Added support for persistent variables to the

expression parser.  It is now possible to type:

(lldb) expr int $i = 5; $i + 1
(int) 6
(lldb) expr $i + 2
(int) 7

The skeleton for automatic result variables is
also implemented.  The changes affect:

- the process, which now contains a 
  ClangPersistentVariables object that holds
  persistent variables associated with it
- the expression parser, which now uses
  the persistent variables during variable
  lookup
- TaggedASTType, where I loaded some commonly
  used tags into a header so that they are
  interchangeable between different clients of
  the class

llvm-svn: 110777

1 files changed, 59 insertions, 0 deletions

diff --git a/lldb/source/Expression/ClangPersistentVariables.cpp b/lldb/source/Expression/ClangPersistentVariables.cpp
new file mode 100644
index 00000000000..dbeac006250
--- /dev/null
+++ b/lldb/source/Expression/ClangPersistentVariables.cpp
@@ -0,0 +1,59 @@
+//===-- ClangPersistentVariables.cpp ----------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangPersistentVariables.h"
+#include "lldb/Core/Log.h"
+#include "lldb/Core/StreamString.h"
+
+using namespace lldb_private;
+using namespace clang;
+
+ClangPersistentVariables::ClangPersistentVariables () :
+    m_variables(),
+    m_result_counter(0)
+{
+}
+
+ClangPersistentVariable *
+ClangPersistentVariables::CreateVariable (ConstString name, 
+                                          TypeFromUser user_type)
+{    
+    ClangPersistentVariable new_var(user_type);
+    
+    if (m_variables.find(name) != m_variables.end())
+        return NULL;
+    
+    m_variables[name] = new_var;
+    
+    return &m_variables[name];
+}
+
+ClangPersistentVariable *
+ClangPersistentVariables::CreateResultVariable (TypeFromUser user_type)
+{    
+    StreamString s;
+    s.Printf("$%llu", m_result_counter);
+    ConstString name(s.GetString().c_str());
+    
+    ClangPersistentVariable *ret = CreateVariable (name, user_type);
+    
+    if (ret != NULL)
+        ++m_result_counter;
+    
+    return ret;
+}
+
+ClangPersistentVariable *
+ClangPersistentVariables::GetVariable (ConstString name)
+{    
+    if (m_variables.find(name) == m_variables.end())
+        return NULL;
+    
+    return &m_variables[name];
+}