1 //===-- DWARFDebugInfoEntry.h -----------------------------------*- 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 #ifndef LLVM_LIB_DEBUGINFO_DWARFDEBUGINFOENTRY_H
11 #define LLVM_LIB_DEBUGINFO_DWARFDEBUGINFOENTRY_H
12 
13 #include "llvm/ADT/SmallVector.h"
14 #include "llvm/DebugInfo/DIContext.h"
15 #include "llvm/DebugInfo/DWARF/DWARFAbbreviationDeclaration.h"
16 #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
17 #include "llvm/Support/DataTypes.h"
18 
19 namespace llvm {
20 
21 class DWARFDebugAranges;
22 class DWARFCompileUnit;
23 class DWARFUnit;
24 class DWARFContext;
25 class DWARFFormValue;
26 struct DWARFDebugInfoEntryInlinedChain;
27 
28 /// DWARFDebugInfoEntryMinimal - A DIE with only the minimum required data.
29 class DWARFDebugInfoEntryMinimal {
30   /// Offset within the .debug_info of the start of this entry.
31   uint32_t Offset;
32 
33   /// How many to add to "this" to get the sibling.
34   uint32_t SiblingIdx;
35 
36   const DWARFAbbreviationDeclaration *AbbrevDecl;
37 public:
DWARFDebugInfoEntryMinimal()38   DWARFDebugInfoEntryMinimal()
39     : Offset(0), SiblingIdx(0), AbbrevDecl(nullptr) {}
40 
41   void dump(raw_ostream &OS, DWARFUnit *u, unsigned recurseDepth,
42             unsigned indent = 0) const;
43   void dumpAttribute(raw_ostream &OS, DWARFUnit *u, uint32_t *offset_ptr,
44                      uint16_t attr, uint16_t form, unsigned indent = 0) const;
45 
46   /// Extracts a debug info entry, which is a child of a given unit,
47   /// starting at a given offset. If DIE can't be extracted, returns false and
48   /// doesn't change OffsetPtr.
49   bool extractFast(const DWARFUnit *U, uint32_t *OffsetPtr);
50 
getTag()51   uint32_t getTag() const { return AbbrevDecl ? AbbrevDecl->getTag() : 0; }
isNULL()52   bool isNULL() const { return AbbrevDecl == nullptr; }
53 
54   /// Returns true if DIE represents a subprogram (not inlined).
55   bool isSubprogramDIE() const;
56   /// Returns true if DIE represents a subprogram or an inlined
57   /// subroutine.
58   bool isSubroutineDIE() const;
59 
getOffset()60   uint32_t getOffset() const { return Offset; }
hasChildren()61   bool hasChildren() const { return !isNULL() && AbbrevDecl->hasChildren(); }
62 
63   // We know we are kept in a vector of contiguous entries, so we know
64   // our sibling will be some index after "this".
getSibling()65   const DWARFDebugInfoEntryMinimal *getSibling() const {
66     return SiblingIdx > 0 ? this + SiblingIdx : nullptr;
67   }
68 
69   // We know we are kept in a vector of contiguous entries, so we know
70   // we don't need to store our child pointer, if we have a child it will
71   // be the next entry in the list...
getFirstChild()72   const DWARFDebugInfoEntryMinimal *getFirstChild() const {
73     return hasChildren() ? this + 1 : nullptr;
74   }
75 
setSibling(const DWARFDebugInfoEntryMinimal * Sibling)76   void setSibling(const DWARFDebugInfoEntryMinimal *Sibling) {
77     if (Sibling) {
78       // We know we are kept in a vector of contiguous entries, so we know
79       // our sibling will be some index after "this".
80       SiblingIdx = Sibling - this;
81     } else
82       SiblingIdx = 0;
83   }
84 
getAbbreviationDeclarationPtr()85   const DWARFAbbreviationDeclaration *getAbbreviationDeclarationPtr() const {
86     return AbbrevDecl;
87   }
88 
89   bool getAttributeValue(const DWARFUnit *U, const uint16_t Attr,
90                          DWARFFormValue &FormValue) const;
91 
92   const char *getAttributeValueAsString(const DWARFUnit *U, const uint16_t Attr,
93                                         const char *FailValue) const;
94 
95   uint64_t getAttributeValueAsAddress(const DWARFUnit *U, const uint16_t Attr,
96                                       uint64_t FailValue) const;
97 
98   uint64_t getAttributeValueAsUnsignedConstant(const DWARFUnit *U,
99                                                const uint16_t Attr,
100                                                uint64_t FailValue) const;
101 
102   uint64_t getAttributeValueAsReference(const DWARFUnit *U, const uint16_t Attr,
103                                         uint64_t FailValue) const;
104 
105   uint64_t getAttributeValueAsSectionOffset(const DWARFUnit *U,
106                                             const uint16_t Attr,
107                                             uint64_t FailValue) const;
108 
109   uint64_t getRangesBaseAttribute(const DWARFUnit *U, uint64_t FailValue) const;
110 
111   /// Retrieves DW_AT_low_pc and DW_AT_high_pc from CU.
112   /// Returns true if both attributes are present.
113   bool getLowAndHighPC(const DWARFUnit *U, uint64_t &LowPC,
114                        uint64_t &HighPC) const;
115 
116   DWARFAddressRangesVector getAddressRanges(const DWARFUnit *U) const;
117 
118   void collectChildrenAddressRanges(const DWARFUnit *U,
119                                     DWARFAddressRangesVector &Ranges) const;
120 
121   bool addressRangeContainsAddress(const DWARFUnit *U,
122                                    const uint64_t Address) const;
123 
124   /// If a DIE represents a subprogram (or inlined subroutine),
125   /// returns its mangled name (or short name, if mangled is missing).
126   /// This name may be fetched from specification or abstract origin
127   /// for this subprogram. Returns null if no name is found.
128   const char *getSubroutineName(const DWARFUnit *U, DINameKind Kind) const;
129 
130   /// Return the DIE name resolving DW_AT_sepcification or
131   /// DW_AT_abstract_origin references if necessary.
132   /// Returns null if no name is found.
133   const char *getName(const DWARFUnit *U, DINameKind Kind) const;
134 
135   /// Retrieves values of DW_AT_call_file, DW_AT_call_line and
136   /// DW_AT_call_column from DIE (or zeroes if they are missing).
137   void getCallerFrame(const DWARFUnit *U, uint32_t &CallFile,
138                       uint32_t &CallLine, uint32_t &CallColumn) const;
139 
140   /// Get inlined chain for a given address, rooted at the current DIE.
141   /// Returns empty chain if address is not contained in address range
142   /// of current DIE.
143   DWARFDebugInfoEntryInlinedChain
144   getInlinedChainForAddress(const DWARFUnit *U, const uint64_t Address) const;
145 };
146 
147 /// DWARFDebugInfoEntryInlinedChain - represents a chain of inlined_subroutine
148 /// DIEs, (possibly ending with subprogram DIE), all of which are contained
149 /// in some concrete inlined instance tree. Address range for each DIE
150 /// (except the last DIE) in this chain is contained in address
151 /// range for next DIE in the chain.
152 struct DWARFDebugInfoEntryInlinedChain {
DWARFDebugInfoEntryInlinedChainDWARFDebugInfoEntryInlinedChain153   DWARFDebugInfoEntryInlinedChain() : U(nullptr) {}
154   SmallVector<DWARFDebugInfoEntryMinimal, 4> DIEs;
155   const DWARFUnit *U;
156 };
157 
158 }
159 
160 #endif
161