Re: [bug-gnulib] Re: use of program_name

[Bruno Haible]

James Youngman wrote on 2006-01-05:
> My problem is that we have changed the interface without making it
> impossible for the user to use the new interface wrongly.  I would
> prefer an arrangement which results in a compilation or link failure
> if the user (i.e. software maintainer) fails to initialise things
> properly.  A runtime failure is insufficiently helpful in my opinion.

The appended patch will help against a direct assignment of program_name,
reminding the developer to call set_program_name().

Against a missing set_program_name call, we'll only have the core dump of
the error() function. Like now, against a missing program_name assignment.

> A runtime failure is insufficiently helpful in my opinion.

And how about a runtime failure that occurs in every invocation? We could
add a check in getopt() and getopt_long(), verifying that program_name is
non-NULL. Most GNU programs use getopt() and getopt_long().

Bruno


*** progname.h.bak      2005-05-14 15:46:42.000000000 +0200
--- progname.h  2006-01-07 03:10:40.000000000 +0100
***************
*** 30,36 ****
  
  
  /* String containing name the program is called with.  */
! extern const char *program_name;
  
  /* Set program_name, based on argv[0].  */
  extern void set_program_name (const char *argv0);
--- 30,36 ----
  
  
  /* String containing name the program is called with.  */
! extern const char * const program_name;
  
  /* Set program_name, based on argv[0].  */
  extern void set_program_name (const char *argv0);
*** progname.c.bak      2005-09-21 13:08:21.000000000 +0200
--- progname.c  2006-01-07 03:10:22.000000000 +0100
***************
*** 22,28 ****
--- 22,30 ----
  #endif
  
  /* Specification.  */
+ #define program_name readonly_program_name
  #include "progname.h"
+ #undef program_name
  
  #include <string.h>