xref: /freebsd/contrib/llvm-project/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h (revision b1879975794772ee51f0b4865753364c7d7626c3)
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 
31 namespace llvm {
32 
33 class AsmPrinter;
34 class DIE;
35 class DIELoc;
36 class DIEValueList;
37 class DwarfFile;
38 class GlobalVariable;
39 class MCExpr;
40 class MCSymbol;
41 class MDNode;
42 
43 enum class UnitKind { Skeleton, Full };
44 
45 class 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 
142 public:
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