From 6e2743687202c58a6553ae632ebbada3de38ad48 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Fri, 8 Apr 2022 09:16:30 +0200 Subject: [PATCH] c: Error on va_arg with function type [PR105149] In the PR Joseph said that the C standard for va_arg talks about pointers to object type and as a function type is not object type, it is invalid. The following patch diagnoses it in the FE, instead of ICEing later on when optimizations are turned on (and with -O0 doing something weird at runtime). 2022-04-08 Jakub Jelinek PR c/105149 * c-typeck.cc (c_build_va_arg): Reject function types. * gcc.dg/pr105149.c: New test. --- gcc/c/c-typeck.cc | 6 ++++++ gcc/testsuite/gcc.dg/pr105149.c | 16 ++++++++++++++++ 2 files changed, 22 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/pr105149.c diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc index 6c4af5e..e130196 100644 --- a/gcc/c/c-typeck.cc +++ b/gcc/c/c-typeck.cc @@ -15896,6 +15896,12 @@ c_build_va_arg (location_t loc1, tree expr, location_t loc2, tree type) "type %qT", type); return error_mark_node; } + else if (TREE_CODE (type) == FUNCTION_TYPE) + { + error_at (loc2, "second argument to % is a function type %qT", + type); + return error_mark_node; + } else if (warn_cxx_compat && TREE_CODE (type) == ENUMERAL_TYPE) warning_at (loc2, OPT_Wc___compat, "C++ requires promoted type, not enum type, in %"); diff --git a/gcc/testsuite/gcc.dg/pr105149.c b/gcc/testsuite/gcc.dg/pr105149.c new file mode 100644 index 0000000..b748f45 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr105149.c @@ -0,0 +1,16 @@ +/* PR c/105149 */ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ + +#include + +void +foo (int s, ...) +{ + int e; + va_list ap; + + va_start (ap, s); + e = va_arg (ap, int (void)) (); /* { dg-error "second argument to 'va_arg' is a function type" } */ + va_end (ap); +} -- 2.7.4