ccea3@rivm.UUCP (Adri Verhoef) (11/10/88)
- I have this fortran-file "m.f":
program main
call hello()
end
- and I have this C++-file "s.c":
#include <stream.h>
void hello_()
{
STATEMENTS;
}
- I compile "m.f":
$ f77 -c m.f
- Then I compile "s.c", and execute a.out:
- The first time, I replace STATEMENTS by:
printf("Hello, %s\n", "world");
$ CC -c s.c
$ f77 m.o s.o -lC
$ a.out
Hello, world
- The second time, I replace STATEMENTS by:
cout << "Hello, world\n";
$ CC -c s.c
$ f77 m.o s.o -lC
$ a.out
Bus error - core dumped
$ adb
$c
__ostream__lshiftFPC__(14598,11ff1)
_hello_()
_MAIN__()
_main(1,7fffef30,7fffef38)
- The third time, I replace STATEMENTS by:
char str[128]; cin >> str;
$ CC -c s.c
$ f77 m.o s.o -lC
$ a.out
Memory fault - core dumped
$ adb
$c
__istream__rshiftFPC__(13320,7fffee5c)
_hello_()
_MAIN__()
_main(1,7fffef30,7fffef38)
- At this point, I got behold of the "s..c"-file.
- The following line was contained in the "s..c"-file:
_istream__rshiftFPC__ ( & cin , _auto_str ) ;
- I don't know what the trouble could be. Maybe the f77-compiler?mjs@cbnews.ATT.COM (martin.j.shannon) (11/10/88)
In article <1118@rivm05.UUCP> ccea3@rivm05.UUCP (Adri Verhoef) writes: >- I have this fortran-file "m.f": > program main > call hello() > end >- and I have this C++-file "s.c": >#include <stream.h> >void hello_() >{ > STATEMENTS; >} >- The first time, I replace STATEMENTS by: > printf("Hello, %s\n", "world"); >$ a.out >Hello, world This works because there are no static constructors involved, so it doesn't matter which compiler generates main. >- The second time, I replace STATEMENTS by: > cout << "Hello, world\n"; >$ a.out >Bus error - core dumped Since the static constructor for cout was never invoked, there is no initialiaztion performed for the stream, and the constents of the class are garbage. >- The third time, I replace STATEMENTS by: > char str[128]; cin >> str; >$ a.out >Memory fault - core dumped Since the static constructor for cin was never invoked, there is no initialiaztion performed for the stream, and the constents of the class are garbage. In general: Cfront recognizes that main is the 1st executable statement in a source file, and appropriately replaces the user's main with code that arranges to make sure that static constructors are called. Thus, when mixing languages (not a particularly safe thing to do; though possible in many systems), the executable code generated for main must come from cfront. l i n e c o u n t e r f o o d . -- Marty Shannon; AT&T Bell Labs; Liberty Corner, NJ (Affiliation given for identification only.)
newsuser@LTH.Se (LTH network news server) (11/11/88)
In article <1118@rivm05.UUCP> ccea3@rivm05.UUCP (Adri Verhoef) writes: >- I have this fortran-file "m.f": > program main > call hello() > end > >- and I have this C++-file "s.c": >#include <stream.h> >void hello_() >{ > STATEMENTS; >} I have successfully mixed FORTRAN and C++ code. The problem was: 1. The FORTRAN run-time system (including i/o) must be initialized in some way unknown to me. 2. Static constructors must be called in C++ before any of my code. The solution, which may be peculiar to our Silicon Graphics IRIS, is: 1. My FORTRAN ``main'' program calls a C initialization function (reason is exaplained in 2.): PROGRAM MAIN CALL CINIT() ... END 2. The purpose of the C function is to call the C++ initialization function _main(), which is supplied by the compiler. My FORTRAN can't call a subroutine beginning in ``_''. void cinit() { _main(); } I have written no FORTRAN in my application, but I do use a major run-time library written i FORTRAN. The approach above works in my particular application, but I cannot guarantee it will help you. I you *have* to use FORTRAN, good luck -- may the force be with you. Dag Bruck -- Department of Automatic Control Internet: dag@control.lth.se Lund Institute of Technology P. O. Box 118 Phone: +46 46-108779 S-221 00 Lund, SWEDEN Fax: +46 46-138118
ccea3@rivm.UUCP (Adri Verhoef) (11/12/88)
Thanks, world! I put an example in a possible solution: >- I have this fortran-file "m.f": subroutine f call hello() end >- and I have this C++-file "s.c": >#include <stream.h> main() { extern void f_(); f_(); } >void hello_() >{ > STATEMENTS; >} >- I compile "m.f": >$ f77 -c m.f > >- I replace STATEMENTS by: char str[256]; printf("__printf__Hello, %s\n", "world"); cout << " __cout__ Type your name: "; cin >> str; cout << " __cout__ Hello, " << str << ".\n"; >- Then I compile "s.c", and execute a.out: $ CC s.c m.o -lF77 -lI77 >$ a.out __printf__Hello, world __cout__ Type your name: a3 __cout__ Hello, a3. And everything runs as expected (namely OK). A certain point of attention is that I changed "program main" into "subroutine f". That really helped. PS. Thanks to all who helped so quickly, especially Marty Shannon, and also Dag Bruck. Good work!
hugh@maths.tcd.ie (Hugh Grant) (11/17/88)
In article <1118@rivm05.UUCP> ccea3@rivm05.UUCP (Adri Verhoef) writes: > [Describes problems using f77 and C++ together that causes a core > dump when using the streams routines] As other people have pointed out, the problem arises from the fact that the static constructors used in streams are not being initialised properly inside the program resulting in a core dump. The suggestions put forward do NOT work with any of the following: designer C++ Glockenspiel C++ domain C++ Advantage C++ (which are all the same progam under different names). If you don't use one of these, then refer to the previous postings. There are two cases: --------- CASE 1: Calling C++ code from within a Fortran program The C++ initialisation routine is called _entry() in these versions and so the following (based on a previous posting) is required: Declare the following function in your C++ code cxxinit() { _entry(); } and call CXXINIT from within your F77 code before you call any C++ routines. -------- CASE 2: Calling fortran libraries from within a C++ program You should have no problems providing the "mxx" constructor linker is run on the resulting executable, which should have happened if you used the "ccxx" driver program to do the linking, e.g. f77 -c myfortran.f ccxx -o myprog myfortran.o f1.cxx f2.cxx If you link the code by hand, just remember to run "mxx" afterwards. Hope this helps, Hugh -- Hugh Grant hugh@maths.tcd.ie, hugh@puschi.uucp Glockenspiel Ltd., Ireland Phone: +353-1-364515 void Posting::Disclaimer() { Default(); }