[GR-11888] Fix arity checking and NULL arguments to rb_scan_args to match MRI.

PullRequest: truffleruby/732

Author: aardvark179

lib/cext/include/truffleruby/truffleruby.h

@@ -228,6 +228,8 @@ MUST_INLINE int rb_tr_scan_args(int argc, VALUE *argv, const char *format, VALUE
   const char *formatp = format;
   int pre = 0;
   int optional = 0;
+  int n_mand = 0;
+  int n_opt = 0;
   bool rest;
   int post = 0;
   bool kwargs;
@@ -281,6 +283,9 @@ MUST_INLINE int rb_tr_scan_args(int argc, VALUE *argv, const char *format, VALUE
     rb_raise(rb_eArgError, "not enough arguments for required");
   }
 
+  n_mand = pre + post;
+  n_opt = optional;
+
   // Read arguments
 
   int argn = 0;
@@ -360,26 +365,30 @@ MUST_INLINE int rb_tr_scan_args(int argc, VALUE *argv, const char *format, VALUE
     // Don't assign the correct v to a temporary VALUE* and then assign arg to it - this doesn't optimise well
 
     switch (valuen) {
-      case 1: *v1 = arg; break;
-      case 2: *v2 = arg; break;
-      case 3: *v3 = arg; break;
-      case 4: *v4 = arg; break;
-      case 5: *v5 = arg; break;
-      case 6: *v6 = arg; break;
-      case 7: *v7 = arg; break;
-      case 8: *v8 = arg; break;
-      case 9: *v9 = arg; break;
-      case 10: *v10 = arg; break;
+    case 1: if (v1 != NULL) { *v1 = arg; } break;
+    case 2: if (v2 != NULL) { *v2 = arg; } break;
+    case 3: if (v3 != NULL) { *v3 = arg; } break;
+    case 4: if (v4 != NULL) { *v4 = arg; } break;
+    case 5: if (v5 != NULL) { *v5 = arg; } break;
+    case 6: if (v6 != NULL) { *v6 = arg; } break;
+    case 7: if (v7 != NULL) { *v7 = arg; } break;
+    case 8: if (v8 != NULL) { *v8 = arg; } break;
+    case 9: if (v9 != NULL) { *v9 = arg; } break;
+    case 10: if (v10 != NULL) { *v10 = arg; } break;
     }
 
     valuen++;
   }
 
   if (found_kwargs) {
-    return argc - 1;
-  } else {
-    return argc;
+    argc = argc - 1;
   }
+
+  if (argn < argc) {
+	rb_error_arity(argc, n_mand, rest ? UNLIMITED_ARGUMENTS : n_mand + n_opt);
+  }
+
+  return argc;
 }
 
 #if defined(__cplusplus)

lib/truffle/truffle/cext.rb

@@ -1142,6 +1142,10 @@ def rb_check_arity(arg_count, min, max)
     Truffle::Type.check_arity arg_count, min, max
   end
 
+  def rb_arity_error_string(arg_count, min, max)
+    Truffle::Type.arity_error_string(arg_count, min, max)
+  end
+
   def rb_raise(object, name)
     raise 'not implemented'
   end

spec/ruby/optional/capi/util_spec.rb

@@ -23,6 +23,10 @@
       lambda { @o.rb_scan_args([1, 2], "3", 0, @acc) }.should raise_error(ArgumentError)
     end
 
+    it "raises an ArgumentError if there are too many arguments" do
+      lambda { @o.rb_scan_args([1, 2, 3, 4], "3", 0, @acc) }.should raise_error(ArgumentError)
+    end
+
     it "assigns the required and optional arguments scanned" do
       @o.rb_scan_args([1, 2], "11", 2, @acc).should == 2
       ScratchPad.recorded.should == [1, 2]

src/main/c/cext/ruby.c

@@ -3468,6 +3468,11 @@ VALUE rb_enum_values_pack(int argc, const VALUE *argv) {
   rb_tr_error("rb_enum_values_pack not implemented");
 }
 
+
+NORETURN(void rb_error_arity(int argc, int min, int max)) {
+  rb_exc_raise(rb_exc_new3(rb_eArgError, rb_tr_wrap(polyglot_invoke(RUBY_CEXT, "rb_arity_error_string", argc, min, max))));
+}
+
 void rb_error_untrusted(VALUE obj) {
   rb_tr_error("rb_error_untrusted not implemented");
 }

src/main/ruby/core/type.rb

@@ -611,15 +611,18 @@ def self.object_respond_to_marshal_load?(obj)
 
     def self.check_arity(arg_count, min, max)
       if arg_count < min || (max != -1 && arg_count > max)
-        error_message = case
-                        when min == max
-                          'wrong number of arguments (given %d, expected %d)' % [arg_count, min]
-                        when max == -1
-                          'wrong number of arguments (given %d, expected %d+)' % [arg_count, min]
-                        else
-                          'wrong number of arguments (given %d, expected %d..%d)' % [arg_count, min, max]
-                        end
-        raise ArgumentError, error_message
+        raise ArgumentError, arity_error_string(arg_count, min, max)
+      end
+    end
+
+    def self.arity_error_string(arg_count, min, max)
+      case
+      when min == max
+        'wrong number of arguments (given %d, expected %d)' % [arg_count, min]
+      when max == -1
+        'wrong number of arguments (given %d, expected %d+)' % [arg_count, min]
+      else
+        'wrong number of arguments (given %d, expected %d..%d)' % [arg_count, min, max]
       end
     end