xref: /llvm-project/clang/lib/CodeGen/CoverageMappingGen.h (revision 397ac44f623f891d8f05d6673a95984ac0a26671)
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/CommandLine.h"
23 #include "llvm/Support/raw_ostream.h"
24 
25 namespace llvm::coverage {
26 extern cl::opt<bool> SystemHeadersCoverage;
27 }
28 
29 namespace clang {
30 
31 class LangOptions;
32 class SourceManager;
33 class FileEntry;
34 class Preprocessor;
35 class Decl;
36 class Stmt;
37 
38 struct SkippedRange {
39   enum Kind {
40     PPIfElse, // Preprocessor #if/#else ...
41     EmptyLine,
42     Comment,
43   };
44 
45   SourceRange Range;
46   // The location of token before the skipped source range.
47   SourceLocation PrevTokLoc;
48   // The location of token after the skipped source range.
49   SourceLocation NextTokLoc;
50   // The nature of this skipped range
51   Kind RangeKind;
52 
53   bool isComment() { return RangeKind == Comment; }
54   bool isEmptyLine() { return RangeKind == EmptyLine; }
55   bool isPPIfElse() { return RangeKind == PPIfElse; }
56 
57   SkippedRange(SourceRange Range, Kind K,
58                SourceLocation PrevTokLoc = SourceLocation(),
59                SourceLocation NextTokLoc = SourceLocation())
60       : Range(Range), PrevTokLoc(PrevTokLoc), NextTokLoc(NextTokLoc),
61         RangeKind(K) {}
62 };
63 
64 /// Stores additional source code information like skipped ranges which
65 /// is required by the coverage mapping generator and is obtained from
66 /// the preprocessor.
67 class CoverageSourceInfo : public PPCallbacks,
68                            public CommentHandler,
69                            public EmptylineHandler {
70   // A vector of skipped source ranges and PrevTokLoc with NextTokLoc.
71   std::vector<SkippedRange> SkippedRanges;
72 
73   SourceManager &SourceMgr;
74 
75 public:
76   // Location of the token parsed before HandleComment is called. This is
77   // updated every time Preprocessor::Lex lexes a new token.
78   SourceLocation PrevTokLoc;
79 
80   CoverageSourceInfo(SourceManager &SourceMgr) : SourceMgr(SourceMgr) {}
81 
82   std::vector<SkippedRange> &getSkippedRanges() { return SkippedRanges; }
83 
84   void AddSkippedRange(SourceRange Range, SkippedRange::Kind RangeKind);
85 
86   void SourceRangeSkipped(SourceRange Range, SourceLocation EndifLoc) override;
87 
88   void HandleEmptyline(SourceRange Range) override;
89 
90   bool HandleComment(Preprocessor &PP, SourceRange Range) override;
91 
92   void updateNextTokLoc(SourceLocation Loc);
93 };
94 
95 namespace CodeGen {
96 
97 class CodeGenModule;
98 class CounterPair;
99 
100 namespace MCDC {
101 struct State;
102 }
103 
104 /// Organizes the cross-function state that is used while generating
105 /// code coverage mapping data.
106 class CoverageMappingModuleGen {
107   /// Information needed to emit a coverage record for a function.
108   struct FunctionInfo {
109     uint64_t NameHash;
110     uint64_t FuncHash;
111     std::string CoverageMapping;
112     bool IsUsed;
113   };
114 
115   CodeGenModule &CGM;
116   CoverageSourceInfo &SourceInfo;
117   llvm::SmallDenseMap<FileEntryRef, unsigned, 8> FileEntries;
118   std::vector<llvm::Constant *> FunctionNames;
119   std::vector<FunctionInfo> FunctionRecords;
120 
121   std::string getCurrentDirname();
122   std::string normalizeFilename(StringRef Filename);
123 
124   /// Emit a function record.
125   void emitFunctionMappingRecord(const FunctionInfo &Info,
126                                  uint64_t FilenamesRef);
127 
128 public:
129   static CoverageSourceInfo *setUpCoverageCallbacks(Preprocessor &PP);
130 
131   CoverageMappingModuleGen(CodeGenModule &CGM, CoverageSourceInfo &SourceInfo);
132 
133   CoverageSourceInfo &getSourceInfo() const {
134     return SourceInfo;
135   }
136 
137   /// Add a function's coverage mapping record to the collection of the
138   /// function mapping records.
139   void addFunctionMappingRecord(llvm::GlobalVariable *FunctionName,
140                                 StringRef FunctionNameValue,
141                                 uint64_t FunctionHash,
142                                 const std::string &CoverageMapping,
143                                 bool IsUsed = true);
144 
145   /// Emit the coverage mapping data for a translation unit.
146   void emit();
147 
148   /// Return the coverage mapping translation unit file id
149   /// for the given file.
150   unsigned getFileID(FileEntryRef File);
151 
152   /// Return an interface into CodeGenModule.
153   CodeGenModule &getCodeGenModule() { return CGM; }
154 };
155 
156 /// Organizes the per-function state that is used while generating
157 /// code coverage mapping data.
158 class CoverageMappingGen {
159   CoverageMappingModuleGen &CVM;
160   SourceManager &SM;
161   const LangOptions &LangOpts;
162   llvm::DenseMap<const Stmt *, CounterPair> *CounterMap;
163   MCDC::State *MCDCState;
164 
165 public:
166   CoverageMappingGen(CoverageMappingModuleGen &CVM, SourceManager &SM,
167                      const LangOptions &LangOpts)
168       : CVM(CVM), SM(SM), LangOpts(LangOpts), CounterMap(nullptr),
169         MCDCState(nullptr) {}
170 
171   CoverageMappingGen(CoverageMappingModuleGen &CVM, SourceManager &SM,
172                      const LangOptions &LangOpts,
173                      llvm::DenseMap<const Stmt *, CounterPair> *CounterMap,
174                      MCDC::State *MCDCState)
175       : CVM(CVM), SM(SM), LangOpts(LangOpts), CounterMap(CounterMap),
176         MCDCState(MCDCState) {}
177 
178   /// Emit the coverage mapping data which maps the regions of
179   /// code to counters that will be used to find the execution
180   /// counts for those regions.
181   void emitCounterMapping(const Decl *D, llvm::raw_ostream &OS);
182 
183   /// Emit the coverage mapping data for an unused function.
184   /// It creates mapping regions with the counter of zero.
185   void emitEmptyMapping(const Decl *D, llvm::raw_ostream &OS);
186 };
187 
188 } // end namespace CodeGen
189 } // end namespace clang
190 
191 #endif
192