[libclang] Add a flag to create the precompiled preamble on the first parse.
Summary:
The current default is to create the preamble on the first reparse, aka
second parse. This is useful for clients that do not want to block when
opening a file because serializing the preamble takes a bit of time.
However, this makes the reparse much more expensive and that may be on the
critical path as it's the first interaction a user has with the source code.
YouCompleteMe currently optimizes for the first code interaction by parsing
the file twice when loaded. That's just unnecessarily slow and this flag
helps to avoid that.
Reviewers: doug.gregor, klimek
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D15490
llvm-svn: 255635
diff --git a/clang/tools/c-index-test/c-index-test.c b/clang/tools/c-index-test/c-index-test.c
index 948195d..48f22eb 100644
--- a/clang/tools/c-index-test/c-index-test.c
+++ b/clang/tools/c-index-test/c-index-test.c
@@ -76,7 +76,9 @@
options |= CXTranslationUnit_SkipFunctionBodies;
if (getenv("CINDEXTEST_COMPLETION_BRIEF_COMMENTS"))
options |= CXTranslationUnit_IncludeBriefCommentsInCodeCompletion;
-
+ if (getenv("CINDEXTEST_CREATE_PREAMBLE_ON_FIRST_PARSE"))
+ options |= CXTranslationUnit_CreatePreambleOnFirstParse;
+
return options;
}