Added support for persistent types to the

expression parser.  You can use a persistent
type like this:

(lldb) expr struct $foo { int a; int b; };
(lldb) struct $foo i; i.a = 2; i.b = 3; i
($foo) $0 = {
  (int) a = 2
  (int) b = 3
}

typedefs work similarly.

This patch affects the following files:

test/expression_command/persistent_types/*
  A test case for persistent types,
  in particular structs and typedefs.

ClangForward.h
  Added TypeDecl, needed to declare some
  functions in ASTResultSynthesizer.h

ClangPersistentVariables.[h,cpp]
  Added a list of persistent types to the
  persistent variable store.

ASTResultSynthesizer.[h,cpp]
  Made the AST result synthesizer iterate
  across TypeDecls in the expression, and
  record any persistent types found.  Also
  made a minor documentation fix.

ClangUserExpression.[h,cpp]
  Extended the user expression class to
  keep the state needed to report the
  persistent variable store for the target
  to the AST result synthesizers. 

  Also introduced a new error code for
  expressions that executed normally but
  did not return a result.

CommandObjectExpression.cpp
  Improved output for expressions (like 
  declarations of new persistent types) that
  don't return a result.  This is no longer
  treated as an error.

llvm-svn: 138383

1 files changed, 13 insertions, 3 deletions

diff --git a/lldb/source/Expression/ClangUserExpression.cpp b/lldb/source/Expression/ClangUserExpression.cpp
index 9cd84894854..f0a6359eea0 100644
--- a/lldb/source/Expression/ClangUserExpression.cpp
+++ b/lldb/source/Expression/ClangUserExpression.cpp
@@ -53,7 +53,8 @@ ClangUserExpression::ClangUserExpression (const char *expr,
     m_objectivec (false),
     m_needs_object_ptr (false),
     m_const_object (false),
-    m_const_result ()
+    m_const_result (),
+    m_target (NULL)
 {
 }
 
@@ -64,8 +65,15 @@ ClangUserExpression::~ClangUserExpression ()
 clang::ASTConsumer *
 ClangUserExpression::ASTTransformer (clang::ASTConsumer *passthrough)
 {
+    ClangASTContext *clang_ast_context = m_target->GetScratchClangASTContext();
+    
+    if (!clang_ast_context)
+        return NULL;
+    
     return new ASTResultSynthesizer(passthrough,
-                                    m_desired_type);
+                                    m_desired_type,
+                                    *m_target->GetScratchClangASTContext()->getASTContext(),
+                                    m_target->GetPersistentVariables());
 }
 
 void
@@ -88,6 +96,8 @@ ClangUserExpression::ScanContext(ExecutionContext &exe_ctx)
         
     if (!decl_context)
         return;
+    
+    m_target = exe_ctx.target;
         
     if (clang::CXXMethodDecl *method_decl = llvm::dyn_cast<clang::CXXMethodDecl>(decl_context))
     {
@@ -718,7 +728,7 @@ ClangUserExpression::EvaluateWithError (ExecutionContext &exe_ctx,
                     if (log)
                         log->Printf("== [ClangUserExpression::Evaluate] Execution completed normally with no result ==");
                     
-                    error.SetErrorString ("Expression did not return a result");
+                    error.SetError(ClangUserExpression::kNoResult, lldb::eErrorTypeGeneric);
                 }
             }
         }