gen_esp_err_to_name.py includes files like
components/lwip/include/apps/esp_ping.h as "apps/esp_ping.h" because all
subdirectories of "include" are used. If "components/lwip/include/apps"
is in the path of the compiler instead of "components/lwip/include" then
include "apps/esp_ping.h" will fail. This fix allows to process lines
like:
'// gen_esp_err_to_name.py: some text "esp_ping.h" some text'
in header files for overwriting the include.
Before LwIP was moved into a submodule, sntp and esp_ping were
available as the following includes:
#include "apps/sntp/sntp.h"
#include "esp_ping.h"
This commit makes header files available at the old location, and adds
a deprecation warning for sntp.h.
Closes https://github.com/espressif/esp-idf/issues/2392
suda-morris