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/IR/DebugInfo.h"
19 #include "llvm/Support/Dwarf.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 : 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   /// \brief Construct a DIE for the given DbgVariable without initializing the
72   /// DbgVariable's DIE reference.
73   DIE *constructVariableDIEImpl(const DbgVariable &DV, bool Abstract);
74 
75   bool isDwoUnit() const override;
76 
77   bool includeMinimalInlineScopes() const;
78 
79 public:
80   DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A,
81                    DwarfDebug *DW, DwarfFile *DWU);
82 
83   unsigned getUniqueID() const { return UniqueID; }
84 
85   DwarfCompileUnit *getSkeleton() const {
86     return Skeleton;
87   }
88 
89   void initStmtList();
90 
91   /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE.
92   void applyStmtList(DIE &D);
93 
94   /// getOrCreateGlobalVariableDIE - get or create global variable DIE.
95   DIE *getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV,
96                                     const GlobalVariable *Global);
97 
98   /// addLabelAddress - Add a dwarf label attribute data and value using
99   /// either DW_FORM_addr or DW_FORM_GNU_addr_index.
100   void addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
101                        const MCSymbol *Label);
102 
103   /// addLocalLabelAddress - Add a dwarf label attribute data and value using
104   /// DW_FORM_addr only.
105   void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute,
106                             const MCSymbol *Label);
107 
108   /// addSectionDelta - Add a label delta attribute data and value.
109   DIE::value_iterator addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
110                                       const MCSymbol *Hi, const MCSymbol *Lo);
111 
112   DwarfCompileUnit &getCU() override { return *this; }
113 
114   unsigned getOrCreateSourceID(StringRef FileName, StringRef DirName) override;
115 
116   void addImportedEntity(const DIImportedEntity* IE) {
117     DIScope *Scope = IE->getScope();
118     assert(Scope && "Invalid Scope encoding!");
119     if (!isa<DILocalScope>(Scope))
120       // No need to add imported enities that are not local declaration.
121       return;
122 
123     auto *LocalScope = cast<DILocalScope>(Scope)->getNonLexicalBlockFileScope();
124     ImportedEntities[LocalScope].push_back(IE);
125   }
126 
127   /// addRange - Add an address range to the list of ranges for this unit.
128   void addRange(RangeSpan Range);
129 
130   void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End);
131 
132   /// addSectionLabel - Add a Dwarf section label attribute data and value.
133   ///
134   DIE::value_iterator addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
135                                       const MCSymbol *Label,
136                                       const MCSymbol *Sec);
137 
138   /// \brief Find DIE for the given subprogram and attach appropriate
139   /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
140   /// variables in this scope then create and insert DIEs for these
141   /// variables.
142   DIE &updateSubprogramScopeDIE(const DISubprogram *SP);
143 
144   void constructScopeDIE(LexicalScope *Scope,
145                          SmallVectorImpl<DIE *> &FinalChildren);
146 
147   /// \brief A helper function to construct a RangeSpanList for a given
148   /// lexical scope.
149   void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range);
150 
151   void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges);
152 
153   void attachRangesOrLowHighPC(DIE &D,
154                                const SmallVectorImpl<InsnRange> &Ranges);
155   /// \brief This scope represents inlined body of a function. Construct
156   /// DIE to represent this concrete inlined copy of the function.
157   DIE *constructInlinedScopeDIE(LexicalScope *Scope);
158 
159   /// \brief Construct new DW_TAG_lexical_block for this scope and
160   /// attach DW_AT_low_pc/DW_AT_high_pc labels.
161   DIE *constructLexicalScopeDIE(LexicalScope *Scope);
162 
163   /// constructVariableDIE - Construct a DIE for the given DbgVariable.
164   DIE *constructVariableDIE(DbgVariable &DV, bool Abstract = false);
165 
166   DIE *constructVariableDIE(DbgVariable &DV, const LexicalScope &Scope,
167                             DIE *&ObjectPointer);
168 
169   /// A helper function to create children of a Scope DIE.
170   DIE *createScopeChildrenDIE(LexicalScope *Scope,
171                               SmallVectorImpl<DIE *> &Children,
172                               unsigned *ChildScopeCount = nullptr);
173 
174   /// \brief Construct a DIE for this subprogram scope.
175   void constructSubprogramScopeDIE(LexicalScope *Scope);
176 
177   DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE);
178 
179   void constructAbstractSubprogramScopeDIE(LexicalScope *Scope);
180 
181   /// \brief Construct import_module DIE.
182   DIE *constructImportedEntityDIE(const DIImportedEntity *Module);
183 
184   void finishSubprogramDefinition(const DISubprogram *SP);
185 
186   /// Set the skeleton unit associated with this unit.
187   void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; }
188 
189   unsigned getLength() {
190     return sizeof(uint32_t) + // Length field
191         getHeaderSize() + getUnitDie().getSize();
192   }
193 
194   void emitHeader(bool UseOffsets) override;
195 
196   MCSymbol *getLabelBegin() const {
197     assert(getSection());
198     return LabelBegin;
199   }
200 
201   MCSymbol *getMacroLabelBegin() const {
202     return MacroLabelBegin;
203   }
204 
205   /// Add a new global name to the compile unit.
206   void addGlobalName(StringRef Name, DIE &Die, const DIScope *Context) override;
207 
208   /// Add a new global type to the compile unit.
209   void addGlobalType(const DIType *Ty, const DIE &Die,
210                      const DIScope *Context) override;
211 
212   const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; }
213   const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; }
214 
215   /// Add DW_AT_location attribute for a DbgVariable based on provided
216   /// MachineLocation.
217   void addVariableAddress(const DbgVariable &DV, DIE &Die,
218                           MachineLocation Location);
219   /// Add an address attribute to a die based on the location provided.
220   void addAddress(DIE &Die, dwarf::Attribute Attribute,
221                   const MachineLocation &Location);
222 
223   /// Start with the address based on the location provided, and generate the
224   /// DWARF information necessary to find the actual variable (navigating the
225   /// extra location information encoded in the type) based on the starting
226   /// location.  Add the DWARF information to the die.
227   void addComplexAddress(const DbgVariable &DV, DIE &Die,
228                          dwarf::Attribute Attribute,
229                          const MachineLocation &Location);
230 
231   /// Add a Dwarf loclistptr attribute data and value.
232   void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index);
233   void applyVariableAttributes(const DbgVariable &Var, DIE &VariableDie);
234 
235   /// Add a Dwarf expression attribute data and value.
236   void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr);
237 
238   void applySubprogramAttributesToDefinition(const DISubprogram *SP,
239                                              DIE &SPDie);
240 
241   /// getRangeLists - Get the vector of range lists.
242   const SmallVectorImpl<RangeSpanList> &getRangeLists() const {
243     return (Skeleton ? Skeleton : this)->CURangeLists;
244   }
245 
246   /// getRanges - Get the list of ranges for this unit.
247   const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; }
248   SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); }
249 
250   void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; }
251   const MCSymbol *getBaseAddress() const { return BaseAddress; }
252 };
253 
254 } // end llvm namespace
255 
256 #endif
257