Modify llvm-gsymutil to ignore invalid file indexes. #70876
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@llvm/pr-subscribers-debuginfo Author: Greg Clayton (clayborg) ChangesDWARF produced by LTO and BOLT can sometimes be broken where file indexes are beyond the end of the line table's file list in the prologue. This patch allows llvm-gsymutil to convert this DWARF without crashing, and emits errors when:
Full diff: https://github.com/llvm/llvm-project/pull/70876.diff 2 Files Affected:
diff --git a/llvm/lib/DebugInfo/GSYM/DwarfTransformer.cpp b/llvm/lib/DebugInfo/GSYM/DwarfTransformer.cpp
index d720c1e33495515..92d1ce148c23f1d 100644
--- a/llvm/lib/DebugInfo/GSYM/DwarfTransformer.cpp
+++ b/llvm/lib/DebugInfo/GSYM/DwarfTransformer.cpp
@@ -65,10 +65,10 @@ struct llvm::gsym::CUInfo {
/// the first client that asks for a compile unit file index will end up
/// doing the conversion, and subsequent clients will get the cached GSYM
/// index.
- uint32_t DWARFToGSYMFileIndex(GsymCreator &Gsym, uint32_t DwarfFileIdx) {
- if (!LineTable)
- return 0;
- assert(DwarfFileIdx < FileCache.size());
+ std::optional<uint32_t>
+ DWARFToGSYMFileIndex(GsymCreator &Gsym, uint32_t DwarfFileIdx) {
+ if (!LineTable || DwarfFileIdx >= FileCache.size())
+ return std::nullopt;
uint32_t &GsymFileIdx = FileCache[DwarfFileIdx];
if (GsymFileIdx != UINT32_MAX)
return GsymFileIdx;
@@ -272,14 +272,24 @@ static void parseInlineInfo(GsymCreator &Gsym, raw_ostream *Log, CUInfo &CUI,
if (auto NameIndex = getQualifiedNameIndex(Die, CUI.Language, Gsym))
II.Name = *NameIndex;
- II.CallFile = CUI.DWARFToGSYMFileIndex(
- Gsym, dwarf::toUnsigned(Die.find(dwarf::DW_AT_call_file), 0));
- II.CallLine = dwarf::toUnsigned(Die.find(dwarf::DW_AT_call_line), 0);
- // parse all children and append to parent
- for (DWARFDie ChildDie : Die.children())
- parseInlineInfo(Gsym, Log, CUI, ChildDie, Depth + 1, FI, II,
- AllInlineRanges, WarnIfEmpty);
- Parent.Children.emplace_back(std::move(II));
+ const uint64_t DwarfFileIdx =
+ dwarf::toUnsigned(Die.find(dwarf::DW_AT_call_file), UINT32_MAX);
+ std::optional<uint32_t> OptGSymFileIdx =
+ CUI.DWARFToGSYMFileIndex(Gsym, DwarfFileIdx);
+ if (OptGSymFileIdx) {
+ II.CallFile = OptGSymFileIdx.value();
+ II.CallLine = dwarf::toUnsigned(Die.find(dwarf::DW_AT_call_line), 0);
+ // parse all children and append to parent
+ for (DWARFDie ChildDie : Die.children())
+ parseInlineInfo(Gsym, Log, CUI, ChildDie, Depth + 1, FI, II,
+ AllInlineRanges, WarnIfEmpty);
+ Parent.Children.emplace_back(std::move(II));
+ } else if (Log) {
+ *Log << "error: inlined function DIE at " << HEX32(Die.getOffset())
+ << " has an invalid file index " << DwarfFileIdx << " in its "
+ << "DW_AT_call_file attribute, this inline entry and all "
+ << "children will be removed.\n";
+ }
return;
}
if (Tag == dwarf::DW_TAG_subprogram || Tag == dwarf::DW_TAG_lexical_block) {
@@ -306,8 +316,20 @@ static void convertFunctionLineTable(raw_ostream *Log, CUInfo &CUI,
// the DW_AT_decl_file an d DW_AT_decl_line if we have both attributes.
std::string FilePath = Die.getDeclFile(
DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath);
- if (FilePath.empty())
+ if (FilePath.empty()) {
+ // If we had a DW_AT_decl_file, but got no file then we need to emit a
+ // warning.
