[ThinLTO] Option to control path of distributed backend files
Summary:
Add support to control where files for a distributed backend (the
individual index files and optional imports files) are created.
This is invoked with a new thinlto-prefix-replace option in the gold
plugin and llvm-lto. If specified, expects a string of the form
"oldprefix:newprefix", and instead of generating these files in the
same directory path as the corresponding bitcode file, will use a path
formed by replacing the bitcode file's path prefix matching oldprefix
with newprefix.
Also add a new replace_path_prefix helper to Path.h in libSupport.
Depends on D19636.
Reviewers: joker.eph
Subscribers: llvm-commits, joker.eph
Differential Revision: http://reviews.llvm.org/D19644
llvm-svn: 269771
diff --git a/llvm/lib/Support/Path.cpp b/llvm/lib/Support/Path.cpp
index f9a71b9..406a37b 100644
--- a/llvm/lib/Support/Path.cpp
+++ b/llvm/lib/Support/Path.cpp
@@ -522,6 +522,29 @@
path.append(ext.begin(), ext.end());
}
+void replace_path_prefix(SmallVectorImpl<char> &Path,
+ const StringRef &OldPrefix,
+ const StringRef &NewPrefix) {
+ if (OldPrefix.empty() && NewPrefix.empty())
+ return;
+
+ StringRef OrigPath(Path.begin(), Path.size());
+ if (!OrigPath.startswith(OldPrefix))
+ return;
+
+ // If prefixes have the same size we can simply copy the new one over.
+ if (OldPrefix.size() == NewPrefix.size()) {
+ std::copy(NewPrefix.begin(), NewPrefix.end(), Path.begin());
+ return;
+ }
+
+ StringRef RelPath = OrigPath.substr(OldPrefix.size());
+ SmallString<256> NewPath;
+ path::append(NewPath, NewPrefix);
+ path::append(NewPath, RelPath);
+ Path.swap(NewPath);
+}
+
void native(const Twine &path, SmallVectorImpl<char> &result) {
assert((!path.isSingleStringRef() ||
path.getSingleStringRef().data() != result.data()) &&