Automerge: [LLDB][NativePDB] Use original struct name when searching for constants (#166845)

We used to search for constants using the name we parsed. For C++, this
would mean using the demangled struct name (from the unique name). This
name is not always equal to the one used for the struct's name by the
compiler. For example:

```
  0x105E | LF_STRUCTURE [size = 120, hash = 0xF38F] ``anonymous namespace'::Anonymous<A::B::C<void> >::D`
           unique name: `.?AUD@?$Anonymous@U?$C@X@B@A@@@?A0x8C295248@@`
```
We would use the unique name and get to `(anonymous
namespace)::Anonymous<struct A::B::C<void>>::D`. Then, when finding the
constant in the field list, we'd search for `(anonymous
namespace)::Anonymous<struct A::B::C<void>>::D::StaticMember`. This
wouldn't yield any results, because the constant will use the demangled
name as given by the compiler.

With this PR, we use the struct's name as given in the PDB and append
the member name.

Author: Nerixyz

lldb/source/Plugins/SymbolFile/NativePDB/UdtRecordCompleter.cpp

@@ -41,30 +41,22 @@ UdtRecordCompleter::UdtRecordCompleter(
     llvm::DenseMap<lldb::opaque_compiler_type_t,
                    llvm::SmallSet<std::pair<llvm::StringRef, CompilerType>, 8>>
         &cxx_record_map)
-    : m_id(id), m_derived_ct(derived_ct), m_tag_decl(tag_decl),
+    : m_cv_tag_record(CVTagRecord::create(index.tpi().getType(id.index))),
+      m_id(id), m_derived_ct(derived_ct), m_tag_decl(tag_decl),
       m_ast_builder(ast_builder), m_index(index),
       m_decl_to_status(decl_to_status), m_cxx_record_map(cxx_record_map) {
-  CVType cvt = m_index.tpi().getType(m_id.index);
-  switch (cvt.kind()) {
-  case LF_ENUM:
-    m_cvr.er.Options = ClassOptions::None;
-    llvm::cantFail(TypeDeserializer::deserializeAs<EnumRecord>(cvt, m_cvr.er));
+  switch (m_cv_tag_record.kind()) {
+  case CVTagRecord::Enum:
     break;
-  case LF_UNION:
-    m_cvr.ur.Options = ClassOptions::None;
-    llvm::cantFail(TypeDeserializer::deserializeAs<UnionRecord>(cvt, m_cvr.ur));
-    m_layout.bit_size = m_cvr.ur.getSize() * 8;
+  case CVTagRecord::Union:
+    m_layout.bit_size = m_cv_tag_record.asUnion().getSize() * 8;
     m_record.record.kind = Member::Union;
     break;
-  case LF_CLASS:
-  case LF_STRUCTURE:
-    m_cvr.cr.Options = ClassOptions::None;
-    llvm::cantFail(TypeDeserializer::deserializeAs<ClassRecord>(cvt, m_cvr.cr));
-    m_layout.bit_size = m_cvr.cr.getSize() * 8;
+  case CVTagRecord::Class:
+  case CVTagRecord::Struct:
+    m_layout.bit_size = m_cv_tag_record.asClass().getSize() * 8;
     m_record.record.kind = Member::Struct;
     break;
-  default:
-    llvm_unreachable("unreachable!");
   }
 }
 
@@ -168,7 +160,11 @@ Error UdtRecordCompleter::visitKnownMember(
   // Static constant members may be a const[expr] declaration.
   // Query the symbol's value as the variable initializer if valid.
   if (member_ct.IsConst() && member_ct.IsCompleteType()) {
-    std::string qual_name = decl->getQualifiedNameAsString();
+    // Reconstruct the full name for the static member. Use the names as given
+    // in the PDB. This ensures we match the compiler's style of names (e.g.
+    // "A<B<int> >::Foo" vs "A<B<int>>::Foo").
+    std::string qual_name =
+        (m_cv_tag_record.name() + "::" + static_data_member.Name).str();
 
     auto results =
         m_index.globals().findRecordsByName(qual_name, m_index.symrecords());

lldb/source/Plugins/SymbolFile/NativePDB/UdtRecordCompleter.h

@@ -11,6 +11,7 @@
 
 #include "PdbAstBuilder.h"
 #include "PdbSymUid.h"
+#include "PdbUtil.h"
 #include "Plugins/ExpressionParser/Clang/ClangASTImporter.h"
 #include "llvm/DebugInfo/CodeView/CVRecord.h"
 #include "llvm/DebugInfo/CodeView/TypeRecord.h"
@@ -41,13 +42,7 @@ class UdtRecordCompleter : public llvm::codeview::TypeVisitorCallbacks {
   using IndexedBase =
       std::pair<uint64_t, std::unique_ptr<clang::CXXBaseSpecifier>>;
 
