : iterator_adaptor(X.wrapped()) {}
730 explicit const_value_iterator(ListTy::const_iterator X)
731 : iterator_adaptor(X) {}
732
733 explicit operator bool() const { return bool(wrapped()); }
734 const DIEValue &operator*() const { return wrapped()->V; }
735 };
736
737 using value_range = iterator_range<value_iterator>;
738 using const_value_range = iterator_range<const_value_iterator>;
739
740 value_iterator addValue(BumpPtrAllocator &Alloc, const DIEValue &V) {
741 List.push_back(N&: *new (Alloc) Node(V));
742 return value_iterator(ListTy::toIterator(N&: List.back()));
743 }
744 template <class T>
745 value_iterator addValue(BumpPtrAllocator &Alloc, dwarf::Attribute Attribute,
746 dwarf::Form Form, T &&Value) {
747 return addValue(Alloc, V: DIEValue(Attribute, Form, std::forward<T>(Value)));
748 }
749
750 /* zr33: add method here */
751 template <class T>
752 bool replaceValue(BumpPtrAllocator &Alloc, dwarf::Attribute Attribute,
753 dwarf::Attribute NewAttribute, dwarf::Form Form,
754 T &&NewValue) {
755 for (llvm::DIEValue &val : values()) {
756 if (val.getAttribute() == Attribute) {
757 val = *new (Alloc)
758 DIEValue(NewAttribute, Form, std::forward<T>(NewValue));
759 return true;
760 }
761 }
762
763 return false;
764 }
765
766 template <class T>
767 bool replaceValue(BumpPtrAllocator &Alloc, dwarf::Attribute Attribute,
768 dwarf::Form Form, T &&NewValue) {
769 for (llvm::DIEValue &val : values()) {
770 if (val.getAttribute() == Attribute) {
771 val = *new (Alloc) DIEValue(Attribute, Form, std::forward<T>(NewValue));
772 return true;
773 }
774 }
775
776 return false;
777 }
778
779 bool replaceValue(BumpPtrAllocator &Alloc, dwarf::Attribute Attribute,
780 dwarf::Form Form, DIEValue &NewValue) {
781 for (llvm::DIEValue &val : values()) {
782 if (val.getAttribute() == Attribute) {
783 val = NewValue;
784 return true;
785 }
786 }
787
788 return false;
789 }
790
791 bool deleteValue(dwarf::Attribute Attribute) {
792
793 for (auto &node : List) {
794 if (node.V.getAttribute() == Attribute) {
795 return List.deleteNode(N&: node);
796 }
797 }
798
799 return false;
800 }
801 /* end */
802
803 /// Take ownership of the nodes in \p Other, and append them to the back of
804 /// the list.
805 void takeValues(DIEValueList &Other) { List.takeNodes(Other&: Other.List); }
806
807 value_range values() {
808 return make_range(x: value_iterator(List.begin()), y: value_iterator(List.end()));
809 }
810 const_value_range values() const {
811 return make_range(x: const_value_iterator(List.begin()),
812 y: const_value_iterator(List.end()));
813 }
814};
815
816//===--------------------------------------------------------------------===//
817/// A structured debug information entry. Has an abbreviation which
818/// describes its organization.
819class DIE : IntrusiveBackListNode, public DIEValueList {
820 friend class IntrusiveBackList<DIE>;
821 friend class DIEUnit;
822
823 /// Dwarf unit relative offset.
824 unsigned Offset = 0;
825 /// Size of instance + children.
826 unsigned Size = 0;
827 unsigned AbbrevNumber = ~0u;
828 /// Dwarf tag code.
829 dwarf::Tag Tag = (dwarf::Tag)0;
830 /// Set to true to force a DIE to emit an abbreviation that says it has
831 /// children even when it doesn't. This is used for unit testing purposes.
832 bool ForceChildren = false;
833 /// Children DIEs.
834 IntrusiveBackList<DIE> Children;
835
836 /// The owner is either the parent DIE for children of other DIEs, or a
837 /// DIEUnit which contains this DIE as its unit DIE.
838 PointerUnion<DIE *, DIEUnit *> Owner;
839
840 explicit DIE(dwarf::Tag Tag) : Tag(Tag) {}
841
842public:
843 DIE() = delete;
844 DIE(const DIE &RHS) = delete;
845 DIE(DIE &&RHS) = delete;
846 DIE &operator=(const DIE &RHS) = delete;
847 DIE &operator=(const DIE &&RHS) = delete;
848
849 static DIE *get(BumpPtrAllocator &Alloc, dwarf::Tag Tag) {
850 return new (Alloc) DIE(Tag);
851 }
852
853 // Accessors.
