[binutils-gdb] Garbage collecting debug sections

[Alan Modra <amodra at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=d422d1c433073ba412287334a7ec3aa95e03c5e9

commit d422d1c433073ba412287334a7ec3aa95e03c5e9
Author: Senthil Kumar Selvaraj <senthil_kumar.selvaraj@atmel.com>
Date:   Tue Mar 24 19:18:04 2015 +0530

    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.

Diff:
---
 bfd/ChangeLog                           |  5 +++
 bfd/elflink.c                           |  1 -
 ld/testsuite/ChangeLog                  |  6 ++++
 ld/testsuite/ld-gc/all-debug-sections.d | 10 ++++++
 ld/testsuite/ld-gc/all-debug-sections.s | 56 +++++++++++++++++++++++++++++++++
 ld/testsuite/ld-gc/gc.exp               |  3 ++
 6 files changed, 80 insertions(+), 1 deletion(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 469066b..78895be 100644
--- a/bfd/ChangeLog
+++ b/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
diff --git a/bfd/elflink.c b/bfd/elflink.c
index f93293b..9ccad8c 100644
--- a/bfd/elflink.c
+++ b/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;
 		  }
 	      }
 	  }
diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog
index 6e13e9c..8eef67e 100644
--- a/ld/testsuite/ChangeLog
+++ b/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.
diff --git a/ld/testsuite/ld-gc/all-debug-sections.d b/ld/testsuite/ld-gc/all-debug-sections.d
new file mode 100644
index 0000000..5e3373a
--- /dev/null
+++ b/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
+#...
diff --git a/ld/testsuite/ld-gc/all-debug-sections.s b/ld/testsuite/ld-gc/all-debug-sections.s
new file mode 100644
index 0000000..076f183
--- /dev/null
+++ b/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
+
diff --git a/ld/testsuite/ld-gc/gc.exp b/ld/testsuite/ld-gc/gc.exp
index 5ff6485..58f3a2a 100644
--- a/ld/testsuite/ld-gc/gc.exp
+++ b/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 ""