Merge topic 'doc-FortranCInterface-variables'

4f3f75a2 FortranCInterface: Document mangling result variables publicly
47f24cbc FortranCInterface: Improve documentation formatting and organization
9d1f40cc FortranCInterface: Convert docs to a bracket comment
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Brad King 2016-02-11 10:41:13 -05:00 committed by CMake Topic Stage
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#.rst:
# FortranCInterface
# -----------------
#
# Fortran/C Interface Detection
#
# This module automatically detects the API by which C and Fortran
# languages interact. Variables indicate if the mangling is found:
#
# ::
#
# FortranCInterface_GLOBAL_FOUND = Global subroutines and functions
# FortranCInterface_MODULE_FOUND = Module subroutines and functions
# (declared by "MODULE PROCEDURE")
#
# A function is provided to generate a C header file containing macros
# to mangle symbol names:
#
# ::
#
# FortranCInterface_HEADER(<file>
# [MACRO_NAMESPACE <macro-ns>]
# [SYMBOL_NAMESPACE <ns>]
# [SYMBOLS [<module>:]<function> ...])
#
# It generates in <file> definitions of the following macros:
#
# ::
#
# #define FortranCInterface_GLOBAL (name,NAME) ...
# #define FortranCInterface_GLOBAL_(name,NAME) ...
# #define FortranCInterface_MODULE (mod,name, MOD,NAME) ...
# #define FortranCInterface_MODULE_(mod,name, MOD,NAME) ...
#
# These macros mangle four categories of Fortran symbols, respectively:
#
# ::
#
# - Global symbols without '_': call mysub()
# - Global symbols with '_' : call my_sub()
# - Module symbols without '_': use mymod; call mysub()
# - Module symbols with '_' : use mymod; call my_sub()
#
# If mangling for a category is not known, its macro is left undefined.
# All macros require raw names in both lower case and upper case. The
# MACRO_NAMESPACE option replaces the default "FortranCInterface_"
# prefix with a given namespace "<macro-ns>".
#
# The SYMBOLS option lists symbols to mangle automatically with C
# preprocessor definitions:
#
# ::
#
# <function> ==> #define <ns><function> ...
# <module>:<function> ==> #define <ns><module>_<function> ...
#
# If the mangling for some symbol is not known then no preprocessor
# definition is created, and a warning is displayed. The
# SYMBOL_NAMESPACE option prefixes all preprocessor definitions
# generated by the SYMBOLS option with a given namespace "<ns>".
#
# Example usage:
#
# ::
#
# include(FortranCInterface)
# FortranCInterface_HEADER(FC.h MACRO_NAMESPACE "FC_")
#
# This creates a "FC.h" header that defines mangling macros FC_GLOBAL(),
# FC_GLOBAL_(), FC_MODULE(), and FC_MODULE_().
#
# Example usage:
#
# ::
#
# include(FortranCInterface)
# FortranCInterface_HEADER(FCMangle.h
# MACRO_NAMESPACE "FC_"
# SYMBOL_NAMESPACE "FC_"
# SYMBOLS mysub mymod:my_sub)
#
# This creates a "FCMangle.h" header that defines the same FC_*()
# mangling macros as the previous example plus preprocessor symbols
# FC_mysub and FC_mymod_my_sub.
#
# Another function is provided to verify that the Fortran and C/C++
# compilers work together:
#
# ::
#
# FortranCInterface_VERIFY([CXX] [QUIET])
#
# It tests whether a simple test executable using Fortran and C (and C++
# when the CXX option is given) compiles and links successfully. The
# result is stored in the cache entry FortranCInterface_VERIFIED_C (or
# FortranCInterface_VERIFIED_CXX if CXX is given) as a boolean. If the
# check fails and QUIET is not given the function terminates with a
# FATAL_ERROR message describing the problem. The purpose of this check
# is to stop a build early for incompatible compiler combinations. The
# test is built in the Release configuration.
