Commit Graph

4 Commits

Author SHA1 Message Date
Luboš Luňák a45f713c67 add option to instantiate templates already in the PCH
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
2020-06-21 17:05:52 +02:00
Richard Smith 55b6f68f4b Revert "Fix rejects-valid when referencing an implicit operator== from within a"
This change may have caused some self-host failures. Reverting while
investigating.

This reverts commit c7fbe2191b.
2020-06-17 16:05:26 -07:00
Richard Smith c7fbe2191b Fix rejects-valid when referencing an implicit operator== from within a
templated class.

When a defaulted operator<=> results in the injection of a defaulted
operator==, that operator== can be named by unqualified name within the
same class, even if the class is templated. To make this work, perform
the transform from defaulted operator<=> to defaulted operator== in the
template definition context instead of the template instantiation
context.

This results in our substituting into a declaration from a context where
we don't have a full list of template arguments (or indeed any), for
which we are now more careful to not spuriously instantiate declarations
that are not dependent on the arguments we're substituting.
2020-06-17 15:12:04 -07:00
Richard Smith 848934c67d [c++20] Fix handling of unqualified lookups from a defaulted comparison
function.

We need to perform unqualified lookups from the context of a defaulted
comparison, but not until we implicitly define the function, at which
point we can't do those lookups any more. So perform the lookup from the
end of the class containing the =default declaration and store the
lookup results on the defaulted function until we synthesize the body.
2019-12-09 17:40:36 -08:00