Implement PR1240


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34959 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/System/Disassembler.h b/include/llvm/System/Disassembler.h
index 37a8761..fd08f2d 100644
--- a/include/llvm/System/Disassembler.h
+++ b/include/llvm/System/Disassembler.h
@@ -21,6 +21,10 @@
 namespace llvm {
 namespace sys {
 
+/// This function returns true, if there is possible to use some external
+/// disassembler library. False otherwise.
+bool hasDisassembler(void); 
+
 /// This function provides some "glue" code to call external disassembler
 /// libraries.
 std::string disassembleBuffer(uint8_t* start, size_t length, uint64_t pc = 0);
diff --git a/lib/ExecutionEngine/JIT/JITEmitter.cpp b/lib/ExecutionEngine/JIT/JITEmitter.cpp
index a52ce86d..99dd0c9 100644
--- a/lib/ExecutionEngine/JIT/JITEmitter.cpp
+++ b/lib/ExecutionEngine/JIT/JITEmitter.cpp
@@ -876,8 +876,9 @@
   Relocations.clear();
 
 #ifndef NDEBUG
-  DOUT << "Disassembled code:\n"
-       << sys::disassembleBuffer(FnStart, FnEnd-FnStart, (uintptr_t)FnStart);
+  if (sys::hasDisassembler())
+    DOUT << "Disassembled code:\n"
+         << sys::disassembleBuffer(FnStart, FnEnd-FnStart, (uintptr_t)FnStart);
 #endif
   
   return false;
diff --git a/lib/System/Disassembler.cpp b/lib/System/Disassembler.cpp
index 30d3fb7..4aec698 100644
--- a/lib/System/Disassembler.cpp
+++ b/lib/System/Disassembler.cpp
@@ -26,6 +26,16 @@
 
 using namespace llvm;
 
+bool llvm::sys::hasDisassembler(void) 
+{
+#if defined (__i386__) || defined (__amd64__) || defined (__x86_64__)
+  // We have option to enable udis86 library.
+  return true;
+#else
+  return false;
+#endif
+}
+
 std::string llvm::sys::disassembleBuffer(uint8_t* start, size_t length,
                                          uint64_t pc) {
   std::stringstream res;