Suppress more variable-set-but-not-used warnings from clang 15.

tglsfdc · tglsfdc · commit 88c947cb5261 · 2022-09-21T13:52:38.000-04:00
Mop up assorted set-but-not-used warnings in the back branches. This includes back-patching relevant fixes from commit 152c9f7 the rest of the way, but there are also several cases that did not appear in HEAD. Some of those we'd fixed in a retail way but not back-patched, and others I think just got rewritten out of existence during nearby refactoring. While here, also back-patch b1980f6 (PL/Tcl: Fix compiler warnings with Tcl 8.6) into 9.2, so that that branch compiles warning-free with modern Tcl. Per project policy, this is a candidate for back-patching into out-of-support branches: it suppresses annoying compiler warnings but changes no behavior. Hence, back-patch all the way to 9.2. Discussion: https://postgr.es/m/514615.1663615243@sss.pgh.pa.us
diff --git a/src/backend/optimizer/util/var.c b/src/backend/optimizer/util/var.c
@@ -761,16 +761,13 @@ flatten_join_alias_vars_mutator(Node *node,
 			RowExpr    *rowexpr;
 			List	   *fields = NIL;
 			List	   *colnames = NIL;
-			AttrNumber	attnum;
 			ListCell   *lv;
 			ListCell   *ln;
 
-			attnum = 0;
 			Assert(list_length(rte->joinaliasvars) == list_length(rte->eref->colnames));
 			forboth(lv, rte->joinaliasvars, ln, rte->eref->colnames)
 			{
 				newvar = (Node *) lfirst(lv);
-				attnum++;
 				/* Ignore dropped columns */
 				if (newvar == NULL)
 					continue;
