.. envvar:: COM_SPEED

   Default baud rate for serial port.

   This will recompile your application to use the revised baud rate.
   Note that this will change the default speed used for both flashing and serial comms.
   See also :component:`esptool` and :component:`terminal` for further details.

make COM_SPEED=921600

.. envvar:: DEBUG_VERBOSE_LEVEL

   When compiled in debug mode (:envvar:SMING_RELEASE undefined) there are four debug levels in increasing level of verbosity:

   * 0: errors
   * 1: warnings
   * 2: information (default)
   * 3: debug

make DEBUG_VERBOSE_LEVEL=3

.. envvar:: DEBUG_PRINT_FILENAME_AND_LINE

   Set this to 1 to include the filename and line number in every line of debug output.
   This will require extra space on flash.

.. envvar:: STRICT

   * default: undefined (standard warnings, treat as errors)
   * 1: Enable all warnings but do not treat as errors

   By default, Sming builds code with a few warnings disabled:

   - sign-compare: Comparison between signed and unsigned values could produce an incorrect result when the signed value is converted to unsigned.
   - parentheses: Parentheses are omitted in certain contexts.
   - unused-variable: A local or static variable is unused aside from its declaration.
   - unused-but-set-variable: A local variable is assigned to, but otherwise unused.
   - strict-aliasing: Casts which can violate alignment rules.

   These can be indicative of problematic code rather than errors.
   Because new compiler releases can increase the level of checking, this set may also need to change
   but it is kept minimal. See ``Sming/build.mk`` for the actual settings.
   See https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html for further details
   about all compiler settings.
   See also :doc:`/information/develop/clang-tools`.

   Any remaining warnings will be treated as errors and compilation will be halted.

   It is a good idea to check your codebase with ``STRICT=1`` which enables **all** warnings,
   plus a few additional ones such as ``unused-parameter``.

   When enabled, warnings are not treated as errors.

.. envvar:: ENABLE_GDB

   undefined (default)
      Compile normally
   1
      Compile with debugging support.

      In order to be able to debug live directly on the microcontroller you
      should re-compile your application with this setting enabled (set to 1).

      This setting reduces optimisation levels and ensures full symbolic debugging information is available.
      However, because this affects the code produced it can mask some types of bug which only present in regular or release builds.
      For this reason, when :envvar:`ENABLE_GDB` is changed only the application is recompiled automatically
      to ensure that the necessary GDB stub code is linked to enable communication with the debugger.

      If you need to debug only a specific Component, rebuild **just** that component like this::

         make ssl-clean
         make ENABLE_GDB=1

      The application code and ``ssl`` Component will now have debugging information, but everything else will remain unchanged.
      To rebuild the entire framework::

         make clean components-clean
         make ENABLE_GDB=1

      Note also that gdb can always be used to examine the source disassembly without requiring connection
      to an actual device.

.. envvar:: ENABLE_CCACHE

   Default: 0 (disabled)

   Set to 1 to run (most) compilation through `ccache <https://ccache.dev/>`__.
   This speeds up re-compilation of code considerably at the expense of disk space
   and slightly extended initial compilation.

   This setting was introduced mainly for CI builds as relatively little changes between runs.

.. envvar:: ENABLE_SANITIZERS

   default: 0 (off)

   Enable this option to build with lots of runtime checking.

   This provides some of the capabilities of valgrind but by instrumenting
   the code when it is compiled, rather than patching at runtime.

   It also links in some additional runtime support libraries.

   Run a full rebuild after changing this setting (or :envvar:`SANITIZERS`)::

       make clean components-clean
       make

   .. note::

      Applications cannot link when this setting is enabled as sanitizer runtime libraries
      are not currently available for embedded toolchains.

      With Host builds using :envvar:`CLANG_BUILD`, all runtime libraries should already be available.
      For GCC you will also need to install ``libasan`` and ``libubsan``.

.. envvar:: SANITIZERS

   Selects which sanitizers are used. See :envvar:`ENABLE_SANITIZERS`.

.. envvar:: SMING_RELEASE

   By default, this value is undefined to produce a build with debug output.
   To build for release, do this::

      make SMING_RELEASE=1

   This remains in force until you change it back::

      make SMING_RELEASE=

.. envvar:: LOCALE

   Sming can format dates/time values based on a country code identified by this value.
   This is provided as a #define symbol for your application to use.
   See :source:`Sming/Core/SmingLocale.h` for further details.

.. envvar:: DISABLE_NETWORK

   0 (Default)
   1 - Remove core networking support

   Applications which do not require networking can set this flag to avoid building
   or linking the core :component:`Network` library.

   This will reduce build times, application size and RAM usage.
   Builds will not succeeded if network code has been inadvertently included.

.. envvar:: DISABLE_WIFI

   .. note::

      EXPERIMENTAL

   0 (Default)
   1 - Exclude WiFi initialisation code

   Keeps the core :component:`Network` library but excludes WiFi code.
   Applications using ethernet can use this to reduce code size. See :sample:`Basic_Ethernet`.