Suppress compiler warnings from commit ee895a655.

For obscure reasons, some buildfarm members are now generating
complaints about plpgsql_call_handler's "retval" variable possibly
being used uninitialized.  It seems no less safe than it was before
that commit, but these complaints are (mostly?) new.  I trust that
initializing the variable where it's declared will be enough to
shut that up.

I also notice that some compilers are warning about setjmp clobber
of the same variable, which is maybe a bit more defensible.  Mark
it volatile to silence that.

Also, rearrange the logic to give procedure_resowner a single
point of initialization, in hopes of silencing some setjmp-clobber
warnings about that.  (Marking it volatile would serve too, but
its sibling variables are depending on single assignment, so let's
stick with that method.)

Discussion: https://postgr.es/m/E1l4F1z-0000cN-Lx@gemulon.postgresql.org

diff --git a/src/pl/plpgsql/src/pl_handler.c b/src/pl/plpgsql/src/pl_handler.c
index 97f4264c287265ea994d2448ad28b281d205e3a3..00aace2f39fb32395564b1d995f3d1ff13b3cdd1 100644 (file)
--- a/src/pl/plpgsql/src/pl_handler.c
+++ b/src/pl/plpgsql/src/pl_handler.c
@@ -224,8 +224,8 @@ plpgsql_call_handler(PG_FUNCTION_ARGS)
        bool            nonatomic;
        PLpgSQL_function *func;
        PLpgSQL_execstate *save_cur_estate;
-       ResourceOwner procedure_resowner = NULL;
-       Datum           retval;
+       ResourceOwner procedure_resowner;
+       volatile Datum retval = (Datum) 0;
        int                     rc;
 
        nonatomic = fcinfo->context &&
@@ -254,9 +254,9 @@ plpgsql_call_handler(PG_FUNCTION_ARGS)
         * Therefore, be very wary of adding any code between here and the PG_TRY
         * block.
         */
-       if (nonatomic && func->requires_procedure_resowner)
-               procedure_resowner =
-                       ResourceOwnerCreate(NULL, "PL/pgSQL procedure resources");
+       procedure_resowner =
+               (nonatomic && func->requires_procedure_resowner) ?
+               ResourceOwnerCreate(NULL, "PL/pgSQL procedure resources") : NULL;
 
        PG_TRY();
        {
@@ -271,7 +271,7 @@ plpgsql_call_handler(PG_FUNCTION_ARGS)
                {
                        plpgsql_exec_event_trigger(func,
                                                                           (EventTriggerData *) fcinfo->context);
-                       retval = (Datum) 0;
+                       /* there's no return value in this case */
                }
                else
                        retval = plpgsql_exec_function(func, fcinfo,