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Merged
Michael137 merged 7 commits into from
Aug 13, 2025
Merged

[LLDB][NativePDB] Resolve declaration for tag types #152579

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2f4c134
[LLDB][NativePDB] Resolve declaration for tag types
Nerixyz Aug 7, 2025
e7c51c5
fix: use std::once_flag
Nerixyz Aug 12, 2025
4066478
fix: use llvm::Expected
Nerixyz Aug 12, 2025
2f0c1dc
feat: handle `LF_UDT_SRC_LINE` as well
Nerixyz Aug 12, 2025
4391dd6
test: add test for rustc's `<unknown>`
Nerixyz Aug 12, 2025
934f575
fix: use native path style
Nerixyz Aug 12, 2025
bd4bb25
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Nerixyz Aug 13, 2025
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82 changes: 81 additions & 1 deletion lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -644,8 +644,14 @@ SymbolFileNativePDB::CreateClassStructUnion(PdbTypeSymId type_id,

std::string uname = GetUnqualifiedTypeName(record);

// FIXME: Search IPI stream for LF_UDT_MOD_SRC_LINE.
llvm::Expected maybeDecl = ResolveUdtDeclaration(type_id);
Declaration decl;
if (maybeDecl)
decl = std::move(*maybeDecl);
else
LLDB_LOG_ERROR(GetLog(LLDBLog::Symbols), maybeDecl.takeError(),
"Failed to resolve declaration for '{1}': {0}", uname);

return MakeType(toOpaqueUid(type_id), ConstString(uname), size, nullptr,
LLDB_INVALID_UID, Type::eEncodingIsUID, decl, ct,
Type::ResolveState::Forward);
Expand All @@ -668,7 +674,14 @@ lldb::TypeSP SymbolFileNativePDB::CreateTagType(PdbTypeSymId type_id,
CompilerType ct) {
std::string uname = GetUnqualifiedTypeName(er);

llvm::Expected maybeDecl = ResolveUdtDeclaration(type_id);
Declaration decl;
if (maybeDecl)
decl = std::move(*maybeDecl);
else
LLDB_LOG_ERROR(GetLog(LLDBLog::Symbols), maybeDecl.takeError(),
"Failed to resolve declaration for '{1}': {0}", uname);

TypeSP underlying_type = GetOrCreateType(er.UnderlyingType);

return MakeType(
Expand Down Expand Up @@ -2556,3 +2569,70 @@ SymbolFileNativePDB::GetContextForType(TypeIndex ti) {
}
return ctx;
}

void SymbolFileNativePDB::CacheUdtDeclarations() {
for (CVType cvt : m_index->ipi().typeArray()) {
switch (cvt.kind()) {
case LF_UDT_SRC_LINE: {
UdtSourceLineRecord udt_src;
llvm::cantFail(TypeDeserializer::deserializeAs(cvt, udt_src));
m_udt_declarations.try_emplace(
udt_src.UDT, UdtDeclaration{/*FileNameIndex=*/udt_src.SourceFile,
/*IsIpiIndex=*/true,
/*Line=*/udt_src.LineNumber});
} break;
case LF_UDT_MOD_SRC_LINE: {
UdtModSourceLineRecord udt_mod_src;
llvm::cantFail(TypeDeserializer::deserializeAs(cvt, udt_mod_src));
// Some types might be contributed by multiple modules. We assume that
// they all point to the same file and line because we can only provide
// one location.
m_udt_declarations.try_emplace(
udt_mod_src.UDT,
UdtDeclaration{/*FileNameIndex=*/udt_mod_src.SourceFile,
/*IsIpiIndex=*/false,
/*Line=*/udt_mod_src.LineNumber});
} break;
default:
break;
}
}
}

llvm::Expected<Declaration>
SymbolFileNativePDB::ResolveUdtDeclaration(PdbTypeSymId type_id) {
std::call_once(m_cached_udt_declarations, [this] { CacheUdtDeclarations(); });

auto it = m_udt_declarations.find(type_id.index);
if (it == m_udt_declarations.end())
return llvm::createStringError("No UDT declaration found");

llvm::StringRef file_name;
if (it->second.IsIpiIndex) {
CVType cvt = m_index->ipi().getType(it->second.FileNameIndex);
if (cvt.kind() != LF_STRING_ID)
return llvm::createStringError("File name was not a LF_STRING_ID");

