turn on -w flag, the waring output is as follows
Warning: cannot stat 'abs'. ignored.
Warning: cannot stat 'lib32_debug'. ignored.
Warning: cannot stat 'lib32_release'. ignored.
Warning: cannot stat 'lib64_debug'. ignored.
Warning: cannot stat 'lib64'. ignored.
Warning: cannot stat 'lib64_release'. ignored.
Warning: different level before and after #define macro. reseted.
Warning: '{' doesn't exist after 'operator'.
Warning: failed to parse template
Warning: missing left '{'
Warning: missing left '{' (at 33).
Warning: missing left '{' (at 452).
Warning: missing left '{' (at 468).
Warning: missing left '{' (at 666).
Warning: missing left '{' (at 843).
Warning: missing namespace block.
Warning: Out of function. break
Warning: Out of function. case
Warning: Out of function. catch
Warning: Out of function. continue
Warning: Out of function. default
Warning: Out of function. delete
Warning: Out of function. do
Warning: Out of function. else
Warning: Out of function. for
Warning: Out of function. if
Warning: Out of function. return
Warning: Out of function. try
Warning: Out of function. while
Warning: template <...> isn't closed.
Warning: uneven level.
Warning: unexpected eof.
Warning: unmatched {} block. (last at level -1.)
Warning: unmatched {} block. (last at level 1.)
Warning: unmatched {} block. (last at level 16.)
Warning: unmatched {} block. (last at level 2.)
Warning: unmatched {} block. (last at level 3.)
Warning: unmatched {} block. (last at level 4.)
Warning: unmatched {} block. (last at level 5.)
Warning: unmatched #if block. (last at level 1.)
Warning: unmatched #if block. (last at level 2.)
Warning: unmatched #if block. (last at level 6.)
Warning: unmatched #if block. reseted.