Split TRY_CATCH into TRY + CATCH

This patch splits the TRY_CATCH macro into three, so that we go from
this:

~~~
  volatile gdb_exception ex;

  TRY_CATCH (ex, RETURN_MASK_ERROR)
    {
    }
  if (ex.reason < 0)
    {
    }
~~~

to this:

~~~
  TRY
    {
    }
  CATCH (ex, RETURN_MASK_ERROR)
    {
    }
  END_CATCH
~~~

Thus, we'll be getting rid of the local volatile exception object, and
declaring the caught exception in the catch block.

This allows reimplementing TRY/CATCH in terms of C++ exceptions when
building in C++ mode, while still allowing to build GDB in C mode
(using setjmp/longjmp), as a transition step.

TBC, after this patch, is it _not_ valid to have code between the TRY
and the CATCH blocks, like:

  TRY
    {
    }

  // some code here.

  CATCH (ex, RETURN_MASK_ERROR)
    {
    }
  END_CATCH

Just like it isn't valid to do that with C++'s native try/catch.

By switching to creating the exception object inside the CATCH block
scope, we can get rid of all the explicitly allocated volatile
exception objects all over the tree, and map the CATCH block more
directly to C++'s catch blocks.

The majority of the TRY_CATCH -> TRY+CATCH+END_CATCH conversion was
done with a script, rerun from scratch at every rebase, no manual
editing involved.  After the mechanical conversion, a few places
needed manual intervention, to fix preexisting cases where we were
using the exception object outside of the TRY_CATCH block, and cases
where we were using "else" after a 'if (ex.reason) < 0)' [a CATCH
after this patch].  The result was folded into this patch so that GDB
still builds at each incremental step.

END_CATCH is necessary for two reasons:

First, because we name the exception object in the CATCH block, which
requires creating a scope, which in turn must be closed somewhere.
Declaring the exception variable in the initializer field of a for
block, like:

  #define CATCH(EXCEPTION, mask) \
    for (struct gdb_exception EXCEPTION; \
         exceptions_state_mc_catch (&EXCEPTION, MASK); \
	 EXCEPTION = exception_none)

would avoid needing END_CATCH, but alas, in C mode, we build with C90,
which doesn't allow mixed declarations and code.

Second, because when TRY/CATCH are wired to real C++ try/catch, as
long as we need to handle cleanup chains, even if there's no CATCH
block that wants to catch the exception, we need for stop at every
frame in the unwind chain and run cleanups, then rethrow.  That will
be done in END_CATCH.

After we require C++, we'll still need TRY/CATCH/END_CATCH until
cleanups are completely phased out -- TRY/CATCH in C++ mode will
save/restore the current cleanup chain, like in C mode, and END_CATCH
catches otherwise uncaugh exceptions, runs cleanups and rethrows, so
that C++ cleanups and exceptions can coexist.

IMO, this still makes the TRY/CATCH code look a bit more like a
newcomer would expect, so IMO worth it even if we weren't considering
C++.

gdb/ChangeLog.
2015-03-07  Pedro Alves  <palves@redhat.com>

	* common/common-exceptions.c (struct catcher) <exception>: No
	longer a pointer to volatile exception.  Now an exception value.
	<mask>: Delete field.
	(exceptions_state_mc_init): Remove all parameters.  Adjust.
	(exceptions_state_mc): No longer pop the catcher here.
	(exceptions_state_mc_catch): New function.
	(throw_exception): Adjust.
	* common/common-exceptions.h (exceptions_state_mc_init): Remove
	all parameters.
	(exceptions_state_mc_catch): Declare.
	(TRY_CATCH): Rename to ...
	(TRY): ... this.  Remove EXCEPTION and MASK parameters.
	(CATCH, END_CATCH): New.
	All callers adjusted.

gdb/gdbserver/ChangeLog:
2015-03-07  Pedro Alves  <palves@redhat.com>

	Adjust all callers of TRY_CATCH to use TRY/CATCH/END_CATCH
	instead.

