Hi Edgar,
I don't think this mailing list --8<-- accept{s} attachments.
I live in a bubble :P .
Second best would be to paste a diff into
the body of an email (assuming it's not too long, in which case the
first
option should be used).
Third best: create a fork on notabug.org or GNU Savannah and send you
the link to the corresponding branch, right? ;D
In any case, below is the original suggestion. Let me know if you like
the idea, and I will create the branch on notabug.org :D .
Hello,
I would kindly and respectfully like to suggest turning some macros in
=libmesh_common.h= into functions. As I was exploring libMesh, I naïvely
tried this:
#+CAPTION: Using the =libmesh_error_msg= macro
#+begin_src cpp :libs $(libmesh-config --cxxflags --include --ldflags
--libs)
#include <stdio.h>
#include <iostream>
#include "libmesh/libmesh.h"
#include "libmesh/mesh.h"
int main (int argc, char * argv[]){
libMesh::LibMeshInit init(argc, argv);
if (argc < 4){
libMesh::libmesh_error_msg("Usage: ");
}
}
#+end_src
#+caption: Result from using =libmesh_error_msg= (does not compile).
#+begin_example
In file included from /usr/include/libmesh/libmesh.h:25,
from /tmp/babel-hlBzed/C-src-YQnbkN.cpp:3:
/tmp/babel-hlBzed/C-src-YQnbkN.cpp: In function 'int main(int,
char**)':
/tmp/babel-hlBzed/C-src-YQnbkN.cpp:15:14: error: expected
unqualified-id before 'do'
15 | libMesh::libmesh_error_msg("Usage: " // << argv[0] <<
| ^~~~~~~~~~~~~~~~~
#+end_example
This does not work, because =libmesh_error_msg= is actually a macro
defined in =libmesh_common.h=, and does not need =libMesh::=.
If, however, the macro is replaced with the code, it should produce:
#+caption: Using the raw text from =libmesh_error_msg=
#+begin_src cpp :libs $(libmesh-config --cxxflags --include --ldflags
--libs)
#include <stdio.h>
#include <iostream>
#include "libmesh/libmesh.h"
#include "libmesh/mesh.h"
int main (int argc, char * argv[]){
libMesh::LibMeshInit init(argc, argv);
if (argc < 4){
char msg[] = "Usage: ";
do {
libMesh::err << msg << std::endl;
std::stringstream msg_stream;
msg_stream << msg;
libMesh::MacroFunctions::report_error(__FILE__, __LINE__,
LIBMESH_DATE, LIBMESH_TIME);
LIBMESH_THROW(libMesh::LogicError(msg_stream.str()));
} while (0);
}
}
#+end_src
#+caption: Expected output (error message from libMesh) with raw text
from =libmesh_error_msg=
#+begin_example
Usage:
Stack frames: 5
0: libMesh::print_trace(std::ostream&)
1: libMesh::MacroFunctions::report_error(char const*, int, char
const*, char const*)
2: /tmp/babel-hlBzed/C-bin-tb49Ls(+0xcdee) [0x563818bc5dee]
3: __libc_start_main
4: /tmp/babel-hlBzed/C-bin-tb49Ls(+0xceae) [0x563818bc5eae]
[0] /tmp/babel-hlBzed/C-src-APc5Dz.cpp, line 22, compiled Mar 18
2021 at 17:20:53
--------------------------------------------------------------------------
MPI_ABORT was invoked on rank 0 in communicator MPI_COMM_WORLD
with errorcode 1.
NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
You may or may not see output from other processes, depending on
exactly when Open MPI kills them.
--------------------------------------------------------------------------
#+end_example
This makes me think that we can have a function (or a template) like
this:
#+caption: Fuction to replace =libmesh_error_msg= macro
#+begin_src cpp :libs $(libmesh-config --cxxflags --include --ldflags
--libs)
#include <stdio.h>
#include <iostream>
#include "libmesh/libmesh.h"
#include "libmesh/mesh.h"
void libmesh_error_msg_fun(std::string &msg) {
do {
libMesh::err << msg << std::endl;
std::stringstream msg_stream;
msg_stream << msg;
libMesh::MacroFunctions::report_error(__FILE__, __LINE__,
LIBMESH_DATE, LIBMESH_TIME);
LIBMESH_THROW(libMesh::LogicError(msg_stream.str()));
} while (0);
}
template<typename X, typename Y>
int libmesh_example_requires(X condition, Y option){
do {
if (!(condition)) {
libMesh::out <<
"Configuring libMesh with " <<
option <<
" is required to run this example." << std::endl;
return 77;
}
} while (0);
}
int main (int argc, char * argv[]){
libMesh::LibMeshInit init(argc, argv);
if (argc < 4){
std::string msg = {"Usage: "};
libmesh_error_msg_fun(msg);
}
}
#+end_src
#+RESULTS:
#+begin_example
Usage:
Stack frames: 6
0: libMesh::print_trace(std::ostream&)
1: libMesh::MacroFunctions::report_error(char const*, int, char
const*, char const*)
2: /tmp/babel-CpgWD6/C-bin-mEeZoe(+0xcf4f) [0x55567f87ef4f]
3: /tmp/babel-CpgWD6/C-bin-mEeZoe(+0xcd76) [0x55567f87ed76]
4: __libc_start_main
5: /tmp/babel-CpgWD6/C-bin-mEeZoe(+0xcdbe) [0x55567f87edbe]
[0] /tmp/babel-CpgWD6/C-src-HfTgSq.cpp, line 18, compiled Mar 18
2021 at 20:48:30
--------------------------------------------------------------------------
MPI_ABORT was invoked on rank 0 in communicator MPI_COMM_WORLD
with errorcode 1.
NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
You may or may not see output from other processes, depending on
exactly when Open MPI kills them.
--------------------------------------------------------------------------
#+end_example
I was expecting =libMesh::= to work as well, because =libmesh_*_msg=
look very much like functions, and they are inside a =namespace=. I am
sure that there is a solid reason for which they were kept as macros,
and that is why this is a humble suggestion. Thank you.
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