1//===- llvm/CodeGen/DwarfCompileUnit.h - Dwarf Compile Unit -----*- 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// This file contains support for writing dwarf compile unit.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H
14#define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H
15
16#include "DwarfDebug.h"
17#include "DwarfUnit.h"
18#include "llvm/ADT/ArrayRef.h"
19#include "llvm/ADT/DenseMap.h"
20#include "llvm/ADT/SmallVector.h"
21#include "llvm/ADT/StringMap.h"
22#include "llvm/ADT/StringRef.h"
23#include "llvm/BinaryFormat/Dwarf.h"
24#include "llvm/CodeGen/DbgEntityHistoryCalculator.h"
25#include "llvm/CodeGen/LexicalScopes.h"
26#include "llvm/IR/DebugInfoMetadata.h"
27#include "llvm/Support/Casting.h"
28#include <cstdint>
29#include <memory>
30
31namespace llvm {
32
33class AsmPrinter;
34class DIE;
35class DIELoc;
36class DIEValueList;
37class DwarfFile;
38class GlobalVariable;
39class MCExpr;
40class MCSymbol;
41class MDNode;
42
43enum class UnitKind { Skeleton, Full };
44
45class DwarfCompileUnit final : public DwarfUnit {
46 bool HasRangeLists = false;
47
48 /// The start of the unit line section, this is also
49 /// reused in appyStmtList.
50 MCSymbol *LineTableStartSym;
51
52 /// Skeleton unit associated with this unit.
53 DwarfCompileUnit *Skeleton = nullptr;
54
55 /// The start of the unit macro info within macro section.
56 MCSymbol *MacroLabelBegin;
57
58 /// GlobalNames - A map of globally visible named entities for this unit.
59 StringMap<const DIE *> GlobalNames;
60
61 /// GlobalTypes - A map of globally visible types for this unit.
62 StringMap<const DIE *> GlobalTypes;
63
64 // List of ranges for a given compile unit.
65 SmallVector<RangeSpan, 2> CURanges;
66
67 // The base address of this unit, if any. Used for relative references in
68 // ranges/locs.
69 const MCSymbol *BaseAddress = nullptr;
70
71 using MDNodeSetVector =
72 SetVector<const MDNode *, SmallVector<const MDNode *, 4>,
73 SmallPtrSet<const MDNode *, 4>>;
74
75 // List of entities (either static locals, types or imports) that
76 // belong to subprograms within this CU.
77 MDNodeSetVector DeferredLocalDecls;
78
79 // List of concrete lexical block scopes belong to subprograms within this CU.
80 DenseMap<const DILocalScope *, DIE *> LexicalBlockDIEs;
81
82 // List of abstract local scopes (either DISubprogram or DILexicalBlock).
83 DenseMap<const DILocalScope *, DIE *> AbstractLocalScopeDIEs;
84
85 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> AbstractEntities;
86
87 /// DWO ID for correlating skeleton and split units.
88 uint64_t DWOId = 0;
89
90 const DIFile *LastFile = nullptr;
91 unsigned LastFileID;
92
93 /// \anchor applyConcreteDbgVariableAttribute
94 /// \name applyConcreteDbgVariableAttribute
95 /// Overload set which applies attributes to \c VariableDie based on
96 /// the active variant of \c DV, which is passed as the first argument.
