Merge pull request #3707 from michaellilltokiwa/issue/3647

fe: fix check condition failure

src/dev/flang/ast/AstErrors.java

@@ -944,23 +944,28 @@ public static void repeatedInheritanceCannotBeResolved(SourcePosition pos, Abstr
           "To solve this, you could add a redefinition of " + sbnf(f1) + " to " + s(heir) + ".");
   }
 
-  public static void duplicateFeatureDeclaration(SourcePosition pos, AbstractFeature f, AbstractFeature existing)
+  public static void duplicateFeatureDeclaration(AbstractFeature a, AbstractFeature b)
   {
     // suppress error message if errors were reported already and any feature
     // involved is f_ERROR
-    if (!any() || (f                != Types.f_ERROR &&
-                         f       .outer() != Types.f_ERROR &&
-                         existing         != Types.f_ERROR &&
-                         existing.outer() != Types.f_ERROR    ))
+    if (!any() || (a                != Types.f_ERROR &&
+                   a       .outer() != Types.f_ERROR &&
+                   b         != Types.f_ERROR &&
+                   b.outer() != Types.f_ERROR    ))
       {
-        var of = f.isTypeFeature() ? f.typeFeatureOrigin() : f;
-        error(pos,
+        // report in source code order to avoid symmetric error with exchanged roles of f and existing
+        var cmpRes = a.pos().show().compareTo(b.pos().show())>0;
+        var aa = cmpRes ? a : b;
+        var bb = cmpRes ? b : a;
+
+        var of = aa.isTypeFeature() ? aa.typeFeatureOrigin() : aa;
+        error(bb.pos(),
               "Duplicate feature declaration",
               "Feature that was declared repeatedly: " + s(of) + "\n" +
-              "originally declared at " + existing.pos().show() + "\n" +
+              "originally declared at " + aa.pos().show() + "\n" +
               "To solve this, consider renaming one of these two features, e.g., as " + sbn(of.featureName().baseNameHuman() + "ʼ") +
               " (using a unicode modifier letter apostrophe " + sbn("ʼ")+ " U+02BC) "+
-              (f.isTypeFeature()
+              (aa.isTypeFeature()
                ? ("or changing it into a routine by returning a " +
                   sbn("unit") + " result, i.e., adding " + sbn("unit") + " before " + code("is") + " or using " + code("=>") +
                   " instead of "+ code("is") + ".")

src/dev/flang/fe/SourceModule.java

@@ -693,7 +693,7 @@ public void addTypeParameter(AbstractFeature outer,
     if (doi != null)
       {
         if (CHECKS) check
-          (!doi.containsKey(fn) || doi.get(fn).size() == 1 && doi.get(fn).getFirst() == typeParameter);
+          (Errors.any() || !doi.containsKey(fn) || doi.get(fn).size() == 1 && doi.get(fn).getFirst() == typeParameter);
         add(doi, fn, typeParameter);
       }
   }
@@ -976,7 +976,7 @@ void addDeclaredInnerFeature(AbstractFeature outer, Feature f)
           }
         else
           {
-            if (existing instanceof Feature ef && ef.isArgument() && f.isArgument())
+            if (existing instanceof Feature ef && ef.isArgument() && f.isArgument() && !f.isTypeParameter())
               {
                 // NYI: CLEANUP: there should not be two places where
                 // similar error is raised.
@@ -986,7 +986,7 @@ void addDeclaredInnerFeature(AbstractFeature outer, Feature f)
               }
             else
               {
-                AstErrors.duplicateFeatureDeclaration(f.pos(), f, existing);
+                AstErrors.duplicateFeatureDeclaration(f, existing);
               }
           }
       }
@@ -1902,7 +1902,7 @@ private void checkDuplicateFeatures(AbstractFeature outer, FeatureName fn, List<
                 else
                   {
                     // NYI: if (!isInherited && !sameModule(f, outer))
-                    AstErrors.duplicateFeatureDeclaration(f1.pos(), f1, f2);
+                    AstErrors.duplicateFeatureDeclaration(f1, f2);
                   }
               }
           }

tests/reg_issue3647/Makefile

@@ -0,0 +1,25 @@
+# This file is part of the Fuzion language implementation.
+#
+# The Fuzion language implementation is free software: you can redistribute it
+# and/or modify it under the terms of the GNU General Public License as published
+# by the Free Software Foundation, version 3 of the License.
+#
+# The Fuzion language implementation is distributed in the hope that it will be
+# useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+# License for more details.
+#
+# You should have received a copy of the GNU General Public License along with The
+# Fuzion language implementation.  If not, see <https://www.gnu.org/licenses/>.
+
+
+# -----------------------------------------------------------------------
+#
+#  Tokiwa Software GmbH, Germany
+#
+#  Source code of Fuzion test Makefile
+#
+# -----------------------------------------------------------------------
+
+override NAME = reg_issue3647
+include ../simple.mk

tests/reg_issue3647/reg_issue3647.fz

@@ -0,0 +1,28 @@
+# This file is part of the Fuzion language implementation.
+#
+# The Fuzion language implementation is free software: you can redistribute it
+# and/or modify it under the terms of the GNU General Public License as published
+# by the Free Software Foundation, version 3 of the License.
+#
+# The Fuzion language implementation is distributed in the hope that it will be
+# useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+# License for more details.
+#
+# You should have received a copy of the GNU General Public License along with The
+# Fuzion language implementation.  If not, see <https://www.gnu.org/licenses/>.
+
+
+# -----------------------------------------------------------------------
+#
+#  Tokiwa Software GmbH, Germany
+#
+#  Source code of Fuzion test reg_issue3647
+#
+# -----------------------------------------------------------------------
+
+reg_issue3647 =>
+
+  Node(T Type, a Node T) ref is
+
+  say (type_as_value (Node i32))

tests/reg_issue3647/reg_issue3647.fz.expected_err

@@ -0,0 +1,11 @@
+
+--CURDIR--/reg_issue3647.fz:26:23: error 1: Duplicate feature declaration
+  Node(T Type, a Node T) ref is
+----------------------^
+Feature that was declared repeatedly: 'reg_issue3647.Node.T'
+originally declared at --CURDIR--/reg_issue3647.fz:26:8:
+  Node(T Type, a Node T) ref is
+-------^
+To solve this, consider renaming one of these two features, e.g., as 'Tʼ' (using a unicode modifier letter apostrophe 'ʼ' U+02BC) or adding an additional argument (e.g. '_ unit' for an ignored unit argument used only to disambiguate these two).
+
+one error.