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From: "bruce at momjian dot us" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c/111240] New: Incorrect warning from -Wmaybe-uninitialized Date: Wed, 30 Aug 2023 15:16:15 +0000 [thread overview] Message-ID: <bug-111240-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111240 Bug ID: 111240 Summary: Incorrect warning from -Wmaybe-uninitialized Product: gcc Version: 12.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: bruce at momjian dot us Target Milestone: --- Compiling this file from the PostgreSQL master source tree generates a warning when I don't think it should. To reproduce, only -O1 produces the bug, not -O0/-O2/-O3: gcc -Wmaybe-uninitialized -O1 -c clauses.i Yields: clauses.c: In function ‘recheck_cast_function_args’: clauses.c:4293:19: warning: ‘actual_arg_types’ may be used uninitialized [-Wmaybe-uninitialized] 4293 | rettype = enforce_generic_type_consistency(actual_arg_types, In file included from clauses.c:45: ../../../../src/include/parser/parse_coerce.h:82:17: note: by argument 1 of type ‘const Oid *’ {aka ‘const unsigned int *’} to ‘enforce_generic_type_consistency’ declared here 82 | extern Oid enforce_generic_type_consistency(const Oid *actual_arg_types, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ clauses.c:4279:24: note: ‘actual_arg_types’ declared here 4279 | Oid actual_arg_types[FUNC_MAX_ARGS]; | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here is the C code. nargs prevents uninitialized values from being used when calling enforce_generic_type_consistency(). ------------------------------------- static void recheck_cast_function_args(List *args, Oid result_type, Oid *proargtypes, int pronargs, HeapTuple func_tuple) { Form_pg_proc funcform = (Form_pg_proc) GETSTRUCT(func_tuple); int nargs; Oid actual_arg_types[FUNC_MAX_ARGS]; Oid declared_arg_types[FUNC_MAX_ARGS]; Oid rettype; ListCell *lc; if (list_length(args) > FUNC_MAX_ARGS) elog(ERROR, "too many function arguments"); nargs = 0; foreach(lc, args) { actual_arg_types[nargs++] = exprType((Node *) lfirst(lc)); } Assert(nargs == pronargs); memcpy(declared_arg_types, proargtypes, pronargs * sizeof(Oid)); rettype = enforce_generic_type_consistency(actual_arg_types, declared_arg_types, nargs, funcform->prorettype, false);
next reply other threads:[~2023-08-30 15:16 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-08-30 15:16 bruce at momjian dot us [this message] 2023-08-30 15:25 ` [Bug tree-optimization/111240] " pinskia at gcc dot gnu.org 2023-08-30 15:27 ` pinskia at gcc dot gnu.org 2023-08-30 15:30 ` bruce at momjian dot us 2023-08-30 15:30 ` bruce at momjian dot us 2023-08-30 15:38 ` pinskia at gcc dot gnu.org 2023-08-31 9:46 ` [Bug tree-optimization/111240] [12/13/14 Regression] " rguenth at gcc dot gnu.org 2024-03-07 23:22 ` law at gcc dot gnu.org
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