97 ///@{
98
99 /// See \ref applyConcreteDbgVariableAttribute
100 void applyConcreteDbgVariableAttributes(const Loc::Single &Single,
101 const DbgVariable &DV,
102 DIE &VariableDie);
103 /// See \ref applyConcreteDbgVariableAttribute
104 void applyConcreteDbgVariableAttributes(const Loc::Multi &Multi,
105 const DbgVariable &DV,
106 DIE &VariableDie);
107 /// See \ref applyConcreteDbgVariableAttribute
108 void applyConcreteDbgVariableAttributes(const Loc::MMI &MMI,
109 const DbgVariable &DV,
110 DIE &VariableDie);
111 /// See \ref applyConcreteDbgVariableAttribute
112 void applyConcreteDbgVariableAttributes(const Loc::EntryValue &EntryValue,
113 const DbgVariable &DV,
114 DIE &VariableDie);
115 /// See \ref applyConcreteDbgVariableAttribute
116 void applyConcreteDbgVariableAttributes(const std::monostate &,
117 const DbgVariable &DV,
118 DIE &VariableDie);
119
120 ///@}
121
122 bool isDwoUnit() const override;
123
124 DenseMap<const DILocalScope *, DIE *> &getAbstractScopeDIEs() {
125 if (isDwoUnit() && !DD->shareAcrossDWOCUs())
126 return AbstractLocalScopeDIEs;
127 return DU->getAbstractScopeDIEs();
128 }
129
130 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> &getAbstractEntities() {
131 if (isDwoUnit() && !DD->shareAcrossDWOCUs())
132 return AbstractEntities;
133 return DU->getAbstractEntities();
134 }
135
136 void finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) override;
137
138 /// Add info for Wasm-global-based relocation.
139 void addWasmRelocBaseGlobal(DIELoc *Loc, StringRef GlobalName,
140 uint64_t GlobalIndex);
141
142public:
143 DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A,
144 DwarfDebug *DW, DwarfFile *DWU,
145 UnitKind Kind = UnitKind::Full);
146
147 bool hasRangeLists() const { return HasRangeLists; }
148
149 DwarfCompileUnit *getSkeleton() const {
150 return Skeleton;
151 }
152
153 bool includeMinimalInlineScopes() const;
154
155 void initStmtList();
156
157 /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE.
158 void applyStmtList(DIE &D);
159
160 /// Get line table start symbol for this unit.
161 MCSymbol *getLineTableStartSym() const { return LineTableStartSym; }
162
163 /// A pair of GlobalVariable and DIExpression.
164 struct GlobalExpr {
165 const GlobalVariable *Var;
166 const DIExpression *Expr;
167 };
168
169 struct BaseTypeRef {
170 BaseTypeRef(unsigned BitSize, dwarf::TypeKind Encoding) :
171 BitSize(BitSize), Encoding(Encoding) {}
172 unsigned BitSize;
173 dwarf::TypeKind Encoding;
174 DIE *Die = nullptr;
175 };
176
177 std::vector<BaseTypeRef> ExprRefedBaseTypes;
178
179 /// Get or create global variable DIE.
180 DIE *
181 getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV,
182 ArrayRef<GlobalExpr> GlobalExprs);
183
184 DIE *getOrCreateCommonBlock(const DICommonBlock *CB,
185 ArrayRef<GlobalExpr> GlobalExprs);
186
187 void addLocationAttribute(DIE *ToDIE, const DIGlobalVariable *GV,
188 ArrayRef<GlobalExpr> GlobalExprs);
189
190 /// addLabelAddress - Add a dwarf label attribute data and value using
191 /// either DW_FORM_addr or DW_FORM_GNU_addr_index.
192 void addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
193 const MCSymbol *Label);
194
195 /// addLocalLabelAddress - Add a dwarf label attribute data and value using
196 /// DW_FORM_addr only.
197 void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute,
198 const MCSymbol *Label);
199
200 DwarfCompileUnit &getCU() override { return *this; }
201
202 unsigned getOrCreateSourceID(const DIFile *File) override;
203
204 /// addRange - Add an address range to the list of ranges for this unit.
205 void addRange(RangeSpan Range);
206
207 void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End);
208
209 /// Find DIE for the given subprogram and attach appropriate
210 /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
211 /// variables in this scope then create and insert DIEs for these
212 /// variables.
213 DIE &updateSubprogramScopeDIE(const DISubprogram *SP);
214
215 void constructScopeDIE(LexicalScope *Scope, DIE &ParentScopeDIE);
216
217 /// A helper function to construct a RangeSpanList for a given
218 /// lexical scope.
