Merge-request: !2970

Both `LIBXML2_FOUND` and `LibXml2_FOUND` are provided but the modern
convention is to use the case that matches the module name.

Merge-request: !2962

Merge-request: !2958

The naming convention for submodule files varies across compilers.  Add
a table to the compiler information modules and thread the information
through to the Fortran module dependency parser.  Fill out the table for
compiler ids known to support Fortran submodules.

Fixes: #18746

The check added by commit 0a29a311 (VS2017: Verify Windows 8.1 SDK
before using it, 2017-04-25, v3.8.1~2^2) used the wrong path to
`windows.h` within the SDK, leading to it never being detected.

Fixes: #18923

Merge-request: !2956

The `cmsys/Enconding.h` include had a typo in its surrounding ifdef,
possibly causing a missing function declaration (`cmsysEncoding_DupToWide`).
As this is C code, this resulted in the code compiling, but with a truncated
return value, possibly causing crashes.

Merge-request: !2957

Since commit 5990ecb7 (Compute implicit include directories from
compiler output, 2018-12-07, v3.14.0-rc1~108^2) the values of the
`CMAKE_<LANG>_IMPLICIT_INCLUDE_DIRECTORIES` variables are computed from
a real compiler invocation.  In this case the paths under the sysroot
should already have the sysroot prefix so we should no longer have to
add the sysroot prefix.  However, it is also possible for project code
to add its own paths to `CMAKE_<LANG>_IMPLICIT_INCLUDE_DIRECTORIES`
without the sysroot prefix and expect the historical addition of the
sysroot prefix to be preserved.

Try to account for both cases by conditionally adding the sysroot prefix
on implicit include directories that do not already have it.

The change in commit 15ad8300 (Refactor exclusion of -I/usr/include to
avoid per-language values, 2019-01-21, v3.14.0-rc1~108^2~4) caused the
exclusion to apply to Fortran, but it was only meant for C, CXX, and
CUDA.  The purpose of the change was to prepare for the value of
`CMAKE_<LANG>_IMPLICIT_INCLUDE_DIRECTORIES` to be computed from the
actual compiler instead of hard-coded.  We need to preserve exclusion of
`-I/usr/include` if the compiler has any implicit include directory that
looks intended to replace it, e.g. `<sdk>/usr/include` on macOS.

Fixes: #18914

In commit 1293ed85 (ParseImplicitIncludeInfo: keep implicit incl.
consistent when rerunning cmake, 2019-01-30, v3.14.0-rc1~26^2) the
`Platform/UnixPaths` module was updated to add `/usr/include` to
`CMAKE_{C,CXX,CUDA}_IMPLICIT_INCLUDE_DIRECTORIES` through an
initialization variable used by `CMakeDetermineCompilerABI` instead of
directly.  This approach makes it only a default that can be overridden
by detection of the implicit include directories really used by the
compiler.

The addition of `<sdk>/usr/include` to default implicit include
directories by the `Platform/Darwin` module needs the same update but
was accidentally left out of the original commit.

Merge-request: !2954

Fixes: #18894

Merge-request: !2950

In CMake 3.13.x, we had this evaluation for if() conditions:

    if(a) elseif(b) else(a) endif(a)

The sensible intention of the change in commit c2efb3ef (Help: Revise
docs on Scripting Commands, 2018-10-16, v3.14.0-rc1~505^2) was:

> "endif", "endfunction" etc: Explain that the argument is optional and
> maintained for compatibility only

Instead of "endif", it ended up being written to the documentation as
"elseif" by the commit author (oops) to if()'s page.

    if(a) elseif(a!?) else() endif(a?)

Truthfully, endif()'s parameter should be an optional verbatim repeat
and not elseif()'s. If it wasn't, elseif() would be described to be the
same as if(). The rightful intended description is:

    if(a) elseif(b) else() endif()

Fix that typo.

Merge-request: !2949

Merge-request: !2931

Merge-request: !2934

This change adds the Octave::Octinterp target to make the octinterp
library available without users having to resort to using the
Octave_INTERP_LIBRARY variable.

Merge-request: !2943

Merge-request: !2937

Merge-request: !2942

-- Also change variable name to CMAKE_GHS_NO_SOURCE_GROUP_FILE

Since commit dc688857 (Pass EXCLUDE_FROM_ALL from directory to
targets, 2019-01-15, v3.14.0-rc1~83^2) we automatically forward the
`EXCLUDE_FROM_ALL` to targets as they are created.  This regressed
support for interface libraries on which the property is not allowed.

Skip forwarding the `EXCLUDE_FROM_ALL` property for interface libraries.
It is not needed on them because they do not participate in the
generated build system anyway.

Fixes: #18896

Merge-request: !2933

Revise the note from commit bab24e78 (target_link_libraries: Propagate
dependencies of object libraries, 2018-12-10, v3.14.0-rc1~260^2).

Merge-request: !2928

Merge-request: !2916

Merge-request: !2919

Closes: #18396