1 files changed, 166 insertions, 78 deletions

diff --git a/gdb/guile/scm-value.c b/gdb/guile/scm-value.c
index cacc55c..b10460d 100644
--- a/gdb/guile/scm-value.c
+++ b/gdb/guile/scm-value.c
@@ -143,7 +143,6 @@ vlscm_print_value_smob (SCM self, SCM port, scm_print_state *pstate)
   value_smob *v_smob = (value_smob *) SCM_SMOB_DATA (self);
   char *s = NULL;
   struct value_print_options opts;
-  volatile struct gdb_exception except;
 
   if (pstate->writingp)
     gdbscm_printf (port, "#<%s ", value_smob_name);
@@ -157,7 +156,7 @@ vlscm_print_value_smob (SCM self, SCM port, scm_print_state *pstate)
      instead of writingp.  */
   opts.raw = !!pstate->writingp;
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       struct ui_file *stb = mem_fileopen ();
       struct cleanup *old_chain = make_cleanup_ui_file_delete (stb);
@@ -167,7 +166,11 @@ vlscm_print_value_smob (SCM self, SCM port, scm_print_state *pstate)
 
       do_cleanups (old_chain);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   if (s != NULL)
     {
@@ -192,13 +195,16 @@ vlscm_equal_p_value_smob (SCM v1, SCM v2)
   const value_smob *v1_smob = (value_smob *) SCM_SMOB_DATA (v1);
   const value_smob *v2_smob = (value_smob *) SCM_SMOB_DATA (v2);
   int result = 0;
-  volatile struct gdb_exception except;
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       result = value_equal (v1_smob->value, v2_smob->value);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   return scm_from_bool (result);
 }
@@ -360,7 +366,6 @@ gdbscm_make_lazy_value (SCM type_scm, SCM address_scm)
   struct value *value = NULL;
   SCM result;
   struct cleanup *cleanups;
-  volatile struct gdb_exception except;
 
   t_smob = tyscm_get_type_smob_arg_unsafe (type_scm, SCM_ARG1, FUNC_NAME);
   type = tyscm_type_smob_type (t_smob);
@@ -372,11 +377,15 @@ gdbscm_make_lazy_value (SCM type_scm, SCM address_scm)
 
   /* There's no (current) need to wrap this in a TRY_CATCH, but for consistency
      and future-proofing we do.  */
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
   {
     value = value_from_contents_and_address (type, NULL, address);
   }
-  GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+    }
+  END_CATCH
 
   result = vlscm_scm_from_value (value);
 
@@ -396,13 +405,16 @@ gdbscm_value_optimized_out_p (SCM self)
     = vlscm_get_value_smob_arg_unsafe (self, SCM_ARG1, FUNC_NAME);
   struct value *value = v_smob->value;
   int opt = 0;
-  volatile struct gdb_exception except;
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       opt = value_optimized_out (value);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   return scm_from_bool (opt);
 }
@@ -423,15 +435,18 @@ gdbscm_value_address (SCM self)
       struct cleanup *cleanup
 	= make_cleanup_value_free_to_mark (value_mark ());
       SCM address;
-      volatile struct gdb_exception except;
 
-      TRY_CATCH (except, RETURN_MASK_ALL)
+      TRY
 	{
 	  res_val = value_addr (value);
 	}
-      if (except.reason < 0)
-	address = SCM_BOOL_F;
-      else
+      CATCH (except, RETURN_MASK_ALL)
+	{
+	  address = SCM_BOOL_F;
+	}
+      END_CATCH
+
+      if (res_val != NULL)
 	address = vlscm_scm_from_value (res_val);
 
       do_cleanups (cleanup);
@@ -457,15 +472,18 @@ gdbscm_value_dereference (SCM self)
   SCM result;
   struct value *res_val = NULL;
   struct cleanup *cleanups;
-  volatile struct gdb_exception except;
 
   cleanups = make_cleanup_value_free_to_mark (value_mark ());
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       res_val = value_ind (value);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+    }
+  END_CATCH
 
   result = vlscm_scm_from_value (res_val);
 
