Revert "Merge pull request #4653 from tamasvajk/feature/csharp9-relational-pattern"

This reverts commit 5e75a41, reversing
changes made to c751c51.

Author: tamasvajk

csharp/change-notes/2020-11-19-Relational-pattern.md

@@ -42,9 +42,6 @@ internal static Expression Create(Context cx, PatternSyntax syntax, IExpressionP
                 case RecursivePatternSyntax recPattern:
                     return new RecursivePattern(cx, recPattern, parent, child);
 
-                case RelationalPatternSyntax relPattern:
-                    return new RelationalPattern(cx, relPattern, parent, child);
-
                 case VarPatternSyntax varPattern:
                     switch (varPattern.Designation)
                     {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Patterns/Pattern.cs

@@ -15,6 +15,7 @@ internal class RecursivePattern : Expression
         /// <param name="syntax">The syntax node of the recursive pattern.</param>
         /// <param name="parent">The parent pattern/expression.</param>
         /// <param name="child">The child index of this pattern.</param>
+        /// <param name="isTopLevel">If this pattern is in the top level of a case/is. In that case, the variable and type access are populated elsewhere.</param>
         public RecursivePattern(Context cx, RecursivePatternSyntax syntax, IExpressionParentEntity parent, int child) :
             base(new ExpressionInfo(cx, Entities.NullType.Create(cx), cx.Create(syntax.GetLocation()), ExprKind.RECURSIVE_PATTERN, parent, child, false, null))
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Patterns/RecursivePattern.cs

@@ -115,10 +115,6 @@ public enum ExprKind
         SWITCH_CASE = 118,
         ASSIGN_COALESCE = 119,
         SUPPRESS_NULLABLE_WARNING = 120,
-        NAMESPACE_ACCESS = 121,
-        LT_PATTERN = 122,
-        GT_PATTERN = 123,
-        LE_PATTERN = 124,
-        GE_PATTERN = 125,
+        NAMESPACE_ACCESS = 121
     }
 }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Patterns/RelationalPattern.cs

@@ -342,45 +342,6 @@ class ConstantPatternExpr extends PatternExpr {
   override string getAPrimaryQlClass() { result = "ConstantPatternExpr" }
 }
 
-/** A relational pattern, for example `>1` in `x is >1`. */
-class RelationalPatternExpr extends PatternExpr, @relational_pattern_expr {
-  /** Gets the name of the operator in this pattern. */
-  string getOperator() { none() }
-
-  /** Gets the expression of this relational pattern. */
-  Expr getExpr() { result = this.getChild(0) }
-
-  override string toString() { result = getOperator() + " ..." }
-}
-
-/** A less-than pattern, for example `< 10` in `x is < 10`. */
-class LTPattern extends RelationalPatternExpr, @lt_pattern_expr {
-  override string getOperator() { result = "<" }
-
-  override string getAPrimaryQlClass() { result = "LTPattern" }
-}
-
-/** A greater-than pattern, for example `> 10` in `x is > 10`. */
-class GTPattern extends RelationalPatternExpr, @gt_pattern_expr {
-  override string getOperator() { result = ">" }
-
-  override string getAPrimaryQlClass() { result = "GTPattern" }
-}
-
-/** A less-than or equals pattern, for example `<= 10` in `x is <= 10`. */
-class LEPattern extends RelationalPatternExpr, @le_pattern_expr {
-  override string getOperator() { result = "<=" }
-
-  override string getAPrimaryQlClass() { result = "LEPattern" }
-}
-
-/** A greater-than or equals pattern, for example `>= 10` in `x is >= 10` */
-class GEPattern extends RelationalPatternExpr, @ge_pattern_expr {
-  override string getOperator() { result = ">=" }
-
-  override string getAPrimaryQlClass() { result = "GEPattern" }
-}
-
 /**
  * A type pattern, for example `string` in `x is string`, `string s` in
  * `x is string s`, or `string _` in `x is string _`.

