[patch] Discontiguous PSYMTABs [Re: [patch] Parse DW_AT_ranges into PSYMTABS (for childless CU, for vDSO32)]

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

On Fri, 30 Nov 2007 15:56:13 +0100, Daniel Jacobowitz wrote:
> On Fri, Nov 30, 2007 at 12:10:21PM +0100, Jan Kratochvil wrote:
> > It was not reproducible for me but the problem is Vladimir's i386 crti.S has
> > DW_AT_ranges which overlap the main code (due to its .fini part).  The main
> > code full-symbols get ignored now due to it.
...
> Jim, can we get your addrmap changes in as they are,
...
> After that, it's simple to solve this problem more accurately by using
> addrmaps for symtabs too, not just blocks.

Attaching the fix for discontiguous psymtabs based on the addrmap framework.

This one is a conservative one - it tries to just fix it with minimal changes.
It is bidirectionally compatible:
 * Producer (dwarf2read.c) still tries to set the bounds TEXTLOW and TEXTHIGH.
 * Consumer (symtab.c) deals with both set and unset PSYMTABS_ADDRMAP.

#1 With the new OBJFILE->PSYMTABS_ADDRMAP I believe the whole
   PARTIAL_SYMTAB->{TEXTLOW,TEXTHIGH} can be removed.  It requires updating of all
   the producers and consumers.  Dumb producers may even just set contiguous
   ranges in PSYMTABS_ADDRMAP.

#2 My folowup mail will offer a future removal of FIND_PC_SECT_PSYMTAB_IS_VALID.


The included testcase (FAIL->PASS by this patch) is the one posted here as:
	http://sources.redhat.com/ml/gdb-patches/2007-11/msg00565.html

Testsuite has been run on x86_64 Fedora 8.


Regards,
Jan

2007-12-09  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* Makefile.in: Update dependencies.
	* dwarf2read.c: Include "addrmap.h"
	(struct dwarf2_cu): New fields RANGES_OFFSET and HAS_RANGES_OFFSET.
	(dwarf2_ranges_read): New prototype.
	(dwarf2_build_psymtabs_hard): Initialize and prepare PSYMTABS_ADDRMAP.
	Add discontiguous range to PSYMTABS_ADDRMAP by DWARF2_RANGES_READ on
	HAS_RANGES_OFFSET, otherwise add there the contiguous range.
	(dwarf2_ranges_read): New parameter RANGES_PST, update the function
	comment for it.  Add the found ranges to RANGES_PST.  New variable
	BASEADDR, initialize it the common way.
	(dwarf2_get_pc_bounds): Update the caller for the new parameter.
	(read_partial_die): `DW_AT_ranges' now only sets RANGES_OFFSET and
	HAS_RANGES_OFFSET for the later processing.
	* objfiles.h (struct objfile): New field PSYMTABS_ADDRMAP.
	* symtab.c: Include "addrmap.h"
	(find_pc_sect_psymtab): Support reading the field PSYMTABS_ADDRMAP.
	Move the psymtab locator into ...
	(find_pc_sect_psymtab_is_valid): ... a new function.

2007-11-30  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.dwarf2/dw2-ranges2.S: New file.
	* gdb.dwarf2/dw2-ranges.S: Merge the secondary section with `.fini'.
	* gdb.dwarf2/dw2-ranges.exp: Compile also "dw2-ranges2.S" and test also
	its MAIN2 and FUNC2 symbols.