+ if (Log) {
+ const uint64_t DwarfFileIdx =
+ dwarf::toUnsigned(Die.findRecursively(dwarf::DW_AT_decl_file),
+ UINT32_MAX);
+ *Log << "error: function DIE at " << HEX32(Die.getOffset())
+ << " has an invalid file index " << DwarfFileIdx << " in its "
+ "DW_AT_decl_file attribute, unable to create a single line "
+ "entry from the DW_AT_decl_file/DW_AT_decl_line attributes.\n";
+ }
return;
+ }
if (auto Line =
dwarf::toUnsigned(Die.findRecursively({dwarf::DW_AT_decl_line}))) {
LineEntry LE(StartAddress, Gsym.insertFile(FilePath), *Line);
@@ -322,7 +344,19 @@ static void convertFunctionLineTable(raw_ostream *Log, CUInfo &CUI,
for (uint32_t RowIndex : RowVector) {
// Take file number and line/column from the row.
const DWARFDebugLine::Row &Row = CUI.LineTable->Rows[RowIndex];
- const uint32_t FileIdx = CUI.DWARFToGSYMFileIndex(Gsym, Row.File);
+ std::optional<uint32_t> OptFileIdx = CUI.DWARFToGSYMFileIndex(Gsym, Row.File);
+ if (!OptFileIdx) {
+ if (Log) {
+ *Log << "error: function DIE at " << HEX32(Die.getOffset()) << " has "
+ << "a line entry with invalid DWARF file index, this entry will "
+ << "be removed:\n";
+ Row.dumpTableHeader(*Log, /*Indent=*/0);
+ Row.dump(*Log);
+ *Log << "\n";
+ }
+ continue;
+ }
+ const uint32_t FileIdx = OptFileIdx.value();
uint64_t RowAddress = Row.Address.Address;
// Watch out for a RowAddress that is in the middle of a line table entry
// in the DWARF. If we pass an address in between two line table entries
diff --git a/llvm/unittests/DebugInfo/GSYM/GSYMTest.cpp b/llvm/unittests/DebugInfo/GSYM/GSYMTest.cpp
index ad81a2fcd16441a..5956324ca7e08ac 100644
--- a/llvm/unittests/DebugInfo/GSYM/GSYMTest.cpp
+++ b/llvm/unittests/DebugInfo/GSYM/GSYMTest.cpp
@@ -4157,3 +4157,359 @@ TEST(GSYMTest, TestEmptyLinkageName) {
// Make sure we don't see spurious errors in the output:
EXPECT_TRUE(errors.find("error:") == std::string::npos);
}
+
+
+TEST(GSYMTest, TestHandlingOfInvalidFileIndexes) {
+ // Test that llvm-gsymutil can handle invalid file indexes in the following
+ // cases:
+ // - In line entries in the line table
+ // - When parsing inline entries that have a DW_AT_call_file
+ // - When parsing function dies with no line table entries and it tries to
+ // use the DW_AT_decl_file
+ //
+ //
+ // 0x0000000b: DW_TAG_compile_unit
+ // DW_AT_name ("/tmp/main.cpp")
+ // DW_AT_language (DW_LANG_C)
+ // DW_AT_stmt_list (0x00000000)
+ //
+ // 0x00000015: DW_TAG_subprogram
+ // DW_AT_name ("foo")
+ // DW_AT_low_pc (0x0000000000001000)
+ // DW_AT_high_pc (0x0000000000001050)
+ //
+ // 0x0000002a: DW_TAG_inlined_subroutine
+ // DW_AT_name ("inline_with_invalid_call_file")
+ // DW_AT_low_pc (0x0000000000001010)