StringIdRecord sid;
llvm::cantFail(TypeDeserializer::deserializeAs(cvt, sid));
file_name = sid.String;
} else {
// The file name index is an index into the string table
auto string_table = m_index->pdb().getStringTable();
if (!string_table)
return string_table.takeError();

llvm::Expected<llvm::StringRef> string =
string_table->getStringTable().getString(
it->second.FileNameIndex.getIndex());
if (!string)
return string.takeError();
file_name = *string;
}

// rustc sets the filename to "<unknown>" for some files
if (file_name == "\\<unknown>")
return Declaration();

return Declaration(FileSpec(file_name), it->second.Line);
}
15 changes: 15 additions & 0 deletions lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.h
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Original file line number Diff line number Diff line change
Expand Up @@ -262,6 +262,9 @@ class SymbolFileNativePDB : public SymbolFileCommon {

void CacheFunctionNames();

void CacheUdtDeclarations();
llvm::Expected<Declaration> ResolveUdtDeclaration(PdbTypeSymId type_id);

llvm::BumpPtrAllocator m_allocator;

lldb::addr_t m_obj_load_address = 0;
Expand All @@ -283,6 +286,18 @@ class SymbolFileNativePDB : public SymbolFileCommon {
llvm::DenseMap<llvm::codeview::TypeIndex, llvm::codeview::TypeIndex>
m_parent_types;

struct UdtDeclaration {
/// This could either be an index into the `/names` section (string table,
/// LF_UDT_MOD_SRC_LINE) or, this could be an index into the IPI stream to a
/// LF_STRING_ID record (LF_UDT_SRC_LINE).
llvm::codeview::TypeIndex FileNameIndex;
bool IsIpiIndex;

uint32_t Line;
};
llvm::DenseMap<llvm::codeview::TypeIndex, UdtDeclaration> m_udt_declarations;
std::once_flag m_cached_udt_declarations;

lldb_private::UniqueCStringMap<uint32_t> m_type_base_names;

/// mangled name/full function name -> Global ID(s)
Expand Down
56 changes: 56 additions & 0 deletions lldb/test/Shell/SymbolFile/NativePDB/unknown-udt-decl.ll
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Original file line number Diff line number Diff line change
@@ -0,0 +1,56 @@
; Test that the declaration for UDTs won't be "<unknown>" or "\<unknown>".
; Rustc sets the location of some builtin types to this string.

; REQUIRES: system-windows
; RUN: %build --compiler=clang-cl --nodefaultlib -o %t.exe -- %s
; RUN: lldb-test symbols %t.exe | FileCheck %s

; there shouldn't be a declaration (would be between size and compiler_type)
; CHECK: Type{{.*}} , name = "Foo", size = 1, compiler_type = {{.*}} struct Foo {

; This is edited output from clang simulates rustc behavior (see !17)
; Source:
; struct Foo {};
;
; int main() { Foo f; }


; ModuleID = 'main.cpp'
source_filename = "main.cpp"
target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-windows-msvc19.44.35207"

%struct.Foo = type { i8 }

; Function Attrs: mustprogress noinline norecurse nounwind optnone uwtable
define dso_local noundef i32 @main() #0 !dbg !9 {
%1 = alloca %struct.Foo, align 1
#dbg_declare(ptr %1, !14, !DIExpression(), !16)
ret i32 0, !dbg !16
}

attributes #0 = { mustprogress noinline norecurse nounwind optnone uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }

!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!2, !3, !4, !5, !6, !7}
!llvm.ident = !{!8}

