Merge pull request github#11834 from michaelnebel/csharp/operators

C# 11: Extractor and library support for Unsigned right shift.

Author: michaelnebel

cpp/ql/lib/semmle/code/cpp/ir/implementation/Opcode.qll

@@ -30,6 +30,7 @@ private newtype TOpcode =
   TNegate() or
   TShiftLeft() or
   TShiftRight() or
+  TUnsignedShiftRight() or
   TBitAnd() or
   TBitOr() or
   TBitXor() or
@@ -652,6 +653,15 @@ module Opcode {
     final override string toString() { result = "ShiftRight" }
   }
 
+  /**
+   * The `Opcode` for a `UnsignedShiftRightInstruction`.
+   *
+   * See the `UnsignedShiftRightInstruction` documentation for more details.
+   */
+  class UnsignedShiftRight extends BinaryBitwiseOpcode, TUnsignedShiftRight {
+    final override string toString() { result = "UnsignedShiftRight" }
+  }
+
   /**
    * The `Opcode` for a `BitAndInstruction`.
    *

cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/Instruction.qll

@@ -1204,6 +1204,17 @@ class ShiftRightInstruction extends BinaryBitwiseInstruction {
   ShiftRightInstruction() { this.getOpcode() instanceof Opcode::ShiftRight }
 }
 
+/**
+ * An instruction that shifts its left operand to the right by the number of bits specified by its
+ * right operand.
+ *
+ * Both operands must have an integer type. The result has the same type as the left operand.
+ * The leftmost bits are zero-filled.
+ */
+class UnsignedShiftRightInstruction extends BinaryBitwiseInstruction {
+  UnsignedShiftRightInstruction() { this.getOpcode() instanceof Opcode::UnsignedShiftRight }
+}
+
 /**
  * An instruction that performs a binary arithmetic operation involving at least one pointer
  * operand.

cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/Instruction.qll

@@ -1204,6 +1204,17 @@ class ShiftRightInstruction extends BinaryBitwiseInstruction {
   ShiftRightInstruction() { this.getOpcode() instanceof Opcode::ShiftRight }
 }
 
+/**
+ * An instruction that shifts its left operand to the right by the number of bits specified by its
+ * right operand.
+ *
+ * Both operands must have an integer type. The result has the same type as the left operand.
+ * The leftmost bits are zero-filled.
+ */
+class UnsignedShiftRightInstruction extends BinaryBitwiseInstruction {
+  UnsignedShiftRightInstruction() { this.getOpcode() instanceof Opcode::UnsignedShiftRight }
+}
+
 /**
  * An instruction that performs a binary arithmetic operation involving at least one pointer
  * operand.

cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/Instruction.qll

@@ -1204,6 +1204,17 @@ class ShiftRightInstruction extends BinaryBitwiseInstruction {
   ShiftRightInstruction() { this.getOpcode() instanceof Opcode::ShiftRight }
 }
 
+/**
+ * An instruction that shifts its left operand to the right by the number of bits specified by its
+ * right operand.
+ *
+ * Both operands must have an integer type. The result has the same type as the left operand.
+ * The leftmost bits are zero-filled.
+ */
+class UnsignedShiftRightInstruction extends BinaryBitwiseInstruction {
+  UnsignedShiftRightInstruction() { this.getOpcode() instanceof Opcode::UnsignedShiftRight }
+}
+
 /**
  * An instruction that performs a binary arithmetic operation involving at least one pointer
  * operand.

csharp/downgrades/d0fba103f7dee477dd7d9f6c038518b3f683b2c7/expressions.ql

@@ -0,0 +1,13 @@
+class Expression extends @expr {
+  string toString() { none() }
+}
+
+class TypeOrRef extends @type_or_ref {
+  string toString() { none() }
+}
+
+from Expression e, int k, int kind, TypeOrRef t
+where
+  expressions(e, k, t) and
+  if k = [133, 134] then kind = 106 else kind = k
+select e, kind, t