gcc/doc/libgdiagnostics/tutorial/05-warnings.rst

.. Copyright (C) 2024-2025 Free Software Foundation, Inc.
   Originally contributed by David Malcolm <dmalcolm@redhat.com>

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.. default-domain:: c

Tutorial part 5: warnings
=========================

So far we've only emitted errors, but other kinds of diagnostic are possible,
such as warnings.

We can select different kinds of diagnostic via :enum:`diagnostic_level`
when calling :func:`diagnostic_begin`:

.. literalinclude:: ../../../testsuite/libgdiagnostics.dg/test-warning.c
   :language: c
   :start-after: /* begin quoted source */
   :end-before:  /* end quoted source */

On compiling and running the program, we should get output similar to::

   test-warning.c:17:11: warning: this is a warning
   17 | #include <foo.h>
      |           ^~~~~

Various severities are possible, see  :enum:`diagnostic_level` for more
information.

In :doc:`the next section of the tutorial <06-fix-it-hints>` we'll look
at adding fix-it hints to diagnostics.