219 void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range);
220
221 void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges);
222
223 void attachRangesOrLowHighPC(DIE &D,
224 const SmallVectorImpl<InsnRange> &Ranges);
225
226 /// This scope represents an inlined body of a function. Construct a
227 /// DIE to represent this concrete inlined copy of the function.
228 DIE *constructInlinedScopeDIE(LexicalScope *Scope, DIE &ParentScopeDIE);
229
230 /// Construct new DW_TAG_lexical_block for this scope and
231 /// attach DW_AT_low_pc/DW_AT_high_pc labels.
232 DIE *constructLexicalScopeDIE(LexicalScope *Scope);
233
234 /// Get a DIE for the given DILexicalBlock.
235 /// Note that this function assumes that the DIE has been already created
236 /// and it's an error, if it hasn't.
237 DIE *getLexicalBlockDIE(const DILexicalBlock *LB);
238
239 /// Construct a DIE for the given DbgVariable.
240 DIE *constructVariableDIE(DbgVariable &DV, bool Abstract = false);
241
242 /// Convenience overload which writes the DIE pointer into an out variable
243 /// ObjectPointer in addition to returning it.
244 DIE *constructVariableDIE(DbgVariable &DV, const LexicalScope &Scope,
245 DIE *&ObjectPointer);
246
247 /// Construct a DIE for the given DbgLabel.
248 DIE *constructLabelDIE(DbgLabel &DL, const LexicalScope &Scope);
249
250 void createBaseTypeDIEs();
251
252 /// Construct a DIE for a given scope.
253 /// This instance of 'getOrCreateContextDIE()' can handle DILocalScope.
254 DIE *getOrCreateContextDIE(const DIScope *Ty) override;
255
256 /// Construct a DIE for this subprogram scope.
257 DIE &constructSubprogramScopeDIE(const DISubprogram *Sub,
258 LexicalScope *Scope);
259
260 DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE);
261
262 void constructAbstractSubprogramScopeDIE(LexicalScope *Scope);
263
264 /// Whether to use the GNU analog for a DWARF5 tag, attribute, or location
265 /// atom. Only applicable when emitting otherwise DWARF4-compliant debug info.
266 bool useGNUAnalogForDwarf5Feature() const;
267
268 /// This takes a DWARF 5 tag and returns it or a GNU analog.
269 dwarf::Tag getDwarf5OrGNUTag(dwarf::Tag Tag) const;
270
271 /// This takes a DWARF 5 attribute and returns it or a GNU analog.
272 dwarf::Attribute getDwarf5OrGNUAttr(dwarf::Attribute Attr) const;
273
274 /// This takes a DWARF 5 location atom and either returns it or a GNU analog.
275 dwarf::LocationAtom getDwarf5OrGNULocationAtom(dwarf::LocationAtom Loc) const;
276
277 /// Construct a call site entry DIE describing a call within \p Scope to a
278 /// callee described by \p CalleeSP.
279 /// \p IsTail specifies whether the call is a tail call.
280 /// \p PCAddr points to the PC value after the call instruction.
281 /// \p CallAddr points to the PC value at the call instruction (or is null).
282 /// \p CallReg is a register location for an indirect call. For direct calls
283 /// the \p CallReg is set to 0.
284 DIE &constructCallSiteEntryDIE(DIE &ScopeDIE, const DISubprogram *CalleeSP,
285 bool IsTail, const MCSymbol *PCAddr,
286 const MCSymbol *CallAddr, unsigned CallReg);
287 /// Construct call site parameter DIEs for the \p CallSiteDIE. The \p Params
288 /// were collected by the \ref collectCallSiteParameters.
289 /// Note: The order of parameters does not matter, since debuggers recognize
290 /// call site parameters by the DW_AT_location attribute.
291 void constructCallSiteParmEntryDIEs(DIE &CallSiteDIE,
292 SmallVector<DbgCallSiteParam, 4> &Params);
293
294 /// Get or create a DIE for an imported entity.
