* elflink.c (elf_link_output_extsym): Weaken assertion: if --gc-section is set, there may be no TLS segment.

* lib/ld-lib.exp (check_gc_sections_available): New proc, based on the version in gcc/testsuite/lib/target-supports.exp.
* ld-elf/eld.exp: Use check_gc_sections_available.

bfd/ChangeLog

@@ -1,3 +1,8 @@
+2007-11-16  Tristan Gingold  <gingold@adacore.com>
+
+	* elflink.c (elf_link_output_extsym): Weaken assertion: if
+	--gc-section is set, there may be no TLS segment.
+
 2007-11-19  Alan Modra  <amodra@bigpond.net.au>
 
 	* elf-bfd.h (bfd_elf_perform_complex_relocation): Update prototype.

bfd/elflink.c

@@ -8536,10 +8536,15 @@ elf_link_output_extsym (struct elf_link_hash_entry *h, void *data)
 		sym.st_value += input_sec->output_section->vma;
 		if (h->type == STT_TLS)
 		  {
-		    /* STT_TLS symbols are relative to PT_TLS segment
-		       base.  */
-		    BFD_ASSERT (elf_hash_table (finfo->info)->tls_sec != NULL);
-		    sym.st_value -= elf_hash_table (finfo->info)->tls_sec->vma;
+		    asection *tls_sec = elf_hash_table (finfo->info)->tls_sec;
+		    if (tls_sec != NULL)
+		      sym.st_value -= tls_sec->vma;
+		    else
+		      {
+			/* The TLS section may have been garbage collected.  */
+			BFD_ASSERT (finfo->info->gc_sections
+				    && !input_sec->gc_mark);
+		      }
 		  }
 	      }
 	  }

ld/testsuite/ChangeLog

@@ -1,3 +1,14 @@
+2007-11-20  Nick Clifton  <nickc@redhat.com>
+
+	* lib/ld-lib.exp (check_gc_sections_available): New proc, based
+	on the version in gcc/testsuite/lib/target-supports.exp.
+	* ld-elf/elf.exp: Use check_gc_sections_available.
+
+2007-11-20  Tristan Gingold  <gingold@adacore.com>
+
+	* ld-elf/tls_gc.s: New test.
+	* ld-elf/elf.exp: Add tls_gc test.
+
 2007-11-17  Thiemo Seufer  <ths@mips.com>
 
 	* ld-mips-elf/attr-gnu-4-14.d, ld-mips-elf/attr-gnu-4-41.d:

ld/testsuite/ld-elf/elf.exp

@@ -53,6 +53,13 @@ if { [istarget *-*-linux*] } {
     }
 }
 
+if { [check_gc_sections_available] } {
+    run_ld_link_tests {
+	{"--gc-sections on tls variable"
+	    "--gc-section" "" {tls_gc.s} {} "tls_gc"}
+    }
+}
+
 # The following tests require running the executable generated by ld.
 if ![isnative] {
     return

ld/testsuite/lib/ld-lib.exp

@@ -1535,3 +1535,45 @@ proc run_cc_link_tests { ldtests } {
 	}
     }
 }
+
+# Returns true if --gc-sections is supported on the target.
+
+proc check_gc_sections_available { } {
+    global gc_sections_available_saved
+    global ld
+    
+    if {![info exists gc_sections_available_saved]} {
+	# Some targets don't support gc-sections despite whatever's
+	# advertised by ld's options.
+	if { [istarget alpha*-*-*]
+	     || [istarget ia64-*-*] } {
+	    set gc_sections_available_saved 0
+	    return 0
+	}
+
+	# elf2flt uses -q (--emit-relocs), which is incompatible with
+	# --gc-sections.
+	if { [board_info target exists ldflags]
+	     && [regexp " -elf2flt\[ =\]" " [board_info target ldflags] "] } {
+	    set gc_sections_available_saved 0
+	    return 0
+	}
+
+	# VxWorks kernel modules are relocatable objects linked with -r,
+	# while RTP executables are linked with -q (--emit-relocs).
+	# Both of these options are incompatible with --gc-sections.
+	if { [istarget *-*-vxworks*] } {
+	    set gc_sections_available_saved 0
+	    return 0
+	}
+
+	# Check if the ld used by gcc supports --gc-sections.
+	set ld_output [remote_exec host $ld "--help"]
+	if { [ string first "--gc-sections" $ld_output ] >= 0 } {
+	    set gc_sections_available_saved 1
+	} else {
+	    set gc_sections_available_saved 0
+	}
+    }
+    return $gc_sections_available_saved
+}