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-rw-r--r--llvm/include/llvm/LTO/Caching.h11
-rw-r--r--llvm/lib/LTO/Caching.cpp33
-rw-r--r--llvm/tools/gold/gold-plugin.cpp8
-rw-r--r--llvm/tools/llvm-lto2/llvm-lto2.cpp11
4 files changed, 41 insertions, 22 deletions
diff --git a/llvm/include/llvm/LTO/Caching.h b/llvm/include/llvm/LTO/Caching.h
index fe18009b14c..f5ec70e081c 100644
--- a/llvm/include/llvm/LTO/Caching.h
+++ b/llvm/include/llvm/LTO/Caching.h
@@ -24,14 +24,19 @@ namespace lto {
/// This type defines the callback to add a pre-existing native object file
/// (e.g. in a cache).
///
-/// File callbacks must be thread safe.
-typedef std::function<void(unsigned Task, StringRef Path)> AddFileFn;
+/// MB->getBufferIdentifier() is a valid path for the file at the time that it
+/// was opened, but clients should prefer to access MB directly in order to
+/// avoid a potential race condition.
+///
+/// Buffer callbacks must be thread safe.
+typedef std::function<void(unsigned Task, std::unique_ptr<MemoryBuffer> MB)>
+ AddBufferFn;
/// Create a local file system cache which uses the given cache directory and
/// file callback. This function also creates the cache directory if it does not
/// already exist.
Expected<NativeObjectCache> localCache(StringRef CacheDirectoryPath,
- AddFileFn AddFile);
+ AddBufferFn AddBuffer);
} // namespace lto
} // namespace llvm
diff --git a/llvm/lib/LTO/Caching.cpp b/llvm/lib/LTO/Caching.cpp
index b7542049dbf..d8b91c48ee3 100644
--- a/llvm/lib/LTO/Caching.cpp
+++ b/llvm/lib/LTO/Caching.cpp
@@ -22,7 +22,7 @@ using namespace llvm;
using namespace llvm::lto;
Expected<NativeObjectCache> lto::localCache(StringRef CacheDirectoryPath,
- AddFileFn AddFile) {
+ AddBufferFn AddBuffer) {
if (std::error_code EC = sys::fs::create_directories(CacheDirectoryPath))
return errorCodeToError(EC);
@@ -30,34 +30,49 @@ Expected<NativeObjectCache> lto::localCache(StringRef CacheDirectoryPath,
// First, see if we have a cache hit.
SmallString<64> EntryPath;
sys::path::append(EntryPath, CacheDirectoryPath, Key);
- if (sys::fs::exists(EntryPath)) {
- AddFile(Task, EntryPath);
+ ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
+ MemoryBuffer::getFile(EntryPath);
+ if (MBOrErr) {
+ AddBuffer(Task, std::move(*MBOrErr));
return AddStreamFn();
}
+ if (MBOrErr.getError() != std::errc::no_such_file_or_directory)
+ report_fatal_error(Twine("Failed to open cache file ") + EntryPath +
+ ": " + MBOrErr.getError().message() + "\n");
+
// This native object stream is responsible for commiting the resulting
- // file to the cache and calling AddFile to add it to the link.
+ // file to the cache and calling AddBuffer to add it to the link.
struct CacheStream : NativeObjectStream {
- AddFileFn AddFile;
+ AddBufferFn AddBuffer;
std::string TempFilename;
std::string EntryPath;
unsigned Task;
- CacheStream(std::unique_ptr<raw_pwrite_stream> OS, AddFileFn AddFile,
+ CacheStream(std::unique_ptr<raw_pwrite_stream> OS, AddBufferFn AddBuffer,
std::string TempFilename, std::string EntryPath,
unsigned Task)
- : NativeObjectStream(std::move(OS)), AddFile(std::move(AddFile)),
+ : NativeObjectStream(std::move(OS)), AddBuffer(std::move(AddBuffer)),
TempFilename(std::move(TempFilename)),
EntryPath(std::move(EntryPath)), Task(Task) {}
~CacheStream() {
+ // FIXME: This code could race with the cache pruner, but it is unlikely
+ // that the cache pruner will choose to remove a newly created file.
