CPP: Improve the regexp.

Author: geoffw0

cpp/ql/src/Documentation/CommentedOutCode.qll

@@ -30,7 +30,7 @@ private predicate looksLikeCode(string line) {
         )
       ) or (
         // Match comment lines that look like preprocessor code
-        trimmed.regexpMatch("#(include|define|undef|if|ifdef|ifndef|elif|else|endif|error)(\\s.*|)")
+        trimmed.regexpMatch("#\\s*(include|define|undef|if|ifdef|ifndef|elif|else|endif|error|pragma)\\b.*")
       )
     ) and (
       // Exclude lines that start with '>' or contain '@{' or '@}'.

cpp/ql/test/query-tests/Documentation/CommentedOutCode/CommentedOutCode.expected

@@ -4,6 +4,10 @@
 | test2.cpp:43:1:43:18 | // #define MYMACRO | This comment appears to contain commented-out code |
 | test2.cpp:45:1:45:23 | // #include "include.h" | This comment appears to contain commented-out code |
 | test2.cpp:47:1:51:2 | /*\n#ifdef\nvoid myFunction();\n#endif\n*/ | This comment appears to contain commented-out code |
+| test2.cpp:59:1:59:24 | // #if(defined(MYMACRO)) | This comment appears to contain commented-out code |
+| test2.cpp:63:1:63:15 | // #pragma once | This comment appears to contain commented-out code |
+| test2.cpp:65:1:65:17 | //  # pragma once | This comment appears to contain commented-out code |
+| test2.cpp:67:1:67:19 | /*#error"myerror"*/ | This comment appears to contain commented-out code |
 | test.c:2:1:2:22 | // commented out code; | This comment appears to contain commented-out code |
 | test.c:4:1:7:8 | // some; | This comment appears to contain commented-out code |
 | test.c:9:1:13:8 | // also; | This comment appears to contain commented-out code |