1 //===- lib/Support/CodeGenCoverage.cpp -------------------------------------==// 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 /// \file 10 /// This file implements the CodeGenCoverage class. 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/Support/CodeGenCoverage.h" 14 15 #include "llvm/Support/Endian.h" 16 #include "llvm/Support/FileSystem.h" 17 #include "llvm/Support/MemoryBuffer.h" 18 #include "llvm/Support/Mutex.h" 19 #include "llvm/Support/ScopedPrinter.h" 20 #include "llvm/Support/ToolOutputFile.h" 21 22 #if LLVM_ON_UNIX 23 #include <unistd.h> 24 #elif LLVM_ON_WIN32 25 #include <windows.h> 26 #endif 27 28 using namespace llvm; 29 30 static sys::SmartMutex<true> OutputMutex; 31 32 CodeGenCoverage::CodeGenCoverage() {} 33 34 void CodeGenCoverage::setCovered(uint64_t RuleID) { 35 if (RuleCoverage.size() <= RuleID) 36 RuleCoverage.resize(RuleID + 1, 0); 37 RuleCoverage[RuleID] = true; 38 } 39 40 bool CodeGenCoverage::isCovered(uint64_t RuleID) { 41 if (RuleCoverage.size() <= RuleID) 42 return false; 43 return RuleCoverage[RuleID]; 44 } 45 46 bool CodeGenCoverage::parse(MemoryBuffer &Buffer, StringRef BackendName) { 47 const char *CurPtr = Buffer.getBufferStart(); 48 49 while (CurPtr != Buffer.getBufferEnd()) { 50 // Read the backend name from the input. 51 const char *LexedBackendName = CurPtr; 52 while (*CurPtr++ != 0) 53 ; 54 if (CurPtr == Buffer.getBufferEnd()) 55 return false; // Data is invalid, expected rule id's to follow. 56 57 bool IsForThisBackend = BackendName.equals(LexedBackendName); 58 while (CurPtr != Buffer.getBufferEnd()) { 59 if (std::distance(CurPtr, Buffer.getBufferEnd()) < 8) 60 return false; // Data is invalid. Not enough bytes for another rule id. 61 62 uint64_t RuleID = support::endian::read64(CurPtr, support::native); 63 CurPtr += 8; 64 65 // ~0ull terminates the rule id list. 66 if (RuleID == ~0ull) 67 break; 68 69 // Anything else, is recorded or ignored depending on whether it's 70 // intended for the backend we're interested in. 71 if (IsForThisBackend) 72 setCovered(RuleID); 73 } 74 } 75 76 return true; 77 } 78 79 bool CodeGenCoverage::emit(StringRef CoveragePrefix, 80 StringRef BackendName) const { 81 if (!CoveragePrefix.empty() && !RuleCoverage.empty()) { 82 sys::SmartScopedLock<true> Lock(OutputMutex); 83 84 // We can handle locking within a process easily enough but we don't want to 85 // manage it between multiple processes. Use the process ID to ensure no 86 // more than one process is ever writing to the same file at the same time. 87 std::string Pid = 88 #if LLVM_ON_UNIX 89 llvm::to_string(::getpid()); 90 #elif LLVM_ON_WIN32 91 llvm::to_string(::GetCurrentProcessId()); 92 #else 93 ""; 94 #endif 95 96 std::string CoverageFilename = (CoveragePrefix + Pid).str(); 97 98 std::error_code EC; 99 sys::fs::OpenFlags OpenFlags = sys::fs::F_Append; 100 std::unique_ptr<ToolOutputFile> CoverageFile = 101 llvm::make_unique<ToolOutputFile>(CoverageFilename, EC, OpenFlags); 102 if (EC) 103 return false; 104 105 uint64_t Zero = 0; 106 uint64_t InvZero = ~0ull; 107 CoverageFile->os() << BackendName; 108 CoverageFile->os().write((const char *)&Zero, sizeof(unsigned char)); 109 for (uint64_t I : RuleCoverage.set_bits()) 110 CoverageFile->os().write((const char *)&I, sizeof(uint64_t)); 111 CoverageFile->os().write((const char *)&InvZero, sizeof(uint64_t)); 112 113 CoverageFile->keep(); 114 } 115 116 return true; 117 } 118 119 void CodeGenCoverage::reset() { RuleCoverage.resize(0); } 120