--- ./gdb/Makefile.in	6 Dec 2007 11:17:03 -0000	1.965
+++ ./gdb/Makefile.in	9 Dec 2007 19:45:11 -0000
@@ -2057,7 +2057,8 @@ dwarf2-frame.o: dwarf2-frame.c $(defs_h)
 dwarf2loc.o: dwarf2loc.c $(defs_h) $(ui_out_h) $(value_h) $(frame_h) \
 	$(gdbcore_h) $(target_h) $(inferior_h) $(ax_h) $(ax_gdb_h) \
 	$(regcache_h) $(objfiles_h) $(exceptions_h) $(elf_dwarf2_h) \
-	$(dwarf2expr_h) $(dwarf2loc_h) $(gdb_string_h) $(gdb_assert_h)
+	$(dwarf2expr_h) $(dwarf2loc_h) $(gdb_string_h) $(gdb_assert_h) \
+	$(addrmap_h)
 dwarf2read.o: dwarf2read.c $(defs_h) $(bfd_h) $(symtab_h) $(gdbtypes_h) \
 	$(objfiles_h) $(elf_dwarf2_h) $(buildsym_h) $(demangle_h) \
 	$(expression_h) $(filenames_h) $(macrotab_h) $(language_h) \
@@ -2856,7 +2857,7 @@ symtab.o: symtab.c $(defs_h) $(symtab_h)
 	$(filenames_h) $(objc_lang_h) $(ada_lang_h) $(hashtab_h) \
 	$(gdb_obstack_h) $(block_h) $(dictionary_h) $(gdb_string_h) \
 	$(gdb_stat_h) $(cp_abi_h) $(observer_h) $(gdb_assert_h) \
-	$(solist_h) $(p_lang_h)
+	$(solist_h) $(p_lang_h) $(addrmap_h)
 target.o: target.c $(defs_h) $(gdb_string_h) $(target_h) $(gdbcmd_h) \
 	$(symtab_h) $(inferior_h) $(bfd_h) $(symfile_h) $(objfiles_h) \
 	$(gdb_wait_h) $(dcache_h) $(regcache_h) $(gdb_assert_h) $(gdbcore_h) \
--- ./gdb/dwarf2read.c	4 Dec 2007 23:43:57 -0000	1.239
+++ ./gdb/dwarf2read.c	9 Dec 2007 19:45:23 -0000
@@ -45,6 +45,7 @@
 #include "hashtab.h"
 #include "command.h"
 #include "gdbcmd.h"
+#include "addrmap.h"
 
 #include <fcntl.h>
 #include "gdb_string.h"
@@ -297,6 +298,9 @@ struct dwarf2_cu
   /* Hash table holding all the loaded partial DIEs.  */
   htab_t partial_dies;
 
+  /* `.debug_ranges' offset for this `DW_TAG_compile_unit' DIE.  */
+  unsigned long ranges_offset;
+
   /* Storage for things with the same lifetime as this read-in compilation
      unit, including partial DIEs.  */
   struct obstack comp_unit_obstack;
@@ -339,6 +343,9 @@ struct dwarf2_cu
      DIEs for namespaces, we don't need to try to infer them
      from mangled names.  */
   unsigned int has_namespace_info : 1;
+
+  /* Field `ranges_offset' is filled in; flag as the value may be zero.  */
+  unsigned int has_ranges_offset : 1;
 };
 
 /* Persistent data held for a compilation unit, even when not
@@ -888,6 +895,9 @@ static void read_func_scope (struct die_
 
 static void read_lexical_block_scope (struct die_info *, struct dwarf2_cu *);
 
+static int dwarf2_ranges_read (unsigned, CORE_ADDR *, CORE_ADDR *,
+			       struct dwarf2_cu *, struct partial_symtab *);
+
 static int dwarf2_get_pc_bounds (struct die_info *,
 				 CORE_ADDR *, CORE_ADDR *, struct dwarf2_cu *);
 
@@ -1416,6 +1426,9 @@ dwarf2_build_psymtabs_hard (struct objfi
 
   create_all_comp_units (objfile);
 
+  objfile->psymtabs_addrmap = addrmap_create_mutable
+						    (&objfile->objfile_obstack);
+
   /* Since the objects we're extracting from .debug_info vary in
      length, only the individual functions to extract them (like
      read_comp_unit_head and load_partial_die) can really know whether
@@ -1481,7 +1494,8 @@ dwarf2_build_psymtabs_hard (struct objfi
       /* Allocate a new partial symbol table structure */
       pst = start_psymtab_common (objfile, objfile->section_offsets,
 				  comp_unit_die.name ? comp_unit_die.name : "",
-				  comp_unit_die.lowpc,
+				  /* TEXTLOW and TEXTHIGH are set below.  */
+				  0,
 				  objfile->global_psymbols.next,
 				  objfile->static_psymbols.next);
 
@@ -1514,6 +1528,15 @@ dwarf2_build_psymtabs_hard (struct objfi
 
       this_cu->psymtab = pst;
 
