| Message ID | Yk8I1bPkZArnv0S+@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | c: Error on va_arg with function type [PR105149] | expand |
On Thu, Apr 07, 2022 at 05:52:53PM +0200, Jakub Jelinek wrote: > Hi! > > 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). > > Bootstrapped/regtested on powerpc64le-linux, ok for trunk? Ok, thanks. > 2022-04-07 Jakub Jelinek <jakub@redhat.com> > > PR c/105149 > * c-typeck.cc (c_build_va_arg): Reject function types. > > * gcc.dg/pr105149.c: New test. > > --- gcc/c/c-typeck.cc.jj 2022-03-23 10:29:20.172967605 +0100 > +++ gcc/c/c-typeck.cc 2022-04-07 12:26:17.236469809 +0200 > @@ -15896,6 +15896,12 @@ c_build_va_arg (location_t loc1, tree ex > "type %qT", type); > return error_mark_node; > } > + else if (TREE_CODE (type) == FUNCTION_TYPE) > + { > + error_at (loc2, "second argument to %<va_arg%> 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 %<va_arg%>"); > --- gcc/testsuite/gcc.dg/pr105149.c.jj 2022-04-07 12:39:08.202711511 +0200 > +++ gcc/testsuite/gcc.dg/pr105149.c 2022-04-07 12:38:21.418364583 +0200 > @@ -0,0 +1,16 @@ > +/* PR c/105149 */ > +/* { dg-do compile } */ > +/* { dg-options "-O2" } */ > + > +#include <stdarg.h> > + > +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); > +} Marek
--- gcc/c/c-typeck.cc.jj 2022-03-23 10:29:20.172967605 +0100 +++ gcc/c/c-typeck.cc 2022-04-07 12:26:17.236469809 +0200 @@ -15896,6 +15896,12 @@ c_build_va_arg (location_t loc1, tree ex "type %qT", type); return error_mark_node; } + else if (TREE_CODE (type) == FUNCTION_TYPE) + { + error_at (loc2, "second argument to %<va_arg%> 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 %<va_arg%>"); --- gcc/testsuite/gcc.dg/pr105149.c.jj 2022-04-07 12:39:08.202711511 +0200 +++ gcc/testsuite/gcc.dg/pr105149.c 2022-04-07 12:38:21.418364583 +0200 @@ -0,0 +1,16 @@ +/* PR c/105149 */ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ + +#include <stdarg.h> + +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); +}