Swift: Add File.getRelativePath and update swift/diagnostics/successfully-extracted-files.

Author: geoffw0

swift/ql/lib/codeql/swift/elements/File.qll

@@ -32,4 +32,23 @@ class File extends Generated::File {
         )
       )
   }
+
+  /**
+   * Gets the relative path of this file from the root folder of the
+   * analyzed source location. The relative path of the root folder itself
+   * would be the empty string.
+   *
+   * This has no result if the file is outside the source root, that is,
+   * if the root folder is not a reflexive, transitive parent of this file.
+   */
+  string getRelativePath() {
+    exists(string absPath, string pref |
+      absPath = this.getAbsolutePath() and sourceLocationPrefix(pref)
+    |
+      absPath = pref and result = ""
+      or
+      absPath = pref.regexpReplaceAll("/$", "") + "/" + result and
+      not result.matches("/%")
+    )
+  }
 }

swift/ql/src/diagnostics/SuccessfullyExtractedFiles.ql

@@ -1,6 +1,6 @@
 /**
- * @name Successfully extracted files
- * @description Lists all files in the source code directory that were extracted without encountering a problem in the file.
+ * @name Extracted files
+ * @description Lists all files in the source code directory that were extracted.
  * @kind diagnostic
  * @id swift/diagnostics/successfully-extracted-files
  * @tags successfully-extracted-files
@@ -9,5 +9,5 @@
 import swift
 
 from File f
-where f.isSuccessfullyExtracted()
+where exists(f.getRelativePath())
 select f, "File successfully extracted."

swift/ql/test/query-tests/Diagnostics/SuccessfullyExtractedFiles.expected

@@ -1 +1,2 @@
+| error.swift:0:0:0:0 | error.swift | File successfully extracted. |
 | main.swift:0:0:0:0 | main.swift | File successfully extracted. |