Merge pull request diffblue#2232 from owen-jones-diffblue/owen-jones-diffblue/generic-bounded-types

Java generic bounded types in method signatures

Author: smowton

jbmc/src/java_bytecode/java_types.cpp

@@ -462,6 +462,18 @@ typet java_type_from_string(
         throw unsupported_java_class_signature_exceptiont(
           "Failed to find generic signature closing delimiter");
       }
+
+      // If there are any bounds between '<' and '>' then we cannot currently
+      // parse them, so we give up. This only happens when parsing the
+      // signature, so we'll fall back to the result of parsing the
+      // descriptor, which will respect the bounds correctly.
+      const size_t colon_pos = src.find(':');
+      if(colon_pos != std::string::npos && colon_pos < closing_generic)
+      {
+        throw unsupported_java_class_signature_exceptiont(
+          "Cannot currently parse bounds on generic types");
+      }
+
       const typet &method_type=java_type_from_string(
         src.substr(closing_generic+1, std::string::npos), class_name_prefix);
 

jbmc/unit/java_bytecode/java_bytecode_parse_generics/BoundedGenericInnerClasses$BoundedInner.class

@@ -8,6 +8,9 @@ class Inner<E>
   class BoundedInner<NUM extends java.lang.Number>
   {
     NUM elem;
+
+    public void f(NUM x) {
+    }
   }
 
   BoundedInner<Integer> belem;

jbmc/unit/java_bytecode/java_bytecode_parse_generics/BoundedGenericInnerClasses$DoubleBoundedInner.class

@@ -17,6 +17,11 @@ public static <T extends Interface_Implementation> void processUpperBoundClass(G
 
   }
 
+  public static <T extends java.lang.Number> void processUpperBoundClass2(T x)
+  {
+
+  }
+
   public static <T extends Interface_Implementation & Interface> void processDoubleUpperBoundClass(Generic<T> x)
   {
 

jbmc/unit/java_bytecode/java_bytecode_parse_generics/BoundedGenericInnerClasses$TwoElementInner.class

@@ -68,6 +68,24 @@ SCENARIO(
             to_struct_type(class_symbol.type), "elem");
         require_type::require_java_generic_parameter(
           elem.type(), boundedinner_name + "::NUM");
+
+        std::string method_name =
+          boundedinner_name + ".f:(Ljava/lang/Number;)V";
+        REQUIRE(new_symbol_table.has_symbol(method_name));
+        THEN("The method parameter type should respect its bound")
+        {
+          const symbolt &method_symbol =
+            new_symbol_table.lookup_ref(method_name);
+          const code_typet &method_type =
+            require_type::require_code(method_symbol.type);
+          const code_typet::parametert &param =
+            require_type::require_parameter(method_type, "x");
+          require_type::require_java_generic_parameter(
+            param.type(), boundedinner_name + "::NUM");
+
+          // TODO: the bounds are not parsed yet; extend tests when fixed -
+          // issue TG-1286
+        }
       }
     }
   }