Deal with error handling better.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34887 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ExecutionEngine/JIT/TargetSelect.cpp b/lib/ExecutionEngine/JIT/TargetSelect.cpp
index c30f88c..30fd2fa 100644
--- a/lib/ExecutionEngine/JIT/TargetSelect.cpp
+++ b/lib/ExecutionEngine/JIT/TargetSelect.cpp
@@ -38,11 +38,15 @@
 /// create - Create an return a new JIT compiler if there is one available
 /// for the current target.  Otherwise, return null.
 ///
-ExecutionEngine *JIT::create(ModuleProvider *MP) {
+ExecutionEngine *JIT::create(ModuleProvider *MP, std::string *ErrorStr) {
   if (MArch == 0) {
     std::string Error;
     MArch = TargetMachineRegistry::getClosestTargetForJIT(Error);
-    if (MArch == 0) return 0;
+    if (MArch == 0) {
+      if (ErrorStr)
+        *ErrorStr = Error;
+      return 0;
+    }
   } else if (MArch->JITMatchQualityFn() == 0) {
     cerr << "WARNING: This target JIT is not designed for the host you are"
          << " running.  If bad things happen, please choose a different "
@@ -66,5 +70,8 @@
   // If the target supports JIT code generation, return a new JIT now.
   if (TargetJITInfo *TJ = Target->getJITInfo())
     return new JIT(MP, *Target, *TJ);
+
+  if (ErrorStr)
+    *ErrorStr = "target does not support JIT code generation";
   return 0;
 }