Garbage collecting debug sections

I noticed that _bfd_elf_gc_mark_extra_sections attempts to unmark
related debug sections when it finds an unmarked code section.
When it finds .text.foo is unmarked, for example, it removes
.debug_line.text.foo as well (using the section name as a suffix
match check.

However, it bails out after finding one such section.

bfd/
	* elflink.c (_bfd_elf_gc_mark_extra_sections): Don't break on
	first matching debug section.
ld/testsuite/
	* ld-gc/all-debug-sections.d: New file.
	* ld-gc/all-debug-sections.s: Likewise.
	* ld-gc/gc.exp: Execute new testcase.

bfd/ChangeLog

@@ -1,3 +1,8 @@
+2015-03-25  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>
+
+	* elflink.c (_bfd_elf_gc_mark_extra_sections): Don't break on
+	first matching debug section.
+
 2015-03-24  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR gas/18087

bfd/elflink.c

@@ -12102,7 +12102,6 @@ _bfd_elf_gc_mark_extra_sections (struct bfd_link_info *info,
 				isec->name, ilen) == 0)
 		  {
 		    dsec->gc_mark = 0;
-		    break;
 		  }
 	      }
 	  }

ld/testsuite/ChangeLog

@@ -1,3 +1,9 @@
+2015-03-25  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>
+
+	* ld-gc/all-debug-sections.d: New file.
+	* ld-gc/all-debug-sections.s: Likewise.
+	* ld-gc/gc.exp: Execute new testcase.
+
 2015-03-11  Alan Modra  <amodra@gmail.com>
 
 	* ld-powerpc/tls32.s: Add GOT pointer setup.

ld/testsuite/ld-gc/all-debug-sections.d

@@ -0,0 +1,10 @@
+#name: --gc-sections with multiple debug sections for a function section
+#as: -gdwarf-sections
+#ld: --gc-sections -e _start
+#PROG: nm
+
+#...
+[0-9a-f]+ N +debug_aranges_main
+[0-9a-f]+ N +debug_info_main
+[0-9a-f]+ N +debug_line_main
+#...

ld/testsuite/ld-gc/all-debug-sections.s

@@ -0,0 +1,56 @@
+ .section .text.useless,"ax",%progbits
+ .globl	useless
+ .type useless, %function
+useless:
+ .long 1
+
+ .section .text.main,"ax",%progbits
+ .globl _start
+_start:
+ .globl main
+ .type main, %function
+main:
+ .long 2
+
+ .section .text,"ax",%progbits
+ .long main
+
+ .section .debug_info.text.main,"",%progbits
+debug_info_main:
+ .long 0x3c
+ .long main
+
+ .section .debug_info.text.useless,"",%progbits
+debug_info_useless:
+ .long 0x38
+ .long useless
+
+ .section .debug_info,"",%progbits
+ .long 0x49
+
+ .section .debug_aranges,"",%progbits
+ .long 0x3c
+
+ .section .debug_aranges.text.main,"",%progbits
+debug_aranges_main:
+ .long 0x2c
+ .long main
+
+ .section .debug_aranges.text.useless,"",%progbits
+debug_aranges_useless:
+ .long 0x2c
+ .long useless
+
+ .section .debug_line,"",%progbits
+ .long 0x3c
+
+ .section .debug_line.text.main,"",%progbits
+debug_line_main:
+ .long 0x2c
+ .long main
+
+ .section .debug_line.text.useless,"",%progbits
+debug_line_useless:
+ .long 0x2c
+ .long useless
+

ld/testsuite/ld-gc/gc.exp

@@ -101,6 +101,9 @@ test_gc "Check --gc-section/-r/-u" "gcrel" $ld "-r --gc-sections -u used_func"
 run_dump_test "noent"
 run_dump_test "abi-note"
 run_dump_test "start"
+if { [is_elf_format] } then {
+    run_dump_test "all-debug-sections"
+}
 
 if { [is_elf_format] && [check_shared_lib_support] } then {
     set gasopt ""