[PATCH] D106466: [llvm+lldb] Fix#2 of DW_AT_ranges DW_FORM_sec_offset not using DW_AT_rnglists_base (used by GCC)

[Jan Kratochvil via Phabricator via llvm-commits]

jankratochvil updated this revision to Diff 366676.
jankratochvil edited the summary of this revision.
jankratochvil added a comment.

@dblaikie do you think it is OK for check-in now?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D106466/new/

https://reviews.llvm.org/D106466

Files:
  lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
  lldb/test/Shell/SymbolFile/DWARF/DW_AT_range-DW_FORM_sec_offset.s


Index: lldb/test/Shell/SymbolFile/DWARF/DW_AT_range-DW_FORM_sec_offset.s
===================================================================
--- lldb/test/Shell/SymbolFile/DWARF/DW_AT_range-DW_FORM_sec_offset.s
+++ lldb/test/Shell/SymbolFile/DWARF/DW_AT_range-DW_FORM_sec_offset.s
@@ -29,7 +29,7 @@
 # RUN:   -o exit 2>&1 | FileCheck --check-prefix=RNGLISTBASE %s
 
 # RNGLISTBASE-LABEL: image lookup -v -s lookup_rnglists
-# RNGLISTBASE: error: {{.*}}-rnglistbase {0x00000043}: DIE has DW_AT_ranges(DW_FORM_rnglistx 0x0) attribute, but range extraction failed (invalid range list table index 0; OffsetEntryCount is 0, DW_AT_rnglists_base is 12), please file a bug and attach the file at the start of this error message
+# RNGLISTBASE: error: {{.*}}-rnglistbase {0x00000043}: DIE has DW_AT_ranges(DW_FORM_rnglistx 0x0) attribute, but range extraction failed (invalid range list table index 0; OffsetEntryCount is 0, DW_AT_rnglists_base is 24), please file a bug and attach the file at the start of this error message
 
         .text
 rnglists:
@@ -97,7 +97,7 @@
         .long   .Lrnglists_end-rnglists # DW_AT_high_pc
         .long   .Laddr_table_base0      # DW_AT_addr_base
 .ifdef RNGLISTBASE
-        .long   .Ldebug_ranges0         # DW_AT_rnglists_base
+        .long   .Ldebug_ranges1         # DW_AT_rnglists_base
 .endif
         .byte   2                       # Abbrev [2] 0x2b:0x37 DW_TAG_subprogram
         .quad   rnglists                # DW_AT_low_pc
@@ -105,7 +105,7 @@
         .asciz  "rnglists"              # DW_AT_name
         .byte   5                       # Abbrev [5] 0x52:0xf DW_TAG_lexical_block
 .ifndef RNGLISTX
-        .long   .Ldebug_ranges0         # DW_AT_ranges DW_FORM_sec_offset
+        .long   .Ldebug_ranges1         # DW_AT_ranges DW_FORM_sec_offset
 .else
         .uleb128 0                      # DW_AT_ranges DW_FORM_rnglistx
 .endif
@@ -130,9 +130,17 @@
         .byte   8                       # Address size
         .byte   0                       # Segment selector size
         .long   0                       # Offset entry count
-.Ldebug_ranges0:
+.Ldebug_rnglist_table_end0:
+
+        .long   .Ldebug_rnglist_table_end1-.Ldebug_rnglist_table_start1 # Length
+.Ldebug_rnglist_table_start1:
+        .short  5                       # Version
+        .byte   8                       # Address size
+        .byte   0                       # Segment selector size
+        .long   0                       # Offset entry count
+.Ldebug_ranges1:
         .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:
+.Ldebug_rnglist_table_end1:
Index: lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
===================================================================
--- lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
+++ lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp
@@ -437,15 +437,20 @@
   // We are expected to be called with Offset 0 or pointing just past the table
   // header. Correct Offset in the latter case so that it points to the start
   // of the header.
-  if (offset > 0) {
-    uint64_t HeaderSize = llvm::DWARFListTableHeader::getHeaderSize(format);
-    if (offset < HeaderSize)
-      return llvm::createStringError(errc::invalid_argument,
-                                     "did not detect a valid"
-                                     " list table with base = 0x%" PRIx64 "\n",
-                                     offset);
-    offset -= HeaderSize;
+  if (offset == 0) {
+    // This means DW_AT_rnglists_base is missing and therefore DW_FORM_rnglistx
+    // cannot be handled. Returning a default-constructed ListTableType allows
+    // DW_FORM_sec_offset to be supported.
+    return ListTableType();
   }
+
+  uint64_t HeaderSize = llvm::DWARFListTableHeader::getHeaderSize(format);
+  if (offset < HeaderSize)
+    return llvm::createStringError(errc::invalid_argument,
+                                   "did not detect a valid"
+                                   " list table with base = 0x%" PRIx64 "\n",
+                                   offset);
+  offset -= HeaderSize;
   ListTableType Table;
   if (llvm::Error E = Table.extractHeaderAndOffsets(data, &offset))
     return std::move(E);
@@ -996,8 +1001,12 @@
     return llvm::createStringError(errc::invalid_argument,
                                    "missing or invalid range list table");
 
-  auto range_list_or_error = GetRnglistTable()->findList(
-      m_dwarf.GetDWARFContext().getOrLoadRngListsData().GetAsLLVM(), offset);
+  llvm::DWARFDataExtractor data =
+      m_dwarf.GetDWARFContext().getOrLoadRngListsData().GetAsLLVM();
+
+  // As DW_AT_rnglists_base may be missing we need to call setAddressSize.
+  data.setAddressSize(m_header.GetAddressByteSize());
+  auto range_list_or_error = GetRnglistTable()->findList(data, offset);
   if (!range_list_or_error)
     return range_list_or_error.takeError();
 


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D106466.366676.patch
Type: text/x-patch
Size: 5098 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20210816/5cd35390/attachment.bin>