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 // List of inlined lexical block scopes that belong to subprograms within this
86 // CU.
87 DenseMap<const DILocalScope *, SmallVector<DIE *, 2>> InlinedLocalScopeDIEs;
88
89 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> AbstractEntities;
90
91 /// DWO ID for correlating skeleton and split units.
92 uint64_t DWOId = 0;
93
94 const DIFile *LastFile = nullptr;
95 unsigned LastFileID;
96
97 /// \anchor applyConcreteDbgVariableAttribute
98 /// \name applyConcreteDbgVariableAttribute
99 /// Overload set which applies attributes to \c VariableDie based on
100 /// the active variant of \c DV, which is passed as the first argument.
101 ///@{
102
103 /// See \ref applyConcreteDbgVariableAttribute
104 void applyConcreteDbgVariableAttributes(const Loc::Single &Single,
105 const DbgVariable &DV,
106 DIE &VariableDie);
107 /// See \ref applyConcreteDbgVariableAttribute
108 void applyConcreteDbgVariableAttributes(const Loc::Multi &Multi,
109 const DbgVariable &DV,
110 DIE &VariableDie);
111 /// See \ref applyConcreteDbgVariableAttribute
112 void applyConcreteDbgVariableAttributes(const Loc::MMI &MMI,
113 const DbgVariable &DV,
114 DIE &VariableDie);
115 /// See \ref applyConcreteDbgVariableAttribute
116 void applyConcreteDbgVariableAttributes(const Loc::EntryValue &EntryValue,
117 const DbgVariable &DV,
118 DIE &VariableDie);
119 /// See \ref applyConcreteDbgVariableAttribute
120 void applyConcreteDbgVariableAttributes(const std::monostate &,
121 const DbgVariable &DV,
122 DIE &VariableDie);
123
124 ///@}
125
126 bool isDwoUnit() const override;
127
128 DenseMap<const DILocalScope *, DIE *> &getAbstractScopeDIEs() {
129 if (isDwoUnit() && !DD->shareAcrossDWOCUs())
130 return AbstractLocalScopeDIEs;
131 return DU->getAbstractScopeDIEs();
132 }
133
134 DenseMap<const DINode *, std::unique_ptr<DbgEntity>> &getAbstractEntities() {
135 if (isDwoUnit() && !DD->shareAcrossDWOCUs())
136 return AbstractEntities;
137 return DU->getAbstractEntities();
138 }
139
140 void finishNonUnitTypeDIE(DIE& D, const DICompositeType *CTy) override;
141
142 /// Add info for Wasm-global-based relocation.
143 void addWasmRelocBaseGlobal(DIELoc *Loc, StringRef GlobalName,
144 uint64_t GlobalIndex);
145
146public:
147 DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A,
148 DwarfDebug *DW, DwarfFile *DWU,
149 UnitKind Kind = UnitKind::Full);
150
151 bool hasRangeLists() const { return HasRangeLists; }
152
153 DwarfCompileUnit *getSkeleton() const {
154 return Skeleton;
155 }
156
157 bool includeMinimalInlineScopes() const;
158
159 bool emitFuncLineTableOffsets() const;
160
161 void initStmtList();
162
163 /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE.
164 void applyStmtList(DIE &D);
165
166 /// Get line table start symbol for this unit.
167 MCSymbol *getLineTableStartSym() const { return LineTableStartSym; }
168
169 /// A pair of GlobalVariable and DIExpression.
170 struct GlobalExpr {
171 const GlobalVariable *Var;
172 const DIExpression *Expr;
173 };
174
175 struct BaseTypeRef {
176 BaseTypeRef(unsigned BitSize, dwarf::TypeKind Encoding) :
177 BitSize(BitSize), Encoding(Encoding) {}
178 unsigned BitSize;
179 dwarf::TypeKind Encoding;
180 DIE *Die = nullptr;
181 };
182
183 std::vector<BaseTypeRef> ExprRefedBaseTypes;
184
185 /// Get or create global variable DIE.
186 DIE *
187 getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV,
188 ArrayRef<GlobalExpr> GlobalExprs);
189
190 DIE *getOrCreateCommonBlock(const DICommonBlock *CB,
191 ArrayRef<GlobalExpr> GlobalExprs);
192
193 void addLocationAttribute(DIE *ToDIE, const DIGlobalVariable *GV,
194 ArrayRef<GlobalExpr> GlobalExprs);
195
196 /// addLabelAddress - Add a dwarf label attribute data and value using
197 /// either DW_FORM_addr or DW_FORM_GNU_addr_index.
198 void addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
199 const MCSymbol *Label);
200
201 /// addLocalLabelAddress - Add a dwarf label attribute data and value using
202 /// DW_FORM_addr only.
203 void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute,
204 const MCSymbol *Label);
205
206 DwarfCompileUnit &getCU() override { return *this; }
207
208 unsigned getOrCreateSourceID(const DIFile *File) override;
209
210 /// addRange - Add an address range to the list of ranges for this unit.
211 void addRange(RangeSpan Range);
212
213 void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End);
214
215 /// Find DIE for the given subprogram and attach appropriate
216 /// DW_AT_low_pc, DW_AT_high_pc and DW_AT_LLVM_stmt_sequence attributes.
217 /// If there are global variables in this scope then create and insert DIEs
218 /// for these variables.
219 DIE &updateSubprogramScopeDIE(const DISubprogram *SP, MCSymbol *LineTableSym);
220
221 void constructScopeDIE(LexicalScope *Scope, DIE &ParentScopeDIE);
222
223 /// A helper function to construct a RangeSpanList for a given
224 /// lexical scope.
225 void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range);
226
227 void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges);
228
229 void attachRangesOrLowHighPC(DIE &D,
230 const SmallVectorImpl<InsnRange> &Ranges);
231
232 /// This scope represents an inlined body of a function. Construct a
233 /// DIE to represent this concrete inlined copy of the function.
234 DIE *constructInlinedScopeDIE(LexicalScope *Scope, DIE &ParentScopeDIE);
235
236 /// Construct new DW_TAG_lexical_block for this scope and
237 /// attach DW_AT_low_pc/DW_AT_high_pc labels.
238 DIE *constructLexicalScopeDIE(LexicalScope *Scope);
239
240 /// Get a DIE for the given DILexicalBlock.
241 /// Note that this function assumes that the DIE has been already created
242 /// and it's an error, if it hasn't.
243 DIE *getLexicalBlockDIE(const DILexicalBlock *LB);
244
245 /// Construct a DIE for the given DbgVariable.
246 DIE *constructVariableDIE(DbgVariable &DV, bool Abstract = false);
247
248 /// Convenience overload which writes the DIE pointer into an out variable
249 /// ObjectPointer in addition to returning it.
250 DIE *constructVariableDIE(DbgVariable &DV, const LexicalScope &Scope,
251 DIE *&ObjectPointer);
252
253 /// Construct a DIE for the given DbgLabel.
254 DIE *constructLabelDIE(DbgLabel &DL, const LexicalScope &Scope);
255
256 void createBaseTypeDIEs();
257
258 /// Construct a DIE for a given scope.
259 /// This instance of 'getOrCreateContextDIE()' can handle DILocalScope.
260 DIE *getOrCreateContextDIE(const DIScope *Ty) override;
261
262 /// Construct a DIE for this subprogram scope.
263 DIE &constructSubprogramScopeDIE(const DISubprogram *Sub, LexicalScope *Scope,
264 MCSymbol *LineTableSym);
265
266 DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE);
267
268 void constructAbstractSubprogramScopeDIE(LexicalScope *Scope);
269
270 /// Whether to use the GNU analog for a DWARF5 tag, attribute, or location
271 /// atom. Only applicable when emitting otherwise DWARF4-compliant debug info.
272 bool useGNUAnalogForDwarf5Feature() const;
273
274 /// This takes a DWARF 5 tag and returns it or a GNU analog.
275 dwarf::Tag getDwarf5OrGNUTag(dwarf::Tag Tag) const;
276
277 /// This takes a DWARF 5 attribute and returns it or a GNU analog.
278 dwarf::Attribute getDwarf5OrGNUAttr(dwarf::Attribute Attr) const;
279
280 /// This takes a DWARF 5 location atom and either returns it or a GNU analog.
281 dwarf::LocationAtom getDwarf5OrGNULocationAtom(dwarf::LocationAtom Loc) const;
282
283 /// Construct a call site entry DIE describing a call within \p Scope to a
284 /// callee described by \p CalleeSP.
285 /// \p IsTail specifies whether the call is a tail call.
286 /// \p PCAddr points to the PC value after the call instruction.
287 /// \p CallAddr points to the PC value at the call instruction (or is null).
288 /// \p CallReg is a register location for an indirect call. For direct calls
289 /// the \p CallReg is set to 0.
290 DIE &constructCallSiteEntryDIE(DIE &ScopeDIE, const DISubprogram *CalleeSP,
291 bool IsTail, const MCSymbol *PCAddr,
292 const MCSymbol *CallAddr, unsigned CallReg);
293 /// Construct call site parameter DIEs for the \p CallSiteDIE. The \p Params
294 /// were collected by the \ref collectCallSiteParameters.
