From e8fb03087513f6b7446855b59eb52eb0afbcf27d Mon Sep 17 00:00:00 2001
From: Bernd Edlinger <bernd.edlinger@hotmail.de>
Date: Tue, 10 Nov 2020 14:44:56 +0100
Subject: [PATCH] readelf: Fix output of rnglists section

Noticed this when examining the debug info in the following
gdb test case binutils-gdb/gdb/testsuite/gdb.cp/step-and-next-inline.cc:

$ gcc -g -gdwarf-5 -O2 step-and-next-inline.cc
$ readelf --debug-dump=Ranges a.out
Contents of the .debug_rnglists section:

    Offset   Begin    End
    0000000c 0000000000401160 00000000004011ca
    00000016 0000000000401060 0000000000401065
    00000020 <End of list>
    00000021 0000000000401165 (base address)
    0000002a 0000000000401165 0000000000401165 (start == end)
    0000002d 0000000000401169 0000000000401173
    00000030 00000000008021c5 00000000008021ca <== wrong
    0000003a <End of list>
    0000003b 0000000000401160 00000000004011ca
    00000045 0000000000401060 0000000000401065
    0000004f 0000000000401070 0000000000401085
    00000059 <End of list>

It turns out that the .s file contans this:

.LLRL2:
        .byte   0x5
        .quad   .LBB8
        .byte   0x4
        .uleb128 .LBB8-.LBB8
        .uleb128 .LBE8-.LBB8
        .byte   0x4
        .uleb128 .LBB12-.LBB8
        .uleb128 .LBE12-.LBB8
        .byte   0x7
        .quad   .LBB17
        .uleb128 .LBE17-.LBB17
        .byte   0

So 0x7 = DW_RLE_start_length is wrong decoded and got the
base address added unexpectedly.
while 0x4 = DW_RLE_offset_pair is the only entry that needs
to add the base address.

BTW: gdb does it right, see:
commit d0ce17d8537 ("gdb: fix issues with handling DWARF v5 rnglists & .dwo files.").

2020-11-10  Bernd Edlinger  <bernd.edlinger@hotmail.de>

	* dwarf.c (display_debug_rnglists_list): Only DW_RLE_offset_pair
	needs the base address added.
---
 binutils/dwarf.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/binutils/dwarf.c b/binutils/dwarf.c
index 5807744..0722518 100644
--- a/binutils/dwarf.c
+++ b/binutils/dwarf.c
@@ -7516,8 +7516,15 @@ display_debug_rnglists_list (unsigned char *start, unsigned char *finish,
       if (rlet == DW_RLE_base_address)
 	continue;
 
-      print_dwarf_vma (begin + base_address, pointer_size);
-      print_dwarf_vma (end + base_address, pointer_size);
+      /* Only DW_RLE_offset_pair needs the base address added.  */
+      if (rlet == DW_RLE_offset_pair)
+	{
+	  begin += base_address;
+	  end += base_address;
+	}
+
+      print_dwarf_vma (begin, pointer_size);
+      print_dwarf_vma (end, pointer_size);
 
       if (begin == end)
 	fputs (_("(start == end)"), stdout);
-- 
1.9.1