-  union UdtTagRecord {
-    UdtTagRecord() {}
-    llvm::codeview::UnionRecord ur;
-    llvm::codeview::ClassRecord cr;
-    llvm::codeview::EnumRecord er;
-  } m_cvr;
-
+  CVTagRecord m_cv_tag_record;
   PdbTypeSymId m_id;
   CompilerType &m_derived_ct;
   clang::TagDecl &m_tag_decl;

lldb/test/Shell/SymbolFile/NativePDB/Inputs/ast-types.lldbinit

@@ -19,6 +19,7 @@ target variable ADE
 target variable AnonInt
 target variable AnonABCVoid
 target variable AnonABCVoidD
+target variable AnonABCVoidU
 
 target variable mp1 mp2 mp3 mp4 mp5 mp6 mp7 mp8 mp9
 

lldb/test/Shell/SymbolFile/NativePDB/ast-types.cpp

@@ -56,8 +56,14 @@ namespace {
     int AnonymousMember;
     // And a nested class within an anonymous namespace
     struct D {
+      static constexpr int StaticMember = 1;
       int AnonymousDMember;
     };
+
+    union U {
+      static constexpr int StaticMember = 2;
+      int AnonymousUMember;
+    };
   };
 }
 
@@ -85,6 +91,7 @@ A::D::E ADE;
 Anonymous<int> AnonInt;
 Anonymous<A::B::C<void>> AnonABCVoid;
 Anonymous<A::B::C<void>>::D AnonABCVoidD;
+Anonymous<A::B::C<void>>::U AnonABCVoidU;
 
 // The following tests that MSInheritanceAttr are set for record decls.
 class  SI { int si; };
@@ -131,6 +138,7 @@ int SI::*mp9 = nullptr;
 // CHECK: (Anonymous<int>) AnonInt = (AnonymousMember = 0)
 // CHECK: (Anonymous<A::B::C<void>>) AnonABCVoid = (AnonymousMember = 0)
 // CHECK: (Anonymous<A::B::C<void>>::D) AnonABCVoidD = (AnonymousDMember = 0)
+// CHECK: (Anonymous<A::B::C<void>>::U) AnonABCVoidU = (AnonymousUMember = 0)
 // CHECK: (void (SI::*)()) mp1 = 0x0000000000000000
 // CHECK: (void (MI::*)()) mp2 = 0x0000000000000000
 // CHECK: (void (MI2::*)()) mp3 = 0x0000000000000000
@@ -176,13 +184,21 @@ int SI::*mp9 = nullptr;
 // CHECK: | | `-FieldDecl {{.*}} AnonymousMember 'int'
 // CHECK: | `-CXXRecordDecl {{.*}} struct Anonymous<A::B::C<void>> definition
 // CHECK: |   |-FieldDecl {{.*}} AnonymousMember 'int'
-// CHECK: |   `-CXXRecordDecl {{.*}} struct D definition
-// CHECK: |     `-FieldDecl {{.*}} AnonymousDMember 'int'
+// CHECK: |   |-CXXRecordDecl {{.*}} struct D definition
+// CHECK: |   | |-VarDecl {{.*}} StaticMember 'const int' static cinit
+// CHECK: |   | | `-IntegerLiteral {{.*}} 'int' 1
+// CHECK: |   | `-FieldDecl {{.*}} AnonymousDMember 'int'
+// CHECK: |   `-CXXRecordDecl {{.*}} union U definition
+// CHECK: |     |-VarDecl {{.*}} StaticMember 'const int' static
+// CHECK: |     | `-IntegerLiteral {{.*}} 'int' 2
+// CHECK: |     `-FieldDecl {{.*}} AnonymousUMember 'int'
+
 
 int main(int argc, char **argv) {
   AnonInt.AnonymousMember = 1;
   AnonABCVoid.AnonymousMember = 2;
   AnonABCVoidD.AnonymousDMember = 3;
+  AnonABCVoidU.AnonymousUMember = 4;
 
-  return 0;
+  return AnonABCVoidD.StaticMember + AnonABCVoidU.StaticMember;
 }