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      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 /// \brief Find subprogram that is enclosing this scope.
     32 DISubprogram *getDISubprogram(const MDNode *Scope);
     33 
     34 /// \brief 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 /// \brief Return Debug Info Metadata Version by checking module flags.
     55 unsigned getDebugMetadataVersionFromModule(const Module &M);
     56 
     57 /// \brief 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   /// \brief Process entire module and collect debug info anchors.
     68   void processModule(const Module &M);
     69 
     70   /// \brief Process DbgDeclareInst.
     71   void processDeclare(const Module &M, const DbgDeclareInst *DDI);
     72   /// \brief Process DbgValueInst.
     73   void processValue(const Module &M, const DbgValueInst *DVI);
     74   /// \brief Process debug info location.
     75   void processLocation(const Module &M, const DILocation *Loc);
     76 
     77   /// \brief Clear all lists.
     78   void reset();
     79 
     80 private:
     81   void InitializeTypeMap(const Module &M);
     82 
     83   void processType(DIType *DT);
     84   void processSubprogram(DISubprogram *SP);
     85   void processScope(DIScope *Scope);
     86   bool addCompileUnit(DICompileUnit *CU);
     87   bool addGlobalVariable(DIGlobalVariableExpression *DIG);
     88   bool addSubprogram(DISubprogram *SP);
     89   bool addType(DIType *DT);
     90   bool addScope(DIScope *Scope);
     91 
     92 public:
     93   using compile_unit_iterator =
     94       SmallVectorImpl<DICompileUnit *>::const_iterator;
     95   using subprogram_iterator = SmallVectorImpl<DISubprogram *>::const_iterator;
     96   using global_variable_expression_iterator =
     97       SmallVectorImpl<DIGlobalVariableExpression *>::const_iterator;
     98   using type_iterator = SmallVectorImpl<DIType *>::const_iterator;
     99   using scope_iterator = SmallVectorImpl<DIScope *>::const_iterator;
    100 
    101   iterator_range<compile_unit_iterator> compile_units() const {
    102     return make_range(CUs.begin(), CUs.end());
    103   }
    104 
    105   iterator_range<subprogram_iterator> subprograms() const {
    106     return make_range(SPs.begin(), SPs.end());
    107   }
    108 
    109   iterator_range<global_variable_expression_iterator> global_variables() const {
    110     return make_range(GVs.begin(), GVs.end());
    111   }
    112 
    113   iterator_range<type_iterator> types() const {
    114     return make_range(TYs.begin(), TYs.end());
    115   }
    116 
    117   iterator_range<scope_iterator> scopes() const {
    118     return make_range(Scopes.begin(), Scopes.end());
    119   }
    120 
    121   unsigned compile_unit_count() const { return CUs.size(); }
    122   unsigned global_variable_count() const { return GVs.size(); }
    123   unsigned subprogram_count() const { return SPs.size(); }
    124   unsigned type_count() const { return TYs.size(); }
    125   unsigned scope_count() const { return Scopes.size(); }
    126 
    127 private:
    128   SmallVector<DICompileUnit *, 8> CUs;
    129   SmallVector<DISubprogram *, 8> SPs;
    130   SmallVector<DIGlobalVariableExpression *, 8> GVs;
    131   SmallVector<DIType *, 8> TYs;
    132   SmallVector<DIScope *, 8> Scopes;
    133   SmallPtrSet<const MDNode *, 32> NodesSeen;
    134 };
    135 
    136 } // end namespace llvm
    137 
    138 #endif // LLVM_IR_DEBUGINFO_H
    139