Do away with hash table line lookup in dwarf2dbg.c

Hash lookup is silly when we can attach the line table info directly
to sections instead.  Worse, hash lookup fails when we have multiple
sections with the same name.

gas/
	* dwarf2dbg.c (all_segs_hash): Delete.
	(get_line_subseg): Delete last_seg, last_subseg, last_line_subseg.
	Retrieve line_seg for section via seg_info.
	* subsegs.h (segment_info_typet): Add dwarf2_line_seg.
gas/testsuite/
	* gas/elf/group2.d, * gas/elf/group2.s: New test.
	* gas/elf/elf.exp: Run it.

gas/ChangeLog

@@ -1,3 +1,10 @@
+2014-09-27  Alan Modra  <amodra@gmail.com>
+
+	* dwarf2dbg.c (all_segs_hash): Delete.
+	(get_line_subseg): Delete last_seg, last_subseg, last_line_subseg.
+	Retrieve line_seg for section via seg_info.
+	* subsegs.h (segment_info_typet): Add dwarf2_line_seg.
+
 2014-09-23  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR gas/17421

gas/dwarf2dbg.c

@@ -186,9 +186,6 @@ struct line_seg {
 
 /* Collects data for all line table entries during assembly.  */
 static struct line_seg *all_segs;
-/* Hash used to quickly lookup a segment by name, avoiding the need to search
-   through the all_segs list.  */
-static struct hash_control *all_segs_hash;
 static struct line_seg **last_seg_ptr;
 
 struct file_entry {
@@ -248,17 +245,9 @@ generic_dwarf2_emit_offset (symbolS *symbol, unsigned int size)
 static struct line_subseg *
 get_line_subseg (segT seg, subsegT subseg, bfd_boolean create_p)
 {
-  static segT last_seg;
-  static subsegT last_subseg;
-  static struct line_subseg *last_line_subseg;
-
-  struct line_seg *s;
+  struct line_seg *s = seg_info (seg)->dwarf2_line_seg;
   struct line_subseg **pss, *lss;
 
-  if (seg == last_seg && subseg == last_subseg)
-    return last_line_subseg;
-
-  s = (struct line_seg *) hash_find (all_segs_hash, seg->name);
   if (s == NULL)
     {
       if (!create_p)
@@ -270,7 +259,7 @@ get_line_subseg (segT seg, subsegT subseg, bfd_boolean create_p)
       s->head = NULL;
       *last_seg_ptr = s;
       last_seg_ptr = &s->next;
-      hash_insert (all_segs_hash, seg->name, s);
+      seg_info (seg)->dwarf2_line_seg = s;
     }
   gas_assert (seg == s->seg);
 
@@ -291,10 +280,6 @@ get_line_subseg (segT seg, subsegT subseg, bfd_boolean create_p)
   *pss = lss;
 
  found_subseg:
-  last_seg = seg;
-  last_subseg = subseg;
-  last_line_subseg = lss;
-
   return lss;
 }
 
@@ -1847,7 +1832,6 @@ out_debug_info (segT info_seg, segT abbrev_seg, segT line_seg, segT ranges_seg)
 void
 dwarf2_init (void)
 {
-  all_segs_hash = hash_new ();
   last_seg_ptr = &all_segs;
 }
 

gas/subsegs.h

@@ -90,6 +90,9 @@ typedef struct segment_info_struct {
      this section.  sym->bsym and bfd_section->symbol should be the same.  */
   symbolS *sym;
 
+  /* Used by dwarf2dbg.c for this section's line table entries.  */
+  void *dwarf2_line_seg;
+
   union {
     /* Current size of section holding stabs strings.  */
     unsigned long stab_string_size;

gas/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2014-09-27  Alan Modra  <amodra@gmail.com>
+
+	* gas/elf/group2.d, * gas/elf/group2.s: New test.
+	* gas/elf/elf.exp: Run it.
+
 2014-09-23  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR gas/17421

gas/testsuite/gas/elf/elf.exp

@@ -110,6 +110,7 @@ if { [is_elf_format] } then {
     run_dump_test "group0c"
     run_dump_test "group1a"
     run_dump_test "group1b"
+    run_dump_test "group2"
     case $target_triplet in {
 	{ hppa64*-*-hpux* } { }
 	default {

gas/testsuite/gas/elf/group2.d

@@ -0,0 +1,12 @@
+#readelf: -SW
+#name: debug info in group section and non-group section with same name
+#source: group2.s
+# The RX port uses non-standard section names.
+#not-target: rx-*
+
+#...
+[ 	]*\[.*\][ 	]+\.group[ 	]+GROUP.*
+#...
+[ 	]*\[.*\][ 	]+\.text\.startup[ 	]+PROGBITS.*[ 	]+AXG[ 	]+.*
+[ 	]*\[.*\][ 	]+\.text\.startup[ 	]+PROGBITS.*[ 	]+AX[ 	]+.*
+#pass

gas/testsuite/gas/elf/group2.s

@@ -0,0 +1,9 @@
+ .file 1 "test.c"
+
+ .section .text.startup,"axG",%progbits,test,comdat
+ .loc 1 1
+ .org 8
+
+ .section .text.startup,"ax",%progbits
+ .loc 1 1
+ .org 8