Add support for "dynamic values" for C++ classes. This currently only works for "frame var" and for the

expressions that are simple enough to get passed to the "frame var" underpinnings.  The parser code will
have to be changed to also query for the dynamic types & offsets as it is looking up variables.

The behavior of "frame var" is controlled in two ways.  You can pass "-d {true/false} to the frame var
command to get the dynamic or static value of the variables you are printing.

There's also a general setting:

target.prefer-dynamic-value (boolean) = 'true'

which is consulted if you call "frame var" without supplying a value for the -d option.

llvm-svn: 129623

1 files changed, 40 insertions, 1 deletions

diff --git a/lldb/source/Commands/CommandObjectExpression.cpp b/lldb/source/Commands/CommandObjectExpression.cpp
index 7b9f01cd3c8..82d2197e7cc 100644
--- a/lldb/source/Commands/CommandObjectExpression.cpp
+++ b/lldb/source/Commands/CommandObjectExpression.cpp
@@ -77,6 +77,23 @@ CommandObjectExpression::CommandOptions::SetOptionValue (uint32_t option_idx, co
         print_object = true;
         break;
         
+    case 'd':
+        {
+            bool success;
+            bool result;
+            result = Args::StringToBoolean(option_arg, true, &success);
+            if (!success)
+                error.SetErrorStringWithFormat("Invalid dynamic value setting: \"%s\".\n", option_arg);
+            else
+            {
+                if (result)
+                    use_dynamic  = eLazyBoolYes;  
+                else
+                    use_dynamic = eLazyBoolNo;
+            }
+        }
+        break;
+        
     case 'u':
         bool success;
         unwind_on_error = Args::StringToBoolean(option_arg, true, &success);
@@ -99,6 +116,7 @@ CommandObjectExpression::CommandOptions::OptionParsingStarting ()
     debug = false;
     format = eFormatDefault;
     print_object = false;
+    use_dynamic = eLazyBoolCalculate;
     unwind_on_error = true;
     show_types = true;
     show_summary = true;
@@ -239,8 +257,27 @@ CommandObjectExpression::EvaluateExpression
         ExecutionResults exe_results;
         
         bool keep_in_memory = true;
+        bool use_dynamic;
+        // If use dynamic is not set, get it from the target:
+        switch (m_options.use_dynamic)
+        {
+        case eLazyBoolCalculate:
+            {   
+                if (m_exe_ctx.target->GetPreferDynamicValue())
+                    use_dynamic = true;
+                else
+                    use_dynamic = false;
+            }
+            break;
+        case eLazyBoolYes:
+            use_dynamic = true;
+            break;
+        case eLazyBoolNo:
+            use_dynamic = false;
+            break;
+        }
         
-        exe_results = m_exe_ctx.target->EvaluateExpression(expr, m_exe_ctx.frame, m_options.unwind_on_error, keep_in_memory, result_valobj_sp);
+        exe_results = m_exe_ctx.target->EvaluateExpression(expr, m_exe_ctx.frame, m_options.unwind_on_error, use_dynamic, keep_in_memory, result_valobj_sp);
         
         if (exe_results == eExecutionInterrupted && !m_options.unwind_on_error)
         {
@@ -266,6 +303,7 @@ CommandObjectExpression::EvaluateExpression
                                               m_options.show_types,     // Show types when dumping?
                                               false,                    // Show locations of variables, no since this is a host address which we don't care to see
                                               m_options.print_object,   // Print the objective C object?
+                                              use_dynamic,
                                               true,                     // Scope is already checked. Const results are always in scope.
                                               false);                   // Don't flatten output
                 if (result)
@@ -389,6 +427,7 @@ CommandObjectExpression::CommandOptions::g_option_table[] =
 //{ LLDB_OPT_SET_1, false, "format",     'f', required_argument, NULL, 0, "[ [bool|b] | [bin] | [char|c] | [oct|o] | [dec|i|d|u] | [hex|x] | [float|f] | [cstr|s] ]",  "Specify the format that the expression output should use."},
 { LLDB_OPT_SET_1, false, "format",             'f', required_argument, NULL, 0, eArgTypeExprFormat,  "Specify the format that the expression output should use."},
 { LLDB_OPT_SET_2, false, "object-description", 'o', no_argument,       NULL, 0, eArgTypeNone, "Print the object description of the value resulting from the expression."},
+{ LLDB_OPT_SET_2, false, "dynamic-value", 'd', required_argument,       NULL, 0, eArgTypeBoolean, "Upcast the value resulting from the expression to its dynamic type if available."},
 { LLDB_OPT_SET_ALL, false, "unwind-on-error",  'u', required_argument, NULL, 0, eArgTypeBoolean, "Clean up program state if the expression causes a crash, breakpoint hit or signal."},
 { LLDB_OPT_SET_ALL, false, "debug",            'g', no_argument,       NULL, 0, eArgTypeNone, "Enable verbose debug logging of the expression parsing and evaluation."},
 { LLDB_OPT_SET_ALL, false, "use-ir",           'i', no_argument,       NULL, 0, eArgTypeNone, "[Temporary] Instructs the expression evaluator to use IR instead of ASTs."},