Coverage Report

Created: 2017-10-03 07:32

/Users/buildslave/jenkins/sharedspace/clang-stage2-coverage-R@2/llvm/lib/LTO/Caching.cpp
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//===-Caching.cpp - LLVM Link Time Optimizer Cache Handling ---------------===//
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//
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//                     The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the Caching for ThinLTO.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/LTO/Caching.h"
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#include "llvm/ADT/StringExtras.h"
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#include "llvm/Support/Errc.h"
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#include "llvm/Support/FileSystem.h"
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#include "llvm/Support/MemoryBuffer.h"
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#include "llvm/Support/Path.h"
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#include "llvm/Support/raw_ostream.h"
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using namespace llvm;
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using namespace llvm::lto;
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Expected<NativeObjectCache> lto::localCache(StringRef CacheDirectoryPath,
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                                            AddBufferFn AddBuffer) {
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  if (std::error_code EC = sys::fs::create_directories(CacheDirectoryPath))
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    return errorCodeToError(EC);
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return [=](unsigned Task, StringRef Key) -> AddStreamFn 32
{
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    // This choice of file name allows the cache to be pruned (see pruneCache()
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    // in include/llvm/Support/CachePruning.h).
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    SmallString<64> EntryPath;
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    sys::path::append(EntryPath, CacheDirectoryPath, "llvmcache-" + Key);
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    // First, see if we have a cache hit.
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    ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
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        MemoryBuffer::getFile(EntryPath);
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    if (
MBOrErr46
) {
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      AddBuffer(Task, std::move(*MBOrErr), EntryPath);
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      return AddStreamFn();
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    }
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if (42
MBOrErr.getError() != errc::no_such_file_or_directory42
)
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      report_fatal_error(Twine("Failed to open cache file ") + EntryPath +
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                         ": " + MBOrErr.getError().message() + "\n");
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    // This native object stream is responsible for commiting the resulting
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    // file to the cache and calling AddBuffer to add it to the link.
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    struct CacheStream : NativeObjectStream {
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      AddBufferFn AddBuffer;
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      std::string TempFilename;
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      std::string EntryPath;
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      unsigned Task;
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      CacheStream(std::unique_ptr<raw_pwrite_stream> OS, AddBufferFn AddBuffer,
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                  std::string TempFilename, std::string EntryPath,
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                  unsigned Task)
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          : NativeObjectStream(std::move(OS)), AddBuffer(std::move(AddBuffer)),
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            TempFilename(std::move(TempFilename)),
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            EntryPath(std::move(EntryPath)), Task(Task) {}
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      ~CacheStream() {
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        // Make sure the file is closed before committing it.
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        OS.reset();
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        // Open the file first to avoid racing with a cache pruner.
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        ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
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            MemoryBuffer::getFile(TempFilename);
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        // This is atomic on POSIX systems.
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        if (auto EC = sys::fs::rename(TempFilename, EntryPath))
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          report_fatal_error(Twine("Failed to rename temporary file ") +
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                             TempFilename + ": " + EC.message() + "\n");
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if (42
!MBOrErr42
)
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          report_fatal_error(Twine("Failed to open cache file ") + EntryPath +
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                             ": " + MBOrErr.getError().message() + "\n");
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        AddBuffer(Task, std::move(*MBOrErr), EntryPath);
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      }
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    };
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    return [=](size_t Task) -> std::unique_ptr<NativeObjectStream> {
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      // Write to a temporary to avoid race condition
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      int TempFD;
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      SmallString<64> TempFilenameModel, TempFilename;
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      sys::path::append(TempFilenameModel, CacheDirectoryPath, "Thin-%%%%%%.tmp.o");
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      std::error_code EC =
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          sys::fs::createUniqueFile(TempFilenameModel, TempFD, TempFilename,
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                                    sys::fs::owner_read | sys::fs::owner_write);
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      if (
EC42
) {
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        errs() << "Error: " << EC.message() << "\n";
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        report_fatal_error("ThinLTO: Can't get a temporary file");
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      }
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      // This CacheStream will move the temporary file into the cache when done.
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      return llvm::make_unique<CacheStream>(
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          llvm::make_unique<raw_fd_ostream>(TempFD, /* ShouldClose */ true),
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          AddBuffer, TempFilename.str(), EntryPath.str(), Task);
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    };
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  };
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}