Hi! ARM defaults to -fshort-enums and the following testcase FAILs there in 2 lines. The difference is that in C++, E0 has enum E type, which normally has unsigned int underlying type, so it isn't int nor something that promotes to int, which is why we diagnose it (in C it is promoted to int). But with -fshort-enums, the underlying type is unsigned char in that case, which promotes to int just fine.
The following patch adjusts the expectations, such that we don't expect it on arm or when people manually test with -fshort-enums. Tested on x86_64-linux and i686-linux, ok for trunk? 2023-11-21 Jakub Jelinek <ja...@redhat.com> PR c/111309 * c-c++-common/pr111309-2.c (foo): Don't expect errors for C++ with -fshort-enums if second argument is E0. --- gcc/testsuite/c-c++-common/pr111309-2.c.jj 2023-11-14 10:52:16.191276028 +0100 +++ gcc/testsuite/c-c++-common/pr111309-2.c 2023-11-20 17:52:30.606386073 +0100 @@ -32,7 +32,7 @@ foo (void) __builtin_clzg (0U, 2LL); /* { dg-error "does not have 'int' type" } */ __builtin_clzg (0U, 2U); /* { dg-error "does not have 'int' type" } */ __builtin_clzg (0U, true); - __builtin_clzg (0U, E0); /* { dg-error "does not have 'int' type" "" { target c++ } } */ + __builtin_clzg (0U, E0); /* { dg-error "does not have 'int' type" "" { target { c++ && { ! short_enums } } } } */ __builtin_ctzg (); /* { dg-error "too few arguments" } */ __builtin_ctzg (0U, 1, 2); /* { dg-error "too many arguments" } */ __builtin_ctzg (0); /* { dg-error "has signed type" } */ @@ -51,7 +51,7 @@ foo (void) __builtin_ctzg (0U, 2LL); /* { dg-error "does not have 'int' type" } */ __builtin_ctzg (0U, 2U); /* { dg-error "does not have 'int' type" } */ __builtin_ctzg (0U, true); - __builtin_ctzg (0U, E0); /* { dg-error "does not have 'int' type" "" { target c++ } } */ + __builtin_ctzg (0U, E0); /* { dg-error "does not have 'int' type" "" { target { c++ && { ! short_enums } } } } */ __builtin_clrsbg (); /* { dg-error "too few arguments" } */ __builtin_clrsbg (0, 1); /* { dg-error "too many arguments" } */ __builtin_clrsbg (0U); /* { dg-error "has unsigned type" } */ Jakub