Mark debugger related variables and functions as EXTERNALLY_VISIBLE

so that they do not get optimized away.

* configure.in (EXTERNALLY_VISIBLE): New definition.

* src/emacs.c (gdb_use_union, gdb_valbits,gdb_gctypebits)
(gdb_data_seg_bits, gdb_array_mark_flag, PVEC_FLAG)
(gdb_pvec_type):
* src/print.c (print_output_debug_flag):
* src/lisp.h (debug_print): Mark as EXTERNALLY_VISIBLE.
(safe_debug_print): New declaration.

5 files changed, 27 insertions, 13 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 75a141dabc6..d8518e5cdda 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,12 @@
 2010-11-23  Dan Nicolaescu  <dann@ics.uci.edu>
 
+        * emacs.c (gdb_use_union, gdb_valbits,gdb_gctypebits)
+        (gdb_data_seg_bits, gdb_array_mark_flag, PVEC_FLAG)
+        (gdb_pvec_type):
+        * print.c (print_output_debug_flag):
+        * lisp.h (debug_print): Mark as EXTERNALLY_VISIBLE.
+        (safe_debug_print): New declaration.
+
         * xterm.c:
         * systty.h:
         * sound.c: Include <sys/ioctl.h> unconditionally.
diff --git a/src/config.in b/src/config.in
index b9e9d7c720d..487009b4511 100644
--- a/src/config.in
+++ b/src/config.in
@@ -1197,6 +1197,12 @@ typedef unsigned size_t;
 #define NO_INLINE
 #endif
 
+#if (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
+#define EXTERNALLY_VISIBLE __attribute__((externally_visible))
+#else
+#define EXTERNALLY_VISIBLE
+#endif
+
 /* Some versions of GNU/Linux define noinline in their headers.  */
 #ifdef noinline
 #undef noinline
diff --git a/src/emacs.c b/src/emacs.c
index 0d3b37ae27c..49716c7eb4a 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -100,27 +100,27 @@ static const char emacs_version[] = "24.0.50";
 /* Make these values available in GDB, which doesn't see macros.  */
 
 #ifdef USE_LSB_TAG
-int gdb_use_lsb = 1;
+int gdb_use_lsb EXTERNALLY_VISIBLE = 1;
 #else
-int gdb_use_lsb = 0;
+int gdb_use_lsb EXTERNALLY_VISIBLE = 0;
 #endif
 #ifndef USE_LISP_UNION_TYPE
-int gdb_use_union = 0;
+int gdb_use_union EXTERNALLY_VISIBLE  = 0;
 #else
-int gdb_use_union = 1;
+int gdb_use_union EXTERNALLY_VISIBLE = 1;
 #endif
-EMACS_INT gdb_valbits = VALBITS;
-EMACS_INT gdb_gctypebits = GCTYPEBITS;
+EMACS_INT gdb_valbits EXTERNALLY_VISIBLE = VALBITS;
+EMACS_INT gdb_gctypebits EXTERNALLY_VISIBLE = GCTYPEBITS;
 #if defined (DATA_SEG_BITS) && ! defined (USE_LSB_TAG)
-EMACS_INT gdb_data_seg_bits = DATA_SEG_BITS;
+EMACS_INT gdb_data_seg_bits EXTERNALLY_VISIBLE = DATA_SEG_BITS;
 #else
-EMACS_INT gdb_data_seg_bits = 0;
+EMACS_INT gdb_data_seg_bits EXTERNALLY_VISIBLE = 0;
 #endif
-EMACS_INT PVEC_FLAG = PSEUDOVECTOR_FLAG;
-EMACS_INT gdb_array_mark_flag = ARRAY_MARK_FLAG;
+EMACS_INT PVEC_FLAG EXTERNALLY_VISIBLE = PSEUDOVECTOR_FLAG;
+EMACS_INT gdb_array_mark_flag EXTERNALLY_VISIBLE = ARRAY_MARK_FLAG;
 /* GDB might say "No enum type named pvec_type" if we don't have at
    least one symbol with that type, and then xbacktrace could fail.  */
-enum pvec_type gdb_pvec_type = PVEC_TYPE_MASK;
+enum pvec_type gdb_pvec_type EXTERNALLY_VISIBLE = PVEC_TYPE_MASK;
 
 /* Command line args from shell, as list of strings.  */
 Lisp_Object Vcommand_line_args;
diff --git a/src/lisp.h b/src/lisp.h
index 117e810e565..623ba5382eb 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -2832,7 +2832,8 @@ extern void syms_of_chartab (void);
 /* Defined in print.c */
 extern Lisp_Object Vprin1_to_string_buffer;
 extern Lisp_Object Vprint_level, Vprint_length;
-extern void debug_print (Lisp_Object);
+extern void debug_print (Lisp_Object) EXTERNALLY_VISIBLE;
+extern void safe_debug_print (Lisp_Object) EXTERNALLY_VISIBLE;
 EXFUN (Fprin1, 2);
 EXFUN (Fprin1_to_string, 2);
 EXFUN (Fprinc, 2);
diff --git a/src/print.c b/src/print.c
index ea88ba72f65..a95498ae668 100644
--- a/src/print.c
+++ b/src/print.c
@@ -163,7 +163,7 @@ Lisp_Object Vprint_number_table;
 void print_interval (INTERVAL interval, Lisp_Object printcharfun);
 
 /* GDB resets this to zero on W32 to disable OutputDebugString calls.  */
-int print_output_debug_flag = 1;
+int print_output_debug_flag EXTERNALLY_VISIBLE = 1;
 
 
 /* Low level output routines for characters and strings */