XCOFF: add support for TLS relocations on hidden symbols

This patch adds support for TLS relocation targeting C_HIDEXT symbols.
In gas, TLS relocations, except R_TLSM and R_TLMSL, must keep the value
of their target symbol.
In ld, it simply ensures that internal TLS symbols are added to the
linker hash table for xcoff_reloc_type_tls.

It also improves the tests made by both.

bfd/ChangeLog:

	* coff-rs6000.c (xcoff_howto_table): Fix name of R_TLSML.
	(xcoff_reloc_type_tls): Replace the error when h is NULL by
	an assert.
	(xcoff_complain_overflow_unsigned_func): Adjust comments.
	* coff64-rs6000.c (xcoff64_howto_table): Fix name of R_TLSML.
	* xcofflink.c (xcoff_link_add_symbols_to_hash_table): New
	function.
	(xcoff_link_add_symbols): Add C_HIDEXT TLS symbols to the linker
	hash table.

gas/ChangeLog:

	* config/tc-ppc.c (md_apply_fix): Enable support for TLS
	relocation over internal symbols.
	* testsuite/gas/ppc/aix.exp: Replace xcoff-tlms by xcoff-tls.
	* testsuite/gas/ppc/xcoff-tlsm-32.d: Removed.
	* testsuite/gas/ppc/xcoff-tlsm-64.d: Removed.
	* testsuite/gas/ppc/xcoff-tlsm.s: Removed.
	* testsuite/gas/ppc/xcoff-tls-32.d: New test.
	* testsuite/gas/ppc/xcoff-tls-64.d: New test.
	* testsuite/gas/ppc/xcoff-tls.s: New test.

ld/ChangeLog:

	* testsuite/ld-powerpc/aix52.exp: Improve aix-tls-reloc test.
	* testsuite/ld-powerpc/aix-tls-reloc.s: Likewise.
	* testsuite/ld-powerpc/aix-tls-reloc-32.d: Removed.
	* testsuite/ld-powerpc/aix-tls-reloc-64.d: Removed.
	* testsuite/ld-powerpc/aix-tls-reloc-32.dd: New test.
	* testsuite/ld-powerpc/aix-tls-reloc-32.dt: New test.
	* testsuite/ld-powerpc/aix-tls-reloc-64.dd: New test.
	* testsuite/ld-powerpc/aix-tls-reloc-64.dt: New test.

1 files changed, 12 insertions, 21 deletions

diff --git a/bfd/coff-rs6000.c b/bfd/coff-rs6000.c
index 3248670..97e84a4 100644
--- a/bfd/coff-rs6000.c
+++ b/bfd/coff-rs6000.c
@@ -1106,7 +1106,7 @@ reloc_howto_type xcoff_howto_table[] =
 	 0,			/* bitpos */
 	 complain_overflow_bitfield, /* complain_on_overflow */
 	 0,			/* special_function */
-	 "R_TLSM",		/* name */
+	 "R_TLSML",		/* name */
 	 true,			/* partial_inplace */
 	 0xffffffff,		/* src_mask */
 	 0xffffffff,		/* dst_mask */
@@ -3236,27 +3236,19 @@ xcoff_reloc_type_tls (bfd *input_bfd ATTRIBUTE_UNUSED,
 
   h = obj_xcoff_sym_hashes (input_bfd)[rel->r_symndx];
 
-  /* FIXME: R_TLSML is targeting a internal TOC symbol, which will
-     make the following checks failing. It should be moved with
-     R_TLSM bellow once it works.  */
+  /* R_TLSML is handled by the loader but must be from a
+     TOC entry targeting itslef.  This is already verified in
+     xcoff_link_add_symbols.
+     The value must be 0.  */
   if (howto->type == R_TLSML)
     {
       *relocation = 0;
       return true;
     }
 
-  /* FIXME: h is sometimes null, if the TLS symbol is not exported.  */
-  if (!h)
-    {
-      char vaddr_buf[128];
-
-      sprintf_vma (vaddr_buf, rel->r_vaddr);
-      _bfd_error_handler
-	(_("%pB: TLS relocation at 0x%s over internal symbols (C_HIDEXT) not yet possible\n"),
-	 input_bfd, vaddr_buf);
-      return false;
-    }
-
+  /* The target symbol should always be available even if it's not
+     exported.  */
+  BFD_ASSERT (h != NULL);
 
   /* TLS relocations must target a TLS symbol.  */
   if (h->smclas != XMC_TL && h->smclas != XMC_UL)
@@ -3286,9 +3278,8 @@ xcoff_reloc_type_tls (bfd *input_bfd ATTRIBUTE_UNUSED,
       return false;
     }
 
-  /* R_TLSM and R_TLSML are relocations used by the loader.
-     The value must be 0.
-     FIXME: move R_TLSML here.  */
+  /* R_TLSM are relocations used by the loader.
+     The value must be 0.  */
   if (howto->type == R_TLSM)
     {
       *relocation = 0;
@@ -3621,10 +3612,10 @@ xcoff_complain_overflow_unsigned_func (bfd *input_bfd,
    R_TLS_LE:
    Thread-local storage relocation using local-exec model.
 
-   R_TLS:
+   R_TLSM:
    Tread-local storage relocation used by the loader.
 
-   R_TLSM:
+   R_TLSML:
    Tread-local storage relocation used by the loader.
 
    R_TOCU: