Added a mechanism for the IR interpreter to return

an error along with its boolean result.  The
expression parser reports this error if the 
interpreter fails and the expression could not be
run in the target.

llvm-svn: 148870

1 files changed, 16 insertions, 18 deletions

diff --git a/lldb/source/Expression/ClangExpressionParser.cpp b/lldb/source/Expression/ClangExpressionParser.cpp
index 7c3e6589621..625b03e28a2 100644
--- a/lldb/source/Expression/ClangExpressionParser.cpp
+++ b/lldb/source/Expression/ClangExpressionParser.cpp
@@ -187,7 +187,6 @@ ClangExpressionParser::ClangExpressionParser (ExecutionContextScope *exe_scope,
     m_expr (expr),
     m_compiler (),
     m_code_generator (NULL),
-    m_execution_engine (),
     m_jitted_functions ()
 {
     // Initialize targets first, so that --version shows registered targets.
@@ -447,6 +446,8 @@ ClangExpressionParser::PrepareForExecution (lldb::addr_t &func_allocation_addr,
 	func_end = LLDB_INVALID_ADDRESS;
     lldb::LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
 
+    std::auto_ptr<llvm::ExecutionEngine> execution_engine;
+    
     Error err;
     
     llvm::Module *module = m_code_generator->ReleaseModule();
@@ -498,7 +499,9 @@ ClangExpressionParser::PrepareForExecution (lldb::addr_t &func_allocation_addr,
             return err;
         }
         
-        if (execution_policy != eExecutionPolicyAlways && ir_for_target.interpretSuccess())
+        Error &interpreter_error(ir_for_target.getInterpreterError());
+        
+        if (execution_policy != eExecutionPolicyAlways && interpreter_error.Success())
         {
             if (const_result)
                 const_result->TransferAddress();
@@ -512,7 +515,10 @@ ClangExpressionParser::PrepareForExecution (lldb::addr_t &func_allocation_addr,
         if (!process || execution_policy == eExecutionPolicyNever)
         {
             err.SetErrorToGenericError();
-            err.SetErrorString("Execution needed to run in the target, but the target can't be run");
+            if (execution_policy == eExecutionPolicyAlways)
+                err.SetErrorString("Execution needed to run in the target, but the target can't be run");
+            else
+                err.SetErrorStringWithFormat("Interpreting the expression locally failed: %s", interpreter_error.AsCString());
             return err;
         }
         
@@ -571,15 +577,6 @@ ClangExpressionParser::PrepareForExecution (lldb::addr_t &func_allocation_addr,
         log->Printf ("Module being sent to JIT: \n%s", s.c_str());
     }
     
-#if defined (USE_STANDARD_JIT)
-    m_execution_engine.reset(llvm::ExecutionEngine::createJIT (module, 
-                                                               &error_string, 
-                                                               jit_memory_manager,
-                                                               CodeGenOpt::Less,
-                                                               true,
-                                                               Reloc::Default,
-                                                               CodeModel::Small));
-#else
     EngineBuilder builder(module);
     builder.setEngineKind(EngineKind::JIT)
         .setErrorStr(&error_string)
@@ -589,24 +586,23 @@ ClangExpressionParser::PrepareForExecution (lldb::addr_t &func_allocation_addr,
         .setAllocateGVsWithCode(true)
         .setCodeModel(CodeModel::Small)
         .setUseMCJIT(true);
-    m_execution_engine.reset(builder.create());
-#endif
+    execution_engine.reset(builder.create());
         
-    if (!m_execution_engine.get())
+    if (!execution_engine.get())
     {
         err.SetErrorToGenericError();
         err.SetErrorStringWithFormat("Couldn't JIT the function: %s", error_string.c_str());
         return err;
     }
     
-    m_execution_engine->DisableLazyCompilation();
+    execution_engine->DisableLazyCompilation();
     
     llvm::Function *function = module->getFunction (function_name.c_str());
     
     // We don't actually need the function pointer here, this just forces it to get resolved.
     
-    void *fun_ptr = m_execution_engine->getPointerToFunction(function);
-    
+    void *fun_ptr = execution_engine->getPointerToFunction(function);
+        
     // Errors usually cause failures in the JIT, but if we're lucky we get here.
     
     if (!function)
@@ -717,6 +713,8 @@ ClangExpressionParser::PrepareForExecution (lldb::addr_t &func_allocation_addr,
         }
     }
     
+    execution_engine.reset();
+    
     err.Clear();
     return err;
 }