1 //===- DebugInfo.h - Debug Information Helpers ------------------*- 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 defines a bunch of datatypes that are useful for creating and
11 // walking debug info in LLVM IR form. They essentially provide wrappers around
12 // the information in the global variables that's needed when constructing the
13 // DWARF information.
14 //
15 //===----------------------------------------------------------------------===//
16 
17 #ifndef LLVM_IR_DEBUGINFO_H
18 #define LLVM_IR_DEBUGINFO_H
19 
20 #include "llvm/ADT/SmallPtrSet.h"
21 #include "llvm/ADT/SmallVector.h"
22 #include "llvm/ADT/iterator_range.h"
23 #include "llvm/IR/DebugInfoMetadata.h"
24 
25 namespace llvm {
26 
27 class DbgDeclareInst;
28 class DbgValueInst;
29 class Module;
30 
31 /// Find subprogram that is enclosing this scope.
32 DISubprogram *getDISubprogram(const MDNode *Scope);
33 
34 /// Strip debug info in the module if it exists.
35 ///
36 /// To do this, we remove all calls to the debugger intrinsics and any named
37 /// metadata for debugging. We also remove debug locations for instructions.
38 /// Return true if module is modified.
39 bool StripDebugInfo(Module &M);
40 bool stripDebugInfo(Function &F);
41 
42 /// Downgrade the debug info in a module to contain only line table information.
43 ///
44 /// In order to convert debug info to what -gline-tables-only would have
45 /// created, this does the following:
46 ///   1) Delete all debug intrinsics.
47 ///   2) Delete all non-CU named metadata debug info nodes.
48 ///   3) Create new DebugLocs for each instruction.
49 ///   4) Create a new CU debug info, and similarly for every metadata node
50 ///      that's reachable from the CU debug info.
51 ///   All debug type metadata nodes are unreachable and garbage collected.
52 bool stripNonLineTableDebugInfo(Module &M);
53 
54 /// Return Debug Info Metadata Version by checking module flags.
55 unsigned getDebugMetadataVersionFromModule(const Module &M);
56 
57 /// Utility to find all debug info in a module.
58 ///
59 /// DebugInfoFinder tries to list all debug info MDNodes used in a module. To
60 /// list debug info MDNodes used by an instruction, DebugInfoFinder uses
61 /// processDeclare, processValue and processLocation to handle DbgDeclareInst,
62 /// DbgValueInst and DbgLoc attached to instructions. processModule will go
63 /// through all DICompileUnits in llvm.dbg.cu and list debug info MDNodes
64 /// used by the CUs.
65 class DebugInfoFinder {
66 public:
67   /// Process entire module and collect debug info anchors.
68   void processModule(const Module &M);
69   /// Process a single instruction and collect debug info anchors.
70   void processInstruction(const Module &M, const Instruction &I);
71 
72   /// Process DbgDeclareInst.
73   void processDeclare(const Module &M, const DbgDeclareInst *DDI);
74   /// Process DbgValueInst.
75   void processValue(const Module &M, const DbgValueInst *DVI);
76   /// Process debug info location.
77   void processLocation(const Module &M, const DILocation *Loc);
78 
79   /// Clear all lists.
80   void reset();
81 
82 private:
83   void InitializeTypeMap(const Module &M);
84 
85   void processCompileUnit(DICompileUnit *CU);
86   void processScope(DIScope *Scope);
87   void processSubprogram(DISubprogram *SP);
88   void processType(DIType *DT);
89   bool addCompileUnit(DICompileUnit *CU);
90   bool addGlobalVariable(DIGlobalVariableExpression *DIG);
91   bool addScope(DIScope *Scope);
92   bool addSubprogram(DISubprogram *SP);
93   bool addType(DIType *DT);
94 
95 public:
96   using compile_unit_iterator =
97       SmallVectorImpl<DICompileUnit *>::const_iterator;
98   using subprogram_iterator = SmallVectorImpl<DISubprogram *>::const_iterator;
99   using global_variable_expression_iterator =
100       SmallVectorImpl<DIGlobalVariableExpression *>::const_iterator;
101   using type_iterator = SmallVectorImpl<DIType *>::const_iterator;
102   using scope_iterator = SmallVectorImpl<DIScope *>::const_iterator;
103 
compile_units()104   iterator_range<compile_unit_iterator> compile_units() const {
105     return make_range(CUs.begin(), CUs.end());
106   }
107 
subprograms()108   iterator_range<subprogram_iterator> subprograms() const {
109     return make_range(SPs.begin(), SPs.end());
110   }
111 
global_variables()112   iterator_range<global_variable_expression_iterator> global_variables() const {
113     return make_range(GVs.begin(), GVs.end());
114   }
115 
types()116   iterator_range<type_iterator> types() const {
117     return make_range(TYs.begin(), TYs.end());
118   }
119 
scopes()120   iterator_range<scope_iterator> scopes() const {
121     return make_range(Scopes.begin(), Scopes.end());
122   }
123 
compile_unit_count()124   unsigned compile_unit_count() const { return CUs.size(); }
global_variable_count()125   unsigned global_variable_count() const { return GVs.size(); }
subprogram_count()126   unsigned subprogram_count() const { return SPs.size(); }
type_count()127   unsigned type_count() const { return TYs.size(); }
scope_count()128   unsigned scope_count() const { return Scopes.size(); }
129 
130 private:
131   SmallVector<DICompileUnit *, 8> CUs;
132   SmallVector<DISubprogram *, 8> SPs;
133   SmallVector<DIGlobalVariableExpression *, 8> GVs;
134   SmallVector<DIType *, 8> TYs;
135   SmallVector<DIScope *, 8> Scopes;
136   SmallPtrSet<const MDNode *, 32> NodesSeen;
137 };
138 
139 } // end namespace llvm
140 
141 #endif // LLVM_IR_DEBUGINFO_H
142