112 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8/// \file9/// 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 22using namespace llvm;23 24CodeGenCoverage::CodeGenCoverage() = default;25 26void CodeGenCoverage::setCovered(uint64_t RuleID) {27 if (RuleCoverage.size() <= RuleID)28 RuleCoverage.resize(RuleID + 1, false);29 RuleCoverage[RuleID] = true;30}31 32bool CodeGenCoverage::isCovered(uint64_t RuleID) const {33 if (RuleCoverage.size() <= RuleID)34 return false;35 return RuleCoverage[RuleID];36}37 38iterator_range<CodeGenCoverage::const_covered_iterator>39CodeGenCoverage::covered() const {40 return RuleCoverage.set_bits();41}42 43bool CodeGenCoverage::parse(MemoryBuffer &Buffer, StringRef BackendName) {44 const char *CurPtr = Buffer.getBufferStart();45 46 while (CurPtr != Buffer.getBufferEnd()) {47 // Read the backend name from the input.48 const char *LexedBackendName = CurPtr;49 while (*CurPtr++ != 0)50 ;51 if (CurPtr == Buffer.getBufferEnd())52 return false; // Data is invalid, expected rule id's to follow.53 54 bool IsForThisBackend = BackendName == LexedBackendName;55 while (CurPtr != Buffer.getBufferEnd()) {56 if (std::distance(CurPtr, Buffer.getBufferEnd()) < 8)57 return false; // Data is invalid. Not enough bytes for another rule id.58 59 uint64_t RuleID =60 support::endian::read64(CurPtr, llvm::endianness::native);61 CurPtr += 8;62 63 // ~0ull terminates the rule id list.64 if (RuleID == ~0ull)65 break;66 67 // Anything else, is recorded or ignored depending on whether it's68 // intended for the backend we're interested in.69 if (IsForThisBackend)70 setCovered(RuleID);71 }72 }73 74 return true;75}76 77bool CodeGenCoverage::emit(StringRef CoveragePrefix,78 StringRef BackendName) const {79 if (!CoveragePrefix.empty() && !RuleCoverage.empty()) {80 static sys::SmartMutex<true> OutputMutex;81 sys::SmartScopedLock<true> Lock(OutputMutex);82 83 // We can handle locking within a process easily enough but we don't want to84 // manage it between multiple processes. Use the process ID to ensure no85 // 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 111void CodeGenCoverage::reset() { RuleCoverage.resize(0); }112