854 unsigned getAbbrevNumber() const { return AbbrevNumber; }
855 dwarf::Tag getTag() const { return Tag; }
856 /// Get the compile/type unit relative offset of this DIE.
857 unsigned getOffset() const {
858 // A real Offset can't be zero because the unit headers are at offset zero.
859 assert(Offset && "Offset being queried before it's been computed.");
860 return Offset;
861 }
862 unsigned getSize() const {
863 // A real Size can't be zero because it includes the non-empty abbrev code.
864 assert(Size && "Size being queried before it's been ocmputed.");
865 return Size;
866 }
867 bool hasChildren() const { return ForceChildren || !Children.empty(); }
868 void setForceChildren(bool B) { ForceChildren = B; }
869
870 using child_iterator = IntrusiveBackList<DIE>::iterator;
871 using const_child_iterator = IntrusiveBackList<DIE>::const_iterator;
872 using child_range = iterator_range<child_iterator>;
873 using const_child_range = iterator_range<const_child_iterator>;
874
875 child_range children() {
876 return make_range(x: Children.begin(), y: Children.end());
877 }
878 const_child_range children() const {
879 return make_range(x: Children.begin(), y: Children.end());
880 }
881
882 DIE *getParent() const;
883
884 /// Generate the abbreviation for this DIE.
885 ///
886 /// Calculate the abbreviation for this, which should be uniqued and
887 /// eventually used to call \a setAbbrevNumber().
888 DIEAbbrev generateAbbrev() const;
889
890 /// Set the abbreviation number for this DIE.
891 void setAbbrevNumber(unsigned I) { AbbrevNumber = I; }
892
893 /// Get the absolute offset within the .debug_info or .debug_types section
894 /// for this DIE.
895 uint64_t getDebugSectionOffset() const;
896
897 /// Compute the offset of this DIE and all its children.
898 ///
899 /// This function gets called just before we are going to generate the debug
900 /// information and gives each DIE a chance to figure out its CU relative DIE
901 /// offset, unique its abbreviation and fill in the abbreviation code, and
902 /// return the unit offset that points to where the next DIE will be emitted
903 /// within the debug unit section. After this function has been called for all
904 /// DIE objects, the DWARF can be generated since all DIEs will be able to
905 /// properly refer to other DIE objects since all DIEs have calculated their
906 /// offsets.
907 ///
908 /// \param FormParams Used when calculating sizes.
909 /// \param AbbrevSet the abbreviation used to unique DIE abbreviations.
910 /// \param CUOffset the compile/type unit relative offset in bytes.
911 /// \returns the offset for the DIE that follows this DIE within the
912 /// current compile/type unit.
913 unsigned computeOffsetsAndAbbrevs(const dwarf::FormParams &FormParams,
914 DIEAbbrevSet &AbbrevSet, unsigned CUOffset);
915
916 /// Climb up the parent chain to get the compile unit or type unit DIE that
917 /// this DIE belongs to.
918 ///
919 /// \returns the compile or type unit DIE that owns this DIE, or NULL if
920 /// this DIE hasn't been added to a unit DIE.
921 const DIE *getUnitDie() const;
922
923 /// Climb up the parent chain to get the compile unit or type unit that this
924 /// DIE belongs to.
925 ///
926 /// \returns the DIEUnit that represents the compile or type unit that owns
927 /// this DIE, or NULL if this DIE hasn't been added to a unit DIE.
928 DIEUnit *getUnit() const;
929
930 void setOffset(unsigned O) { Offset = O; }
931 void setSize(unsigned S) { Size = S; }
932
933 /// Add a child to the DIE.
934 DIE &addChild(DIE *Child) {
935 assert(!Child->getParent() && "Child should be orphaned");
936 Child->Owner = this;
937 Children.push_back(N&: *Child);
938 return Children.back();
939 }
940
941 DIE &addChildFront(DIE *Child) {
942 assert(!Child->getParent() && "Child should be orphaned");
943 Child->Owner = this;
944 Children.push_front(N&: *Child);
945 return Children.front();
946 }
947
948 /// Find a value in the DIE with the attribute given.
949 ///
950 /// Returns a default-constructed DIEValue (where \a DIEValue::getType()
951 /// gives \a DIEValue::isNone) if no such attribute exists.
952 DIEValue findAttribute(dwarf::Attribute Attribute) const;
953
954 void print(raw_ostream &O, unsigned IndentCount = 0) const;
955 void dump() const;
956};
957
958//===--------------------------------------------------------------------===//
959/// Represents a compile or type unit.
960class DIEUnit {
961 /// The compile unit or type unit DIE. This variable must be an instance of
962 /// DIE so that we can calculate the DIEUnit from any DIE by traversing the
963 /// parent backchain and getting the Unit DIE, and then casting itself to a
964 /// DIEUnit. This allows us to be able to find the DIEUnit for any DIE without
965 /// having to store a pointer to the DIEUnit in each DIE instance.