#
# FortranCInterface is aware of possible GLOBAL and MODULE manglings for
# many Fortran compilers, but it also provides an interface to specify
# new possible manglings. Set the variables
#
# ::
#
# FortranCInterface_GLOBAL_SYMBOLS
# FortranCInterface_MODULE_SYMBOLS
#
# before including FortranCInterface to specify manglings of the symbols
# "MySub", "My_Sub", "MyModule:MySub", and "My_Module:My_Sub". For
# example, the code:
#
# ::
#
# set(FortranCInterface_GLOBAL_SYMBOLS mysub_ my_sub__ MYSUB_)
# # ^^^^^ ^^^^^^ ^^^^^
# set(FortranCInterface_MODULE_SYMBOLS
# __mymodule_MOD_mysub __my_module_MOD_my_sub)
# # ^^^^^^^^ ^^^^^ ^^^^^^^^^ ^^^^^^
# include(FortranCInterface)
#
# tells FortranCInterface to try given GLOBAL and MODULE manglings.
# (The carets point at raw symbol names for clarity in this example but
# are not needed.)
#[=======================================================================[.rst:
FortranCInterface
-----------------
Fortran/C Interface Detection
This module automatically detects the API by which C and Fortran
languages interact.
Module Variables
^^^^^^^^^^^^^^^^
Variables that indicate if the mangling is found:
``FortranCInterface_GLOBAL_FOUND``
Global subroutines and functions.
``FortranCInterface_MODULE_FOUND``
Module subroutines and functions (declared by "MODULE PROCEDURE").
This module also provides the following variables to specify
the detected mangling, though a typical use case does not need
to reference them and can use the `Module Functions`_ below.
``FortranCInterface_GLOBAL_PREFIX``
Prefix for a global symbol without an underscore.
``FortranCInterface_GLOBAL_SUFFIX``
Suffix for a global symbol without an underscore.
``FortranCInterface_GLOBAL_CASE``
The case for a global symbol without an underscore,
either ``UPPER`` or ``LOWER``.
``FortranCInterface_GLOBAL__PREFIX``
Prefix for a global symbol with an underscore.
``FortranCInterface_GLOBAL__SUFFIX``
Suffix for a global symbol with an underscore.
``FortranCInterface_GLOBAL__CASE``
The case for a global symbol with an underscore,
either ``UPPER`` or ``LOWER``.
``FortranCInterface_MODULE_PREFIX``
Prefix for a module symbol without an underscore.
``FortranCInterface_MODULE_MIDDLE``
Middle of a module symbol without an underscore that appears
between the name of the module and the name of the symbol.
``FortranCInterface_MODULE_SUFFIX``
Suffix for a module symbol without an underscore.
``FortranCInterface_MODULE_CASE``
The case for a module symbol without an underscore,
either ``UPPER`` or ``LOWER``.
``FortranCInterface_MODULE__PREFIX``
Prefix for a module symbol with an underscore.
``FortranCInterface_MODULE__MIDDLE``
Middle of a module symbol with an underscore that appears
between the name of the module and the name of the symbol.
``FortranCInterface_MODULE__SUFFIX``
Suffix for a module symbol with an underscore.
``FortranCInterface_MODULE__CASE``
The case for a module symbol with an underscore,
either ``UPPER`` or ``LOWER``.
Module Functions
^^^^^^^^^^^^^^^^
.. command:: FortranCInterface_HEADER
The ``FortranCInterface_HEADER`` function is provided to generate a
C header file containing macros to mangle symbol names::
FortranCInterface_HEADER(<file>
[MACRO_NAMESPACE <macro-ns>]
[SYMBOL_NAMESPACE <ns>]
[SYMBOLS [<module>:]<function> ...])
It generates in ``<file>`` definitions of the following macros::
#define FortranCInterface_GLOBAL (name,NAME) ...
#define FortranCInterface_GLOBAL_(name,NAME) ...
