WI #1991 Check reference modifiers

TypeCobol.Test/Parser/CodeElements/SEARCH.cbl

@@ -5,8 +5,8 @@ SEARCH x VARYING y
 SEARCH ALL x VARYING y
 * ERROR p409: identifier-1 must not be subscripted or reference-modified.
 SEARCH identifier1 (ALL)
-SEARCH identifier1 (0:1)
-SEARCH identifier1 (ALL)(0:1)
+SEARCH identifier1 (1:1)
+SEARCH identifier1 (ALL)(1:1)
 * explicit scope
 SEARCH ALL someIdentifier
   AT END

TypeCobol.Test/Parser/Programs/Cobol85/ReferenceModifiers.rdz.cbl

@@ -0,0 +1,64 @@
+       IDENTIFICATION DIVISION.
+       PROGRAM-ID. Pgm.
+       DATA DIVISION.
+       WORKING-STORAGE SECTION.
+       01 item   PIC X(20).
+       01 part   PIC X(20).
+       01 var0   PIC 9 VALUE 0.
+       01 var1   PIC 9 VALUE 1.
+
+       PROCEDURE DIVISION.
+      * OK this is a shorthand
+           MOVE item(2:) TO part
+      * KO zero position
+           MOVE item(0:) TO part
+      * KO negative position
+           MOVE item(-1:) TO part
+      * KO by a previous step
+           MOVE item(:2) TO part
+
+      * KO zero position
+           MOVE item(0:5) TO part
+      * KO zero length
+           MOVE item(1:0) TO part
+      * KO*2 zero values
+           MOVE item(0:0) TO part
+      * KO negative position
+           MOVE item(-1:5) TO part
+      * KO negative length
+           MOVE item(1:-5) TO part
+      * KO*2 negative values
+           MOVE item(-1:-5) TO part
+      * OK
+           MOVE item(1.32:5) TO part
+      * OK
+           MOVE item(1:5.84) TO part
+      * OK
+           MOVE item(1.32:5.84) TO part
+      * KO zero position
+           MOVE item(0.0:5) TO part
+      * KO zero length
+           MOVE item(1:0.0) TO part
+      * KO*2 zero values
+           MOVE item(0.0:0.0) TO part
+      * KO negative position
+           MOVE item(-1.32:5) TO part
+      * KO negative length
+           MOVE item(1:-5.84) TO part
+      * KO*2 negative values
+           MOVE item(-1.32:-5.84) TO part
+
+      * OK Variables are not checked
+           MOVE item(var0:) TO part
+           MOVE item(var1:) TO part
+           MOVE item(2:var0) TO part
+           MOVE item(2:var1) TO part
+
+      * OK Expressions are not checked
+           MOVE item(2 * 3  : 4     ) TO part
+           MOVE item(2      : 4 * 2 ) TO part
+           MOVE item(2 * 2  : 4 * 2 ) TO part
+           MOVE item(-2 + 1 : 2     ) TO part
+           MOVE item(2      : 4 * -2) TO part
+           .
+       END PROGRAM Pgm.

