Cut down the number of open/close system calls for output files.
For PCH files, have only one open/close for temporary + rename to be safe from race conditions.
For all other output files open/close the output file directly.
Depends on llvm r136310. rdar://9082880 & http://llvm.org/PR9374.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@136315 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/ASTUnit.cpp b/lib/Frontend/ASTUnit.cpp
index c2901c1..dea9ed1 100644
--- a/lib/Frontend/ASTUnit.cpp
+++ b/lib/Frontend/ASTUnit.cpp
@@ -2309,23 +2309,17 @@
// Write to a temporary file and later rename it to the actual file, to avoid
// possible race conditions.
- llvm::sys::Path TempPath(File);
- if (TempPath.makeUnique(/*reuse_current=*/false, /*ErrMsg*/0))
+ llvm::SmallString<128> TempPath;
+ TempPath = File;
+ TempPath += "-%%%%%%%%";
+ int fd;
+ if (llvm::sys::fs::unique_file(TempPath.str(), fd, TempPath,
+ /*makeAbsolute=*/false))
return CXSaveError_Unknown;
- // makeUnique may or may not have created the file. Try deleting before
- // opening so that we can use F_Excl for exclusive access.
- TempPath.eraseFromDisk();
// FIXME: Can we somehow regenerate the stat cache here, or do we need to
// unconditionally create a stat cache when we parse the file?
- std::string ErrorInfo;
- llvm::raw_fd_ostream Out(TempPath.c_str(), ErrorInfo,
- llvm::raw_fd_ostream::F_Binary |
- // if TempPath already exists, we should not try to
- // overwrite it, we want to avoid race conditions.
- llvm::raw_fd_ostream::F_Excl);
- if (!ErrorInfo.empty() || Out.has_error())
- return CXSaveError_Unknown;
+ llvm::raw_fd_ostream Out(fd, /*shouldClose=*/true);
serialize(Out);
Out.close();
diff --git a/lib/Frontend/CompilerInstance.cpp b/lib/Frontend/CompilerInstance.cpp
index ef0796a..026cb5a 100644
--- a/lib/Frontend/CompilerInstance.cpp
+++ b/lib/Frontend/CompilerInstance.cpp
@@ -437,11 +437,13 @@
CompilerInstance::createOutputFile(StringRef OutputPath,
bool Binary, bool RemoveFileOnSignal,
StringRef InFile,
- StringRef Extension) {
+ StringRef Extension,
+ bool UseTemporary) {
std::string Error, OutputPathName, TempPathName;
llvm::raw_fd_ostream *OS = createOutputFile(OutputPath, Error, Binary,
RemoveFileOnSignal,
InFile, Extension,
+ UseTemporary,
&OutputPathName,
&TempPathName);
if (!OS) {
@@ -465,6 +467,7 @@
bool RemoveFileOnSignal,
StringRef InFile,
StringRef Extension,
+ bool UseTemporary,
std::string *ResultPathName,
std::string *TempPathName) {
std::string OutFile, TempFile;
@@ -480,8 +483,11 @@
} else {
OutFile = "-";
}
-
- if (OutFile != "-") {
+
+ llvm::OwningPtr<llvm::raw_fd_ostream> OS;
+ std::string OSFile;
+
+ if (UseTemporary && OutFile != "-") {
llvm::sys::Path OutPath(OutFile);
// Only create the temporary if we can actually write to OutPath, otherwise
// we want to fail early.
@@ -489,21 +495,26 @@
if ((llvm::sys::fs::exists(OutPath.str(), Exists) || !Exists) ||
(OutPath.isRegularFile() && OutPath.canWrite())) {
// Create a temporary file.
- llvm::sys::Path TempPath(OutFile);
- if (!TempPath.makeUnique(/*reuse_current=*/false, /*ErrMsg*/0))
- TempFile = TempPath.str();
+ llvm::SmallString<128> TempPath;
+ TempPath = OutFile;
+ TempPath += "-%%%%%%%%";
+ int fd;
+ if (llvm::sys::fs::unique_file(TempPath.str(), fd, TempPath,
+ /*makeAbsolute=*/false) == llvm::errc::success) {
+ OS.reset(new llvm::raw_fd_ostream(fd, /*shouldClose=*/true));
+ OSFile = TempFile = TempPath.str();
+ }
}
}
- std::string OSFile = OutFile;
- if (!TempFile.empty())
- OSFile = TempFile;
-
- llvm::OwningPtr<llvm::raw_fd_ostream> OS(
- new llvm::raw_fd_ostream(OSFile.c_str(), Error,
- (Binary ? llvm::raw_fd_ostream::F_Binary : 0)));
- if (!Error.empty())
- return 0;
+ if (!OS) {
+ OSFile = OutFile;
+ OS.reset(
+ new llvm::raw_fd_ostream(OSFile.c_str(), Error,
+ (Binary ? llvm::raw_fd_ostream::F_Binary : 0)));
+ if (!Error.empty())
+ return 0;
+ }
// Make sure the out stream file gets removed if we crash.
if (RemoveFileOnSignal)
diff --git a/lib/Frontend/FrontendActions.cpp b/lib/Frontend/FrontendActions.cpp
index 44cd2df..4eb9cda 100644
--- a/lib/Frontend/FrontendActions.cpp
+++ b/lib/Frontend/FrontendActions.cpp
@@ -102,8 +102,10 @@
// We use createOutputFile here because this is exposed via libclang, and we
// must disable the RemoveFileOnSignal behavior.
+ // We use a temporary to avoid race conditions.
OS = CI.createOutputFile(CI.getFrontendOpts().OutputFile, /*Binary=*/true,
- /*RemoveFileOnSignal=*/false, InFile);
+ /*RemoveFileOnSignal=*/false, InFile,
+ /*Extension=*/"", /*useTemporary=*/true);
if (!OS)
return true;