[Bug analyzer/58237] gcc fails to detect obvious resource leaks

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58237

--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by David Malcolm <dmalc...@gcc.gnu.org>:

https://gcc.gnu.org/g:697251b7a1bb7c14d3805de22248e83a23b90d1a

commit r10-5963-g697251b7a1bb7c14d3805de22248e83a23b90d1a
Author: David Malcolm <dmalc...@redhat.com>
Date:   Thu Dec 19 15:59:04 2019 -0500

    analyzer: add known stdio functions to sm-file.cc (PR analyzer/58237)

    The analyzer ought to report various file leaks for the reproducer in
    PR analyzer/58237, such as:

      void f1(const char *str)
      {
        FILE * fp = fopen(str, "r");
        char buf[10];
        while (fgets(buf, 10, fp) != NULL)
        {
          /* Do something with buf */
        }
        /* Missing call to fclose. Need warning here for resource leak */
      }

    but fails to do so, due to not recognizing fgets, and thus
    conservatively assuming that it could close "fp".

    This patch adds a function_set to sm-file.cc of numerous stdio.h
    functions that are known to not close the file (and which require a
    valid FILE *, but that's a matter for a followup), fixing the issue.

    gcc/analyzer/ChangeLog:
        PR analyzer/58237
        * analyzer-selftests.cc (selftest::run_analyzer_selftests): Call
        selftest::analyzer_sm_file_cc_tests.
        * analyzer-selftests.h (selftest::analyzer_sm_file_cc_tests): New
        decl.
        * sm-file.cc: Include "analyzer/function-set.h" and
        "analyzer/analyzer-selftests.h".
        (get_file_using_fns): New function.
        (is_file_using_fn_p): New function.
        (fileptr_state_machine::on_stmt): Return true for known functions.
        (selftest::analyzer_sm_file_cc_tests): New function.

    gcc/testsuite/ChangeLog:
        PR analyzer/58237
        * gcc.dg/analyzer/file-1.c (test_4): New.
        * gcc.dg/analyzer/file-pr58237.c: New test.