TypeCobol.Test/Parser/Programs/Cobol85/ReferenceModifiers.rdzMix.txt

@@ -0,0 +1,83 @@
+       IDENTIFICATION DIVISION.
+       PROGRAM-ID. Pgm.
+       DATA DIVISION.
+       WORKING-STORAGE SECTION.
+       01 item   PIC X(20).
+       01 part   PIC X(20).
+       01 var0   PIC 9 VALUE 0.
+       01 var1   PIC 9 VALUE 1.
+
+       PROCEDURE DIVISION.
+      * OK this is a shorthand
+           MOVE item(2:) TO part
+      * KO zero position
+Line 14[22,22] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(0:) TO part
+      * KO negative position
+Line 16[22,23] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(-1:) TO part
+      * KO by a previous step
+Line 18[21,21] <27, Error, Syntax> - Syntax error : mismatched input '(' expecting TO
+           MOVE item(:2) TO part
+
+      * KO zero position
+Line 21[22,22] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(0:5) TO part
+      * KO zero length
+Line 23[22,22] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(1:0) TO part
+      * KO*2 zero values
+Line 25[22,22] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+Line 25[22,22] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(0:0) TO part
+      * KO negative position
+Line 27[22,23] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(-1:5) TO part
+      * KO negative length
+Line 29[22,22] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(1:-5) TO part
+      * KO*2 negative values
+Line 31[22,23] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+Line 31[22,23] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(-1:-5) TO part
+      * OK
+           MOVE item(1.32:5) TO part
+      * OK
+           MOVE item(1:5.84) TO part
+      * OK
+           MOVE item(1.32:5.84) TO part
+      * KO zero position
+Line 39[22,24] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(0.0:5) TO part
+      * KO zero length
+Line 41[22,22] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(1:0.0) TO part
+      * KO*2 zero values
+Line 43[22,24] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+Line 43[22,24] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(0.0:0.0) TO part
+      * KO negative position
+Line 45[22,26] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(-1.32:5) TO part
+      * KO negative length
+Line 47[22,22] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(1:-5.84) TO part
+      * KO*2 negative values
+Line 49[22,26] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+Line 49[22,26] <27, Error, Syntax> - Syntax error : Reference modifiers should be positive non-zero values.
+           MOVE item(-1.32:-5.84) TO part
+
+      * OK Variables are not checked
+           MOVE item(var0:) TO part
+           MOVE item(var1:) TO part
+           MOVE item(2:var0) TO part
+           MOVE item(2:var1) TO part
+
+      * OK Expressions are not checked
+           MOVE item(2 * 3  : 4     ) TO part
+           MOVE item(2      : 4 * 2 ) TO part
+           MOVE item(2 * 2  : 4 * 2 ) TO part
+           MOVE item(-2 + 1 : 2     ) TO part
+           MOVE item(2      : 4 * -2) TO part
+           .
+       END PROGRAM Pgm.

TypeCobol/Compiler/Diagnostics/CodeElementCheckers.cs

@@ -407,6 +407,53 @@ public static void OnCodeElement(StopStatement statement, CodeElementsParser.Sto
         }
     }
 
+    internal static class ReferenceModifierChecker
+    {
+        private static Diagnostic CreateDiagnostic(string message, IParseTree location)
+        {
+            var position = ParseTreeUtils.GetFirstToken(location).Position();
+            return new Diagnostic(MessageCode.SyntaxErrorInParser, position, message);
+        }
+
+        public static void Check(ReferenceModifier referenceModifier, CodeElementsParser.ReferenceModifierContext context)
+        {
+            if (referenceModifier.LeftmostCharacterPosition == null)
+            {
+                context.AttachDiagnostic(CreateDiagnostic("Left-most position of a reference modifier is required.", context));
+            }
+            else
+            {
+                ValidateModifierValue(referenceModifier.LeftmostCharacterPosition);
+            }
+
+            if (referenceModifier.Length != null)
+            {
+                ValidateModifierValue(referenceModifier.Length);
+            }
+
+            void ValidateModifierValue(ArithmeticExpression arithmeticExpression)
+            {
+                switch (arithmeticExpression.NodeType)
+                {
+                    case ExpressionNodeType.ArithmeticOperation:
+                        // Cannot do anything in that case
+                        break;
+                    case ExpressionNodeType.NumericVariable:
+                        var numericVariableOperand = (NumericVariableOperand)arithmeticExpression;
+                        var numericVariable = numericVariableOperand.NumericVariable;
+                        // Only negative literals are erroneous
+                        if (numericVariable?.Value?.Value <= 0)
+                        {
+                            context.AttachDiagnostic(CreateDiagnostic("Reference modifiers should be positive non-zero values.", context));
+                        }
+                        break;
+                    default:
+                        throw new InvalidOperationException("Unexpected expression type: " + arithmeticExpression.NodeType);
+                }
+            }
+        }
+    }
+
     /// <summary>
     /// Create diagnostics for language level restricted elements used in a lower level parsing context
     /// (typically TypeCobol syntax used in Cobol85 code).

TypeCobol/Compiler/Parser/CodeElementBuilder/CobolExpressionsBuilder.cs

@@ -469,7 +469,9 @@ private ReferenceModifier CreateReferenceModifier(CodeElementsParser.ReferenceMo
 			{
 				length = CreateArithmeticExpression(context.length);
 			}
-			return new ReferenceModifier(leftmostCharacterPosition, length);
+			var referenceModifier = new ReferenceModifier(leftmostCharacterPosition, length);
+			ReferenceModifierChecker.Check(referenceModifier, context);
+			return referenceModifier;
 		}
 
 		internal StorageArea CreateIdentifierOrIndexName(CodeElementsParser.IdentifierOrIndexNameContext context)