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//===- lib/Support/CodeGenCoverage.cpp -------------------------------------==//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
/// This file implements the CodeGenCoverage class.
//===----------------------------------------------------------------------===//
#include "llvm/Support/CodeGenCoverage.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Mutex.h"
#include "llvm/Support/Process.h"
#include "llvm/Support/ScopedPrinter.h"
#include "llvm/Support/ToolOutputFile.h"
using namespace llvm;
static sys::SmartMutex<true> OutputMutex;
CodeGenCoverage::CodeGenCoverage() {}
void CodeGenCoverage::setCovered(uint64_t RuleID) {
if (RuleCoverage.size() <= RuleID)
RuleCoverage.resize(RuleID + 1, 0);
RuleCoverage[RuleID] = true;
}
bool CodeGenCoverage::isCovered(uint64_t RuleID) const {
if (RuleCoverage.size() <= RuleID)
return false;
return RuleCoverage[RuleID];
}
iterator_range<CodeGenCoverage::const_covered_iterator>
CodeGenCoverage::covered() const {
return RuleCoverage.set_bits();
}
bool CodeGenCoverage::parse(MemoryBuffer &Buffer, StringRef BackendName) {
const char *CurPtr = Buffer.getBufferStart();
while (CurPtr != Buffer.getBufferEnd()) {
// Read the backend name from the input.
const char *LexedBackendName = CurPtr;
while (*CurPtr++ != 0)
;
if (CurPtr == Buffer.getBufferEnd())
return false; // Data is invalid, expected rule id's to follow.
bool IsForThisBackend = BackendName.equals(LexedBackendName);
while (CurPtr != Buffer.getBufferEnd()) {
if (std::distance(CurPtr, Buffer.getBufferEnd()) < 8)
return false; // Data is invalid. Not enough bytes for another rule id.
uint64_t RuleID = support::endian::read64(CurPtr, support::native);
CurPtr += 8;
// ~0ull terminates the rule id list.
if (RuleID == ~0ull)
break;
// Anything else, is recorded or ignored depending on whether it's
// intended for the backend we're interested in.
if (IsForThisBackend)
setCovered(RuleID);
}
}
return true;
}
bool CodeGenCoverage::emit(StringRef CoveragePrefix,
StringRef BackendName) const {
if (!CoveragePrefix.empty() && !RuleCoverage.empty()) {
sys::SmartScopedLock<true> Lock(OutputMutex);
// We can handle locking within a process easily enough but we don't want to
// manage it between multiple processes. Use the process ID to ensure no
// more than one process is ever writing to the same file at the same time.
std::string Pid = llvm::to_string(sys::Process::getProcessId());
std::string CoverageFilename = (CoveragePrefix + Pid).str();
std::error_code EC;
sys::fs::OpenFlags OpenFlags = sys::fs::OF_Append;
std::unique_ptr<ToolOutputFile> CoverageFile =
std::make_unique<ToolOutputFile>(CoverageFilename, EC, OpenFlags);
if (EC)
return false;
uint64_t Zero = 0;
uint64_t InvZero = ~0ull;
CoverageFile->os() << BackendName;
CoverageFile->os().write((const char *)&Zero, sizeof(unsigned char));
for (uint64_t I : RuleCoverage.set_bits())
CoverageFile->os().write((const char *)&I, sizeof(uint64_t));
CoverageFile->os().write((const char *)&InvZero, sizeof(uint64_t));
CoverageFile->keep();
}
return true;
}
void CodeGenCoverage::reset() { RuleCoverage.resize(0); }