Ticket #279: diff-unused-01.patch

CobraParser.cobra

@@ -1852 +1852 @@
         identifier = token.value to String
         .checkStartsLowercase(identifier, 'Parameter')
         dir = Direction.In
+        declaredAsUnused = false
         type as ITypeProxy?
         if .optional('AS')
+
+            # to detect usage of syntax {AS {UNUSED} {OUT,INOUT} <type>}
+            if .optional('UNUSED')
+                declaredAsUnused = true
+                    
             # code below expresses an undocumented dependency and ordering
             # allows only    VARI <type>  or  {OUT,INOUT} <type>
             # i.e cant have VARI and {OUT,INOUT}, if have VARI or OUT,INOUT must specify type
@@ -1882 +1888 @@
             attribs.add(AttributeDecl(.attribExpr(0)))
         # note: isMissingType is currently used to generate a warning in .paramDecls above
         # and may be used for anonymous method parameter type inference at some point
-        return Param(token, type, isMissingType=isMissingType, direction=dir, attributes=attribs)
+        return Param(token, type, isMissingType=isMissingType, direction=dir, isDeclaredAsUnused=declaredAsUnused, attributes=attribs)
 
 
     ##

KeywordSpecs.cobra

@@ -85 +85 @@
                 'def         | declarative: Declare a method.',
                 'sig         | declarative: Declare a method signature.',
                 'as          | declarative: Declare the type for an argument, variable, method return, property, etc.',
+                'unused      | declarative: Declare the parameter as unused.',
                 'get         | declarative: Declare property reader/accessor. | expression: The evaluation result on a `for` expression.',
                 'set         | declarative: Declare property writer/mutator.',
                 'pro         | declarative: Declare a property.',

Members.cobra

@@ -905 +905 @@
         if _requirePart, _requirePart.checkConnectToken
         if _ensurePart, _ensurePart.checkConnectToken
         .checkForUnmarkedOverrideOrNew  # have to do this after statements bindImp since using base can add `override`
+        .checkForUnusedParams
         .checkForUnusedVariables
 
     var _didComputeMatchingBaseMember = true
@@ -952 +953 @@
             if not local.isUsed
                 .compiler.warning(local, 'The value of variable "[local.name]" is never used.')
 
+    def checkForUnusedParams
+        if 'abstract' not in .isNames and .statements.count
+            if not .statements[0] inherits PassStmt
+                for param in _params
+                    if not param.isUsed and not param.isOut and not param.isDeclaredAsUnused
+                        .compiler.warning(param, 'The value of parameter "[param.name]" is never used in [.parentBox.name].[.name].')
 
     ## Generics
 

Vars.cobra

@@ -187 +187 @@
         In the future, the type may be inferred for an anon method in the context it is used (a specific delegate or event).
         """
 
+    pro isDeclaredAsUnused from var as bool
+        """
+        Returns true if parameter was declared as unused.
+        """
+
     pro isAnonymousParam from var as bool
 
     pro direction from var as Direction