1 //===-- llvm/CodeGen/DwarfCompileUnit.h - Dwarf Compile Unit ---*- C++ -*--===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains support for writing dwarf compile unit.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H
15 #define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H
16 
17 #include "DwarfUnit.h"
18 #include "llvm/BinaryFormat/Dwarf.h"
19 #include "llvm/IR/DebugInfo.h"
20 
21 namespace llvm {
22 
23 class StringRef;
24 class AsmPrinter;
25 class DIE;
26 class DwarfDebug;
27 class DwarfFile;
28 class MCSymbol;
29 class LexicalScope;
30 
31 class DwarfCompileUnit final : public DwarfUnit {
32   /// A numeric ID unique among all CUs in the module
33   unsigned UniqueID;
34 
35   /// The attribute index of DW_AT_stmt_list in the compile unit DIE, avoiding
36   /// the need to search for it in applyStmtList.
37   DIE::value_iterator StmtListValue;
38 
39   /// Skeleton unit associated with this unit.
40   DwarfCompileUnit *Skeleton;
41 
42   /// The start of the unit within its section.
43   MCSymbol *LabelBegin;
44 
45   /// The start of the unit macro info within macro section.
46   MCSymbol *MacroLabelBegin;
47 
48   typedef llvm::SmallVector<const MDNode *, 8> ImportedEntityList;
49   typedef llvm::DenseMap<const MDNode *, ImportedEntityList>
50   ImportedEntityMap;
51 
52   ImportedEntityMap ImportedEntities;
53 
54   /// GlobalNames - A map of globally visible named entities for this unit.
55   StringMap<const DIE *> GlobalNames;
56 
57   /// GlobalTypes - A map of globally visible types for this unit.
58   StringMap<const DIE *> GlobalTypes;
59 
60   // List of range lists for a given compile unit, separate from the ranges for
61   // the CU itself.
62   SmallVector<RangeSpanList, 1> CURangeLists;
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;
70 
71   DenseMap<const MDNode *, DIE *> AbstractSPDies;
72   DenseMap<const MDNode *, std::unique_ptr<DbgVariable>> AbstractVariables;
73 
74   /// \brief Construct a DIE for the given DbgVariable without initializing the
75   /// DbgVariable's DIE reference.
76   DIE *constructVariableDIEImpl(const DbgVariable &DV, bool Abstract);
77 
78   bool isDwoUnit() const override;
79 
80   DenseMap<const MDNode *, DIE *> &getAbstractSPDies() {
81     if (isDwoUnit() && !DD->shareAcrossDWOCUs())
82       return AbstractSPDies;
83     return DU->getAbstractSPDies();
84   }
85 
86   DenseMap<const MDNode *, std::unique_ptr<DbgVariable>> &getAbstractVariables() {
87     if (isDwoUnit() && !DD->shareAcrossDWOCUs())
88       return AbstractVariables;
89     return DU->getAbstractVariables();
90   }
91 
92 public:
93   DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A,
94                    DwarfDebug *DW, DwarfFile *DWU);
95 
96   unsigned getUniqueID() const { return UniqueID; }
97 
98   DwarfCompileUnit *getSkeleton() const {
99     return Skeleton;
100   }
101 
102   bool includeMinimalInlineScopes() const;
103 
104   void initStmtList();
105 
106   /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE.
107   void applyStmtList(DIE &D);
108 
109   /// A pair of GlobalVariable and DIExpression.
110   struct GlobalExpr {
111     const GlobalVariable *Var;
112     const DIExpression *Expr;
113   };
114 
115   /// Get or create global variable DIE.
116   DIE *
117   getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV,
118                                ArrayRef<GlobalExpr> GlobalExprs);
119 
120   /// addLabelAddress - Add a dwarf label attribute data and value using
121   /// either DW_FORM_addr or DW_FORM_GNU_addr_index.
122   void addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
123                        const MCSymbol *Label);
124 
125   /// addLocalLabelAddress - Add a dwarf label attribute data and value using
126   /// DW_FORM_addr only.
127   void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute,
128                             const MCSymbol *Label);
129 
130   /// addSectionDelta - Add a label delta attribute data and value.
131   DIE::value_iterator addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
132                                       const MCSymbol *Hi, const MCSymbol *Lo);
133 
134   DwarfCompileUnit &getCU() override { return *this; }
135 
136   unsigned getOrCreateSourceID(StringRef FileName, StringRef DirName) override;
137 
138   void addImportedEntity(const DIImportedEntity* IE) {
139     DIScope *Scope = IE->getScope();
140     assert(Scope && "Invalid Scope encoding!");
141     if (!isa<DILocalScope>(Scope))
142       // No need to add imported enities that are not local declaration.
143       return;
144 
145     auto *LocalScope = cast<DILocalScope>(Scope)->getNonLexicalBlockFileScope();
146     ImportedEntities[LocalScope].push_back(IE);
147   }
148 
149   /// addRange - Add an address range to the list of ranges for this unit.
150   void addRange(RangeSpan Range);
151 
152   void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End);
153 
154   /// addSectionLabel - Add a Dwarf section label attribute data and value.
155   ///
156   DIE::value_iterator addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
157                                       const MCSymbol *Label,
158                                       const MCSymbol *Sec);
159 
160   /// \brief Find DIE for the given subprogram and attach appropriate
161   /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
162   /// variables in this scope then create and insert DIEs for these
163   /// variables.
