From cb67fad44a59cb783d2047a27ad387ed3ec2a466 Mon Sep 17 00:00:00 2001
From: Zachary Turner <zturner@google.com>
Date: Tue, 18 Dec 2018 23:12:08 +0000
Subject: [PATCH] [NativePDB] Correctly reconstruct DeclContext for nested
 enums.

We reconstruct the AST hierarchy by trying to hack up a mangled
name for the parent type using the child type's mangled name.
This was failing for enums because their tag type is represented
with two letters ("W4") instead of one letter ("T", "U", etc) as
it is with classes, structs, and unions.  After accounting for
this we can now correctly determine when an enum is nested
inside of a namespace or a class.

llvm-svn: 349565
---
 .../NativePDB/Inputs/nested-types.lldbinit      |  1 +
 lldb/lit/SymbolFile/NativePDB/nested-types.cpp  | 17 ++++++++++++++---
 .../SymbolFile/NativePDB/PdbAstBuilder.cpp      |  5 ++++-
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/lldb/lit/SymbolFile/NativePDB/Inputs/nested-types.lldbinit b/lldb/lit/SymbolFile/NativePDB/Inputs/nested-types.lldbinit
index 21c3001e3a17..466df81fc421 100644
--- a/lldb/lit/SymbolFile/NativePDB/Inputs/nested-types.lldbinit
+++ b/lldb/lit/SymbolFile/NativePDB/Inputs/nested-types.lldbinit
@@ -8,5 +8,6 @@ target variable -T GlobalE
 target variable -T GlobalF
 target variable -T GlobalG
 target variable -T GlobalH
+target variable -T GlobalEnum
 
 target modules dump ast
diff --git a/lldb/lit/SymbolFile/NativePDB/nested-types.cpp b/lldb/lit/SymbolFile/NativePDB/nested-types.cpp
index 5693f7f320fa..eb2b3ec7e34f 100644
--- a/lldb/lit/SymbolFile/NativePDB/nested-types.cpp
+++ b/lldb/lit/SymbolFile/NativePDB/nested-types.cpp
@@ -11,6 +11,11 @@ struct S {
     int A = 0;
     int B = 1;
   };
+
+  enum class NestedEnum {
+    EnumValue1 = 0,
+    EnumValue2 = 1,
+  };
   int C = 2;
   int D = 3;
   using VoidPtrT = void *;
@@ -70,6 +75,7 @@ constexpr T::U GlobalE;
 constexpr U<int> GlobalF;
 constexpr U<int>::V<int> GlobalG;
 constexpr U<int>::W GlobalH;
+constexpr S::NestedEnum GlobalEnum = S::NestedEnum::EnumValue1;
 
 
 int main(int argc, char **argv) {
@@ -113,6 +119,8 @@ int main(int argc, char **argv) {
 // CHECK:   (int) I = 8
 // CHECK:   (int) J = 9
 // CHECK: }
+// CHECK: (lldb) target variable -T GlobalEnum
+// CHECK: (const S::NestedEnum) GlobalEnum = EnumValue1
 // CHECK: (lldb) target modules dump ast
 // CHECK: Dumping clang ast for 1 modules.
 // CHECK: TranslationUnitDecl {{.*}}
@@ -120,9 +128,12 @@ int main(int argc, char **argv) {
 // CHECK: | |-FieldDecl {{.*}} C 'int'
 // CHECK: | |-FieldDecl {{.*}} D 'int'
 // CHECK: | |-FieldDecl {{.*}} DD 'void *'
-// CHECK: | `-CXXRecordDecl {{.*}} struct NestedStruct definition
-// CHECK: |   |-FieldDecl {{.*}} A 'int'
-// CHECK: |   `-FieldDecl {{.*}} B 'int'
+// CHECK: | |-CXXRecordDecl {{.*}} struct NestedStruct definition
+// CHECK: | | |-FieldDecl {{.*}} A 'int'
+// CHECK: | | `-FieldDecl {{.*}} B 'int'
+// CHECK: | `-EnumDecl {{.*}} NestedEnum
+// CHECK: |   |-EnumConstantDecl {{.*}} EnumValue1 'S::NestedEnum'
+// CHECK: |   `-EnumConstantDecl {{.*}} EnumValue2 'S::NestedEnum'
 // CHECK: |-CXXRecordDecl {{.*}} struct T definition
 // CHECK: | |-FieldDecl {{.*}} NT 'int'
 // CHECK: | |-CXXRecordDecl {{.*}} struct NestedStruct definition
diff --git a/lldb/source/Plugins/SymbolFile/NativePDB/PdbAstBuilder.cpp b/lldb/source/Plugins/SymbolFile/NativePDB/PdbAstBuilder.cpp
index 956e56f504d4..778c40219623 100644
--- a/lldb/source/Plugins/SymbolFile/NativePDB/PdbAstBuilder.cpp
+++ b/lldb/source/Plugins/SymbolFile/NativePDB/PdbAstBuilder.cpp
@@ -188,7 +188,10 @@ GetNestedTagRecord(const NestedTypeRecord &Record, const CVTagRecord &parent,
   // inner tag type is not necessarily the same as the outer tag type, re-write
   // it to match the inner tag type.
   qname[3] = child.asTag().getUniqueName()[3];
-  std::string piece = Record.Name;
+  std::string piece;
+  if (qname[3] == 'W')
+    piece = "4";
+  piece += Record.Name;
   piece.push_back('@');
   qname.insert(4, std::move(piece));
   if (qname != child.asTag().UniqueName)