+      /* Possibly set the default values of LOWPC and HIGHPC from
+         `DW_AT_ranges'.  */
+      if (cu.has_ranges_offset)
+	{
+	  if (dwarf2_ranges_read (cu.ranges_offset, &comp_unit_die.lowpc,
+				  &comp_unit_die.highpc, &cu, pst))
+	    comp_unit_die.has_pc_info = 1;
+	}
+
       /* Check if comp unit has_children.
          If so, read the rest of the partial symbols from this comp unit.
          If not, there's no more debug_info for this comp unit. */
@@ -1544,6 +1567,11 @@ dwarf2_build_psymtabs_hard (struct objfi
       pst->textlow = comp_unit_die.lowpc + baseaddr;
       pst->texthigh = comp_unit_die.highpc + baseaddr;
 
+      /* Store the contiguous range; `DW_AT_ranges' range is stored above.  */
+      if (!cu.has_ranges_offset)
+	addrmap_set_empty (objfile->psymtabs_addrmap, pst->textlow,
+			   pst->texthigh - 1, pst);
+
       pst->n_global_syms = objfile->global_psymbols.next -
 	(objfile->global_psymbols.list + pst->globals_offset);
       pst->n_static_syms = objfile->static_psymbols.next -
@@ -1567,6 +1595,10 @@ dwarf2_build_psymtabs_hard (struct objfi
 
       do_cleanups (back_to_inner);
     }
+
+  objfile->psymtabs_addrmap = addrmap_create_fixed (objfile->psymtabs_addrmap,
+						    &objfile->objfile_obstack);
+
   do_cleanups (back_to);
 }
 
@@ -3078,11 +3110,13 @@ read_lexical_block_scope (struct die_inf
 }
 
 /* Get low and high pc attributes from DW_AT_ranges attribute value OFFSET.
-   Return 1 if the attributes are present and valid, otherwise, return 0.  */
+   Return 1 if the attributes are present and valid, otherwise, return 0.
+   If RANGES_PST is not NULL we should setup `objfile->psymtabs_addrmap'.  */
 
 static int
 dwarf2_ranges_read (unsigned offset, CORE_ADDR *low_return,
-		    CORE_ADDR *high_return, struct dwarf2_cu *cu)
+		    CORE_ADDR *high_return, struct dwarf2_cu *cu,
+		    struct partial_symtab *ranges_pst)
 {
   struct objfile *objfile = cu->objfile;
   struct comp_unit_head *cu_header = &cu->header;
@@ -3098,6 +3132,7 @@ dwarf2_ranges_read (unsigned offset, COR
   int low_set;
   CORE_ADDR low = 0;
   CORE_ADDR high = 0;
+  CORE_ADDR baseaddr;
 
   found_base = cu_header->base_known;
   base = cu_header->base_address;
@@ -3125,6 +3160,9 @@ dwarf2_ranges_read (unsigned offset, COR
 
   low_set = 0;
 
+  if (ranges_pst != NULL)
+    baseaddr = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
+
   while (1)
     {
       CORE_ADDR range_beginning, range_end;
@@ -3164,6 +3202,11 @@ dwarf2_ranges_read (unsigned offset, COR
       range_beginning += base;
       range_end += base;
 
+      if (ranges_pst != NULL)
+	addrmap_set_empty (objfile->psymtabs_addrmap,
+			   range_beginning + baseaddr, range_end - 1 + baseaddr,
+			   ranges_pst);
+
       /* FIXME: This is recording everything as a low-high
 	 segment of consecutive addresses.  We should have a
 	 data structure for discontiguous block ranges
@@ -3228,7 +3271,7 @@ dwarf2_get_pc_bounds (struct die_info *d
 	{
 	  /* Value of the DW_AT_ranges attribute is the offset in the
 	     .debug_ranges section.  */
-	  if (!dwarf2_ranges_read (DW_UNSND (attr), &low, &high, cu))
+	  if (!dwarf2_ranges_read (DW_UNSND (attr), &low, &high, cu, NULL))
 	    return 0;
 	  /* Found discontinuous range of addresses.  */
 	  ret = -1;
@@ -5663,9 +5706,11 @@ read_partial_die (struct partial_die_inf
 	  part_die->highpc = DW_ADDR (&attr);
 	  break;
 	case DW_AT_ranges:
-	  if (dwarf2_ranges_read (DW_UNSND (&attr), &part_die->lowpc,
-				  &part_die->highpc, cu))
-	    has_low_pc_attr = has_high_pc_attr = 1;
+	  if (part_die->tag == DW_TAG_compile_unit)
+	    {
+	      cu->ranges_offset = DW_UNSND (&attr);
+	      cu->has_ranges_offset = 1;
+	    }
 	  break;
 	case DW_AT_location:
           /* Support the .debug_loc offsets */
--- ./gdb/objfiles.h	4 Dec 2007 23:33:00 -0000	1.47
+++ ./gdb/objfiles.h	9 Dec 2007 19:45:27 -0000
@@ -220,6 +220,12 @@ struct objfile
 
