[Lldb-commits] [lldb] [lldb][DWARF] Sort ranges list in dwarf 5. (PR #91343)

[Zequan Wu via lldb-commits]

https://github.com/ZequanWu created https://github.com/llvm/llvm-project/pull/91343

Dwarf 5 says "There is no requirement that the entries be ordered in any particular way" in 2.17.3 Non-Contiguous Address Ranges for rnglist. Some places assume the ranges are already sorted but it's not. This fixes it.

>From eb1b2faa457522e7c11fbd69acea7f7d736c7c74 Mon Sep 17 00:00:00 2001
From: Zequan Wu <zequanwu at google.com>
Date: Tue, 7 May 2024 10:52:59 -0400
Subject: [PATCH] [lldb][DWARF] Sort ranges list in dwarf 5.

---
 lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp    | 1 +
 lldb/test/Shell/SymbolFile/DWARF/x86/debug_rnglists.s | 6 +++---
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
index dabc595427df..3a57ec970b07 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
@@ -1062,6 +1062,7 @@ DWARFUnit::FindRnglistFromOffset(dw_offset_t offset) {
     ranges.Append(DWARFRangeList::Entry(llvm_range.LowPC,
                                         llvm_range.HighPC - llvm_range.LowPC));
   }
+  ranges.Sort();
   return ranges;
 }
 
diff --git a/lldb/test/Shell/SymbolFile/DWARF/x86/debug_rnglists.s b/lldb/test/Shell/SymbolFile/DWARF/x86/debug_rnglists.s
index 89b5d94c68c3..af8a1796f3ab 100644
--- a/lldb/test/Shell/SymbolFile/DWARF/x86/debug_rnglists.s
+++ b/lldb/test/Shell/SymbolFile/DWARF/x86/debug_rnglists.s
@@ -124,12 +124,12 @@ lookup_rnglists2:
 .Lrnglists_table_base0:
         .long   .Ldebug_ranges0-.Lrnglists_table_base0
 .Ldebug_ranges0:
-        .byte   4                       # DW_RLE_offset_pair
-        .uleb128 .Lblock1_begin-rnglists  #   starting offset
-        .uleb128 .Lblock1_end-rnglists    #   ending offset
         .byte   4                       # DW_RLE_offset_pair
         .uleb128 .Lblock2_begin-rnglists  #   starting offset
         .uleb128 .Lblock2_end-rnglists    #   ending offset
+        .byte   4                       # DW_RLE_offset_pair
+        .uleb128 .Lblock1_begin-rnglists  #   starting offset
+        .uleb128 .Lblock1_end-rnglists    #   ending offset
         .byte   0                       # DW_RLE_end_of_list
 .Ldebug_rnglist_table_end0: