CPP: Performance is better as a single regexp.

Author: geoffw0

cpp/ql/src/semmle/code/cpp/AutogeneratedFile.qll

@@ -9,24 +9,27 @@ import semmle.code.cpp.Preprocessor
 private predicate autogeneratedComment(Comment c) {
   // ?s = include newlines in anything (`.`)
   // ?i = ignore case
+  c.getContents().regexpMatch("(?si).*(" +
 
-  // auto-generated, automatically generated etc.
-  c.getContents().regexpMatch("(?si).*(auto[\\w-]*\\s*?generated).*") or
+    // auto-generated, automatically generated etc.
+    "(auto[\\w-]*\\s*?generated)|" +
 
-  // generated by (not used mid-sentence)
-  c.getContents().regexpMatch("(?si).*[^a-zA-Z\\s\\*\\r\\n][\\s\\*\\r\\n]*(generated by).*")  or
+    // generated by (at beginning of sentence)
+    "([^a-z\\s\\*\\r\\n][\\s\\*\\r\\n]*(generated by)[^a-z])|" +
 
-  // generated file
-  c.getContents().regexpMatch("(?si).*(generated file).*")  or
+    // generated file
+    "(generated file)|" +
 
-  // file [is] generated
-  c.getContents().regexpMatch("(?si).*(file( is)? generated).*")  or
+    // file [is] generated
+    "(file( is)? generated)|" +
 
-  // changes made in this file will be lost
-  c.getContents().regexpMatch("(?si).*(changes made in this file will be lost).*") or
+    // changes made in this file will be lost
+    "(changes made in this file will be lost)|" +
 
-  // do not edit/modify
-  c.getContents().regexpMatch("(?si).*(do(n't|nt| not) (edit|modify)).*")
+    // do not edit/modify
+    "(do(n't|nt| not) (edit|modify))" +
+
+  ").*")
 }
 
 /**