C#: Add upgrade script.

Author: michaelnebel

csharp/ql/lib/upgrades/e73ca2c93df8aae162f1704edc4817a5cb330529/assignments.ql

@@ -0,0 +1,117 @@
+class Expr extends @expr {
+  string toString() { none() }
+}
+
+class Location extends @location {
+  string toString() { none() }
+}
+
+class ControlFlowElement extends @control_flow_element {
+  string toString() { none() }
+}
+
+class TypeOrRef extends @type_or_ref {
+  string toString() { none() }
+}
+
+class Callable extends @callable {
+  string toString() { none() }
+}
+
+class Accessible extends @accessible {
+  string toString() { none() }
+}
+
+predicate assignmentKind(int kind) {
+  // | 63 = @simple_assign_expr
+  // | 80 = @add_event_expr
+  // | 81 = @remove_event_expr
+  // | 83 = @local_var_decl_expr
+  kind = [63, 80, 81, 83]
+}
+
+predicate compoundAssignmentKind(int kind) {
+  // | 64 = @assign_add_expr
+  // | 65 = @assign_sub_expr
+  // | 66 = @assign_mul_expr
+  // | 67 = @assign_div_expr
+  // | 68 = @assign_rem_expr
+  // | 69 = @assign_and_expr
+  // | 70 = @assign_xor_expr
+  // | 71 = @assign_or_expr
+  // | 72 = @assign_lshift_expr
+  // | 73 = @assign_rshift_expr
+  // | 119 = @assign_coalesce_expr
+  // | 134 = @assign_urshift_expr
+  kind = [64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 119, 134]
+}
+
+class CompoundAssignmentExpr extends Expr {
+  CompoundAssignmentExpr() {
+    exists(int kind | compoundAssignmentKind(kind) | expressions(this, kind, _))
+  }
+}
+
+predicate isAssignment(Expr ass) {
+  exists(int kind | assignmentKind(kind) |
+    expressions(ass, kind, _) and
+    // Exclude assignments that are part of a compound assignment. These are handled seperatly.
+    not exists(CompoundAssignmentExpr e | expr_parent(ass, 2, e))
+  )
+}
+
+Expr getOperatorCall(CompoundAssignmentExpr e) {
+  exists(Expr assignment |
+    expr_parent(assignment, 2, e) and
+    expr_parent(result, 0, assignment)
+  )
+}
+
+query predicate new_expressions(Expr e, int kind, TypeOrRef t) {
+  expressions(e, kind, t) and
+  // Remove the unused expanded assignment expressions.
+  not exists(CompoundAssignmentExpr parent, Expr assignment | expr_parent(assignment, 2, parent) |
+    e = assignment or
+    expr_parent(e, 0, assignment) or
+    expr_parent(e, 1, assignment)
+  )
+}
+
+query predicate new_expr_parent(Expr e, int child, ControlFlowElement parent) {
+  if isAssignment(parent)
+  then
+    // Swap children for assignments, local variable declarations and add/remove event.
+    child = 0 and expr_parent(e, 1, parent)
+    or
+    child = 1 and expr_parent(e, 0, parent)
+  else (
+    // Case for compound assignments. The parent child relation is contracted.
+    exists(Expr op | op = getOperatorCall(parent) | expr_parent(e, child, op))
+    or
+    // For other expressions (as long as they are included in the new expressions
+    // table), the parent child relation is unchanged.
+    expr_parent(e, child, parent) and
+    new_expressions(e, _, _) and
+    (not parent instanceof Expr or new_expressions(parent, _, _))
+  )
+}
+
+query predicate new_expr_location(Expr e, Location loc) {
+  expr_location(e, loc) and new_expressions(e, _, _)
+}
+
+query predicate new_expr_call(Expr e, Callable c) {
+  exists(Expr op | op = getOperatorCall(e) | expr_call(op, c))
+  or
+  expr_call(e, c) and not e = getOperatorCall(_)
+}
+
+query predicate new_dynamic_member_name(Expr e, string name) {
+  exists(Expr op | op = getOperatorCall(e) | dynamic_member_name(op, name))
+  or
+  dynamic_member_name(e, name) and not e = getOperatorCall(_)
+}
+
+query predicate new_expr_access(Expr e, Accessible a) {
+  expr_access(e, a) and new_expressions(e, _, _)
+}