     struct partial_symtab *psymtabs;
 
+    /* Map addresses to the entries of PSYMTABS.  It would be more efficient to
+       have a map per the whole process but ADDRMAP cannot selectively remove
+       its items during FREE_OBJFILE.  */
+
+    struct addrmap *psymtabs_addrmap;
+
     /* List of freed partial symtabs, available for re-use */
 
     struct partial_symtab *free_psymtabs;
--- ./gdb/symtab.c	24 Oct 2007 13:25:16 -0000	1.167
+++ ./gdb/symtab.c	9 Dec 2007 19:45:38 -0000
@@ -41,6 +41,7 @@
 #include "objc-lang.h"
 #include "ada-lang.h"
 #include "p-lang.h"
+#include "addrmap.h"
 
 #include "hashtab.h"
 
@@ -759,6 +760,83 @@ matching_bfd_sections (asection *first, 
   return 0;
 }
 
+/* Find which partial symtab contains PC and SECTION starting at psymtab PST.
+   We may find a different psymtab than PST.  See FIND_PC_SECT_PSYMTAB.  */
+
+struct partial_symtab *
+find_pc_sect_psymtab_is_valid (CORE_ADDR pc, asection *section,
+			       struct partial_symtab *pst,
+			       struct minimal_symbol *msymbol)
+{
+  struct objfile *objfile = pst->objfile;
+  struct partial_symtab *tpst;
+  struct partial_symtab *best_pst = pst;
+  CORE_ADDR best_addr = pst->textlow;
+
+  /* An objfile that has its functions reordered might have
+     many partial symbol tables containing the PC, but
+     we want the partial symbol table that contains the
+     function containing the PC.  */
+  if (!(objfile->flags & OBJF_REORDERED) &&
+      section == 0)	/* can't validate section this way */
+    return pst;
+
+  if (msymbol == NULL)
+    return (pst);
+
+  /* The code range of partial symtabs sometimes overlap, so, in
+     the loop below, we need to check all partial symtabs and
+     find the one that fits better for the given PC address. We
+     select the partial symtab that contains a symbol whose
+     address is closest to the PC address.  By closest we mean
+     that find_pc_sect_symbol returns the symbol with address
+     that is closest and still less than the given PC.  */
+  for (tpst = pst; tpst != NULL; tpst = tpst->next)
+    {
+      if (pc >= tpst->textlow && pc < tpst->texthigh)
+	{
+	  struct partial_symbol *p;
+	  CORE_ADDR this_addr;
+
+	  /* NOTE: This assumes that every psymbol has a
+	     corresponding msymbol, which is not necessarily
+	     true; the debug info might be much richer than the
+	     object's symbol table.  */
+	  p = find_pc_sect_psymbol (tpst, pc, section);
+	  if (p != NULL
+	      && SYMBOL_VALUE_ADDRESS (p)
+	      == SYMBOL_VALUE_ADDRESS (msymbol))
+	    return tpst;
+
+	  /* Also accept the textlow value of a psymtab as a
+	     "symbol", to provide some support for partial
+	     symbol tables with line information but no debug
+	     symbols (e.g. those produced by an assembler).  */
+	  if (p != NULL)
+	    this_addr = SYMBOL_VALUE_ADDRESS (p);
+	  else
+	    this_addr = tpst->textlow;
+
+	  /* Check whether it is closer than our current
+	     BEST_ADDR.  Since this symbol address is
+	     necessarily lower or equal to PC, the symbol closer
+	     to PC is the symbol which address is the highest.
+	     This way we return the psymtab which contains such
+	     best match symbol. This can help in cases where the
+	     symbol information/debuginfo is not complete, like
+	     for instance on IRIX6 with gcc, where no debug info
+	     is emitted for statics. (See also the nodebug.exp
+	     testcase.) */
+	  if (this_addr > best_addr)
+	    {
+	      best_addr = this_addr;
+	      best_pst = tpst;
+	    }
+	}
+    }
+  return best_pst;
+}
+
 /* Find which partial symtab contains PC and SECTION.  Return 0 if
    none.  We return the psymtab that contains a symbol whose address
    exactly matches PC, or, if we cannot find an exact match, the
@@ -766,7 +844,6 @@ matching_bfd_sections (asection *first, 
 struct partial_symtab *
 find_pc_sect_psymtab (CORE_ADDR pc, asection *section)
 {
-  struct partial_symtab *pst;
   struct objfile *objfile;
   struct minimal_symbol *msymbol;
 
