Add -fpch-instantiate-templates which makes template instantiations be
performed already in the PCH instead of it being done in every single
file that uses the PCH (but every single file will still do it as well
in order to handle its own instantiations). I can see 20-30% build
time saved with the few tests I've tried.
The change may reorder compiler output and also generated code, but
should be generally safe and produce functionally identical code.
There are some rare cases that do not compile with it,
such as test/PCH/pch-instantiate-templates-forward-decl.cpp. If
template instantiation bailed out instead of reporting the error,
these instantiations could even be postponed, which would make them
work.
Enable this by default for clang-cl. MSVC creates PCHs by compiling
them using an empty .cpp file, which means templates are instantiated
while building the PCH and so the .h needs to be self-contained,
making test/PCH/pch-instantiate-templates-forward-decl.cpp to fail
with MSVC anyway. So the option being enabled for clang-cl matches this.
Differential Revision: https://reviews.llvm.org/D69585
This is accomplished by making VerifyDiagnosticsConsumer a CommentHandler,
which then only reads the -verify directives that are actually in live
blocks of code. It also makes it simpler to handle -verify directives that
appear in header files, though we still have to manually reparse some files
depending on how they are generated.
This requires some test changes. In particular, all PCH tests now have their
-verify directives outside the "header" portion of the file, using the @line
syntax added in r159978. Other tests have been modified mostly to make it
clear what is being tested, and to prevent polluting the expected output with
the directives themselves.
Patch by Andy Gibbs! (with slight modifications)
The new Frontend/verify-* tests exercise the functionality of this commit,
as well as r159978, r159979, and r160053 (Andy's other -verify enhancements).
llvm-svn: 160068
Luboš Luňák