+ // DW_AT_high_pc (0x0000000000001020)
+ // DW_AT_call_file (0x0000000a)
+ // DW_AT_call_line (11)
+ //
+ // 0x00000047: DW_TAG_inlined_subroutine
+ // DW_AT_name ("inline_inside_parent_with_invalid_call_file")
+ // DW_AT_low_pc (0x0000000000001010)
+ // DW_AT_high_pc (0x0000000000001015)
+ // DW_AT_call_file ("/tmp/main.cpp")
+ // DW_AT_call_line (12)
+ //
+ // 0x00000064: NULL
+ //
+ // 0x00000065: DW_TAG_inlined_subroutine
+ // DW_AT_name ("inline_with_valid_call_file")
+ // DW_AT_low_pc (0x0000000000001020)
+ // DW_AT_high_pc (0x0000000000001030)
+ // DW_AT_call_file ("/tmp/main.cpp")
+ // DW_AT_call_line (13)
+ //
+ // 0x00000082: DW_TAG_inlined_subroutine
+ // DW_AT_name ("inline_inside_parent_with_valid_call_file")
+ // DW_AT_low_pc (0x0000000000001020)
+ // DW_AT_high_pc (0x0000000000001025)
+ // DW_AT_call_file ("/tmp/main.cpp")
+ // DW_AT_call_line (14)
+ //
+ // 0x0000009f: NULL
+ //
+ // 0x000000a0: NULL
+ //
+ // 0x000000a1: DW_TAG_subprogram
+ // DW_AT_name ("func_with_valid_decl_file")
+ // DW_AT_decl_file ("/tmp/main.cpp")
+ // DW_AT_decl_line (20)
+ // DW_AT_low_pc (0x0000000000002000)
+ // DW_AT_high_pc (0x0000000000002050)
+ //
+ // 0x000000b8: DW_TAG_subprogram
+ // DW_AT_name ("func_with_invalid_decl_file")
+ // DW_AT_decl_file (0x0a)
+ // DW_AT_decl_line (20)
+ // DW_AT_low_pc (0x0000000000003000)
+ // DW_AT_high_pc (0x0000000000003050)
+ //
+ // 0x000000cf: NULL
+ //
+ // The table looks has an entry at address 0x0000000000001010 that has an
+ // invalid file index that needs to be removed.
+ //
+ // Address Line Column File ISA Discriminator Flags
+ // ------------------ ------ ------ ------ --- ------------- -------------
+ // 0x0000000000001000 10 0 1 0 0 is_stmt
+ // 0x0000000000001010 11 0 10 0 0 is_stmt
+ // 0x0000000000001020 11 0 1 0 0 is_stmt
+ // 0x0000000000001030 12 0 1 0 0 is_stmt
+ // 0x0000000000001050 12 0 1 0 0 is_stmt end_sequence
+
+ StringRef yamldata = R"(
+ debug_str:
+ - ''
+ - '/tmp/main.cpp'
+ - foo
+ - inline_with_invalid_call_file
+ - inline_inside_parent_with_invalid_call_file
+ - inline_with_valid_call_file
+ - inline_inside_parent_with_valid_call_file
+ - func_with_valid_decl_file
+ - func_with_invalid_decl_file
+ debug_abbrev:
+ - ID: 0
+ Table:
+ - Code: 0x1
+ Tag: DW_TAG_compile_unit
+ Children: DW_CHILDREN_yes
+ Attributes:
+ - Attribute: DW_AT_name
+ Form: DW_FORM_strp
+ - Attribute: DW_AT_language
+ Form: DW_FORM_udata
+ - Attribute: DW_AT_stmt_list
+ Form: DW_FORM_sec_offset
+ - Code: 0x2
+ Tag: DW_TAG_subprogram
+ Children: DW_CHILDREN_yes
+ Attributes:
+ - Attribute: DW_AT_name
+ Form: DW_FORM_strp
+ - Attribute: DW_AT_low_pc
+ Form: DW_FORM_addr
+ - Attribute: DW_AT_high_pc