csharp/extractor/Semmle.Extraction.CSharp/Kinds/ExprKind.cs

@@ -998,17 +998,11 @@ case @expr.kind of
 | 119 = @assign_coalesce_expr
 | 120 = @suppress_nullable_warning_expr
 | 121 = @namespace_access_expr
-/* C# 9.0 */
-| 122 = @lt_pattern_expr
-| 123 = @gt_pattern_expr
-| 124 = @le_pattern_expr
-| 125 = @ge_pattern_expr
 ;
 
 @switch = @switch_stmt | @switch_expr;
 @case = @case_stmt | @switch_case_expr;
 @pattern_match = @case | @is_expr;
-@relational_pattern_expr = @gt_pattern_expr | @lt_pattern_expr | @ge_pattern_expr | @le_pattern_expr;
 
 @integer_literal_expr = @int_literal_expr | @long_literal_expr | @uint_literal_expr | @ulong_literal_expr;
 @real_literal_expr = @float_literal_expr | @double_literal_expr | @decimal_literal_expr;

csharp/ql/src/semmle/code/csharp/exprs/Expr.qll

@@ -335,63 +335,6 @@ ParenthesizedPattern.cs:
 #   27|               0: [TypeAccessPatternExpr] access to type String
 #   27|                 0: [TypeMention] string
 #   27|               2: [IntLiteral] 5
-RelationalPattern.cs:
-#    3| [Class] RelationalPattern
-#    5|   5: [Method] M1
-#    5|     -1: [TypeMention] bool
-#-----|     2: (Parameters)
-#    5|       0: [Parameter] c
-#    5|         -1: [TypeMention] char
-#    6|     4: [IsExpr] ... is ...
-#    6|       0: [ParameterAccess] access to parameter c
-#    6|       1: [GEPattern] >= ...
-#    6|         0: [CharLiteral] a
-#    7|   6: [Method] M2
-#    7|     -1: [TypeMention] bool
-#-----|     2: (Parameters)
-#    7|       0: [Parameter] c
-#    7|         -1: [TypeMention] char
-#    8|     4: [IsExpr] ... is ...
-#    8|       0: [ParameterAccess] access to parameter c
-#    8|       1: [GTPattern] > ...
-#    8|         0: [CharLiteral] a
-#    9|   7: [Method] M3
-#    9|     -1: [TypeMention] bool
-#-----|     2: (Parameters)
-#    9|       0: [Parameter] c
-#    9|         -1: [TypeMention] char
-#   10|     4: [IsExpr] ... is ...
-#   10|       0: [ParameterAccess] access to parameter c
-#   10|       1: [LEPattern] <= ...
-#   10|         0: [CharLiteral] a
-#   11|   8: [Method] M4
-#   11|     -1: [TypeMention] bool
-#-----|     2: (Parameters)
-#   11|       0: [Parameter] c
-#   11|         -1: [TypeMention] char
-#   12|     4: [IsExpr] ... is ...
-#   12|       0: [ParameterAccess] access to parameter c
-#   12|       1: [LTPattern] < ...
-#   12|         0: [CharLiteral] a
-#   14|   9: [Method] M5
-#   14|     -1: [TypeMention] string
-#-----|     2: (Parameters)
-#   14|       0: [Parameter] i
-#   14|         -1: [TypeMention] int
-#   15|     4: [BlockStmt] {...}
-#   16|       0: [ReturnStmt] return ...;
-#   16|         0: [SwitchExpr] ... switch { ... }
-#   16|           -1: [ParameterAccess] access to parameter i
-#   18|           0: [SwitchCaseExpr] ... => ...
-#   18|             0: [ConstantPatternExpr,IntLiteral] 1
-#   18|             2: [StringLiteral] "1"
-#   19|           1: [SwitchCaseExpr] ... => ...
-#   19|             0: [GTPattern] > ...
-#   19|               0: [IntLiteral] 1
-#   19|             2: [StringLiteral] ">1"
-#   20|           2: [SwitchCaseExpr] ... => ...
-#   20|             0: [DiscardPatternExpr] _
-#   20|             2: [StringLiteral] "other"
 TargetType.cs:
 #    5| [Class] TargetType
 #    7|   5: [Method] M2