#define FortranCInterface_MODULE (mod,name, MOD,NAME) ...
#define FortranCInterface_MODULE_(mod,name, MOD,NAME) ...
These macros mangle four categories of Fortran symbols, respectively:
* Global symbols without '_': ``call mysub()``
* Global symbols with '_' : ``call my_sub()``
* Module symbols without '_': ``use mymod; call mysub()``
* Module symbols with '_' : ``use mymod; call my_sub()``
If mangling for a category is not known, its macro is left undefined.
All macros require raw names in both lower case and upper case.
The options are:
``MACRO_NAMESPACE``
Replace the default ``FortranCInterface_`` prefix with a given
namespace ``<macro-ns>``.
``SYMBOLS``
List symbols to mangle automatically with C preprocessor definitions::
<function> ==> #define <ns><function> ...
<module>:<function> ==> #define <ns><module>_<function> ...
If the mangling for some symbol is not known then no preprocessor
definition is created, and a warning is displayed.
``SYMBOL_NAMESPACE``
Prefix all preprocessor definitions generated by the ``SYMBOLS``
option with a given namespace ``<ns>``.
.. command:: FortranCInterface_VERIFY
The ``FortranCInterface_VERIFY`` function is provided to verify
that the Fortran and C/C++ compilers work together::
FortranCInterface_VERIFY([CXX] [QUIET])
It tests whether a simple test executable using Fortran and C (and C++
when the CXX option is given) compiles and links successfully. The
result is stored in the cache entry ``FortranCInterface_VERIFIED_C``
(or ``FortranCInterface_VERIFIED_CXX`` if ``CXX`` is given) as a boolean.
If the check fails and ``QUIET`` is not given the function terminates with a
fatal error message describing the problem. The purpose of this check
is to stop a build early for incompatible compiler combinations. The
test is built in the ``Release`` configuration.
Example Usage
^^^^^^^^^^^^^
.. code-block:: cmake
include(FortranCInterface)
FortranCInterface_HEADER(FC.h MACRO_NAMESPACE "FC_")
This creates a "FC.h" header that defines mangling macros ``FC_GLOBAL()``,
``FC_GLOBAL_()``, ``FC_MODULE()``, and ``FC_MODULE_()``.
.. code-block:: cmake
include(FortranCInterface)
FortranCInterface_HEADER(FCMangle.h
MACRO_NAMESPACE "FC_"
SYMBOL_NAMESPACE "FC_"
SYMBOLS mysub mymod:my_sub)
This creates a "FCMangle.h" header that defines the same ``FC_*()``
mangling macros as the previous example plus preprocessor symbols
``FC_mysub`` and ``FC_mymod_my_sub``.
Additional Manglings
^^^^^^^^^^^^^^^^^^^^
FortranCInterface is aware of possible ``GLOBAL`` and ``MODULE`` manglings
for many Fortran compilers, but it also provides an interface to specify
new possible manglings. Set the variables::
FortranCInterface_GLOBAL_SYMBOLS
FortranCInterface_MODULE_SYMBOLS
before including FortranCInterface to specify manglings of the symbols
``MySub``, ``My_Sub``, ``MyModule:MySub``, and ``My_Module:My_Sub``.
For example, the code:
.. code-block:: cmake
set(FortranCInterface_GLOBAL_SYMBOLS mysub_ my_sub__ MYSUB_)
# ^^^^^ ^^^^^^ ^^^^^
set(FortranCInterface_MODULE_SYMBOLS
__mymodule_MOD_mysub __my_module_MOD_my_sub)
# ^^^^^^^^ ^^^^^ ^^^^^^^^^ ^^^^^^
include(FortranCInterface)
tells FortranCInterface to try given ``GLOBAL`` and ``MODULE`` manglings.
(The carets point at raw symbol names for clarity in this example but
are not needed.)
#]=======================================================================]
#=============================================================================
# Copyright 2008-2009 Kitware, Inc.