The "desired result type" code in the expression
parser has hitherto been an implementation waiting
for a use.  I have now tied the '-o' option for
the expression command -- which indicates that the
result is an Objective-C object and needs to be
printed -- to the ExpressionParser, which
communicates the desired type to Clang.

Now, if the result of an expression is determined
by an Objective-C method call for which there is
no type information, that result is implicitly
cast to id if and only if the -o option is passed
to the expression command.  (Otherwise if there
is no explicit cast Clang will issue an error.
This behavior is identical to what happened before
r146756.)

Also added a testcase for -o enabled and disabled.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@147099 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Target/Target.cpp b/source/Target/Target.cpp
index 902ffc7..c31b0b1 100644
--- a/source/Target/Target.cpp
+++ b/source/Target/Target.cpp
@@ -1462,6 +1462,7 @@
     const char *expr_cstr,
     StackFrame *frame,
     lldb_private::ExecutionPolicy execution_policy,
+    bool coerce_to_id,
     bool unwind_on_error,
     bool keep_in_memory,
     lldb::DynamicValueType use_dynamic,
@@ -1587,6 +1588,7 @@
             execution_results = ClangUserExpression::Evaluate (exe_ctx, 
                                                                execution_policy,
                                                                lldb::eLanguageTypeUnknown,
+                                                               coerce_to_id ? ClangUserExpression::eResultTypeId : ClangUserExpression::eResultTypeAny,
                                                                unwind_on_error,
                                                                expr_cstr, 
                                                                prefix,