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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199261 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 34 insertions, 17 deletions

diff --git a/tools/lli/RemoteTargetExternal.h b/tools/lli/RemoteTargetExternal.h
index 63548eb52d..5ef67100e3 100644
--- a/tools/lli/RemoteTargetExternal.h
+++ b/tools/lli/RemoteTargetExternal.h
@@ -35,7 +35,7 @@ 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,
@@ -47,7 +47,7 @@ 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, size_t Size);
 
@@ -57,7 +57,7 @@ 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, size_t Size);
 
@@ -68,7 +68,7 @@ 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);
 
@@ -80,7 +80,10 @@ public:
   virtual unsigned getPageAlignment() { return 4096; }
 
   /// Start the remote process.
-  virtual void create();
+  ///
+  /// @returns True on success. On failure, ErrorMsg is updated with
+  ///          descriptive text of the encountered error.
+  virtual bool create();
 
   /// Terminate the remote process.
   virtual void stop();
@@ -91,23 +94,37 @@ public:
 private:
   std::string ChildName;
 
-  // This will get filled in as a point to an OS-specific structure.
-  void *ConnectionData;
-
-  void SendAllocateSpace(uint32_t Alignment, uint32_t Size);
-  void SendLoadSection(uint64_t Addr,
+  bool SendAllocateSpace(uint32_t Alignment, uint32_t Size);
+  bool SendLoadSection(uint64_t Addr,
                        const void *Data,
                        uint32_t Size,
                        bool IsCode);
-  void SendExecute(uint64_t Addr);
-  void SendTerminate();
+  bool SendExecute(uint64_t Addr);
+  bool SendTerminate();
+
+  // High-level wrappers for receiving data
+  bool Receive(LLIMessageType Msg);
+  bool Receive(LLIMessageType Msg, int32_t &Data);
+  bool Receive(LLIMessageType Msg, uint64_t &Data);
+
+  // Lower level target-independent read/write to deal with errors
+  bool ReceiveHeader(LLIMessageType Msg);
+  bool ReceivePayload();
+  bool SendHeader(LLIMessageType Msg);
+  bool SendPayload();
+
+  // Functions to append/retrieve data from the payload
+  SmallVector<const void *, 2> SendData;
+  SmallVector<void *, 1> ReceiveData; // Future proof
+  SmallVector<int, 2> Sizes;
+  void AppendWrite(const void *Data, uint32_t Size);
+  void AppendRead(void *Data, uint32_t Size);
 
-  void Receive(LLIMessageType Msg);
-  void Receive(LLIMessageType Msg, int &Data);
-  void Receive(LLIMessageType Msg, uint64_t &Data);
+  // This will get filled in as a point to an OS-specific structure.
+  void *ConnectionData;
 
-  int WriteBytes(const void *Data, size_t Size);
-  int ReadBytes(void *Data, size_t Size);
+  bool WriteBytes(const void *Data, size_t Size);
+  bool ReadBytes(void *Data, size_t Size);
   void Wait();
 };