295 /// Note: The order of parameters does not matter, since debuggers recognize
296 /// call site parameters by the DW_AT_location attribute.
297 void constructCallSiteParmEntryDIEs(DIE &CallSiteDIE,
298 SmallVector<DbgCallSiteParam, 4> &Params);
299
300 /// Get or create a DIE for an imported entity.
301 DIE *getOrCreateImportedEntityDIE(const DIImportedEntity *IE);
302 DIE *constructImportedEntityDIE(const DIImportedEntity *IE);
303
304 void finishSubprogramDefinition(const DISubprogram *SP);
305 void finishEntityDefinition(const DbgEntity *Entity);
306 void attachLexicalScopesAbstractOrigins();
307
308 /// Find abstract variable associated with Var.
309 using InlinedEntity = DbgValueHistoryMap::InlinedEntity;
310 DbgEntity *getExistingAbstractEntity(const DINode *Node);
311 void createAbstractEntity(const DINode *Node, LexicalScope *Scope);
312
313 /// Set the skeleton unit associated with this unit.
314 void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; }
315
316 unsigned getHeaderSize() const override {
317 // DWARF v5 added the DWO ID to the header for split/skeleton units.
318 unsigned DWOIdSize =
319 DD->getDwarfVersion() >= 5 && DD->useSplitDwarf() ? sizeof(uint64_t)
320 : 0;
321 return DwarfUnit::getHeaderSize() + DWOIdSize;
322 }
323 unsigned getLength() {
324 return Asm->getUnitLengthFieldByteSize() + // Length field
325 getHeaderSize() + getUnitDie().getSize();
326 }
327
328 void emitHeader(bool UseOffsets) override;
329
330 /// Add the DW_AT_addr_base attribute to the unit DIE.
331 void addAddrTableBase();
332
333 MCSymbol *getMacroLabelBegin() const {
334 return MacroLabelBegin;
335 }
336
337 /// Add a new global name to the compile unit.
338 void addGlobalName(StringRef Name, const DIE &Die,
339 const DIScope *Context) override;
340
341 /// Add a new global name present in a type unit to this compile unit.
342 void addGlobalNameForTypeUnit(StringRef Name, const DIScope *Context);
343
344 /// Add a new global type to the compile unit.
345 void addGlobalTypeImpl(const DIType *Ty, const DIE &Die,
346 const DIScope *Context) override;
347
348 /// Add a new global type present in a type unit to this compile unit.
349 void addGlobalTypeUnitType(const DIType *Ty, const DIScope *Context);
350
351 const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; }
352 const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; }
353
354 /// Add DW_AT_location attribute for a DbgVariable based on provided
355 /// MachineLocation.
356 void addVariableAddress(const DbgVariable &DV, DIE &Die,
357 MachineLocation Location);
358 /// Add an address attribute to a die based on the location provided.
359 void addAddress(DIE &Die, dwarf::Attribute Attribute,
360 const MachineLocation &Location);
361
362 /// Start with the address based on the location provided, and generate the
363 /// DWARF information necessary to find the actual variable (navigating the
364 /// extra location information encoded in the type) based on the starting
365 /// location. Add the DWARF information to the die.
366 void addComplexAddress(const DIExpression *DIExpr, DIE &Die,
367 dwarf::Attribute Attribute,
368 const MachineLocation &Location);
369
370 /// Add a Dwarf loclistptr attribute data and value.
371 void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index);
372
373 /// Add attributes to \p Var which reflect the common attributes of \p
374 /// VariableDie, namely those which are not dependant on the active variant.
375 void applyCommonDbgVariableAttributes(const DbgVariable &Var,
376 DIE &VariableDie);
377
378 /// Add a Dwarf expression attribute data and value.
379 void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr);
380
381 void applySubprogramAttributesToDefinition(const DISubprogram *SP,
382 DIE &SPDie);
383
384 void applyLabelAttributes(const DbgLabel &Label, DIE &LabelDie);
385
386 /// getRanges - Get the list of ranges for this unit.
387 const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; }
388 SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); }
389
390 void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; }
391 const MCSymbol *getBaseAddress() const { return BaseAddress; }
392
393 uint64_t getDWOId() const { return DWOId; }
394 void setDWOId(uint64_t DwoId) { DWOId = DwoId; }
395
396 bool hasDwarfPubSections() const;
397
398 void addBaseTypeRef(DIEValueList &Die, int64_t Idx);
399
400 MDNodeSetVector &getDeferredLocalDecls() { return DeferredLocalDecls; }
401};
402
403} // end namespace llvm
404
405#endif // LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H
406