!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 20.1.6", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
!1 = !DIFile(filename: "main.cpp", directory: "F:\\Dev\\rust-dbg-test", checksumkind: CSK_MD5, checksum: "b8942260dadf9ec35328889f05afb954")
!2 = !{i32 2, !"CodeView", i32 1}
!3 = !{i32 2, !"Debug Info Version", i32 3}
!4 = !{i32 1, !"wchar_size", i32 2}
!5 = !{i32 8, !"PIC Level", i32 2}
!6 = !{i32 7, !"uwtable", i32 2}
!7 = !{i32 1, !"MaxTLSAlign", i32 65536}
!8 = !{!"clang version 20.1.6"}
!9 = distinct !DISubprogram(name: "main", scope: !1, file: !1, line: 3, type: !10, scopeLine: 3, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !13)
!10 = !DISubroutineType(types: !11)
!11 = !{!12}
!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!13 = !{}
!14 = !DILocalVariable(name: "f", scope: !9, file: !1, line: 3, type: !15)
!15 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "Foo", file: !17, line: 1, size: 8, flags: DIFlagTypePassByValue, elements: !13, identifier: ".?AUFoo@@")
!16 = !DILocation(line: 3, scope: !9)
; This is how rustc emits some types
!17 = !DIFile(filename: "<unknown>", directory: "")
12 changes: 11 additions & 1 deletion lldb/test/Shell/SymbolFile/PDB/class-layout.test
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Expand Up @@ -12,9 +12,19 @@ RUN: lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck --check-prefix
RUN: lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck --check-prefix=BASE %s
RUN: lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck --check-prefix=FRIEND %s
RUN: lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck --check-prefix=CLASS %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck %s
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@Michael137 Michael137 Aug 12, 2025

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I find it a bit awkward that we have NativePDB tests running outside of the SymbolFile/NativePDB test directory. Can we just put this test into the NativePDB directory too?

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@Nerixyz Nerixyz Aug 12, 2025

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Forgot to reply to this...

My concern was that this would now duplicate the test input and the expected output. We do the mixed tests in Shell/SymbolFile/PDB a few times.

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@Michael137 Michael137 Aug 13, 2025

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Hmmm ok, lets just make sure we don't lose this coverage when we remove the DIA PDB plugin

RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck --check-prefix=ENUM %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck --check-prefix=UNION %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck --check-prefix=STRUCT %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck --check-prefix=COMPLEX %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck --check-prefix=LIST %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck --check-prefix=UNNAMED-STRUCT %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck --check-prefix=BASE %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck --check-prefix=FRIEND %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/ClassLayoutTest.cpp.exe | FileCheck --check-prefix=CLASS %s

CHECK: Module [[MOD:.*]]
CHECK: SymbolFile pdb ([[MOD]])
CHECK: SymbolFile {{(native-)?}}pdb ([[MOD]])
CHECK: {{^[0-9A-F]+}}: CompileUnit{{[{]0x[0-9a-f]+[}]}}, language = "c++", file = '{{.*}}\ClassLayoutTest.cpp'

ENUM: name = "Enum", size = 4, decl = ClassLayoutTest.cpp:5
Expand Down
6 changes: 6 additions & 0 deletions lldb/test/Shell/SymbolFile/PDB/enums-layout.test
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Expand Up @@ -7,6 +7,12 @@ RUN: lldb-test symbols %t.dir/SimpleTypesTest.cpp.enums.exe | FileCheck --check-
RUN: lldb-test symbols %t.dir/SimpleTypesTest.cpp.enums.exe | FileCheck --check-prefix=UCHAR-ENUM %s
RUN: lldb-test symbols %t.dir/SimpleTypesTest.cpp.enums.exe | FileCheck --check-prefix=CLASS-ENUM %s
RUN: lldb-test symbols %t.dir/SimpleTypesTest.cpp.enums.exe | FileCheck --check-prefix=STRUCT-ENUM %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/SimpleTypesTest.cpp.enums.exe | FileCheck --check-prefix=ENUM %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/SimpleTypesTest.cpp.enums.exe | FileCheck --check-prefix=CONST-ENUM %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/SimpleTypesTest.cpp.enums.exe | FileCheck --check-prefix=EMPTY-ENUM %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/SimpleTypesTest.cpp.enums.exe | FileCheck --check-prefix=UCHAR-ENUM %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/SimpleTypesTest.cpp.enums.exe | FileCheck --check-prefix=CLASS-ENUM %s
RUN: env LLDB_USE_NATIVE_PDB_READER=1 lldb-test symbols %t.dir/SimpleTypesTest.cpp.enums.exe | FileCheck --check-prefix=STRUCT-ENUM %s

; FIXME: PDB does not have information about scoped enumeration (Enum class) so the
; compiler type used is the same as the one for unscoped enumeration.
Expand Down
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