Compile error on FS.h: missing time.h import

[Niek]

See 72dd589#r35810441: that commit breaks compilation for me because a <time.h> include is missing:

xtensa-lx106-elf-g++ -o .pio/build/myenv/libf93/ESP8266WiFi/ESP8266WiFiMulti.cpp.o -c -fno-rtti -std=c++11 -g -w -Os -mlongcalls -mtext-section-literals -falign-functions=4 -U__STRICT_ANSI__ -ffunction-sections -fdata-sections -fno-exceptions -Wall -DPLATFORMIO=40003 -DESP8266 -DARDUINO_ARCH_ESP8266 -DARDUINO_ESP8266_ESP01 -DMQTT_MAX_PACKET_SIZE=1024 -DNO_GLOBAL_EEPROM -DPIO_FRAMEWORK_ARDUINO_LWIP2_LOW_MEMORY_LOW_FLASH -DBEARSSL_SSL_BASIC -DUSE_CUSTOM_H -DSECURE_CLIENT=SECURE_CLIENT_BEARSSL -DF_CPU=80000000L -D__ets__ -DICACHE_FLASH -DARDUINO=10805 -DARDUINO_BOARD=\"PLATFORMIO_ESP01_1M\" -DFLASHMODE_DOUT -DLWIP_OPEN_SRC -DNONOSDK22x_190703=1 -DTCP_MSS=536 -DLWIP_FEATURES=0 -DLWIP_IPV6=0 -DVTABLES_IN_FLASH -I~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/libraries/ESP8266WiFi/src -I.pio/build/myenv/core -I~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/tools/sdk/include -I~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/tools/sdk/libc/xtensa-lx106-elf/include -I~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/cores/esp8266 -I~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/tools/sdk/lwip2/include -I~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/variants/generic ~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/libraries/ESP8266WiFi/src/ESP8266WiFiMulti.cpp
In file included from ~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/libraries/ESP8266WiFi/src/CertStoreBearSSL.h:26:0,
                 from ~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.h:30,
                 from ~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/libraries/ESP8266WiFi/src/WiFiClientSecure.h:41,
                 from ~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/libraries/ESP8266WiFi/src/WiFiServerSecure.h:20,
                 from ~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/libraries/ESP8266WiFi/src/ESP8266WiFi.h:41
~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/cores/esp8266/FS.h: In static member function 'static time_t fs::FS::_defaultTimeCB()':
~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/cores/esp8266/FS.h:244:58: error: 'time' was not declared in this scope
     static time_t _defaultTimeCB(void) { return time(NULL); }
                                                          ^

Simply adding #include <time.h> to FS.h doesn't resolve the issue, seemingly because it includes the wrong header file. Adding #include "~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/tools/sdk/libc/xtensa-lx106-elf/include/time.h" or #include "../../tools/sdk/libc/xtensa-lx106-elf/include/time.h" does work, but that doesn't seem like a good solution. Any ideas?

[d-a-v]

From what I can see, time.h should be included in this directory (copy-paste from your cmdline):

-I~/.platformio/packages/framework-arduinoespressif8266@src-31d658a59f41540201fc3726a1394910/tools/sdk/libc/xtensa-lx106-elf/include

I think this is an issue with the character ~ which is not properly expanded to your home directory.
Can you change all occurrences of ~ with /home/you in your graphical/file configuration ?

[Niek]

Found the issue: Time.h from Arduino Time Library conflicts on case-insensitive filesystems. See also:
#2341
PaulStoffregen/Time#74
me-no-dev/ESPAsyncWebServer#60

Closing this issue as it's a problem with the library.

[d-a-v]

Thanks for the links.
Instead of removing the offending Time.h, can you check if you can replace our #include <time.h> by #include <../include/time.h> and see if it works ?

[Niek]

@d-a-v good one, that works as well. So adding #include <../include/time.h> at the top of FS.h fixes the issue too.

[d-a-v]

Are you willing to make a PR with this ?

edit
There are a number of files:

cores/esp8266/HardwareSerial.h
cores/esp8266/libc_replacements.cpp
cores/esp8266/time.cpp
libraries/ESP8266WiFi/examples/BearSSL_CertStore/BearSSL_CertStore.ino
libraries/ESP8266WiFi/examples/BearSSL_Server/BearSSL_Server.ino
libraries/ESP8266WiFi/examples/BearSSL_ServerClientCert/BearSSL_ServerClientCert.ino
libraries/ESP8266WiFi/examples/BearSSL_Sessions/BearSSL_Sessions.ino
libraries/ESP8266WiFi/examples/BearSSL_Validation/BearSSL_Validation.ino
libraries/ESP8266WiFi/examples/HTTPSRequestCACertAxTLS/HTTPSRequestCACertAxTLS.ino
libraries/ESP8266httpUpdate/examples/httpUpdateSecure/httpUpdateSecure.ino
libraries/ESP8266mDNS/examples/LEAmDNS/mDNS_Clock/mDNS_Clock.ino
libraries/esp8266/examples/NTP-TZ-DST/NTP-TZ-DST.ino
libraries/LittleFS/examples/LittleFS_Timestamp/LittleFS_Timestamp.ino

[devyte]

I don't understand the core issue here, or how the suggested fix addresses it.

[Niek]

Are you willing to make a PR with this ?

edit
There are a number of files:

cores/esp8266/HardwareSerial.h
cores/esp8266/libc_replacements.cpp
cores/esp8266/time.cpp
libraries/ESP8266WiFi/examples/BearSSL_CertStore/BearSSL_CertStore.ino
libraries/ESP8266WiFi/examples/BearSSL_Server/BearSSL_Server.ino
libraries/ESP8266WiFi/examples/BearSSL_ServerClientCert/BearSSL_ServerClientCert.ino
libraries/ESP8266WiFi/examples/BearSSL_Sessions/BearSSL_Sessions.ino
libraries/ESP8266WiFi/examples/BearSSL_Validation/BearSSL_Validation.ino
libraries/ESP8266WiFi/examples/HTTPSRequestCACertAxTLS/HTTPSRequestCACertAxTLS.ino
libraries/ESP8266httpUpdate/examples/httpUpdateSecure/httpUpdateSecure.ino
libraries/ESP8266mDNS/examples/LEAmDNS/mDNS_Clock/mDNS_Clock.ino
libraries/esp8266/examples/NTP-TZ-DST/NTP-TZ-DST.ino
libraries/LittleFS/examples/LittleFS_Timestamp/LittleFS_Timestamp.ino

I made one for FS.h only: #6730
You want to change all time.h includes?

[Niek]

I don't understand the core issue here, or how the suggested fix addresses it.

Arduino Time Library (a popular library that offers some time-related functions) ships a header file called Time.h (capital T). When using this library, the issue occurs because on at least macOS and Windows the Time.h of the library is included instead of the correct time.h. Using the relative path forces the compiler to include the correct time.h.

[d-a-v]

@devyte

That comment from @me-no-dev
me-no-dev/ESPAsyncWebServer#60 (comment)

but since it's too late to change that, we are in a sticky situation now and from now on...

and this one from @PaulStoffregen
PaulStoffregen/Time#74 (comment)

This library aims to preserve compatibility with older versions of Arduino.

[d-a-v]

@Niek thanks for the PR.
This workaround may benefit to others, from links you referenced above.

[NitrofMtl]

Using the relative path forces the compiler to include the correct time.h

I install the library via the lib manager, so it is on \libdeps. I did not manage to get it work, what would be the path ?

#include <../libdeps/uno/Time/Time.h>