Rename callee to sym_name and revise checking if specified

Author: marbre

mlir/include/mlir/Dialect/EmitC/IR/EmitC.td

@@ -496,9 +496,9 @@ def EmitC_DeclareFuncOp : EmitC_Op<"declare_func", [
     }
     ```
   }];
-  let arguments = (ins FlatSymbolRefAttr:$callee);
+  let arguments = (ins FlatSymbolRefAttr:$sym_name);
   let assemblyFormat = [{
-    $callee attr-dict
+    $sym_name attr-dict
   }];
 }
 

mlir/lib/Dialect/EmitC/IR/EmitC.cpp

@@ -399,10 +399,10 @@ FunctionType CallOp::getCalleeType() {
 
 LogicalResult
 DeclareFuncOp::verifySymbolUses(SymbolTableCollection &symbolTable) {
-  // Check that the callee attribute was specified.
-  auto fnAttr = (*this)->getAttrOfType<FlatSymbolRefAttr>("callee");
+  // Check that the sym_name attribute was specified.
+  auto fnAttr = getSymNameAttr();
   if (!fnAttr)
-    return emitOpError("requires a 'callee' symbol reference attribute");
+    return emitOpError("requires a 'sym_name' symbol reference attribute");
   FuncOp fn = symbolTable.lookupNearestSymbolFrom<FuncOp>(*this, fnAttr);
   if (!fn)
     return emitOpError() << "'" << fnAttr.getValue()

mlir/lib/Target/Cpp/TranslateToCpp.cpp

@@ -946,7 +946,7 @@ static LogicalResult printOperation(CppEmitter &emitter,
   raw_indented_ostream &os = emitter.ostream();
 
   auto functionOp = SymbolTable::lookupNearestSymbolFrom<emitc::FuncOp>(
-      declareFuncOp, declareFuncOp.getCalleeAttr());
+      declareFuncOp, declareFuncOp.getSymNameAttr());
 
   if (!functionOp)
     return failure();

mlir/test/Dialect/EmitC/invalid_ops.mlir

@@ -329,5 +329,5 @@ emitc.declare_func @bar
 
 // -----
 
-// expected-error@+1 {{'emitc.declare_func' op requires attribute 'callee'}}
+// expected-error@+1 {{'emitc.declare_func' op requires attribute 'sym_name'}}
 "emitc.declare_func"()  : () -> ()