+ Form: DW_FORM_addr
+ - Code: 0x3
+ Tag: DW_TAG_inlined_subroutine
+ Children: DW_CHILDREN_yes
+ Attributes:
+ - Attribute: DW_AT_name
+ Form: DW_FORM_strp
+ - Attribute: DW_AT_low_pc
+ Form: DW_FORM_addr
+ - Attribute: DW_AT_high_pc
+ Form: DW_FORM_addr
+ - Attribute: DW_AT_call_file
+ Form: DW_FORM_data4
+ - Attribute: DW_AT_call_line
+ Form: DW_FORM_data4
+ - Code: 0x4
+ Tag: DW_TAG_inlined_subroutine
+ Children: DW_CHILDREN_no
+ Attributes:
+ - Attribute: DW_AT_name
+ Form: DW_FORM_strp
+ - Attribute: DW_AT_low_pc
+ Form: DW_FORM_addr
+ - Attribute: DW_AT_high_pc
+ Form: DW_FORM_addr
+ - Attribute: DW_AT_call_file
+ Form: DW_FORM_data4
+ - Attribute: DW_AT_call_line
+ Form: DW_FORM_data4
+ - Code: 0x5
+ Tag: DW_TAG_subprogram
+ Children: DW_CHILDREN_no
+ Attributes:
+ - Attribute: DW_AT_name
+ Form: DW_FORM_strp
+ - Attribute: DW_AT_decl_file
+ Form: DW_FORM_data1
+ - Attribute: DW_AT_decl_line
+ Form: DW_FORM_data1
+ - Attribute: DW_AT_low_pc
+ Form: DW_FORM_addr
+ - Attribute: DW_AT_high_pc
+ Form: DW_FORM_addr
+ debug_info:
+ - Length: 0xCC
+ Version: 4
+ AbbrevTableID: 0
+ AbbrOffset: 0x0
+ AddrSize: 8
+ Entries:
+ - AbbrCode: 0x1
+ Values:
+ - Value: 0x1
+ - Value: 0x2
+ - Value: 0x0
+ - AbbrCode: 0x2
+ Values:
+ - Value: 0xF
+ - Value: 0x1000
+ - Value: 0x1050
+ - AbbrCode: 0x3
+ Values:
+ - Value: 0x13
+ - Value: 0x1010
+ - Value: 0x1020
+ - Value: 0xA
+ - Value: 0xB
+ - AbbrCode: 0x4
+ Values:
+ - Value: 0x31
+ - Value: 0x1010
+ - Value: 0x1015
+ - Value: 0x1
+ - Value: 0xC
+ - AbbrCode: 0x0
+ - AbbrCode: 0x3
+ Values:
+ - Value: 0x5D
+ - Value: 0x1020
+ - Value: 0x1030
+ - Value: 0x1
+ - Value: 0xD
+ - AbbrCode: 0x4
+ Values:
+ - Value: 0x79
+ - Value: 0x1020
+ - Value: 0x1025
+ - Value: 0x1
+ - Value: 0xE
+ - AbbrCode: 0x0
+ - AbbrCode: 0x0
+ - AbbrCode: 0x5
+ Values:
+ - Value: 0xA3
+ - Value: 0x1
+ - Value: 0x14
+ - Value: 0x2000
+ - Value: 0x2050
+ - AbbrCode: 0x5
+ Values:
+ - Value: 0xBD
+ - Value: 0xA
+ - Value: 0x14
+ - Value: 0x3000
+ - Value: 0x3050
+ - AbbrCode: 0x0
+ debug_line:
+ - Length: 78
+ Version: 2
+ PrologueLength: 36
+ MinInstLength: 1
+ DefaultIsStmt: 1
+ LineBase: 251
+ LineRange: 14
+ OpcodeBase: 13
+ StandardOpcodeLengths: [ 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1 ]
+ IncludeDirs:
+ - '/tmp'
+ Files:
+ - Name: main.cpp
+ DirIdx: 1
+ ModTime: 0
+ Length: 0
+ Opcodes:
+ - Opcode: DW_LNS_extended_op
+ ExtLen: 9
+ SubOpcode: DW_LNE_set_address
+ Data: 4096
+ - Opcode: DW_LNS_advance_line
+ SData: 9
+ Data: 0
+ - Opcode: DW_LNS_copy
+ Data: 0
+ - Opcode: DW_LNS_advance_pc
+ Data: 16
+ - Opcode: DW_LNS_set_file
+ Data: 10
+ - Opcode: DW_LNS_advance_line
+ SData: 1
+ Data: 0
