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names and years are hard to maintain and often out-of-date or plain wrong.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.
Starting with Xcode 8 the SDK folder also contains an unversioned
entry:
$ ls -l /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs
drwxr-xr-x 5 root wheel 170 Mar 4 2018 MacOSX.sdk
lrwxr-xr-x 1 root wheel 10 Sep 16 20:49 MacOSX10.12.sdk -> MacOSX.sdk
If this unversioned path is used CMake cannot detect the SDK
version. To work around the problem we always invoke the code path
that translates short SDK names like "macosx10.12" into a path.
That way we always end up with a versioned SDK path in
_CMAKE_OSX_SYSROOT_PATH which is later used to determine the version.
Closes: #16323
The `.pbxproj` file must now specify a `SWIFT_VERSION` value.
Set it to the legacy value of "2.3" for now. Later this can
be made configurable (e.g. to "3.0").
All Fortran sources need to be preprocessed before any source may be
compiled so that module dependencies can be (later) extracted. Factor
out an explicit preprocessing step preceding compilation. Use Ninja
depfile dependencies on the preprocessing step and then compile the
already-preprocessed source with a separate build statement that depends
explicitly only on the preprocessor output. Later we will insert
dynamic discovery of module dependencies between these steps.
Since commit v3.6.0-rc1~182^2 (FindOpenSSL: Prefer libs early in search
path regardless of name, 2016-04-04) we use the `NAMES_PER_DIR` option
to `find_library` calls to consider all names in each directory before
moving on to the next directory. Fix our library search directory
ordering to place more-specific (e.g. VC/) directories before the
general directories. Otherwise they may never be considered.
Closes: #16320