MAX_PATH (or PATH_MAX) assumed to be ~255

[Jeffrey Walton]

Hi Everyone,

This caught my eye when running an analyzer build. For the analyzer
you can use Fedora 32 with GCC 10. Just add -fanalyzer to CFLAGS and
LDFLAGS.

call.c: In function ‘cob_resolve_internal.part.0’:
call.c:861:21: warning: ‘%s’ directive output may be truncated writing
up to 255 bytes into a region of size 242 [-Wformat-truncation=]
  861 |       "entry point '%s' not found", (const char *)s);
      |                     ^~
call.c:860:4: note: ‘snprintf’ output between 25 and 280 bytes into a
destination of size 255
  860 |    snprintf (resolve_error_buff, (size_t)CALL_BUFF_MAX,
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  861 |       "entry point '%s' not found", (const char *)s);
      |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
call.c:832:20: warning: ‘%s’ directive output may be truncated writing
up to 255 bytes into a region of size 242 [-Wformat-truncation=]
  832 |      "entry point '%s' not found", (const char *)s);
      |                    ^~
call.c:831:3: note: ‘snprintf’ output between 25 and 280 bytes into a
destination of size 255
  831 |   snprintf (resolve_error_buff, (size_t)CALL_BUFF_MAX,
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  832 |      "entry point '%s' not found", (const char *)s);
      |      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I'm guessing "destination of size 255" comes from MAX_PATH or
PATH_MAX. That likely will not hold on Solaris or OS X. I believe
MAX_PATH is 4096 those OSes.

And here's another from the analyzer:

intrinsic.c:6386:3: warning: ‘strncpy’ output may be truncated copying
25 bytes from a string of length 36 [-Wstringop-truncation]
 6386 |   strncpy (time_format_str, datetime_format_str, COB_TIMESTR_MAX);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
intrinsic.c:6384:3: warning: ‘strncpy’ output may be truncated copying
10 bytes from a string of length 36 [-Wstringop-truncation]
 6384 |   strncpy (date_format_str, datetime_format_str, COB_DATESTR_MAX);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
intrinsic.c:6392:3: warning: ‘strncpy’ output may be truncated copying
10 bytes from a string of length 36 [-Wstringop-truncation]
 6392 |   strncpy (formatted_date, formatted_datetime, COB_DATESTR_MAX);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Jeff