FortranCInterface: Improve documentation formatting and organization

Organize content into sections.  Define functions via explicit markup
blocks so we can cross-reference them.
This commit is contained in:
Brad King 2016-02-09 16:43:27 -05:00
parent 9d1f40ccc1
commit 47f24cbcca
1 changed files with 78 additions and 70 deletions

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@ -5,73 +5,96 @@ 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:
languages interact.
::
Module Variables
^^^^^^^^^^^^^^^^
FortranCInterface_GLOBAL_FOUND = Global subroutines and functions
FortranCInterface_MODULE_FOUND = Module subroutines and functions
(declared by "MODULE PROCEDURE")
Variables that indicate if the mangling is found:
A function is provided to generate a C header file containing macros
to mangle symbol names:
``FortranCInterface_GLOBAL_FOUND``
Global subroutines and functions.
::
``FortranCInterface_MODULE_FOUND``
Module subroutines and functions (declared by "MODULE PROCEDURE").
FortranCInterface_HEADER(<file>
[MACRO_NAMESPACE <macro-ns>]
[SYMBOL_NAMESPACE <ns>]
[SYMBOLS [<module>:]<function> ...])
Module Functions
^^^^^^^^^^^^^^^^
It generates in <file> definitions of the following macros:
.. command:: FortranCInterface_HEADER
::
The ``FortranCInterface_HEADER`` function is provided to generate a
C header file containing macros to mangle symbol names::
#define FortranCInterface_GLOBAL (name,NAME) ...
#define FortranCInterface_GLOBAL_(name,NAME) ...
#define FortranCInterface_MODULE (mod,name, MOD,NAME) ...
#define FortranCInterface_MODULE_(mod,name, MOD,NAME) ...
FortranCInterface_HEADER(<file>
[MACRO_NAMESPACE <macro-ns>]
[SYMBOL_NAMESPACE <ns>]
[SYMBOLS [<module>:]<function> ...])
These macros mangle four categories of Fortran symbols, respectively:
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) ...
- 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()
These macros mangle four categories of Fortran symbols, respectively:
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>".
* 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()``
The SYMBOLS option lists symbols to mangle automatically with C
preprocessor definitions:
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:
<function> ==> #define <ns><function> ...
<module>:<function> ==> #define <ns><module>_<function> ...
``MACRO_NAMESPACE``
Replace the default ``FortranCInterface_`` prefix with a given
namespace ``<macro-ns>``.
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>".
``SYMBOLS``
List symbols to mangle automatically with C preprocessor definitions::
Example usage:
<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_().
This creates a "FC.h" header that defines mangling macros ``FC_GLOBAL()``,
``FC_GLOBAL_()``, ``FC_MODULE()``, and ``FC_MODULE_()``.
Example usage:
::
.. code-block:: cmake
include(FortranCInterface)
FortranCInterface_HEADER(FCMangle.h
@ -79,40 +102,25 @@ Example usage:
SYMBOL_NAMESPACE "FC_"
SYMBOLS mysub mymod:my_sub)
This creates a "FCMangle.h" header that defines the same FC_*()
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.
``FC_mysub`` and ``FC_mymod_my_sub``.
Another function is provided to verify that the Fortran and C/C++
compilers work together:
Additional Manglings
^^^^^^^^^^^^^^^^^^^^
::
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 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:
``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_)
# ^^^^^ ^^^^^^ ^^^^^
@ -121,7 +129,7 @@ example, the code:
# ^^^^^^^^ ^^^^^ ^^^^^^^^^ ^^^^^^
include(FortranCInterface)
tells FortranCInterface to try given GLOBAL and MODULE manglings.
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.)
#]=======================================================================]