1 //===---- CoverageMappingGen.h - Coverage mapping generation ----*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Instrumentation-based code coverage mapping generator
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CLANG_LIB_CODEGEN_COVERAGEMAPPINGGEN_H
14 #define LLVM_CLANG_LIB_CODEGEN_COVERAGEMAPPINGGEN_H
15 
16 #include "clang/Basic/LLVM.h"
17 #include "clang/Basic/SourceLocation.h"
18 #include "clang/Lex/PPCallbacks.h"
19 #include "clang/Lex/Preprocessor.h"
20 #include "llvm/ADT/DenseMap.h"
21 #include "llvm/IR/GlobalValue.h"
22 #include "llvm/Support/raw_ostream.h"
23 
24 namespace clang {
25 
26 class LangOptions;
27 class SourceManager;
28 class FileEntry;
29 class Preprocessor;
30 class Decl;
31 class Stmt;
32 
33 struct SkippedRange {
34   enum Kind {
35     PPIfElse, // Preprocessor #if/#else ...
36     EmptyLine,
37     Comment,
38   };
39 
40   SourceRange Range;
41   // The location of token before the skipped source range.
42   SourceLocation PrevTokLoc;
43   // The location of token after the skipped source range.
44   SourceLocation NextTokLoc;
45   // The nature of this skipped range
46   Kind RangeKind;
47 
48   bool isComment() { return RangeKind == Comment; }
49   bool isEmptyLine() { return RangeKind == EmptyLine; }
50   bool isPPIfElse() { return RangeKind == PPIfElse; }
51 
52   SkippedRange(SourceRange Range, Kind K,
53                SourceLocation PrevTokLoc = SourceLocation(),
54                SourceLocation NextTokLoc = SourceLocation())
55       : Range(Range), PrevTokLoc(PrevTokLoc), NextTokLoc(NextTokLoc),
56         RangeKind(K) {}
57 };
58 
59 /// Stores additional source code information like skipped ranges which
60 /// is required by the coverage mapping generator and is obtained from
61 /// the preprocessor.
62 class CoverageSourceInfo : public PPCallbacks,
63                            public CommentHandler,
64                            public EmptylineHandler {
65   // A vector of skipped source ranges and PrevTokLoc with NextTokLoc.
66   std::vector<SkippedRange> SkippedRanges;
67 
68   SourceManager &SourceMgr;
69 
70 public:
71   // Location of the token parsed before HandleComment is called. This is
72   // updated every time Preprocessor::Lex lexes a new token.
73   SourceLocation PrevTokLoc;
74 
75   CoverageSourceInfo(SourceManager &SourceMgr) : SourceMgr(SourceMgr) {}
76 
77   std::vector<SkippedRange> &getSkippedRanges() { return SkippedRanges; }
78 
79   void AddSkippedRange(SourceRange Range, SkippedRange::Kind RangeKind);
80 
81   void SourceRangeSkipped(SourceRange Range, SourceLocation EndifLoc) override;
82 
83   void HandleEmptyline(SourceRange Range) override;
84 
85   bool HandleComment(Preprocessor &PP, SourceRange Range) override;
86 
87   void updateNextTokLoc(SourceLocation Loc);
88 };
89 
90 namespace CodeGen {
91 
92 class CodeGenModule;
93 
94 /// Organizes the cross-function state that is used while generating
95 /// code coverage mapping data.
96 class CoverageMappingModuleGen {
97   /// Information needed to emit a coverage record for a function.
98   struct FunctionInfo {
99     uint64_t NameHash;
100     uint64_t FuncHash;
101     std::string CoverageMapping;
102     bool IsUsed;
103   };
104 
105   CodeGenModule &CGM;
106   CoverageSourceInfo &SourceInfo;
107   llvm::SmallDenseMap<const FileEntry *, unsigned, 8> FileEntries;
108   std::vector<llvm::Constant *> FunctionNames;
109   std::vector<FunctionInfo> FunctionRecords;
110   std::map<std::string, std::string> CoveragePrefixMap;
111 
112   std::string getCurrentDirname();
113   std::string normalizeFilename(StringRef Filename);
114 
115   /// Emit a function record.
116   void emitFunctionMappingRecord(const FunctionInfo &Info,
117                                  uint64_t FilenamesRef);
118 
119 public:
120   static CoverageSourceInfo *setUpCoverageCallbacks(Preprocessor &PP);
121 
122   CoverageMappingModuleGen(CodeGenModule &CGM, CoverageSourceInfo &SourceInfo);
123 
124   CoverageSourceInfo &getSourceInfo() const {
125     return SourceInfo;
126   }
127 
128   /// Add a function's coverage mapping record to the collection of the
129   /// function mapping records.
130   void addFunctionMappingRecord(llvm::GlobalVariable *FunctionName,
131                                 StringRef FunctionNameValue,
132                                 uint64_t FunctionHash,
133                                 const std::string &CoverageMapping,
134                                 bool IsUsed = true);
135 
136   /// Emit the coverage mapping data for a translation unit.
137   void emit();
138 
139   /// Return the coverage mapping translation unit file id
140   /// for the given file.
141   unsigned getFileID(const FileEntry *File);
142 
143   /// Return an interface into CodeGenModule.
144   CodeGenModule &getCodeGenModule() { return CGM; }
145 };
146 
147 /// Organizes the per-function state that is used while generating
148 /// code coverage mapping data.
149 class CoverageMappingGen {
150   CoverageMappingModuleGen &CVM;
151   SourceManager &SM;
152   const LangOptions &LangOpts;
153   llvm::DenseMap<const Stmt *, unsigned> *CounterMap;
154 
155 public:
156   CoverageMappingGen(CoverageMappingModuleGen &CVM, SourceManager &SM,
157                      const LangOptions &LangOpts)
158       : CVM(CVM), SM(SM), LangOpts(LangOpts), CounterMap(nullptr) {}
159 
160   CoverageMappingGen(CoverageMappingModuleGen &CVM, SourceManager &SM,
161                      const LangOptions &LangOpts,
162                      llvm::DenseMap<const Stmt *, unsigned> *CounterMap)
163       : CVM(CVM), SM(SM), LangOpts(LangOpts), CounterMap(CounterMap) {}
164 
165   /// Emit the coverage mapping data which maps the regions of
166   /// code to counters that will be used to find the execution
167   /// counts for those regions.
168   void emitCounterMapping(const Decl *D, llvm::raw_ostream &OS);
169 
170   /// Emit the coverage mapping data for an unused function.
171   /// It creates mapping regions with the counter of zero.
172   void emitEmptyMapping(const Decl *D, llvm::raw_ostream &OS);
173 };
174 
175 } // end namespace CodeGen
176 } // end namespace clang
177 
178 #endif
179