[Lldb-commits] [lldb] r267842 - Fix an inefficiency in the handling of $__lldb_local_vars in expressions.

[Jim Ingham via lldb-commits]

Author: jingham
Date: Wed Apr 27 21:17:02 2016
New Revision: 267842

URL: http://llvm.org/viewvc/llvm-project?rev=267842&view=rev
Log:
Fix an inefficiency in the handling of $__lldb_local_vars in expressions.

The code in ClangExpressionDeclMap::FindExternalVisibleDecls figures out what the token 
means, and adds the namespace to the lookup context, but since it doesn't mark it as
special in the search context, we go on to pass the name $__lldb_local_vars to the ASTSource
for further lookup.  Unless we've done our job wrong, those lookups will always fail, but
the can be costly.

So I added a bit to m_found & use that to short-circuit the lookup.

<rdar://problem/25613384>

Modified:
    lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangASTSource.h
    lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp

Modified: lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangASTSource.h
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangASTSource.h?rev=267842&r1=267841&r2=267842&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangASTSource.h (original)
+++ lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangASTSource.h Wed Apr 27 21:17:02 2016
@@ -430,6 +430,7 @@ struct NameSearchContext {
         bool variable                   : 1;
         bool function_with_type_info    : 1;
         bool function                   : 1;
+        bool local_vars_nsp             : 1;
     } m_found;
     
     //------------------------------------------------------------------

Modified: lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp?rev=267842&r1=267841&r2=267842&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp (original)
+++ lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp Wed Apr 27 21:17:02 2016
@@ -866,7 +866,7 @@ ClangExpressionDeclMap::FindExternalVisi
                                  current_id);
     }
 
-    if (!context.m_found.variable)
+    if (!context.m_found.variable && !context.m_found.local_vars_nsp)
         ClangASTSource::FindExternalVisibleDecls(context);
 }
 
@@ -1199,6 +1199,7 @@ ClangExpressionDeclMap::FindExternalVisi
                         context.AddNamedDecl(namespace_decl);
                         clang::DeclContext *clang_decl_ctx = clang::Decl::castToDeclContext(namespace_decl);
                         clang_decl_ctx->setHasExternalVisibleStorage(true);
+                        context.m_found.local_vars_nsp = true;
                     }
                 }
             }