tree 082ec112c309c887aaf754b99a464a1be6ad52d1
parent 121babae56e9f08acedf3d6d44757e35556d0a37
author Shivanshu Goyal <Shivanshu.Goyal@microsoft.com> 1601993568 +0200
committer Hans Wennborg <hans@chromium.org> 1602065024 +0200

Add ability to turn off -fpch-instantiate-templates in clang-cl

A lot of our code building with clang-cl.exe using Clang 11 was failing with
the following 2 type of errors:

1. explicit specialization of 'foo' after instantiation
2. no matching function for call to 'bar'

Note that we also use -fdelayed-template-parsing in our builds.

I tried pretty hard to get a small repro for these failures, but couldn't. So
there is some subtle edge case in the -fpch-instantiate-templates feature
introduced by this change: https://reviews.llvm.org/D69585

When I tried turning this off using -fno-pch-instantiate-templates, builds
would silently fail with the same error without any indication that
-fno-pch-instantiate-templates was being ignored by the compiler. Then I
realized this "no" option wasn't actually working when I ran Clang under a
debugger.

Differential revision: https://reviews.llvm.org/D88680

(cherry picked from commit 66e4f07198761bbb4dcd55235024c1081ed15c75)