Rust: tweak/define more toString implementations

Author: Paolo Tranquilli

rust/ql/.generated.list

@@ -20,6 +20,12 @@ module Impl {
    * ```
    */
   class MethodCallExpr extends Generated::MethodCallExpr {
-    override string toString() { result = "... ." + this.getNameRef().toString() + "(...)" }
+    override string toString() {
+      exists(string base, string separator |
+        base = this.getReceiver().toAbbreviatedString() and
+        (if base = "..." then separator = " ." else separator = ".") and
+        result = base + separator + this.getNameRef().toString() + "(...)"
+      )
+    }
   }
 }

rust/ql/.gitattributes

@@ -1,4 +1,3 @@
-// generated by codegen, remove this comment if you wish to edit this file
 /**
  * This module provides a hand-modifiable wrapper around the generated class `Struct`.
  *
@@ -12,11 +11,14 @@ private import codeql.rust.elements.internal.generated.Struct
  * be referenced directly.
  */
 module Impl {
+  // the following QLdoc is generated: if you need to edit it, do it in the schema file
   /**
    * A Struct. For example:
    * ```rust
    * todo!()
    * ```
    */
-  class Struct extends Generated::Struct { }
+  class Struct extends Generated::Struct {
+    override string toString() { result = "struct " + this.getName().getText() }
+  }
 }

rust/ql/lib/codeql/rust/elements/internal/MethodCallExprImpl.qll

@@ -1,4 +1,3 @@
-// generated by codegen, remove this comment if you wish to edit this file
 /**
  * This module provides a hand-modifiable wrapper around the generated class `Variant`.
  *
@@ -12,11 +11,14 @@ private import codeql.rust.elements.internal.generated.Variant
  * be referenced directly.
  */
 module Impl {
+  // the following QLdoc is generated: if you need to edit it, do it in the schema file
   /**
    * A Variant. For example:
    * ```rust
    * todo!()
    * ```
    */
-  class Variant extends Generated::Variant { }
+  class Variant extends Generated::Variant {
+    override string toString() { result = this.getName().getText() }
+  }
 }