The CheckSourceCompiles and CheckCompilerFlag would generally be preferred general
command syntax, but users may not realize they exist, so help point them there.
CMAKE_REQUIRED_FLAGS now notes that space-delimited string, not
;-list is required, which could be surprising compared to similar
options that do use ;-list
The conversion of Check<Lang>CompilerFlag, SourceCompiles, and
SourceRuns over to the new functions has the possibility of breaking
projects that had functions with those existing names.
To reduce the possibility of collisions we now have all the
legacy code call functions that start with `cmake_`, and users
will need to explicitly include the new modules to get the
non-prefixed versions
Fixes: #21359
In commit 357e2ef429 (CheckSoureRuns: Add a unified way to check if a
source runs, 2020-09-14, v3.19.0-rc1~118^2), the default Fortran source
file extension was accidentally changed from `.F90` to `.F`. Fix that.
In commit 10ae907de0 (CheckSoureCompiles: Add a unified way to check if
a source compiles, 2020-09-14, v3.19.0-rc1~118^2~1), the default Fortran
source extension was correctly preserved as `.F`, but `.F90` is a better
default both for consistency and modern usage. Use that for direct
calls to the `check_source_compiles` macro. Update our original
`check_fortran_source_compiles` implementation to use `.F` by default
as it did before.
Fixes: #21307
The test project is compiled with a `-DVAR` compiler flag where `VAR` is
the result variable. Tell `try_compile` to add the flag through
`add_definitions` instead of `CMAKE_Fortran_FLAGS` so that it is not
used for linking. Otherwise some Fortran compilers (e.g. XL 15) do not
like the flag when used to drive linking.
* Replace '::' by '.. code-block:: cmake' wherever it makes sense.
* Convert to definition list where appropriate.
* Prefer '<placeholder>' over 'placeholder'.
Per-source copyright/license notice headers that spell out copyright holder
names and years are hard to maintain and often out-of-date or plain wrong.
Precise contributor information is already maintained automatically by the
version control tool. Ultimately it is the receiver of a file who is
responsible for determining its licensing status, and per-source notices are
merely a convenience. Therefore it is simpler and more accurate for
each source to have a generic notice of the license name and references to
more detailed information on copyright holders and full license terms.
Our `Copyright.txt` file now contains a list of Contributors whose names
appeared source-level copyright notices. It also references version control
history for more precise information. Therefore we no longer need to spell
out the list of Contributors in each source file notice.
Replace CMake per-source copyright/license notice headers with a short
description of the license and links to `Copyright.txt` and online information
available from "https://cmake.org/licensing". The online URL also handles
cases of modules being copied out of our source into other projects, so we
can drop our notices about replacing links with full license text.
Run the `Utilities/Scripts/filter-notices.bash` script to perform the majority
of the replacements mechanically. Manually fix up shebang lines and trailing
newlines in a few files. Manually update the notices in a few files that the
script does not handle.
Copy the CheckCSourceCompiles module and port it to Fortran.
Extend the FortranOnly test to try using the new module.
Suggested-by: Nicolas Bock <nicolasbock@gmail.com>