@@ -782,79 +859,43 @@ find_pc_sect_psymtab (CORE_ADDR pc, asec
 	  || msymbol->type == mst_file_bss))
     return NULL;
 
-  ALL_PSYMTABS (objfile, pst)
-  {
-    if (pc >= pst->textlow && pc < pst->texthigh)
-      {
-	struct partial_symtab *tpst;
-	struct partial_symtab *best_pst = pst;
-	CORE_ADDR best_addr = pst->textlow;
-
-	/* An objfile that has its functions reordered might have
-	   many partial symbol tables containing the PC, but
-	   we want the partial symbol table that contains the
-	   function containing the PC.  */
-	if (!(objfile->flags & OBJF_REORDERED) &&
-	    section == 0)	/* can't validate section this way */
-	  return (pst);
-
-	if (msymbol == NULL)
-	  return (pst);
-
-	/* The code range of partial symtabs sometimes overlap, so, in
-	   the loop below, we need to check all partial symtabs and
-	   find the one that fits better for the given PC address. We
-	   select the partial symtab that contains a symbol whose
-	   address is closest to the PC address.  By closest we mean
-	   that find_pc_sect_symbol returns the symbol with address
-	   that is closest and still less than the given PC.  */
-	for (tpst = pst; tpst != NULL; tpst = tpst->next)
-	  {
-	    if (pc >= tpst->textlow && pc < tpst->texthigh)
+  ALL_OBJFILES (objfile)
+    {
+      if (objfile->psymtabs_addrmap != NULL)
+        {
+	  struct partial_symtab *pst;
+
+	  pst = addrmap_find (objfile->psymtabs_addrmap, pc);
+	  if (pst != NULL)
+	    {
+	      struct partial_symtab *best_pst;
+
+	      best_pst = find_pc_sect_psymtab_is_valid (pc, section, pst,
+							msymbol);
+	      if (best_pst != NULL)
+		return best_pst;
+	    }
+	  /* Existing PSYMTABS_ADDRMAP should cover all the PSYMTABS of
+	     OBJFILE, there is no need to scan the remaining ones by hand.  */
+	}
+      else
+        {
+	  struct partial_symtab *pst;
+
+	  ALL_OBJFILE_PSYMTABS (objfile, pst)
+	    if (pc >= pst->textlow && pc < pst->texthigh)
 	      {
-		struct partial_symbol *p;
-		CORE_ADDR this_addr;
+		struct partial_symtab *best_pst;
 