@@ -495,11 +513,10 @@ gdbscm_value_referenced_value (SCM self)
   SCM result;
   struct value *res_val = NULL;
   struct cleanup *cleanups;
-  volatile struct gdb_exception except;
 
   cleanups = make_cleanup_value_free_to_mark (value_mark ());
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       switch (TYPE_CODE (check_typedef (value_type (value))))
         {
@@ -514,7 +531,11 @@ gdbscm_value_referenced_value (SCM self)
 		   " neither a pointer nor a reference"));
         }
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+    }
+  END_CATCH
 
   result = vlscm_scm_from_value (res_val);
 
@@ -550,12 +571,11 @@ gdbscm_value_dynamic_type (SCM self)
     = vlscm_get_value_smob_arg_unsafe (self, SCM_ARG1, FUNC_NAME);
   struct value *value = v_smob->value;
   struct type *type = NULL;
-  volatile struct gdb_exception except;
 
   if (! SCM_UNBNDP (v_smob->type))
     return v_smob->dynamic_type;
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       struct cleanup *cleanup
 	= make_cleanup_value_free_to_mark (value_mark ());
@@ -594,7 +614,11 @@ gdbscm_value_dynamic_type (SCM self)
 
       do_cleanups (cleanup);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   if (type == NULL)
     v_smob->dynamic_type = gdbscm_value_type (self);
@@ -619,11 +643,10 @@ vlscm_do_cast (SCM self, SCM type_scm, enum exp_opcode op,
   SCM result;
   struct value *res_val = NULL;
   struct cleanup *cleanups;
-  volatile struct gdb_exception except;
 
   cleanups = make_cleanup_value_free_to_mark (value_mark ());
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       if (op == UNOP_DYNAMIC_CAST)
 	res_val = value_dynamic_cast (type, value);
@@ -635,7 +658,11 @@ vlscm_do_cast (SCM self, SCM type_scm, enum exp_opcode op,
 	  res_val = value_cast (type, value);
 	}
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+    }
+  END_CATCH
 
   gdb_assert (res_val != NULL);
   result = vlscm_scm_from_value (res_val);
@@ -686,7 +713,6 @@ gdbscm_value_field (SCM self, SCM field_scm)
   struct value *res_val = NULL;
   SCM result;
   struct cleanup *cleanups;
-  volatile struct gdb_exception except;
 
   SCM_ASSERT_TYPE (scm_is_string (field_scm), field_scm, SCM_ARG2, FUNC_NAME,
 		   _("string"));
@@ -696,13 +722,17 @@ gdbscm_value_field (SCM self, SCM field_scm)
   field = gdbscm_scm_to_c_string (field_scm);
   make_cleanup (xfree, field);
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       struct value *tmp = value;
 
       res_val = value_struct_elt (&tmp, NULL, field, NULL, NULL);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+    }
+  END_CATCH
 
   gdb_assert (res_val != NULL);
   result = vlscm_scm_from_value (res_val);
@@ -730,7 +760,6 @@ gdbscm_value_subscript (SCM self, SCM index_scm)
   struct gdbarch *gdbarch;
   SCM result, except_scm;
   struct cleanup *cleanups;
-  volatile struct gdb_exception except;
 
   /* The sequencing here, as everywhere else, is important.
      We can't have existing cleanups when a Scheme exception is thrown.  */
@@ -749,7 +778,7 @@ gdbscm_value_subscript (SCM self, SCM index_scm)
       gdbscm_throw (except_scm);
     }
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       struct value *tmp = value;
 
@@ -765,7 +794,11 @@ gdbscm_value_subscript (SCM self, SCM index_scm)
 
       res_val = value_subscript (tmp, value_as_long (index));
    }
-  GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+    }
+  END_CATCH
 
