Rust: Add source models for io.

rust/ql/lib/codeql/rust/Concepts.qll

@@ -128,6 +128,32 @@ module FileSource {
   }
 }
 
+/**
+ * A data flow source corresponding to standard input.
+ */
+final class StdInSource = StdInSource::Range;
+
+/**
+ * An externally modeled source for data from standard input.
+ */
+class ModeledStdInSourceSource extends StdInSource::Range {
+  ModeledStdInSourceSource() { sourceNode(this, "stdin") }
+}
+
+/**
+ * Provides a class for modeling new sources for standard input.
+ */
+module StdInSource {
+  /**
+   * A data flow source corresponding to standard input.
+   */
+  abstract class Range extends ThreatModelSource::Range {
+    override string getThreatModel() { result = "stdin" }
+
+    override string getSourceType() { result = "StdInSource" }
+  }
+}
+
 /**
  * A data flow source corresponding to the program's database reads.
  */

rust/ql/lib/codeql/rust/frameworks/stdlib/io.model.yml

@@ -0,0 +1,6 @@
+extensions:
+  - addsTo:
+      pack: codeql/rust-all
+      extensible: sourceModel
+    data:
+      - ["lang:std", "crate::io::stdio::stdin", "ReturnValue", "stdin", "manual"]