966 DIE Die;
967 /// The section this unit will be emitted in. This may or may not be set to
968 /// a valid section depending on the client that is emitting DWARF.
969 MCSection *Section = nullptr;
970 uint64_t Offset = 0; /// .debug_info or .debug_types absolute section offset.
971protected:
972 virtual ~DIEUnit() = default;
973
974public:
975 explicit DIEUnit(dwarf::Tag UnitTag);
976 DIEUnit(const DIEUnit &RHS) = delete;
977 DIEUnit(DIEUnit &&RHS) = delete;
978 void operator=(const DIEUnit &RHS) = delete;
979 void operator=(const DIEUnit &&RHS) = delete;
980 /// Set the section that this DIEUnit will be emitted into.
981 ///
982 /// This function is used by some clients to set the section. Not all clients
983 /// that emit DWARF use this section variable.
984 void setSection(MCSection *Section) {
985 assert(!this->Section);
986 this->Section = Section;
987 }
988
989 virtual const MCSymbol *getCrossSectionRelativeBaseAddress() const {
990 return nullptr;
991 }
992
993 /// Return the section that this DIEUnit will be emitted into.
994 ///
995 /// \returns Section pointer which can be NULL.
996 MCSection *getSection() const { return Section; }
997 void setDebugSectionOffset(uint64_t O) { Offset = O; }
998 uint64_t getDebugSectionOffset() const { return Offset; }
999 DIE &getUnitDie() { return Die; }
1000 const DIE &getUnitDie() const { return Die; }
1001};
1002
1003struct BasicDIEUnit final : DIEUnit {
1004 explicit BasicDIEUnit(dwarf::Tag UnitTag) : DIEUnit(UnitTag) {}
1005};
1006
1007//===--------------------------------------------------------------------===//
1008/// DIELoc - Represents an expression location.
1009//
1010class DIELoc : public DIEValueList {
1011 mutable unsigned Size = 0; // Size in bytes excluding size header.
1012
1013public:
1014 DIELoc() = default;
1015
1016 /// Calculate the size of the location expression.
1017 unsigned computeSize(const dwarf::FormParams &FormParams) const;
1018
1019 // TODO: move setSize() and Size to DIEValueList.
1020 void setSize(unsigned size) { Size = size; }
1021
1022 /// BestForm - Choose the best form for data.
1023 ///
1024 dwarf::Form BestForm(unsigned DwarfVersion) const {
1025 if (DwarfVersion > 3)
1026 return dwarf::DW_FORM_exprloc;
1027 // Pre-DWARF4 location expressions were blocks and not exprloc.
1028 if ((unsigned char)Size == Size)
1029 return dwarf::DW_FORM_block1;
1030 if ((unsigned short)Size == Size)
1031 return dwarf::DW_FORM_block2;
1032 if ((unsigned int)Size == Size)
1033 return dwarf::DW_FORM_block4;
1034 return dwarf::DW_FORM_block;
1035 }
1036
1037 void emitValue(const AsmPrinter *Asm, dwarf::Form Form) const;
1038 unsigned sizeOf(const dwarf::FormParams &, dwarf::Form Form) const;
1039
1040 void print(raw_ostream &O) const;
1041};
1042
1043//===--------------------------------------------------------------------===//
1044/// DIEBlock - Represents a block of values.
1045//
1046class DIEBlock : public DIEValueList {
1047 mutable unsigned Size = 0; // Size in bytes excluding size header.
1048
1049public:
1050 DIEBlock() = default;
1051
1052 /// Calculate the size of the location expression.
1053 unsigned computeSize(const dwarf::FormParams &FormParams) const;
1054
1055 // TODO: move setSize() and Size to DIEValueList.
1056 void setSize(unsigned size) { Size = size; }
1057
1058 /// BestForm - Choose the best form for data.
1059 ///
1060 dwarf::Form BestForm() const {
1061 if ((unsigned char)Size == Size)
1062 return dwarf::DW_FORM_block1;
1063 if ((unsigned short)Size == Size)
1064 return dwarf::DW_FORM_block2;
1065 if ((unsigned int)Size == Size)
1066 return dwarf::DW_FORM_block4;
1067 return dwarf::DW_FORM_block;
1068 }
1069
1070 void emitValue(const AsmPrinter *Asm, dwarf::Form Form) const;
1071 unsigned sizeOf(const dwarf::FormParams &, dwarf::Form Form) const;
1072
1073 void print(raw_ostream &O) const;
1074};
1075
1076} // end namespace llvm
1077
1078#endif // LLVM_CODEGEN_DIE_H
1079

source code of llvm/include/llvm/CodeGen/DIE.h