[PATCH] D23599: [ThinLTO] Add caching to the new LTO API

[Teresa Johnson via llvm-commits]

tejohnson accepted this revision.
tejohnson added a comment.
This revision is now accepted and ready to land.

This now works with the support I added to gold-plugin (will commit as a follow-on) with the following change. This is required because append() will cause EntryPath to be CacheDirectoryPath+"/" and the test later in the destructor will not think they are equal.

diff --git a/lib/LTO/Caching.cpp b/lib/LTO/Caching.cpp
index 11e9fd6..9bba3ab 100644

- a/lib/LTO/Caching.cpp

+++ b/lib/LTO/Caching.cpp
@@ -93,10 +93,12 @@ std::unique_ptr<raw_pwrite_stream> CacheObjectOutput::getStream() {
 bool CacheObjectOutput::tryLoadFromCache(StringRef Key) {

  assert(!CacheDirectoryPath.empty() &&
         "CacheObjectOutput was initialized without a cache path");

- sys::path::append(EntryPath, CacheDirectoryPath, Key);
- if (Key.empty())
- // Client didn't compute a valid key. EntryPath has been set to

+  if (Key.empty()) {
+    // Client didn't compute a valid key. Set EntryPath to

  // CacheDirectoryPath.

+    EntryPath = CacheDirectoryPath;

  return false;

+  }
+  sys::path::append(EntryPath, CacheDirectoryPath, Key);

  return sys::fs::exists(EntryPath);

}


================
Comment at: lib/LTO/LTOBackend.cpp:248
@@ +247,3 @@
+    };
+    codegen(C, TM.get(), AddOutputWrapper, 0, *M);
+  } else {
----------------
Consider refactoring this so the above block from the AddOutput call through the codegen call are in a helper passed a ThreadId, then it can be called here and in splitCodeGen.


https://reviews.llvm.org/D23599