Rust: Cache Element.toString

Author: hvitved

misc/codegen/templates/ql_class.mustache

@@ -29,7 +29,15 @@ module Generated {
     /**
      * Gets the string representation of this element.
      */
-    string toString() { none() } // overridden by subclasses
+    cached
+    final string toString() { result = this.toStringImpl() }
+
+    /**
+     * INTERNAL: Do not use.
+     *
+     * Gets the string representation of this element.
+     */
+    abstract string toStringImpl();
 
     /**
      * Gets the name of a primary CodeQL class to which this element belongs.

rust/ql/.generated.list

@@ -22,6 +22,6 @@ module Impl {
    * ```
    */
   class ArrayListExpr extends Generated::ArrayListExpr {
-    override string toString() { result = "[...]" }
+    override string toStringImpl() { result = "[...]" }
   }
 }

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

@@ -21,7 +21,7 @@ module Impl {
    * ```
    */
   class ArrayRepeatExpr extends Generated::ArrayRepeatExpr {
-    override string toString() {
+    override string toStringImpl() {
       result =
         "[" + this.getRepeatOperand().toAbbreviatedString() + "; " +
           this.getRepeatLength().toAbbreviatedString() + "]"

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

@@ -22,6 +22,6 @@ module Impl {
    * ```
    */
   class AwaitExpr extends Generated::AwaitExpr {
-    override string toString() { result = "await " + this.getExpr().toAbbreviatedString() }
+    override string toStringImpl() { result = "await " + this.getExpr().toAbbreviatedString() }
   }
 }

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

@@ -25,6 +25,6 @@ module Impl {
    * ```
    */
   class BecomeExpr extends Generated::BecomeExpr {
-    override string toString() { result = "become " + this.getExpr().toAbbreviatedString() }
+    override string toStringImpl() { result = "become " + this.getExpr().toAbbreviatedString() }
   }
 }

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

@@ -23,6 +23,6 @@ module Impl {
    * ```
    */
   class BinaryExpr extends Generated::BinaryExpr {
-    override string toString() { result = "... " + this.getOperatorName() + " ..." }
+    override string toStringImpl() { result = "... " + this.getOperatorName() + " ..." }
   }
 }

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

@@ -22,6 +22,6 @@ module Impl {
    * ```
    */
   class BoxPat extends Generated::BoxPat {
-    override string toString() { result = "box " + this.getPat().toAbbreviatedString() }
+    override string toStringImpl() { result = "box " + this.getPat().toAbbreviatedString() }
   }
 }

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

@@ -104,14 +104,14 @@ module Impl {
       )
     }
 
-    override string toString() {
+    override string toStringImpl() {
       result = strictconcat(int i | | this.toStringPart(i), " " order by i)
     }
 
     private string toStringPart(int index) {
       index = 0 and result = "break"
       or
-      index = 1 and result = this.getLifetime().toString()
+      index = 1 and result = this.getLifetime().toStringImpl()
       or
       index = 2 and result = this.getExpr().toAbbreviatedString()
     }

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

@@ -26,7 +26,7 @@ module Impl {
    * ```
    */
   class CallExpr extends Generated::CallExpr {
-    override string toString() { result = this.getFunction().toAbbreviatedString() + "(...)" }
+    override string toStringImpl() { result = this.getFunction().toAbbreviatedString() + "(...)" }
 
     pragma[nomagic]
     private PathResolution::ItemNode getResolvedFunction(int pos) {