+ - Opcode: DW_LNS_copy
+ Data: 0
+ - Opcode: DW_LNS_advance_pc
+ Data: 16
+ - Opcode: DW_LNS_set_file
+ Data: 1
+ - Opcode: DW_LNS_copy
+ Data: 0
+ - Opcode: DW_LNS_advance_pc
+ Data: 16
+ - Opcode: DW_LNS_advance_line
+ SData: 1
+ Data: 0
+ - Opcode: DW_LNS_copy
+ Data: 0
+ - Opcode: DW_LNS_advance_pc
+ Data: 32
+ - Opcode: DW_LNS_extended_op
+ ExtLen: 1
+ SubOpcode: DW_LNE_end_sequence
+ Data: 0
+ )";
+ auto ErrOrSections = DWARFYAML::emitDebugSections(yamldata);
+ ASSERT_THAT_EXPECTED(ErrOrSections, Succeeded());
+ std::unique_ptr<DWARFContext> DwarfContext =
+ DWARFContext::create(*ErrOrSections, 8);
+ ASSERT_TRUE(DwarfContext.get() != nullptr);
+ std::string errors;
+ raw_string_ostream OS(errors);
+ GsymCreator GC;
+ DwarfTransformer DT(*DwarfContext, GC);
+ const uint32_t ThreadCount = 1;
+ ASSERT_THAT_ERROR(DT.convert(ThreadCount, &OS), Succeeded());
+ ASSERT_THAT_ERROR(GC.finalize(OS), Succeeded());
+ OS.flush();
+ SmallString<512> Str;
+ raw_svector_ostream OutStrm(Str);
+ const auto ByteOrder = llvm::endianness::native;
+ FileWriter FW(OutStrm, ByteOrder);
+ ASSERT_THAT_ERROR(GC.encode(FW), Succeeded());
+ Expected<GsymReader> GR = GsymReader::copyBuffer(OutStrm.str());
+ ASSERT_THAT_EXPECTED(GR, Succeeded());
+ // There should be one function in our GSYM.
+ EXPECT_EQ(GR->getNumAddresses(), 3u);
+ // Verify "foo" is present and has a line table and no inline info.
+ auto ExpFI = GR->getFunctionInfo(0x1000);
+ ASSERT_THAT_EXPECTED(ExpFI, Succeeded());
+ ASSERT_EQ(ExpFI->Range, AddressRange(0x1000, 0x1050));
+ StringRef FuncName = GR->getString(ExpFI->Name);
+ EXPECT_EQ(FuncName, "foo");
+
+ EXPECT_TRUE(ExpFI->OptLineTable.has_value());
+ // Make sure we only have 3 entries to show we removed the line entry with
+ // the invalid file index whose address is 0x0000000000001010.
+ ASSERT_EQ(ExpFI->OptLineTable->size(), 3u);
+ EXPECT_TRUE(ExpFI->Inline.has_value());
+
+ // Make sure that we only have one inline function, not two. We remove one of
+ // the inline functions because it has an invalid DW_AT_call_file attribute.
+ ASSERT_EQ(ExpFI->Inline->Children.size(), 1u);
+ StringRef InlineName = GR->getString(ExpFI->Inline->Children[0].Name);
+ EXPECT_EQ(InlineName, "inline_with_valid_call_file");
+
+ ExpFI = GR->getFunctionInfo(0x0000000000002000);
+ ASSERT_THAT_EXPECTED(ExpFI, Succeeded());
+ ASSERT_EQ(ExpFI->Range, AddressRange(0x2000, 0x2050));
+ FuncName = GR->getString(ExpFI->Name);
+ EXPECT_EQ(FuncName, "func_with_valid_decl_file");
+ EXPECT_FALSE(ExpFI->Inline.has_value());
+ // Make sure we only have 1 entry in the line table which indicates we were
+ // able to parse the DW_AT_decl_file/DW_AT_decl_line correctly.