164   DIE &updateSubprogramScopeDIE(const DISubprogram *SP);
165 
166   void constructScopeDIE(LexicalScope *Scope,
167                          SmallVectorImpl<DIE *> &FinalChildren);
168 
169   /// \brief A helper function to construct a RangeSpanList for a given
170   /// lexical scope.
171   void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range);
172 
173   void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges);
174 
175   void attachRangesOrLowHighPC(DIE &D,
176                                const SmallVectorImpl<InsnRange> &Ranges);
177   /// \brief This scope represents inlined body of a function. Construct
178   /// DIE to represent this concrete inlined copy of the function.
179   DIE *constructInlinedScopeDIE(LexicalScope *Scope);
180 
181   /// \brief Construct new DW_TAG_lexical_block for this scope and
182   /// attach DW_AT_low_pc/DW_AT_high_pc labels.
183   DIE *constructLexicalScopeDIE(LexicalScope *Scope);
184 
185   /// constructVariableDIE - Construct a DIE for the given DbgVariable.
186   DIE *constructVariableDIE(DbgVariable &DV, bool Abstract = false);
187 
188   DIE *constructVariableDIE(DbgVariable &DV, const LexicalScope &Scope,
189                             DIE *&ObjectPointer);
190 
191   /// A helper function to create children of a Scope DIE.
192   DIE *createScopeChildrenDIE(LexicalScope *Scope,
193                               SmallVectorImpl<DIE *> &Children,
194                               unsigned *ChildScopeCount = nullptr);
195 
196   /// \brief Construct a DIE for this subprogram scope.
197   void constructSubprogramScopeDIE(const DISubprogram *Sub, LexicalScope *Scope);
198 
199   DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE);
200 
201   void constructAbstractSubprogramScopeDIE(LexicalScope *Scope);
202 
203   /// \brief Construct import_module DIE.
204   DIE *constructImportedEntityDIE(const DIImportedEntity *Module);
205 
206   void finishSubprogramDefinition(const DISubprogram *SP);
207   void finishVariableDefinition(const DbgVariable &Var);
208   /// Find abstract variable associated with Var.
209   typedef DbgValueHistoryMap::InlinedVariable InlinedVariable;
210   DbgVariable *getExistingAbstractVariable(InlinedVariable IV,
211                                            const DILocalVariable *&Cleansed);
212   DbgVariable *getExistingAbstractVariable(InlinedVariable IV);
213   void createAbstractVariable(const DILocalVariable *DV, LexicalScope *Scope);
214 
215   /// Set the skeleton unit associated with this unit.
216   void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; }
217 
218   unsigned getLength() {
219     return sizeof(uint32_t) + // Length field
220         getHeaderSize() + getUnitDie().getSize();
221   }
222 
223   void emitHeader(bool UseOffsets) override;
224 
225   MCSymbol *getLabelBegin() const {
226     assert(getSection());
227     return LabelBegin;
228   }
229 
230   MCSymbol *getMacroLabelBegin() const {
231     return MacroLabelBegin;
232   }
233 
234   /// Add a new global name to the compile unit.
235   void addGlobalName(StringRef Name, const DIE &Die,
236                      const DIScope *Context) override;
237 
238   /// Add a new global name present in a type unit to this compile unit.
239   void addGlobalNameForTypeUnit(StringRef Name, const DIScope *Context);
240 
241   /// Add a new global type to the compile unit.
242   void addGlobalType(const DIType *Ty, const DIE &Die,
243                      const DIScope *Context) override;
244 
245   /// Add a new global type present in a type unit to this compile unit.
246   void addGlobalTypeUnitType(const DIType *Ty, const DIScope *Context);
247 
248   const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; }
249   const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; }
250 
251   /// Add DW_AT_location attribute for a DbgVariable based on provided
252   /// MachineLocation.
253   void addVariableAddress(const DbgVariable &DV, DIE &Die,
254                           MachineLocation Location);
255   /// Add an address attribute to a die based on the location provided.
256   void addAddress(DIE &Die, dwarf::Attribute Attribute,
257                   const MachineLocation &Location);
258 
259   /// Start with the address based on the location provided, and generate the
260   /// DWARF information necessary to find the actual variable (navigating the
261   /// extra location information encoded in the type) based on the starting
262   /// location.  Add the DWARF information to the die.
263   void addComplexAddress(const DbgVariable &DV, DIE &Die,
264                          dwarf::Attribute Attribute,
265                          const MachineLocation &Location);
266 
267   /// Add a Dwarf loclistptr attribute data and value.
268   void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index);
269   void applyVariableAttributes(const DbgVariable &Var, DIE &VariableDie);
270 
271   /// Add a Dwarf expression attribute data and value.
272   void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr);
273 
274   void applySubprogramAttributesToDefinition(const DISubprogram *SP,
275                                              DIE &SPDie);
276 
277   /// getRangeLists - Get the vector of range lists.
278   const SmallVectorImpl<RangeSpanList> &getRangeLists() const {
279     return (Skeleton ? Skeleton : this)->CURangeLists;
280   }
281 
282   /// getRanges - Get the list of ranges for this unit.
283   const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; }
284   SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); }
285 
286   void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; }
287   const MCSymbol *getBaseAddress() const { return BaseAddress; }
288 };
289 
290 } // end llvm namespace
291 
292 #endif
293