From 612e7966127e7f58ae10198250410719df6c1b11 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 20 Sep 2022 12:04:37 -0400 Subject: [PATCH] Suppress variable-set-but-not-used warnings from clang 15. clang 15+ will issue a set-but-not-used warning when the only use of a variable is in autoincrements (e.g., "foo++;"). That's perfectly sensible, but it detects a few more cases that we'd not noticed before. Silence the warnings with our usual methods, such as PG_USED_FOR_ASSERTS_ONLY, or in one case by actually removing a useless variable. One thing that we can't nicely get rid of is that with %pure-parser, Bison emits "yynerrs" as a local variable that falls foul of this warning. To silence those, I inserted "(void) yynerrs;" in the top-level productions of affected grammars. Per recently-established 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 to 9.5, which is as far as these patches go without issues. (A preliminary check shows that the prior branches need some other set-but-not-used cleanups too, so I'll leave them for another day.) Discussion: https://postgr.es/m/514615.1663615243@sss.pgh.pa.us --- src/backend/access/gist/gistxlog.c | 2 +- src/backend/access/transam/xlog.c | 2 +- src/backend/parser/gram.y | 1 + src/backend/utils/adt/array_typanalyze.c | 4 +--- 4 files changed, 4 insertions(+), 5 deletions(-) diff --git a/src/backend/access/gist/gistxlog.c b/src/backend/access/gist/gistxlog.c index fbdbb3c51f2..7a8fdd85354 100644 --- a/src/backend/access/gist/gistxlog.c +++ b/src/backend/access/gist/gistxlog.c @@ -74,7 +74,7 @@ gistRedoPageUpdateRecord(XLogReaderState *record) char *begin; char *data; Size datalen; - int ninserted = 0; + int ninserted PG_USED_FOR_ASSERTS_ONLY = 0; data = begin = XLogRecGetBlockData(record, 0, &datalen); diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index f5a1599cb37..c3fe1271465 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -1905,7 +1905,7 @@ AdvanceXLInsertBuffer(XLogRecPtr upto, bool opportunistic) XLogRecPtr NewPageEndPtr = InvalidXLogRecPtr; XLogRecPtr NewPageBeginPtr; XLogPageHeader NewPage; - int npages = 0; + int npages pg_attribute_unused() = 0; LWLockAcquire(WALBufMappingLock, LW_EXCLUSIVE); diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 617e577b663..24bdb86bc2c 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -732,6 +732,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query); stmtblock: stmtmulti { pg_yyget_extra(yyscanner)->parsetree = $1; + (void) yynerrs; /* suppress compiler warning */ } ; diff --git a/src/backend/utils/adt/array_typanalyze.c b/src/backend/utils/adt/array_typanalyze.c index ffe8035eb4d..e2ded3ccd47 100644 --- a/src/backend/utils/adt/array_typanalyze.c +++ b/src/backend/utils/adt/array_typanalyze.c @@ -216,7 +216,6 @@ compute_array_stats(VacAttrStats *stats, AnalyzeAttrFetchFunc fetchfunc, { ArrayAnalyzeExtraData *extra_data; int num_mcelem; - int null_cnt = 0; int null_elem_cnt = 0; int analyzed_rows = 0; @@ -320,8 +319,7 @@ compute_array_stats(VacAttrStats *stats, AnalyzeAttrFetchFunc fetchfunc, value = fetchfunc(stats, array_no, &isnull); if (isnull) { - /* array is null, just count that */ - null_cnt++; + /* ignore arrays that are null overall */ continue; } -- 2.39.5