Re-apply r196639: Add support for archives and object file caching under MCJIT.

I believe the bot failures on linux systems were due to overestimating the
alignment of object-files within archives, which are only guaranteed to be
two-byte aligned. I have reduced the alignment in
RuntimeDyldELF::createObjectImageFromFile accordingly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198737 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 42 insertions, 0 deletions

diff --git a/include/llvm/ExecutionEngine/ExecutionEngine.h b/include/llvm/ExecutionEngine/ExecutionEngine.h
index ee43cbcf0e..199cf8deb8 100644
--- a/include/llvm/ExecutionEngine/ExecutionEngine.h
+++ b/include/llvm/ExecutionEngine/ExecutionEngine.h
@@ -48,6 +48,11 @@ class RTDyldMemoryManager;
 class Triple;
 class Type;
 
+namespace object {
+  class Archive;
+  class ObjectFile;
+}
+
 /// \brief Helper class for helping synchronize access to the global address map
 /// table.
 class ExecutionEngineState {
@@ -204,6 +209,33 @@ public:
     Modules.push_back(M);
   }
 
+  /// addObjectFile - Add an ObjectFile to the execution engine.
+  ///
+  /// This method is only supported by MCJIT.  MCJIT will immediately load the
+  /// object into memory and adds its symbols to the list used to resolve
+  /// external symbols while preparing other objects for execution.
+  ///
+  /// Objects added using this function will not be made executable until
+  /// needed by another object.
+  ///
+  /// MCJIT will take ownership of the ObjectFile.
+  virtual void addObjectFile(object::ObjectFile *O) {
+    llvm_unreachable(
+      "ExecutionEngine subclass doesn't implement addObjectFile.");
+  }
+
+  /// addArchive - Add an Archive to the execution engine.
+  ///
+  /// This method is only supported by MCJIT.  MCJIT will use the archive to
+  /// resolve external symbols in objects it is loading.  If a symbol is found
+  /// in the Archive the contained object file will be extracted (in memory)
+  /// and loaded for possible execution.
+  ///
+  /// MCJIT will take ownership of the Archive.
+  virtual void addArchive(object::Archive *A) {
+    llvm_unreachable("ExecutionEngine subclass doesn't implement addArchive.");
+  }
+
   //===--------------------------------------------------------------------===//
 
   const DataLayout *getDataLayout() const { return TD; }
diff --git a/include/llvm/ExecutionEngine/RuntimeDyld.h b/include/llvm/ExecutionEngine/RuntimeDyld.h
index b8324387bb..fd9f338669 100644
--- a/include/llvm/ExecutionEngine/RuntimeDyld.h
+++ b/include/llvm/ExecutionEngine/RuntimeDyld.h
@@ -21,6 +21,10 @@
 
 namespace llvm {
 
+namespace object {
+  class ObjectFile;
+}
+
 class RuntimeDyldImpl;
 class ObjectImage;
 
@@ -46,6 +50,12 @@ public:
   /// failure, the input buffer will be deleted.
   ObjectImage *loadObject(ObjectBuffer *InputBuffer);
 
+  /// Prepare the referenced object file for execution.
+  /// Ownership of the input object is transferred to the ObjectImage
+  /// instance returned from this function if successful. In the case of load
+  /// failure, the input object will be deleted.
+  ObjectImage *loadObject(object::ObjectFile *InputObject);
+
   /// Get the address of our local copy of the symbol. This may or may not
   /// be the address used for relocation (clients can copy the data around
   /// and resolve relocatons based on where they put it).