-		/* NOTE: This assumes that every psymbol has a
-		   corresponding msymbol, which is not necessarily
-		   true; the debug info might be much richer than the
-		   object's symbol table.  */
-		p = find_pc_sect_psymbol (tpst, pc, section);
-		if (p != NULL
-		    && SYMBOL_VALUE_ADDRESS (p)
-		    == SYMBOL_VALUE_ADDRESS (msymbol))
-		  return (tpst);
-
-		/* Also accept the textlow value of a psymtab as a
-		   "symbol", to provide some support for partial
-		   symbol tables with line information but no debug
-		   symbols (e.g. those produced by an assembler).  */
-		if (p != NULL)
-		  this_addr = SYMBOL_VALUE_ADDRESS (p);
-		else
-		  this_addr = tpst->textlow;
-
-		/* Check whether it is closer than our current
-		   BEST_ADDR.  Since this symbol address is
-		   necessarily lower or equal to PC, the symbol closer
-		   to PC is the symbol which address is the highest.
-		   This way we return the psymtab which contains such
-		   best match symbol. This can help in cases where the
-		   symbol information/debuginfo is not complete, like
-		   for instance on IRIX6 with gcc, where no debug info
-		   is emitted for statics. (See also the nodebug.exp
-		   testcase.) */
-		if (this_addr > best_addr)
-		  {
-		    best_addr = this_addr;
-		    best_pst = tpst;
-		  }
+	        best_pst = find_pc_sect_psymtab_is_valid (pc, section, pst,
+							  msymbol);
+		if (best_pst != NULL)
+		  return best_pst;
 	      }
-	  }
-	return (best_pst);
-      }
-  }
-  return (NULL);
+	}
+    }
+
+  return NULL;
 }
 
 /* Find which partial symtab contains PC.  Return 0 if none. 
--- ./gdb/testsuite/gdb.dwarf2/dw2-ranges.S	25 Nov 2007 21:40:39 -0000	1.1
+++ ./gdb/testsuite/gdb.dwarf2/dw2-ranges.S	30 Nov 2007 15:01:49 -0000
@@ -32,7 +32,10 @@ main:	.int	0
 	.endfunc
 	.size	main, . - main
 
-	.section	.text.func, "ax", @progbits
+	/* `.fini' section is here to make sure `dw2-ranges.S'
+	   vs. `dw2-ranges2.S' overlap their DW_AT_ranges with eac other.  */
+	.section	.fini, "ax", @progbits
+
 	.globl	func
 	.func	func
 func:	.int	0
--- ./gdb/testsuite/gdb.dwarf2/dw2-ranges.exp	25 Nov 2007 21:40:39 -0000	1.1
+++ ./gdb/testsuite/gdb.dwarf2/dw2-ranges.exp	30 Nov 2007 15:01:49 -0000
@@ -30,9 +30,10 @@ if {![istarget *-*-linux*]
 
 set testfile "dw2-ranges"
 set srcfile ${testfile}.S
-set binfile ${objdir}/${subdir}/${testfile}.o
+set srcfile2 ${testfile}2.S
+set binfile ${objdir}/${subdir}/${testfile}
 
-if {[gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" object debug] != "" } {
+if {[gdb_compile "${srcdir}/${subdir}/${srcfile} ${srcdir}/${subdir}/${srcfile2}" "${binfile}" executable debug] != "" } {
     return -1
 }
 
@@ -46,4 +47,7 @@ gdb_load ${binfile}
 # Wrong output:
 # 	No line number information available for address 0x4
 
+gdb_test "info line main" "Line \[0-9\]* of .* starts at address .* and ends at .*"
 gdb_test "info line func" "Line \[0-9\]* of .* starts at address .* and ends at .*"
+gdb_test "info line main2" "Line \[0-9\]* of .* starts at address .* and ends at .*"
+gdb_test "info line func2" "Line \[0-9\]* of .* starts at address .* and ends at .*"
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ ./gdb/testsuite/gdb.dwarf2/dw2-ranges2.S	30 Nov 2007 15:01:49 -0000
@@ -0,0 +1,43 @@
+/*
+   Copyright 2007 Free Software Foundation, Inc.
+   
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* Despite the sections below will be adjacent the assembler has to produce
+   DW_AT_ranges as the linker could place both sections at arbitrary locations.
+   */
+
+	/* Without this directive GAS will not emit DWARF2 unless we provide an
+	   instruction to assemble.  We want to avoid any instructions to
+	   remain architecture independent.  */
+	.loc_mark_labels	1
+
+	.text
+
+	.globl	main2
+	.func	main2
+main2:	.int	0
+	.endfunc
+	.size	main2, . - main2
+
+	/* `.fini' section is here to make sure `dw2-ranges.S'
+	   vs. `dw2-ranges2.S' overlap their DW_AT_ranges with eac other.  */
+	.section	.fini, "ax", @progbits
+
+	.globl	func2
+	.func	func2
+func2:	.int	0
+	.endfunc
+	.size	func2, . - func2