+
// Make sure the file is closed before committing it.
OS.reset();
// This is atomic on POSIX systems.
if (auto EC = sys::fs::rename(TempFilename, EntryPath))
report_fatal_error(Twine("Failed to rename temporary file ") +
TempFilename + ": " + EC.message() + "\n");
- AddFile(Task, EntryPath);
+
+ ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
+ MemoryBuffer::getFile(EntryPath);
+ if (!MBOrErr)
+ report_fatal_error(Twine("Failed to open cache file ") + EntryPath +
+ ": " + MBOrErr.getError().message() + "\n");
+ AddBuffer(Task, std::move(*MBOrErr));
}
};
@@ -77,7 +92,7 @@ Expected<NativeObjectCache> lto::localCache(StringRef CacheDirectoryPath,
// This CacheStream will move the temporary file into the cache when done.
return llvm::make_unique<CacheStream>(
llvm::make_unique<raw_fd_ostream>(TempFD, /* ShouldClose */ true),
- AddFile, TempFilename.str(), EntryPath.str(), Task);
+ AddBuffer, TempFilename.str(), EntryPath.str(), Task);
};
};
}
diff --git a/llvm/tools/gold/gold-plugin.cpp b/llvm/tools/gold/gold-plugin.cpp
index 123d90df890..38674d20717 100644
--- a/llvm/tools/gold/gold-plugin.cpp
+++ b/llvm/tools/gold/gold-plugin.cpp
@@ -831,11 +831,15 @@ static ld_plugin_status allSymbolsReadHook() {
llvm::make_unique<llvm::raw_fd_ostream>(FD, true));
};
- auto AddFile = [&](size_t Task, StringRef Path) { Filenames[Task] = Path; };
+ auto AddBuffer = [&](size_t Task, std::unique_ptr<MemoryBuffer> MB) {
+ // Note that this requires that the memory buffers provided to AddBuffer are
+ // backed by a file.
+ Filenames[Task] = MB->getBufferIdentifier();
+ };
NativeObjectCache Cache;
if (!options::cache_dir.empty())
- Cache = check(localCache(options::cache_dir, AddFile));
+ Cache = check(localCache(options::cache_dir, AddBuffer));
check(Lto->run(AddStream, Cache));
diff --git a/llvm/tools/llvm-lto2/llvm-lto2.cpp b/llvm/tools/llvm-lto2/llvm-lto2.cpp
index 3fe0487476f..ce0f4b98425 100644
--- a/llvm/tools/llvm-lto2/llvm-lto2.cpp
+++ b/llvm/tools/llvm-lto2/llvm-lto2.cpp
@@ -275,18 +275,13 @@ int main(int argc, char **argv) {
return llvm::make_unique<lto::NativeObjectStream>(std::move(S));
};
- auto AddFile = [&](size_t Task, StringRef Path) {
- auto ReloadedBufferOrErr = MemoryBuffer::getFile(Path);
- if (auto EC = ReloadedBufferOrErr.getError())
- report_fatal_error(Twine("Can't reload cached file '") + Path + "': " +
- EC.message() + "\n");
-
- *AddStream(Task)->OS << (*ReloadedBufferOrErr)->getBuffer();
+ auto AddBuffer = [&](size_t Task, std::unique_ptr<MemoryBuffer> MB) {
+ *AddStream(Task)->OS << MB->getBuffer();
};
NativeObjectCache Cache;
if (!CacheDir.empty())
- Cache = check(localCache(CacheDir, AddFile), "failed to create cache");
+ Cache = check(localCache(CacheDir, AddBuffer), "failed to create cache");
check(Lto.run(AddStream, Cache), "LTO::run failed");
}
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