   gdb_assert (res_val != NULL);
   result = vlscm_scm_from_value (res_val);
@@ -792,13 +825,16 @@ gdbscm_value_call (SCM self, SCM args)
   long args_count;
   struct value **vargs = NULL;
   SCM result = SCM_BOOL_F;
-  volatile struct gdb_exception except;
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       ftype = check_typedef (value_type (function));
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   SCM_ASSERT_TYPE (TYPE_CODE (ftype) == TYPE_CODE_FUNC, self,
 		   SCM_ARG1, FUNC_NAME,
@@ -832,7 +868,7 @@ gdbscm_value_call (SCM self, SCM args)
       gdb_assert (gdbscm_is_true (scm_null_p (args)));
     }
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       struct cleanup *cleanup = make_cleanup_value_free_to_mark (mark);
       struct value *return_value;
@@ -841,7 +877,11 @@ gdbscm_value_call (SCM self, SCM args)
       result = vlscm_scm_from_value (return_value);
       do_cleanups (cleanup);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   if (gdbscm_is_exception (result))
     gdbscm_throw (result);
@@ -861,17 +901,20 @@ gdbscm_value_to_bytevector (SCM self)
   size_t length = 0;
   const gdb_byte *contents = NULL;
   SCM bv;
-  volatile struct gdb_exception except;
 
   type = value_type (value);
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       CHECK_TYPEDEF (type);
       length = TYPE_LENGTH (type);
       contents = value_contents (value);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   bv = scm_c_make_bytevector (length);
   memcpy (SCM_BYTEVECTOR_CONTENTS (bv), contents, length);
@@ -902,27 +945,34 @@ gdbscm_value_to_bool (SCM self)
   struct value *value = v_smob->value;
   struct type *type;
   LONGEST l = 0;
-  volatile struct gdb_exception except;
 
   type = value_type (value);
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       CHECK_TYPEDEF (type);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   SCM_ASSERT_TYPE (is_intlike (type, 1), self, SCM_ARG1, FUNC_NAME,
 		   _("integer-like gdb value"));
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       if (TYPE_CODE (type) == TYPE_CODE_PTR)
 	l = value_as_address (value);
       else
 	l = value_as_long (value);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   return scm_from_bool (l != 0);
 }
@@ -938,27 +988,34 @@ gdbscm_value_to_integer (SCM self)
   struct value *value = v_smob->value;
   struct type *type;
   LONGEST l = 0;
-  volatile struct gdb_exception except;
 
   type = value_type (value);
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       CHECK_TYPEDEF (type);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   SCM_ASSERT_TYPE (is_intlike (type, 1), self, SCM_ARG1, FUNC_NAME,
 		   _("integer-like gdb value"));
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       if (TYPE_CODE (type) == TYPE_CODE_PTR)
 	l = value_as_address (value);
       else
 	l = value_as_long (value);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   if (TYPE_UNSIGNED (type))
     return gdbscm_scm_from_ulongest (l);
@@ -977,24 +1034,31 @@ gdbscm_value_to_real (SCM self)
   struct value *value = v_smob->value;
   struct type *type;
   DOUBLEST d = 0;
-  volatile struct gdb_exception except;
 
   type = value_type (value);
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       CHECK_TYPEDEF (type);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   SCM_ASSERT_TYPE (is_intlike (type, 0) || TYPE_CODE (type) == TYPE_CODE_FLT,
 		   self, SCM_ARG1, FUNC_NAME, _("number"));
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       d = value_as_double (value);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   /* TODO: Is there a better way to check if the value fits?  */
   if (d != (double) d)
@@ -1045,7 +1109,6 @@ gdbscm_value_to_string (SCM self, SCM rest)
   struct type *char_type = NULL;
   SCM result;
   struct cleanup *cleanups;
-  volatile struct gdb_exception except;
 
   /* The sequencing here, as everywhere else, is important.
      We can't have existing cleanups when a Scheme exception is thrown.  */
@@ -1081,11 +1144,15 @@ gdbscm_value_to_string (SCM self, SCM rest)
   /* We don't assume anything about the result of scm_port_conversion_strategy.
      From this point on, if errors is not 'errors, use 'substitute.  */
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       LA_GET_STRING (value, &buffer, &length, &char_type, &la_encoding);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+    }
+  END_CATCH
 
   /* If errors is "error" scm_from_stringn may throw a Scheme exception.
      Make sure we don't leak.  This is done via scm_dynwind_begin, et.al.  */
@@ -1131,7 +1198,7 @@ gdbscm_value_to_lazy_string (SCM self, SCM rest)
   int length = -1;
   SCM result = SCM_BOOL_F; /* -Wall */
   struct cleanup *cleanups;
-  volatile struct gdb_exception except;
+  struct gdb_exception except = exception_none;
 
