Sanitize MCJIT remote execution

MCJIT remote execution (ChildTarget+RemoteTargetExternal) protocol was in
dire need of refactoring. It was fail-prone, had no error reporting and
implemented the same message logic on every single function.

This patch rectifies it, and makes it work on ARM, where it was randomly
failing. Other architectures shall profit from this change as well, making
their buildbots and releases more reliable.

llvm-svn: 199261

1 files changed, 9 insertions, 7 deletions

diff --git a/llvm/tools/lli/RemoteTarget.h b/llvm/tools/lli/RemoteTarget.h
index c95fbd1ae9e..a7d4e59e3bf 100644
--- a/llvm/tools/lli/RemoteTarget.h
+++ b/llvm/tools/lli/RemoteTarget.h
@@ -25,11 +25,13 @@
 namespace llvm {
 
 class RemoteTarget {
-  std::string ErrorMsg;
   bool IsRunning;
 
   SmallVector<sys::MemoryBlock, 16> Allocations;
 
+protected:
+  std::string ErrorMsg;
+
 public:
   StringRef getErrorMsg() const { return ErrorMsg; }
 
@@ -39,7 +41,7 @@ public:
   /// @param      Alignment Required minimum alignment for allocated space.
   /// @param[out] Address   Remote address of the allocated memory.
   ///
-  /// @returns False on success. On failure, ErrorMsg is updated with
+  /// @returns True on success. On failure, ErrorMsg is updated with
   ///          descriptive text of the encountered error.
   virtual bool allocateSpace(size_t Size,
                              unsigned Alignment,
@@ -51,7 +53,7 @@ public:
   /// @param      Data      Source address in the host process.
   /// @param      Size      Number of bytes to copy.
   ///
-  /// @returns False on success. On failure, ErrorMsg is updated with
+  /// @returns True on success. On failure, ErrorMsg is updated with
   ///          descriptive text of the encountered error.
   virtual bool loadData(uint64_t Address,
                         const void *Data,
@@ -63,7 +65,7 @@ public:
   /// @param      Data      Source address in the host process.
   /// @param      Size      Number of bytes to copy.
   ///
-  /// @returns False on success. On failure, ErrorMsg is updated with
+  /// @returns True on success. On failure, ErrorMsg is updated with
   ///          descriptive text of the encountered error.
   virtual bool loadCode(uint64_t Address,
                         const void *Data,
@@ -76,7 +78,7 @@ public:
   ///                       process.
   /// @param[out] RetVal    The integer return value of the called function.
   ///
-  /// @returns False on success. On failure, ErrorMsg is updated with
+  /// @returns True on success. On failure, ErrorMsg is updated with
   ///          descriptive text of the encountered error.
   virtual bool executeCode(uint64_t Address,
                            int &RetVal);
@@ -89,12 +91,12 @@ public:
   virtual unsigned getPageAlignment() { return 4096; }
 
   /// Start the remote process.
-  virtual void create();
+  virtual bool create();
 
   /// Terminate the remote process.
   virtual void stop();
 
-  RemoteTarget() : ErrorMsg(""), IsRunning(false) {}
+  RemoteTarget() : IsRunning(false), ErrorMsg("") {}
   virtual ~RemoteTarget() { if (IsRunning) stop(); }
 
   // Create an instance of the system-specific remote target class.