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/ADT/StringRef.h"
19 #include "llvm/IR/DebugInfo.h"
20 #include "llvm/Support/Dwarf.h"
21 
22 namespace llvm {
23 
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   /// The attribute index of DW_AT_stmt_list in the compile unit DIE, avoiding
33   /// the need to search for it in applyStmtList.
34   unsigned stmtListIndex;
35 
36   /// Skeleton unit associated with this unit.
37   DwarfCompileUnit *Skeleton;
38 
39   /// The start of the unit within its section.
40   MCSymbol *LabelBegin;
41 
42   /// GlobalNames - A map of globally visible named entities for this unit.
43   StringMap<const DIE *> GlobalNames;
44 
45   /// GlobalTypes - A map of globally visible types for this unit.
46   StringMap<const DIE *> GlobalTypes;
47 
48   // List of range lists for a given compile unit, separate from the ranges for
49   // the CU itself.
50   SmallVector<RangeSpanList, 1> CURangeLists;
51 
52   // List of ranges for a given compile unit.
53   SmallVector<RangeSpan, 2> CURanges;
54 
55   // The base address of this unit, if any. Used for relative references in
56   // ranges/locs.
57   const MCSymbol *BaseAddress;
58 
59   /// \brief Construct a DIE for the given DbgVariable without initializing the
60   /// DbgVariable's DIE reference.
61   std::unique_ptr<DIE> constructVariableDIEImpl(const DbgVariable &DV,
62                                                 bool Abstract);
63 
64   bool isDwoUnit() const override;
65 
66   bool includeMinimalInlineScopes() const;
67 
68 public:
69   DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A,
70                    DwarfDebug *DW, DwarfFile *DWU);
71 
72   DwarfCompileUnit *getSkeleton() const {
73     return Skeleton;
74   }
75 
76   void initStmtList();
77 
78   /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE.
79   void applyStmtList(DIE &D);
80 
81   /// getOrCreateGlobalVariableDIE - get or create global variable DIE.
82   DIE *getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV);
83 
84   /// addLabelAddress - Add a dwarf label attribute data and value using
85   /// either DW_FORM_addr or DW_FORM_GNU_addr_index.
86   void addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
87                        const MCSymbol *Label);
88 
89   /// addLocalLabelAddress - Add a dwarf label attribute data and value using
90   /// DW_FORM_addr only.
91   void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute,
92                             const MCSymbol *Label);
93 
94   /// addSectionDelta - Add a label delta attribute data and value.
95   void addSectionDelta(DIE &Die, dwarf::Attribute Attribute, const MCSymbol *Hi,
96                        const MCSymbol *Lo);
97 
98   DwarfCompileUnit &getCU() override { return *this; }
99 
100   unsigned getOrCreateSourceID(StringRef FileName, StringRef DirName) override;
101 
102   /// addRange - Add an address range to the list of ranges for this unit.
103   void addRange(RangeSpan Range);
104 
105   void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End);
106 
107   /// addSectionLabel - Add a Dwarf section label attribute data and value.
108   ///
109   void addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
110                        const MCSymbol *Label, const MCSymbol *Sec);
111 
112   /// \brief Find DIE for the given subprogram and attach appropriate
113   /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
114   /// variables in this scope then create and insert DIEs for these
115   /// variables.
116   DIE &updateSubprogramScopeDIE(const DISubprogram *SP);
117 
118   void constructScopeDIE(LexicalScope *Scope,
119                          SmallVectorImpl<std::unique_ptr<DIE>> &FinalChildren);
120 
121   /// \brief A helper function to construct a RangeSpanList for a given
122   /// lexical scope.
123   void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range);
124 
125   void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges);
126 
127   void attachRangesOrLowHighPC(DIE &D,
128                                const SmallVectorImpl<InsnRange> &Ranges);
129   /// \brief This scope represents inlined body of a function. Construct
130   /// DIE to represent this concrete inlined copy of the function.