   /* The sequencing here, as everywhere else, is important.
      We can't have existing cleanups when a Scheme exception is thrown.  */
@@ -1142,7 +1209,7 @@ gdbscm_value_to_lazy_string (SCM self, SCM rest)
 
   cleanups = make_cleanup (xfree, encoding);
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       struct cleanup *inner_cleanup
 	= make_cleanup_value_free_to_mark (value_mark ());
@@ -1155,6 +1222,12 @@ gdbscm_value_to_lazy_string (SCM self, SCM rest)
 
       do_cleanups (inner_cleanup);
     }
+  CATCH (ex, RETURN_MASK_ALL)
+    {
+      except = ex;
+    }
+  END_CATCH
+
   do_cleanups (cleanups);
   GDBSCM_HANDLE_GDB_EXCEPTION (except);
 
@@ -1184,14 +1257,17 @@ gdbscm_value_fetch_lazy_x (SCM self)
   value_smob *v_smob
     = vlscm_get_value_smob_arg_unsafe (self, SCM_ARG1, FUNC_NAME);
   struct value *value = v_smob->value;
-  volatile struct gdb_exception except;
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       if (value_lazy (value))
 	value_fetch_lazy (value);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   return SCM_UNSPECIFIED;
 }
@@ -1207,12 +1283,11 @@ gdbscm_value_print (SCM self)
   struct value_print_options opts;
   char *s = NULL;
   SCM result;
-  volatile struct gdb_exception except;
 
   get_user_print_options (&opts);
   opts.deref_ref = 0;
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       struct ui_file *stb = mem_fileopen ();
       struct cleanup *old_chain = make_cleanup_ui_file_delete (stb);
@@ -1222,7 +1297,11 @@ gdbscm_value_print (SCM self)
 
       do_cleanups (old_chain);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   /* Use SCM_FAILED_CONVERSION_QUESTION_MARK to ensure this doesn't
      throw an error if the encoding fails.
@@ -1246,7 +1325,6 @@ gdbscm_parse_and_eval (SCM expr_scm)
   struct value *res_val = NULL;
   SCM result;
   struct cleanup *cleanups;
-  volatile struct gdb_exception except;
 
   /* The sequencing here, as everywhere else, is important.
      We can't have existing cleanups when a Scheme exception is thrown.  */
@@ -1257,11 +1335,15 @@ gdbscm_parse_and_eval (SCM expr_scm)
   cleanups = make_cleanup_value_free_to_mark (value_mark ());
   make_cleanup (xfree, expr_str);
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       res_val = parse_and_eval (expr_str);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION_WITH_CLEANUPS (except, cleanups);
+    }
+  END_CATCH
 
   gdb_assert (res_val != NULL);
   result = vlscm_scm_from_value (res_val);
@@ -1282,15 +1364,18 @@ gdbscm_history_ref (SCM index)
 {
   int i;
   struct value *res_val = NULL; /* Initialize to appease gcc warning.  */
-  volatile struct gdb_exception except;
 
   gdbscm_parse_function_args (FUNC_NAME, SCM_ARG1, NULL, "i", index, &i);
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       res_val = access_value_history (i);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   return vlscm_scm_from_value (res_val);
 }
@@ -1304,16 +1389,19 @@ gdbscm_history_append_x (SCM value)
   int res_index = -1;
   struct value *v;
   value_smob *v_smob;
-  volatile struct gdb_exception except;
 
   v_smob = vlscm_get_value_smob_arg_unsafe (value, SCM_ARG1, FUNC_NAME);
   v = v_smob->value;
 
-  TRY_CATCH (except, RETURN_MASK_ALL)
+  TRY
     {
       res_index = record_latest_value (v);
     }
-  GDBSCM_HANDLE_GDB_EXCEPTION (except);
+  CATCH (except, RETURN_MASK_ALL)
+    {
+      GDBSCM_HANDLE_GDB_EXCEPTION (except);
+    }
+  END_CATCH
 
   return scm_from_int (res_index);
 }