mlir printing and parsing fix (#199)

tests/filecheck/mlir-conversion/builtin_attrs.mlir

@@ -106,4 +106,16 @@
 
   // CHECK: "value1" = opaque<"test", "contents">, "value2" = opaque<"test", "contents"> : tensor<2xf64>
 
+  "func.func"() ({}) {function_type = () -> (),
+                      symbol = @some_symbol,
+                      sym_name = "symbol_attr"} : () -> ()
+
+  // CHECK: "symbol" = @some_symbol
+
+  "func.func"() ({}) {function_type = () -> (),
+                      value1 = tensor<?xi32>,
+                      sym_name = "non_static_shaped_tensor"} : () -> ()
+
+  // CHECK: tensor<?xi32>
+
 }) : () -> ()

tests/filecheck/mlir-conversion/with-bindings/symbol_tests.xdsl

@@ -0,0 +1,10 @@
+// RUN: xdsl-opt -t mlir %s | mlir-opt --mlir-print-op-generic > %t-1 && xdsl-opt -t mlir %s | mlir-opt --mlir-print-op-generic > %t-2 && diff %t-1 %t-2
+
+// Tests if the non generic form can be printed.
+
+// CHECK: module {
+builtin.module() {
+  func.func() ["function_type" = !fun<[], []>, "symbol" = @some_symbol, "sym_name" = "symbol_attr", "sym_visibility" = "private"] {}
+
+  func.func() ["function_type" = !fun<[], []>, "value1" = !tensor<[-1 : !index], !i32>, "sym_name" = "unranked_tensor_type", "sym_visibility" = "private"] {}
+}

xdsl/parser.py

@@ -943,6 +943,11 @@ def parse_optional_mlir_attribute(self,
             self.parse_char("]")
             return ArrayAttr.from_list(contents)
 
+        # FlatSymbolRefAttr
+        if self.parse_optional_char("@"):
+            symbol_name = self.parse_alpha_num(skip_white_space=False)
+            return FlatSymbolRefAttr.from_str(symbol_name)
+
         # tensor type
         if (tensor := self.parse_optional_mlir_tensor()) is not None:
             return tensor

xdsl/printer.py

@@ -408,8 +408,9 @@ def print_one_elem(val: Attribute):
             attribute = cast(AnyVectorType, attribute)
             self.print(
                 "vector<" if isinstance(attribute, VectorType) else "tensor<")
-            self.print_list(attribute.shape.data,
-                            lambda x: self.print(x.value.data), "x")
+            self.print_list(
+                attribute.shape.data, lambda x: self.print(x.value.data)
+                if x.value.data != -1 else self.print("?"), "x")
             if len(attribute.shape.data) != 0:
                 self.print("x")
             self.print(attribute.element_type)