[mlir][mlir-link] Initial skeleton for an MLIR-linker

mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td

@@ -1382,6 +1382,9 @@ def LLVM_GlobalOp : LLVM_Op<"mlir.global",
     }
   }];
 
+  let extraClassDefinition = [{
+    bool $cppClass::isDeclarationForLinkage() { return getInitializerRegion().empty(); }
+  }];
   let hasCustomAssemblyFormat = 1;
   let hasVerifier = 1;
   let hasRegionVerifier = 1;
@@ -1629,6 +1632,10 @@ def LLVM_LLVMFuncOp : LLVM_Op<"func", [
 
   }];
 
+  let extraClassDefinition = [{
+    bool $cppClass::isDeclarationForLinkage() { return getBody().empty(); }
+  }];
+
   let hasCustomAssemblyFormat = 1;
   let hasVerifier = 1;
   let hasRegionVerifier = 1;

mlir/include/mlir/Interfaces/LinkageInterfaces.td

@@ -203,11 +203,7 @@ def GlobalValueLinkageOpInterface : OpInterface<"GlobalValueLinkageOpInterface">
       }],
       /*returnType=*/  "bool",
       /*methodName=*/  "isDeclarationForLinkage",
-      /*args=*/        (ins),
-      /*methodBody=*/  [{}],
-      /*defaultImplementation=*/[{
-        return cast<SymbolOpInterface>($_op.getOperation()).isDeclaration();
-      }]
+      /*args=*/        (ins)
     >,
     InterfaceMethod<
       /*desc=*/        "Returns linked name of the operation",

mlir/include/mlir/Linker/IRMover.h

@@ -13,18 +13,26 @@
 
 #include "mlir/Interfaces/LinkageInterfaces.h"
 
+using llvm::Error;
+
 namespace mlir {
 
+
+
+
 class IRMover {
 public:
   IRMover(Operation *composite);
 
   LinkableModuleOpInterface getComposite() { return composite; }
   MLIRContext *getContext() { return composite->getContext(); }
 
-private:
-  LinkableModuleOpInterface composite;
-};
+  Error move(OwningOpRef<Operation *> src,
+                    ArrayRef<Operation *> valuesToLink);
+
+  private:
+    LinkableModuleOpInterface composite;
+  };
 
 } // namespace mlir