+ EXPECT_TRUE(ExpFI->OptLineTable.has_value());
+ ASSERT_EQ(ExpFI->OptLineTable->size(), 1u);
+
+ ExpFI = GR->getFunctionInfo(0x0000000000003000);
+ ASSERT_THAT_EXPECTED(ExpFI, Succeeded());
+ ASSERT_EQ(ExpFI->Range, AddressRange(0x3000, 0x3050));
+ FuncName = GR->getString(ExpFI->Name);
+ EXPECT_EQ(FuncName, "func_with_invalid_decl_file");
+ EXPECT_FALSE(ExpFI->Inline.has_value());
+ // Make sure we only no line table because there are no line entries in the
+ // line table and the DW_AT_decl_file attribute was invalid so we were not
+ // able to parse the DW_AT_decl_file/DW_AT_decl_line correctly.
+ EXPECT_FALSE(ExpFI->OptLineTable.has_value());
+
+ // Make sure we don't see spurious errors in the output:
+ std::vector<std::string> ExpectedLogErrors = {
+ "error: function DIE at 0x00000015 has a line entry with invalid DWARF "
+ "file index, this entry will be removed:",
+ "error: inlined function DIE at 0x0000002a has an invalid file index 10 "
+ "in its DW_AT_call_file attribute, this inline entry and all children "
+ "will be removed.",
+ "error: function DIE at 0x000000b8 has an invalid file index 10 in its "
+ "DW_AT_decl_file attribute, unable to create a single line entry from the "
+ "DW_AT_decl_file/DW_AT_decl_line attributes."
+ };
+ // Make sure all expected errors are in the error stream for the two invalid
+ // inlined functions that we removed due to invalid range scoping.
+ for (const auto &Error: ExpectedLogErrors)
+ EXPECT_TRUE(OS.str().find(Error) != std::string::npos);
+}
|
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✅ With the latest revision this PR passed the C/C++ code formatter. |
ayermolo
reviewed
Nov 1, 2023
| AllInlineRanges, WarnIfEmpty); | ||
| Parent.Children.emplace_back(std::move(II)); | ||
| } else if (Log) { | ||
| *Log << "error: inlined function DIE at " << HEX32(Die.getOffset()) |
There was a problem hiding this comment.
yes, when we run in --quiet mode, Log will be NULL.
|
This feels more like addressing the symptom than the cause. Why is the DWARF broken in the first place? |
Sure, but I think llvm-gsymutil should still continue to convert, and report. |
|
Given this is about LLVM project's compatibility with other LLVM projects, it does feel like fixing the root cause would be good - though I don't fundamentally object to making tools more robust to unexpected inputs. It'd be good to at least get test cases and bugs filed for the cases where this is a problem, perhaps? |
|
(if making the tool more robust also helps isolate/identify the root causes, that's a different situation than only making the tool able to progress in the face of these problems) |
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It might not be llvm tools... |
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@clayborg, the gsym side change looks good to me. How does lldb work in this case? Will it crash or have similar check to emit warning/error? |
It indeed is, but it currently can cause a crash. If DWARF was always produced with no errors then we wouldn't need this, but alas you almost alwasy run into errors when running Many optimization passes, mostly LTO in all of its forms and BOLT can try to re-write the DWARF and often introduce errors. |
Agreed!
I am also on board with this. Often times the LTO bugs and or BOLT issues are hard to reduce to a small enough test case to make them happen. But I am all for filing bugs using a reduced test case for any cases where DWARF is compromised. |
LLDB handles the case of file indexes being out of range without crashing. We don't emit an error each time we see this as if we did, we would most likely spew a ton of error messages to the console which isn't user friendly. |
DWARF produced by LTO and BOLT can sometimes be broken where file indexes are beyond the end of the line table's file list in the prologue. This patch allows llvm-gsymutil to convert this DWARF without crashing, and emits errors when: - line table contains entries with an invalid file index (line entry will be removed) - inline functions that have invalid DW_AT_call_file file indexes - when there are no line table entries for a function and we fall back to making a single line table entry from the functions DW_AT_decl_file/DW_AT_decl_line attributes, we make sure the DW_AT_decl_file attribute is valid before emitting it.
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I fixed the clang format issues and pushed. |
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I can't reopen this PR. I am going to open a new one |
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new PR is here: #71431 |
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DWARF produced by LTO and BOLT can sometimes be broken where file indexes are beyond the end of the line table's file list in the prologue. This patch allows llvm-gsymutil to convert this DWARF without crashing, and emits errors when: