From 6753d2d1803b89cfe1f86631a79c4c435c04af8d Mon Sep 17 00:00:00 2001
From: Zachary Turner <zturner@google.com>
Date: Wed, 12 Dec 2018 17:17:53 +0000
Subject: [PATCH] [ast] CreateParameterDeclaration should use an appropriate
 DeclContext.

Previously CreateParameterDeclaration was always using the translation
unit DeclContext.  We would later go and add parameters to the
FunctionDecl, but internally clang makes a copy when you do this, and
we'd end up with ParmVarDecl's at the global scope as well as in the
function scope.

This fixes the issue.  It's hard to say whether this will introduce
a behavioral change in name lookup, but I know there have been several
hacks introduced in previous years to deal with collisions between
various types of variables, so there's a chance that this patch could
obviate one of those hacks.

Differential Revision: https://reviews.llvm.org/D55571

llvm-svn: 348941
---
 lldb/include/lldb/Symbol/ClangASTContext.h                       | 3 ++-
 lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp     | 5 +++--
 lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp | 4 ++--
 lldb/source/Plugins/SymbolFile/PDB/PDBASTParser.cpp              | 3 ++-
 lldb/source/Symbol/ClangASTContext.cpp                           | 6 +++---
 5 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/lldb/include/lldb/Symbol/ClangASTContext.h b/lldb/include/lldb/Symbol/ClangASTContext.h
index ec2e2b4..9302ddc 100644
--- a/lldb/include/lldb/Symbol/ClangASTContext.h
+++ b/lldb/include/lldb/Symbol/ClangASTContext.h
@@ -401,7 +401,8 @@ public:
                                                type_quals, cc);
   }
 
-  clang::ParmVarDecl *CreateParameterDeclaration(const char *name,
+  clang::ParmVarDecl *CreateParameterDeclaration(clang::DeclContext *decl_ctx,
+                                                 const char *name,
                                                  const CompilerType &param_type,
                                                  int storage);
 
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
index 9981aec..af3c3b4 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserClang.cpp
@@ -3407,8 +3407,9 @@ size_t DWARFASTParserClang::ParseChildParameters(
             function_param_types.push_back(type->GetForwardCompilerType());
 
             clang::ParmVarDecl *param_var_decl =
-                m_ast.CreateParameterDeclaration(
-                    name, type->GetForwardCompilerType(), storage);
+                m_ast.CreateParameterDeclaration(containing_decl_ctx, name,
+                                                 type->GetForwardCompilerType(),
+                                                 storage);
             assert(param_var_decl);
             function_param_decls.push_back(param_var_decl);
 
diff --git a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
index e521c92..898b430 100644
--- a/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
+++ b/lldb/source/Plugins/SymbolFile/NativePDB/SymbolFileNativePDB.cpp
@@ -635,8 +635,8 @@ lldb::FunctionSP SymbolFileNativePDB::CreateFunction(PdbCompilandSymId func_id,
     PdbCompilandSymId param_uid(func_id.modi, record_offset);
     TypeSP type_sp = GetOrCreateType(param_type);
     clang::ParmVarDecl *param = m_clang->CreateParameterDeclaration(
-        param_name.str().c_str(), type_sp->GetForwardCompilerType(),
-        clang::SC_None);
+        function_decl, param_name.str().c_str(),
+        type_sp->GetForwardCompilerType(), clang::SC_None);
     lldbassert(m_uid_to_decl.count(toOpaqueUid(param_uid)) == 0);
 
     m_uid_to_decl[toOpaqueUid(param_uid)] = param;
diff --git a/lldb/source/Plugins/SymbolFile/PDB/PDBASTParser.cpp b/lldb/source/Plugins/SymbolFile/PDB/PDBASTParser.cpp
index 2c7a1a0..37757578 100644
--- a/lldb/source/Plugins/SymbolFile/PDB/PDBASTParser.cpp
+++ b/lldb/source/Plugins/SymbolFile/PDB/PDBASTParser.cpp
@@ -932,7 +932,8 @@ PDBASTParser::GetDeclForSymbol(const llvm::pdb::PDBSymbol &symbol) {
             continue;
 
           clang::ParmVarDecl *param = m_ast.CreateParameterDeclaration(
-              nullptr, arg_type->GetForwardCompilerType(), clang::SC_None);
+              decl, nullptr, arg_type->GetForwardCompilerType(),
+              clang::SC_None);
           if (param)
             params.push_back(param);
         }
diff --git a/lldb/source/Symbol/ClangASTContext.cpp b/lldb/source/Symbol/ClangASTContext.cpp
index f136310..7dd8aec 100644
--- a/lldb/source/Symbol/ClangASTContext.cpp
+++ b/lldb/source/Symbol/ClangASTContext.cpp
@@ -2214,11 +2214,11 @@ CompilerType ClangASTContext::CreateFunctionType(
 }
 
 ParmVarDecl *ClangASTContext::CreateParameterDeclaration(
-    const char *name, const CompilerType &param_type, int storage) {
+    clang::DeclContext *decl_ctx, const char *name,
+    const CompilerType &param_type, int storage) {
   ASTContext *ast = getASTContext();
   assert(ast != nullptr);
-  return ParmVarDecl::Create(*ast, ast->getTranslationUnitDecl(),
-                             SourceLocation(), SourceLocation(),
+  return ParmVarDecl::Create(*ast, decl_ctx, SourceLocation(), SourceLocation(),
                              name && name[0] ? &ast->Idents.get(name) : nullptr,
                              ClangUtil::GetQualType(param_type), nullptr,
                              (clang::StorageClass)storage, nullptr);
-- 
2.7.4