Re: Using Windows GNAT with Cygwin

["Marin David Condic" <marin.condic.auntie.spam@pacemicro.com>]

Having just gone through this, here's another little bit of help: The
following C program was written by Sune Falck to change the registry entries
& can readily be run in an initialization .BAT file. I tweaked the program
ever so slightly from its original design so it may not bit-for-bit match
with the original if you got it from another source.

MDC

/*
 * File:     select_gcc.c
 *
 * Author:   Sune Falck
 *
 * Purpose:  To allow egcs and gnat to coexist by changing the value
 *           GCC under the key LOCAL_MACHINE\Software\Free Software
Foundation
 *           to the installation directory for gnat or egcs.
 *           The installation directories must be manually set up with
 *           REGEDIT in the values GCC_GNAT and GCC_EGCS under the same key.
 *
 * Syntax:   select_gcc gnat|egcs
 *
 * Date:     1999-01-26
 *
 * Changes:  1999-01-27 Sune Falck
 *           Changed protection in RegOpenKeyEx because of ACCESS DENIED
 *           error when running under Windows NT
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define WIN32_LEAN_AND_MEAN
#include <windows.h>

void Test_For_Error (int Error, char *Error_Text);

int main (int argc, char **argv)
{
   LONG rc;                                     /* Return code */
   HKEY Key;                                    /* Key handle  */
   char *Prefix = "GCC_";
   char Name [256];                             /* Constructed key name */
   char Value [256];

   DWORD Value_Type;
   DWORD Value_Length;

   fprintf (stderr, "\n\n argv[0] %s argv[1] %s\n\n", argv[0], argv[1]);

   Test_For_Error (argc != 2, "-I-No parameter given.");

   /* Create a value name from GCC_ and the command parameter */
   strcpy (Name, Prefix);
   strcat (Name, argv [1]);
   Value_Length = sizeof (Value);

   rc = RegOpenKeyEx (HKEY_LOCAL_MACHINE, "Software\\Free Software
Foundation",
                      0, KEY_READ|KEY_SET_VALUE, &Key);
   Test_For_Error (rc != ERROR_SUCCESS, "-E-Can't open registry key "
                   "\"HKLM\\Software\\Free Software Foundation\".");

   rc = RegQueryValueEx (Key, Name, 0, &Value_Type, Value, &Value_Length);
   Test_For_Error (rc != ERROR_SUCCESS,
                   "-E-No saved value GCC_XXXX for given configuration.");

   rc = RegSetValueEx (Key, "GCC", 0, Value_Type, Value, Value_Length);
   Test_For_Error (rc != ERROR_SUCCESS,
                   "-E-New value for GCC could not be stored.");
   RegCloseKey (Key);
   return EXIT_SUCCESS;
}

void Test_For_Error (int Error, char *Error_Text)
{
   if (Error) {
      fprintf (stderr, "select_gcc%s\n\n", Error_Text);
      fprintf
         (stderr,
          "Switch between gnat and egcs by modifying registry\n\n"
          "Manually set up the values GCC_GNAT and GCC_EGCS to the\n"
          "installation directories for gnat and egcs with REGEDIT\n"
          "for the key LOCAL_MACHINE\\Software\\Free Software Foundation.\n"
          "Use select_gcc with gnat or egcs as parameter to switch\n"
          "between the compilers - the path must also be adjusted.\n");
      exit (EXIT_FAILURE);
   }
}


--
Marin David Condic
Senior Software Engineer
Pace Micro Technology Americas    www.pacemicro.com
Enabling the digital revolution
e-Mail:    marin.condic@pacemicro.com
Web:      http://www.mcondic.com/


"Stephen Leake" <stephen.a.leake.1@gsfc.nasa.gov> wrote in message
news:u3da6nx40.fsf@gsfc.nasa.gov...
> Set PATH appropriately. There is also one registry setting that Cygwin
> and GNAT fight over;
>
> HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation
>
> The simplest way to manage this is to use the Registry Editor to
> export this key (to a .reg file) after installing Cygwin, and again
> after installing GNAT. Then run the appropriate .reg file when you
> need to run the compiler.
>
> This use of the registry is totally inappropriate, as far as I can
> tell. It just gets in the way.
>
> You can set PATH and run the .reg file from a batch script; that
> simplifies things a bit.
>
> --
> -- Stephe