Guile QUIT processing updates

This commit contains QUIT processing updates for GDB's Guile support.
As with the Python updates, we don't want to permit this code to
swallow the exception, gdb_exception_forced_quit, which is associated
with GDB receiving a SIGTERM.

I've adopted the same solution that I used for Python; whereever
a gdb_exception is caught in try/catch code in the Guile extension
language support, a catch for gdb_exception_forced_quit has been
added; this catch block will simply call quit_force(), which will
cause the necessary cleanups to occur followed by GDB exiting.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=26761
Tested-by: Tom de Vries <tdevries@suse.de>
Approved-By: Pedro Alves <pedro@palves.net>

gdb/guile/guile-internal.h

@@ -29,6 +29,7 @@
 #include "symtab.h"
 #include "libguile.h"
 #include "objfiles.h"
+#include "top.h"		/* For quit_force().  */
 
 struct block;
 struct frame_info;
@@ -704,6 +705,10 @@ gdbscm_wrap (Function &&func, Args &&... args)
     {
       result = func (std::forward<Args> (args)...);
     }
+  catch (const gdb_exception_forced_quit &e)
+    {
+      quit_force (NULL, 0);
+    }
   catch (const gdb_exception &except)
     {
       exc = unpack (except);

gdb/guile/scm-pretty-print.c

@@ -21,6 +21,7 @@
    conventions, et.al.  */
 
 #include "defs.h"
+#include "top.h"		/* For quit_force().  */
 #include "charset.h"
 #include "symtab.h" /* Needed by language.h.  */
 #include "language.h"
@@ -558,6 +559,10 @@ ppscm_pretty_print_one_value (SCM printer, struct value **out_value,
 	    (_("invalid result from pretty-printer to-string"), result);
 	}
     }
+  catch (const gdb_exception_forced_quit &except)
+    {
+      quit_force (NULL, 0);
+    }
   catch (const gdb_exception &except)
     {
     }

gdb/guile/scm-type.c

@@ -21,6 +21,7 @@
    conventions, et.al.  */
 
 #include "defs.h"
+#include "top.h"		/* For quit_force().  */
 #include "arch-utils.h"
 #include "value.h"
 #include "gdbtypes.h"
@@ -132,6 +133,10 @@ tyscm_type_name (struct type *type)
 				    &type_print_raw_options);
       return stb.release ();
     }
+  catch (const gdb_exception_forced_quit &except)
+    {
+      quit_force (NULL, 0);
+    }
   catch (const gdb_exception &except)
     {
       excp = gdbscm_scm_from_gdb_exception (unpack (except));

gdb/guile/scm-value.c

@@ -21,6 +21,7 @@
    conventions, et.al.  */
 
 #include "defs.h"
+#include "top.h"		/* For quit_force().  */
 #include "arch-utils.h"
 #include "charset.h"
 #include "cp-abi.h"
@@ -416,6 +417,10 @@ gdbscm_value_address (SCM self)
 	    {
 	      address = vlscm_scm_from_value (value_addr (value));
 	    }
+	  catch (const gdb_exception_forced_quit &except)
+	    {
+	      quit_force (NULL, 0);
+	    }
 	  catch (const gdb_exception &except)
 	    {
 	    }

gdb/top.h

@@ -235,7 +235,7 @@ extern void read_command_file (FILE *);
 extern void init_history (void);
 extern void command_loop (void);
 extern int quit_confirm (void);
-extern void quit_force (int *, int);
+extern void quit_force (int *, int) ATTRIBUTE_NORETURN;
 extern void quit_command (const char *, int);
 extern void quit_cover (void);
 extern void execute_command (const char *, int);