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   /// A pair of GlobalVariable and DIExpression.
95   struct GlobalExpr {
96     const GlobalVariable *Var;
97     const DIExpression *Expr;
98   };
99 
100   /// Get or create global variable DIE.
101   DIE *
102   getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV,
103                                ArrayRef<GlobalExpr> GlobalExprs);
104 
105   /// addLabelAddress - Add a dwarf label attribute data and value using
106   /// either DW_FORM_addr or DW_FORM_GNU_addr_index.
107   void addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
108                        const MCSymbol *Label);
109 
110   /// addLocalLabelAddress - Add a dwarf label attribute data and value using
111   /// DW_FORM_addr only.
112   void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute,
113                             const MCSymbol *Label);
114 
115   /// addSectionDelta - Add a label delta attribute data and value.
116   DIE::value_iterator addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
117                                       const MCSymbol *Hi, const MCSymbol *Lo);
118 
119   DwarfCompileUnit &getCU() override { return *this; }
120 
121   unsigned getOrCreateSourceID(StringRef FileName, StringRef DirName) override;
122 
123   void addImportedEntity(const DIImportedEntity* IE) {
124     DIScope *Scope = IE->getScope();
125     assert(Scope && "Invalid Scope encoding!");
126     if (!isa<DILocalScope>(Scope))
127       // No need to add imported enities that are not local declaration.
128       return;
129 
130     auto *LocalScope = cast<DILocalScope>(Scope)->getNonLexicalBlockFileScope();
131     ImportedEntities[LocalScope].push_back(IE);
132   }
133 
134   /// addRange - Add an address range to the list of ranges for this unit.
135   void addRange(RangeSpan Range);
136 
137   void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End);
138 
139   /// addSectionLabel - Add a Dwarf section label attribute data and value.
140   ///
141   DIE::value_iterator addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
142                                       const MCSymbol *Label,
143                                       const MCSymbol *Sec);
144 
145   /// \brief Find DIE for the given subprogram and attach appropriate
146   /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
147   /// variables in this scope then create and insert DIEs for these
148   /// variables.
149   DIE &updateSubprogramScopeDIE(const DISubprogram *SP);
150 
151   void constructScopeDIE(LexicalScope *Scope,
152                          SmallVectorImpl<DIE *> &FinalChildren);
153 
154   /// \brief A helper function to construct a RangeSpanList for a given
155   /// lexical scope.
156   void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range);
157 
158   void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges);
159 
160   void attachRangesOrLowHighPC(DIE &D,
161                                const SmallVectorImpl<InsnRange> &Ranges);
162   /// \brief This scope represents inlined body of a function. Construct
163   /// DIE to represent this concrete inlined copy of the function.
164   DIE *constructInlinedScopeDIE(LexicalScope *Scope);
165 
166   /// \brief Construct new DW_TAG_lexical_block for this scope and
167   /// attach DW_AT_low_pc/DW_AT_high_pc labels.
168   DIE *constructLexicalScopeDIE(LexicalScope *Scope);
169 
170   /// constructVariableDIE - Construct a DIE for the given DbgVariable.
171   DIE *constructVariableDIE(DbgVariable &DV, bool Abstract = false);
172 
173   DIE *constructVariableDIE(DbgVariable &DV, const LexicalScope &Scope,
174                             DIE *&ObjectPointer);
175 
176   /// A helper function to create children of a Scope DIE.
177   DIE *createScopeChildrenDIE(LexicalScope *Scope,
178                               SmallVectorImpl<DIE *> &Children,
179                               unsigned *ChildScopeCount = nullptr);
180 
181   /// \brief Construct a DIE for this subprogram scope.
182   void constructSubprogramScopeDIE(const DISubprogram *Sub, LexicalScope *Scope);
183 
184   DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE);
185 
186   void constructAbstractSubprogramScopeDIE(LexicalScope *Scope);
187 
188   /// \brief Construct import_module DIE.
189   DIE *constructImportedEntityDIE(const DIImportedEntity *Module);
190 
191   void finishSubprogramDefinition(const DISubprogram *SP);
192 
193   /// Set the skeleton unit associated with this unit.
194   void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; }
195 
196   unsigned getLength() {
197     return sizeof(uint32_t) + // Length field
198         getHeaderSize() + getUnitDie().getSize();
199   }
200 
201   void emitHeader(bool UseOffsets) override;
202 
203   MCSymbol *getLabelBegin() const {
204     assert(getSection());
205     return LabelBegin;
206   }
207 
208   MCSymbol *getMacroLabelBegin() const {
209     return MacroLabelBegin;
210   }
211 
212   /// Add a new global name to the compile unit.
213   void addGlobalName(StringRef Name, DIE &Die, const DIScope *Context) override;
214 
215   /// Add a new global type to the compile unit.
216   void addGlobalType(const DIType *Ty, const DIE &Die,
217                      const DIScope *Context) override;
218 
219   const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; }
220   const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; }
221 
222   /// Add DW_AT_location attribute for a DbgVariable based on provided
223   /// MachineLocation.
224   void addVariableAddress(const DbgVariable &DV, DIE &Die,
225                           MachineLocation Location);
226   /// Add an address attribute to a die based on the location provided.
227   void addAddress(DIE &Die, dwarf::Attribute Attribute,
228                   const MachineLocation &Location);
229 
230   /// Start with the address based on the location provided, and generate the
231   /// DWARF information necessary to find the actual variable (navigating the
232   /// extra location information encoded in the type) based on the starting
233   /// location.  Add the DWARF information to the die.
234   void addComplexAddress(const DbgVariable &DV, DIE &Die,
235                          dwarf::Attribute Attribute,
236                          const MachineLocation &Location);
237 
238   /// Add a Dwarf loclistptr attribute data and value.
239   void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index);
240   void applyVariableAttributes(const DbgVariable &Var, DIE &VariableDie);
241 
242   /// Add a Dwarf expression attribute data and value.
243   void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr);
244 
245   void applySubprogramAttributesToDefinition(const DISubprogram *SP,
246                                              DIE &SPDie);
247 
248   /// getRangeLists - Get the vector of range lists.
249   const SmallVectorImpl<RangeSpanList> &getRangeLists() const {
250     return (Skeleton ? Skeleton : this)->CURangeLists;
251   }
252 
253   /// getRanges - Get the list of ranges for this unit.
254   const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; }
255   SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); }
256 
257   void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; }
258   const MCSymbol *getBaseAddress() const { return BaseAddress; }
259 };
260 
261 } // end llvm namespace
262 
263 #endif
264