1 //===- lib/Support/CodeGenCoverage.cpp -------------------------------------==// 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 /// \file 9 /// This file implements the CodeGenCoverage class. 10 //===----------------------------------------------------------------------===// 11 12 #include "llvm/Support/CodeGenCoverage.h" 13 14 #include "llvm/Support/Endian.h" 15 #include "llvm/Support/FileSystem.h" 16 #include "llvm/Support/MemoryBuffer.h" 17 #include "llvm/Support/Mutex.h" 18 #include "llvm/Support/Process.h" 19 #include "llvm/Support/ScopedPrinter.h" 20 #include "llvm/Support/ToolOutputFile.h" 21 22 using namespace llvm; 23 24 static sys::SmartMutex<true> OutputMutex; 25 26 CodeGenCoverage::CodeGenCoverage() = default; 27 28 void CodeGenCoverage::setCovered(uint64_t RuleID) { 29 if (RuleCoverage.size() <= RuleID) 30 RuleCoverage.resize(RuleID + 1, false); 31 RuleCoverage[RuleID] = true; 32 } 33 34 bool CodeGenCoverage::isCovered(uint64_t RuleID) const { 35 if (RuleCoverage.size() <= RuleID) 36 return false; 37 return RuleCoverage[RuleID]; 38 } 39 40 iterator_range<CodeGenCoverage::const_covered_iterator> 41 CodeGenCoverage::covered() const { 42 return RuleCoverage.set_bits(); 43 } 44 45 bool CodeGenCoverage::parse(MemoryBuffer &Buffer, StringRef BackendName) { 46 const char *CurPtr = Buffer.getBufferStart(); 47 48 while (CurPtr != Buffer.getBufferEnd()) { 49 // Read the backend name from the input. 50 const char *LexedBackendName = CurPtr; 51 while (*CurPtr++ != 0) 52 ; 53 if (CurPtr == Buffer.getBufferEnd()) 54 return false; // Data is invalid, expected rule id's to follow. 55 56 bool IsForThisBackend = BackendName.equals(LexedBackendName); 57 while (CurPtr != Buffer.getBufferEnd()) { 58 if (std::distance(CurPtr, Buffer.getBufferEnd()) < 8) 59 return false; // Data is invalid. Not enough bytes for another rule id. 60 61 uint64_t RuleID = support::endian::read64(CurPtr, support::native); 62 CurPtr += 8; 63 64 // ~0ull terminates the rule id list. 65 if (RuleID == ~0ull) 66 break; 67 68 // Anything else, is recorded or ignored depending on whether it's 69 // intended for the backend we're interested in. 70 if (IsForThisBackend) 71 setCovered(RuleID); 72 } 73 } 74 75 return true; 76 } 77 78 bool CodeGenCoverage::emit(StringRef CoveragePrefix, 79 StringRef BackendName) const { 80 if (!CoveragePrefix.empty() && !RuleCoverage.empty()) { 81 sys::SmartScopedLock<true> Lock(OutputMutex); 82 83 // We can handle locking within a process easily enough but we don't want to 84 // manage it between multiple processes. Use the process ID to ensure no 85 // more than one process is ever writing to the same file at the same time. 86 std::string Pid = llvm::to_string(sys::Process::getProcessId()); 87 88 std::string CoverageFilename = (CoveragePrefix + Pid).str(); 89 90 std::error_code EC; 91 sys::fs::OpenFlags OpenFlags = sys::fs::OF_Append; 92 std::unique_ptr<ToolOutputFile> CoverageFile = 93 std::make_unique<ToolOutputFile>(CoverageFilename, EC, OpenFlags); 94 if (EC) 95 return false; 96 97 uint64_t Zero = 0; 98 uint64_t InvZero = ~0ull; 99 CoverageFile->os() << BackendName; 100 CoverageFile->os().write((const char *)&Zero, sizeof(unsigned char)); 101 for (uint64_t I : RuleCoverage.set_bits()) 102 CoverageFile->os().write((const char *)&I, sizeof(uint64_t)); 103 CoverageFile->os().write((const char *)&InvZero, sizeof(uint64_t)); 104 105 CoverageFile->keep(); 106 } 107 108 return true; 109 } 110 111 void CodeGenCoverage::reset() { RuleCoverage.resize(0); } 112