From c67122b3f1bcb695f5fbf1da03cf8043193ff099 Mon Sep 17 00:00:00 2001
From: Simon Friis Vindum <simonfv@gmail.com>
Date: Mon, 23 Mar 2026 12:14:11 +0100
Subject: [PATCH] C++: Add expressions with type data to
 cpp/extraction-information

---
 cpp/ql/src/Telemetry/DatabaseQuality.qll     | 27 +++++++++++++++++++-
 cpp/ql/src/Telemetry/ExtractorInformation.ql |  5 +++-
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/cpp/ql/src/Telemetry/DatabaseQuality.qll b/cpp/ql/src/Telemetry/DatabaseQuality.qll
index 003b7dc01d19..be44a9431aab 100644
--- a/cpp/ql/src/Telemetry/DatabaseQuality.qll
+++ b/cpp/ql/src/Telemetry/DatabaseQuality.qll
@@ -1,9 +1,14 @@
 import cpp
 import codeql.util.ReportStats
 
+/** A file that is included in the quality statistics. */
+private class RelevantFile extends File {
+  RelevantFile() { this.fromSource() and exists(this.getRelativePath()) }
+}
+
 module CallTargetStats implements StatsSig {
   private class RelevantCall extends Call {
-    RelevantCall() { this.getFile() = any(File f | f.fromSource() and exists(f.getRelativePath())) }
+    RelevantCall() { this.getFile() instanceof RelevantFile }
   }
 
   // We assume that calls with an implicit target are calls that could not be
@@ -22,4 +27,24 @@ module CallTargetStats implements StatsSig {
   string getNotOkText() { result = "calls with missing call target" }
 }
 
+private class SourceExpr extends Expr {
+  SourceExpr() { this.getFile() instanceof RelevantFile }
+}
+
+predicate find(SourceExpr e) { not hasGoodType(e) }
+
+private predicate hasGoodType(Expr e) { not e.getType() instanceof ErroneousType }
+
+module ExprTypeStats implements StatsSig {
+  int getNumberOfOk() { result = count(SourceExpr e | hasGoodType(e)) }
+
+  int getNumberOfNotOk() { result = count(SourceExpr e | not hasGoodType(e)) }
+
+  string getOkText() { result = "expressions with known type" }
+
+  string getNotOkText() { result = "expressions with unknown type" }
+}
+
 module CallTargetStatsReport = ReportStats<CallTargetStats>;
+
+module ExprTypeStatsReport = ReportStats<ExprTypeStats>;
diff --git a/cpp/ql/src/Telemetry/ExtractorInformation.ql b/cpp/ql/src/Telemetry/ExtractorInformation.ql
index 6e134ccd05f7..a82b3b86acee 100644
--- a/cpp/ql/src/Telemetry/ExtractorInformation.ql
+++ b/cpp/ql/src/Telemetry/ExtractorInformation.ql
@@ -14,7 +14,10 @@ where
   (
     CallTargetStatsReport::numberOfOk(key, value) or
     CallTargetStatsReport::numberOfNotOk(key, value) or
-    CallTargetStatsReport::percentageOfOk(key, value)
+    CallTargetStatsReport::percentageOfOk(key, value) or
+    ExprTypeStatsReport::numberOfOk(key, value) or
+    ExprTypeStatsReport::numberOfNotOk(key, value) or
+    ExprTypeStatsReport::percentageOfOk(key, value)
   ) and
   /* Infinity */
   value != 1.0 / 0.0 and