apps: Include the headers that are used.

[casaroli]

Summary

Some apps files use declarations from stdlib.h, unistd.h, pthread.h and other headers without including them. They got the declarations only because NuttX's stdio.h included nuttx/lib/lib.h, and through it stdlib.h, nuttx/sched.h and more. apache/nuttx#20565 stops this.

• stdlib.h: adjtime, ads7046, audio_rttl, baromonitor, bmp280, hx711, netpkt_ethercat, nimble_blecent (main, peer), nimble_bleprph (main, gatt_svr), shv-test, stepper, tmp112, dhcpd, netlib_iptables, netlib_ip6tables, adcscope, iptables, ip6tables, nxdiag, sensorscope, nxboot boot.c, nand_sim, pcitest, cachetest, ymodem rb_main.c and sb_main.c.
• unistd.h: nxboot boot.c and flash.c, fbcon, netpkt_ethercat, nimble_blecent, nimble_bleprph, shv-test, stepper, watched, lapi_other, ofloader, nand_sim, ser, setest, drivertest_block, drivertest_i2c_spi, drivertest_relay, epoll, fdsantest_simple, memfd_test, i8sak_acceptassoc, passwd_delete, plcatool. NXDoom: in i_timer.h, which every NXDoom file that calls usleep() includes.
• pthread.h: camera_bkgd, mqttc_pub, nxterm, pty_test, pwfb_events, pwlines_events, ofloader, epoll, memfd_test, ostest sched_thread_local.c, i8sak.h.
• sched.h: ble_main, calib_udelay, drivertest_pm_smp. nuttx/atomic.h: the atomic test. nuttx/kmalloc.h: nand_sim, drivertest_block.
• testing/cmocka: the downloaded cmocka.c uses ftruncate(). cmocka_platform.h, which cmocka.c includes, now includes unistd.h.
• system/zlib: the downloaded gzlib.c, gzread.c and gzwrite.c use lseek(), read() and write(). After the download, the Make and CMake builds now make zconf.h include unistd.h, as zlib's configure does on Unix (#ifdef HAVE_UNISTD_H becomes #if 1), so zlib and the programs that include zlib.h agree on z_off_t.

The first commit fixes the old nxstyle and codespell errors in the changed files, because CI checks each changed file as a whole. Only the layout changes, plus four spelling fixes and one .codespell-ignore-lines entry (the path testing/drivers/ser/ser.c).

Impact

None on master. Needed by apache/nuttx#20565.

Testing

To find every file, each of the 1753 apps C files was compiled with -fsyntax-only -Werror=implicit-function-declaration, once against nuttx master and once against apache/nuttx#20565, for qemu-armv8a:nsh, qemu-armv8a:knsh, sim:citest and sim:ostest. The errors that only #20565 gives are all fixed. Files that include headers of downloaded packages (lvgl, nimble, cmocka and others) were checked again with empty stand-ins for the missing headers and the real include directories of the apps tree. What remains is config dependent (for example apb_alloc() without CONFIG_AUDIO), and in a kernel build, programs that call kernel functions (register_driver(), open_blockdriver(), task_create()), which cannot run there anyway.

Not changed: examples/sensor_fusion/sensor_fusion_main.c (EXIT_SUCCESS) and crypto/openssl_mbedtls_wrapper/mbedtls/bio_lib.c (free()) need stdlib.h too, but nxstyle rejects their mixed-case library names (Fusion, OpenSSL), so CI would fail on any change to them. No configuration in the tree builds them. examples/nanoxterm is not changed either: its errors show only with the stand-ins for the Nano-X headers, which were not available for the check.

Earlier checks, with apache/nuttx#20565, Make, -Werror, on macOS: esp32c6-devkitc:oa_tc6, stm32f746g-disco:dropbear and linum-stm32h753bi:zbus failed before and build after. qemu-armv7a:full (with make -k) compiles the zlib and ymodem files without errors; its remaining errors are in libcxx and mbedtls, as on master. qemu-armv8a:nsh with CONFIG_LIB_ZLIB builds with Make and with CMake.

tools/checkpatch.sh -c -u -m -g passes.

[cederom]

Thank you @casaroli :-)