elf: Drop elf/tls-macros.h in favor of __thread and tls_model attributes [BZ #28152] [BZ #28205]

elf/tls-macros.h was added for TLS testing when GCC did not support
__thread. __thread and tls_model attributes are mature now and have been
used by many newer tests.

Also delete tst-tls2.c which tests .tls_common (unused by modern GCC and
unsupported by Clang/LLD). .tls_common and .tbss definition are almost
identical after linking, so the runtime test doesn't add additional
coverage.  Assembler and linker tests should be on the binutils side.

When LLD 13.0.0 is allowed in configure.ac
(https://sourceware.org/pipermail/libc-alpha/2021-August/129866.html),
`make check` result is on par with glibc built with GNU ld on aarch64
and x86_64.

As a future clean-up, TLS_GD/TLS_LD/TLS_IE/TLS_IE macros can be removed from
sysdeps/*/tls-macros.h. We can add optional -mtls-dialect={gnu2,trad}
tests to ensure coverage.

Tested on aarch64-linux-gnu, powerpc64le-linux-gnu, and x86_64-linux-gnu.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>

1 files changed, 11 insertions, 15 deletions

diff --git a/elf/tst-tls3.c b/elf/tst-tls3.c
index 7e0abb4c58..222b179626 100644
--- a/elf/tst-tls3.c
+++ b/elf/tst-tls3.c
@@ -1,13 +1,12 @@
 /* glibc test for TLS in ld.so.  */
 #include <stdio.h>
 
-#include "tls-macros.h"
 
-
-/* One define int variable, two externs.  */
-COMMON_INT_DECL(foo);
-VAR_INT_DECL(bar);
-VAR_INT_DEF(baz);
+__thread int foo, bar __attribute__ ((tls_model("initial-exec")));
+__thread int baz __attribute__ ((tls_model("local-exec")));
+extern __thread int foo_gd __attribute__ ((alias("foo"), tls_model("global-dynamic")));
+extern __thread int bar_gd __attribute__ ((alias("bar"), tls_model("global-dynamic")));
+extern __thread int baz_ld __attribute__ ((alias("baz"), tls_model("local-dynamic")));
 
 
 extern int in_dso (void);
@@ -22,23 +21,20 @@ do_test (void)
 
   /* Set the variable using the local exec model.  */
   puts ("set baz to 3 (LE)");
-  ap = TLS_LE (baz);
-  *ap = 3;
+  baz = 3;
 
 
   /* Get variables using initial exec model.  */
   puts ("set variables foo and bar (IE)");
-  ap = TLS_IE (foo);
-  *ap = 1;
-  bp = TLS_IE (bar);
-  *bp = 2;
+  foo = 1;
+  bar = 2;
 
 
   /* Get variables using local dynamic model.  */
   fputs ("get sum of foo, bar (GD) and baz (LD)", stdout);
-  ap = TLS_GD (foo);
-  bp = TLS_GD (bar);
-  cp = TLS_LD (baz);
+  ap = &foo_gd;
+  bp = &bar_gd;
+  cp = &baz_ld;
   printf (" = %d\n", *ap + *bp + *cp);
   result |= *ap + *bp + *cp != 6;
   if (*ap != 1)