Brad King 48aac247e9 Compile with explicit language flag when source LANGUAGE property is set ...

This change was originally made by commit 74b1c9fc8e (Explicitly specify
language flag when source LANGUAGE property is set, 2020-06-01,
v3.19.0-rc1~722^2), but it was reverted by commit 30aa715fac (Revert
"specify language flag when source LANGUAGE property is set",
2020-11-19) to restore compatibility with pre-3.19 behavior.

Implement the change again, but add policy CMP0119 to make this change
while preserving compatibility with existing projects.

Note that the `Compiler/{Clang,Intel,MSVC}-CXX` modules do not need to
specify `-TP` for their MSVC-like variants because we already use the
flag in `CMAKE_CXX_COMPILE_OBJECT`.  Similarly for `Compiler/XL-CXX`
and `Platform/Windows-Embarcadero`.

Note also that this does not seem possible to implement for XL C.
Even with `-qsourcetype=c`, `xlc` complains about an unknown suffix:
`1501-218 (W) file /.../AltExtC.zzz contains an incorrect file suffix`.
It returns non-zero even with `-qsuppress=1501-218`.

Co-Author: Robert Maynard <robert.maynard@kitware.com>
Fixes: #14516, #20716

2020-12-02 11:39:11 -05:00

..

bar.c

Compile with explicit language flag when source LANGUAGE property is set

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CMakeLists.txt

Compile with explicit language flag when source LANGUAGE property is set

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foo.c

…

stay_c.c

VS: Restore toleration of target-wide -TP flag with MSVC

2020-07-23 10:54:35 -04:00

stay_cxx.cxx

VS: Restore toleration of target-wide -TP flag with MSVC

2020-07-23 10:54:35 -04:00

zoom.zzz

Compile with explicit language flag when source LANGUAGE property is set

2020-12-02 11:39:11 -05:00