131   std::unique_ptr<DIE> constructInlinedScopeDIE(LexicalScope *Scope);
132 
133   /// \brief Construct new DW_TAG_lexical_block for this scope and
134   /// attach DW_AT_low_pc/DW_AT_high_pc labels.
135   std::unique_ptr<DIE> constructLexicalScopeDIE(LexicalScope *Scope);
136 
137   /// constructVariableDIE - Construct a DIE for the given DbgVariable.
138   std::unique_ptr<DIE> constructVariableDIE(DbgVariable &DV,
139                                             bool Abstract = false);
140 
141   std::unique_ptr<DIE> constructVariableDIE(DbgVariable &DV,
142                                             const LexicalScope &Scope,
143                                             DIE *&ObjectPointer);
144 
145   /// A helper function to create children of a Scope DIE.
146   DIE *createScopeChildrenDIE(LexicalScope *Scope,
147                               SmallVectorImpl<std::unique_ptr<DIE>> &Children,
148                               unsigned *ChildScopeCount = nullptr);
149 
150   /// \brief Construct a DIE for this subprogram scope.
151   void constructSubprogramScopeDIE(LexicalScope *Scope);
152 
153   DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE);
154 
155   void constructAbstractSubprogramScopeDIE(LexicalScope *Scope);
156 
157   /// \brief Construct import_module DIE.
158   std::unique_ptr<DIE>
159   constructImportedEntityDIE(const DIImportedEntity *Module);
160 
161   void finishSubprogramDefinition(const DISubprogram *SP);
162 
163   void collectDeadVariables(const DISubprogram *SP);
164 
165   /// Set the skeleton unit associated with this unit.
166   void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; }
167 
168   const MCSymbol *getSectionSym() const {
169     assert(Section);
170     return Section->getBeginSymbol();
171   }
172 
173   unsigned getLength() {
174     return sizeof(uint32_t) + // Length field
175         getHeaderSize() + UnitDie.getSize();
176   }
177 
178   void emitHeader(bool UseOffsets) override;
179 
180   MCSymbol *getLabelBegin() const {
181     assert(Section);
182     return LabelBegin;
183   }
184 
185   /// Add a new global name to the compile unit.
186   void addGlobalName(StringRef Name, DIE &Die, const DIScope *Context) override;
187 
188   /// Add a new global type to the compile unit.
189   void addGlobalType(const DIType *Ty, const DIE &Die,
190                      const DIScope *Context) override;
191 
192   const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; }
193   const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; }
194 
195   /// Add DW_AT_location attribute for a DbgVariable based on provided
196   /// MachineLocation.
197   void addVariableAddress(const DbgVariable &DV, DIE &Die,
198                           MachineLocation Location);
199   /// Add an address attribute to a die based on the location provided.
200   void addAddress(DIE &Die, dwarf::Attribute Attribute,
201                   const MachineLocation &Location);
202 
203   /// Start with the address based on the location provided, and generate the
204   /// DWARF information necessary to find the actual variable (navigating the
205   /// extra location information encoded in the type) based on the starting
206   /// location.  Add the DWARF information to the die.
207   void addComplexAddress(const DbgVariable &DV, DIE &Die,
208                          dwarf::Attribute Attribute,
209                          const MachineLocation &Location);
210 
211   /// Add a Dwarf loclistptr attribute data and value.
212   void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index);
213   void applyVariableAttributes(const DbgVariable &Var, DIE &VariableDie);
214 
215   /// Add a Dwarf expression attribute data and value.
216   void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr);
217 
218   void applySubprogramAttributesToDefinition(const DISubprogram *SP,
219                                              DIE &SPDie);
220 
221   /// getRangeLists - Get the vector of range lists.
222   const SmallVectorImpl<RangeSpanList> &getRangeLists() const {
223     return (Skeleton ? Skeleton : this)->CURangeLists;
224   }
225 
226   /// getRanges - Get the list of ranges for this unit.
227   const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; }
228   SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); }
229 
230   void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; }
231   const MCSymbol *getBaseAddress() const { return BaseAddress; }
232 };
233 
234 } // end llvm namespace
235 
236 #endif
237