The XL Fortran compiler's `-qmoddir=` flag sets the module output
directory but does not add the directory to the search path for using
modules. This is inconsistent with other compilers like the GNU Fortran
compiler's `-J` flag that does both. In order to make these consistent,
add the module output directory with a `-I` flag on the XL Fortran
compiler so that it will be searched when using modules too.
This fixes our `FortranModules` test's coverage of submodules on
Ninja + XL. That test places module files in a subdirectory that with
Ninja is not the current working directory when the compiler runs.
Fixes: #20400
The Ninja generator's support for Fortran requires that source files
be preprocessed explicitly first. However, the `xlf` compiler does
not have a simple `-E` option or equivalent to do preprocessing.
The only documented way to get preprocessed output is to use `-d`
to leave it behind, but only at an inflexible location.
Instead, create our own `cpp` wrapper script and substitute it for the
real preprocessor using `-tF -B ...`. Teach the wrapper to map the
`cpp` output to the location we need and then invoke the real `cpp`
underneath.
Fixes: #19450
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
Document these variables.
Change our convention for setting these variables from:
set(CMAKE_C_FLAGS_INIT "...")
to
string(APPEND CMAKE_C_FLAGS_INIT " ...")
so that any value previously set by a toolchain file will be used.
Automate the conversion with:
sed -i 's/set *(\(CMAKE_\(C\|CXX\|Fortran\|RC\|ASM\|${[^}]\+}\)_FLAGS\(_[^_]\+\)\?_INIT \+"\)/string(APPEND \1 /' \
Modules/Compiler/*.cmake Modules/Platform/*.cmake
and follow up with some manual fixes (e.g. to cases that already
meant to append). Also revert the automated changes to contexts
that are not protected from running multiple times.
Define a "Fortran_FORMAT" target and source file property. Initialize
the target property from a "CMAKE_Fortran_FORMAT" variable. Interpret
values "FIXED" and "FREE" to indicate the source file format. Append
corresponding flags to the compiler command line.
Factor duplicate information out of Compiler/XL-<lang>.cmake modules
into a macro in a new Compiler/XL.cmake module. Invoke it from the
per-language files to produce the original settings.
Since commit e1729238 (Add initial XL C compiler flags for safer builds,
2009-09-30) CMake sets the initial XL C flags to include "-qthreaded"
and "-qhalt=e". Do the same for C++ and Fortran with this toolchain.
This moves platform-independent XL compiler flags into separate
"Compiler/XL-<lang>.cmake" modules. Platform-specific flags go in
"Platform/<os>-XL-<lang>.cmake" modules.
IBM rebranded its VisualAge compiler to XL starting at version 8.0. We
use the compiler id "XL" for newer versions and "VisualAge" for older
versions. We now also recognize the "z/OS" compiler, which is distinct
from XL.
