Reimplement DJGPP's .gdbinit -> gdb.ini renaming.

This simplifies the .gdbinit filename selection logic.

We have a GDBINIT_FILENAME define that supposedly configurations would
override, but none do so.  Instead, the only configuration that wants
a different file name instead of ".gdbinit", djgpp, does a strcpy over
the gdbinit global array.  This means the array needs to be sized, and
the code that does that is doing the usual
'PATH_MAX/FILENAME_MAX/fallback constant/etc.' mess.

Instead of all that, it's much simpler to have configure specificy the
.gdbinit filename.  As bonus, we can then make the "gdbinit" global
array const.

gdb/
2013-07-01  Pedro Alves  <palves@redhat.com>

	* configure.ac (GDBINIT): Define, depending on host.
	* go32-nat.c (init_go32_ops): Don't override gdbinit here.
	* top.c (PATH_MAX): Delete fallback definition.
	(GDBINIT_FILENAME): Delete.
	(gdbinit): Reimplement as const char array set to the GDBINIT
	string constant.
	* top.h (gdbinit): Make const.

gdb/ChangeLog

@@ -1,3 +1,14 @@
+2013-07-01  Pedro Alves  <palves@redhat.com>
+
+	* configure.ac (GDBINIT): Define, depending on host.
+	* go32-nat.c (init_go32_ops): Don't override gdbinit here.
+	* top.c (PATH_MAX): Delete fallback definition.
+	(GDBINIT_FILENAME): Delete.
+	(gdbinit): Reimplement as const char array set to the GDBINIT
+	string constant.
+	* top.h (gdbinit): Make const.
+	* configure, config.in: Regenerate.
+
 2013-07-01  Pedro Alves  <palves@redhat.com>
 
 	* cli/cli-cmds.c (source_script): Make 'file' parameter const.

gdb/config.in

@@ -37,6 +37,9 @@
    language is requested. */
 #undef ENABLE_NLS
 
+/* The .gdbinit filename. */
+#undef GDBINIT
+
 /* look for global separate data files in this path [DATADIR/gdb] */
 #undef GDB_DATADIR
 

gdb/configure

@@ -12329,6 +12329,20 @@ $as_echo "#define HAVE_PERSONALITY 1" >>confdefs.h
 
 fi
 
+case $host_os in
+  go32* | *djgpp*)
+    gdbinit=gdb.ini
+    ;;
+  *)
+    gdbinit=.gdbinit
+    ;;
+esac
+
+cat >>confdefs.h <<_ACEOF
+#define GDBINIT "$gdbinit"
+_ACEOF
+
+
 
 # Support for --with-sysroot is a copy of GDB_AC_WITH_DIR,
 # except that the argument to --with-sysroot is optional.

gdb/configure.ac

@@ -1881,6 +1881,17 @@ then
 	      [Define if you support the personality syscall.])
 fi
 
+dnl Set the host's .gdbinit filename.
+case $host_os in
+  go32* | *djgpp*)
+    gdbinit=gdb.ini
+    ;;
+  *)
+    gdbinit=.gdbinit
+    ;;
+esac
+AC_DEFINE_UNQUOTED(GDBINIT,"$gdbinit",[The .gdbinit filename.])
+
 dnl Handle optional features that can be enabled.
 
 # Support for --with-sysroot is a copy of GDB_AC_WITH_DIR,

gdb/go32-nat.c

@@ -1028,9 +1028,6 @@ init_go32_ops (void)
 
   /* We are always processing GCC-compiled programs.  */
   processing_gcc_compilation = 2;
-
-  /* Override the default name of the GDB init file.  */
-  strcpy (gdbinit, "gdb.ini");
 }
 
 /* Return the current DOS codepage number.  */

gdb/top.c

@@ -78,20 +78,9 @@ extern void initialize_all_files (void);
 #define DEFAULT_PROMPT	"(gdb) "
 #endif
 
-/* Initialization file name for gdb.  This is overridden in some configs.  */
+/* Initialization file name for gdb.  This is host-dependent.  */
 
-#ifndef PATH_MAX
+const char gdbinit[] = GDBINIT;
-# ifdef FILENAME_MAX
-#  define PATH_MAX FILENAME_MAX
-# else
-#  define PATH_MAX 512
-# endif
-#endif
-
-#ifndef	GDBINIT_FILENAME
-#define	GDBINIT_FILENAME	".gdbinit"
-#endif
-char gdbinit[PATH_MAX + 1] = GDBINIT_FILENAME;
 
 int inhibit_gdbinit = 0;
 

gdb/top.h

@@ -28,7 +28,7 @@ extern int in_user_command;
 extern int confirm;
 extern char gdb_dirbuf[1024];
 extern int inhibit_gdbinit;
-extern char gdbinit[];
+extern const char gdbinit[];
 
 extern void print_gdb_version (struct ui_file *);
 extern void print_gdb_configuration (struct ui_file *);