295 DIE *getOrCreateImportedEntityDIE(const DIImportedEntity *IE);
296 DIE *constructImportedEntityDIE(const DIImportedEntity *IE);
297
298 void finishSubprogramDefinition(const DISubprogram *SP);
299 void finishEntityDefinition(const DbgEntity *Entity);
300
301 /// Find abstract variable associated with Var.
302 using InlinedEntity = DbgValueHistoryMap::InlinedEntity;
303 DbgEntity *getExistingAbstractEntity(const DINode *Node);
304 void createAbstractEntity(const DINode *Node, LexicalScope *Scope);
305
306 /// Set the skeleton unit associated with this unit.
307 void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; }
308
309 unsigned getHeaderSize() const override {
310 // DWARF v5 added the DWO ID to the header for split/skeleton units.
311 unsigned DWOIdSize =
312 DD->getDwarfVersion() >= 5 && DD->useSplitDwarf() ? sizeof(uint64_t)
313 : 0;
314 return DwarfUnit::getHeaderSize() + DWOIdSize;
315 }
316 unsigned getLength() {
317 return Asm->getUnitLengthFieldByteSize() + // Length field
318 getHeaderSize() + getUnitDie().getSize();
319 }
320
321 void emitHeader(bool UseOffsets) override;
322
323 /// Add the DW_AT_addr_base attribute to the unit DIE.
324 void addAddrTableBase();
325
326 MCSymbol *getMacroLabelBegin() const {
327 return MacroLabelBegin;
328 }
329
330 /// Add a new global name to the compile unit.
331 void addGlobalName(StringRef Name, const DIE &Die,
332 const DIScope *Context) override;
333
334 /// Add a new global name present in a type unit to this compile unit.
335 void addGlobalNameForTypeUnit(StringRef Name, const DIScope *Context);
336
337 /// Add a new global type to the compile unit.
338 void addGlobalTypeImpl(const DIType *Ty, const DIE &Die,
339 const DIScope *Context) override;
340
341 /// Add a new global type present in a type unit to this compile unit.
342 void addGlobalTypeUnitType(const DIType *Ty, const DIScope *Context);
343
344 const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; }
345 const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; }
346
347 /// Add DW_AT_location attribute for a DbgVariable based on provided
348 /// MachineLocation.
349 void addVariableAddress(const DbgVariable &DV, DIE &Die,
350 MachineLocation Location);
351 /// Add an address attribute to a die based on the location provided.
352 void addAddress(DIE &Die, dwarf::Attribute Attribute,
353 const MachineLocation &Location);
354
355 /// Start with the address based on the location provided, and generate the
356 /// DWARF information necessary to find the actual variable (navigating the
357 /// extra location information encoded in the type) based on the starting
358 /// location. Add the DWARF information to the die.
359 void addComplexAddress(const DIExpression *DIExpr, DIE &Die,
360 dwarf::Attribute Attribute,
361 const MachineLocation &Location);
362
363 /// Add a Dwarf loclistptr attribute data and value.
364 void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index);
365
366 /// Add attributes to \p Var which reflect the common attributes of \p
367 /// VariableDie, namely those which are not dependant on the active variant.
368 void applyCommonDbgVariableAttributes(const DbgVariable &Var,
369 DIE &VariableDie);
370
371 /// Add a Dwarf expression attribute data and value.
372 void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr);
373
374 void applySubprogramAttributesToDefinition(const DISubprogram *SP,
375 DIE &SPDie);
376
377 void applyLabelAttributes(const DbgLabel &Label, DIE &LabelDie);
378
379 /// getRanges - Get the list of ranges for this unit.
380 const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; }
381 SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); }
382
383 void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; }
384 const MCSymbol *getBaseAddress() const { return BaseAddress; }
385
386 uint64_t getDWOId() const { return DWOId; }
387 void setDWOId(uint64_t DwoId) { DWOId = DwoId; }
388
389 bool hasDwarfPubSections() const;
390
391 void addBaseTypeRef(DIEValueList &Die, int64_t Idx);
392
393 MDNodeSetVector &getDeferredLocalDecls() { return DeferredLocalDecls; }
394};
395
396} // end namespace llvm
397
398#endif // LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H
399