strptime dissapeared on 3.0.0

[asturcon3]

Arduino last IDE, esp8266 just updated to 3.0.0, and I'm getting undefined error for strptime. After playing with and without XSI_VISIBLE, searching the includes, trying with and without time.h and timelib.h, I'm doing a workaround (parsing the old way) and letting you know.

[earlephilhower]

As requested in the template you deleted, please provide an MCVE so we can reproduce. Otherwise there's not much we can do.

FWIW, libc.a looks to contain strptime still:

$ nm libc.a
....


lib_a-strptime.o:
         U _C_time_locale
         U _ctype_
00000000 r _DAYS_BEFORE_MONTH
         U __errno
00000044 t first_day
         U __global_locale
00000000 t is_leap_year
         U localtime_r
00000090 t match_string
         U __modsi3
         U strlen
         U strncasecmp_l
00000888 T strptime
000000ec T strptime_l
         U strtol_l
         U strtoll_l
00000000 R tm_year_base

[dok-net]

#3522
Building that MCVE on current master b4774ed:

sptime.ino: 10:9: error: 'strptime' was not declared in this scope; did you mean 'strftime'?
   %S", &tm) == NULL) midnight = 0
   |         ^~~~~~~~
   |         strftime

In tools/xtensa-lx106-elf/xtensa-lx106-elf/include/sys/features.h,

#ifdef _GNU_SOURCE
#define __GNU_VISIBLE           1
#else
#define __GNU_VISIBLE           0
#endif

always defines __GNU_VISIBLE to 0, thereby disabling strptime and strptime_l. You can define _GNU_SOURCE all you like in your sketch, it doesn't change.

[dok-net]

It builds fine with release 2.7.4

[earlephilhower]

@asturcon3 I can repro with the example @dok-net , but you don't need to write your own version. Just add this line to your code:

extern "C" char *strptime (const char *__restrict, const char *__restrict, struct tm *__restrict);

Basically, the code is there in the library, but the defines in the new build seem to disable the prototype from being parsed. This is most likely related to the Newlib 4.0.0 release (about 5 years newer than the on in 2.7.4), and needs some digging. The above prototype will get you goin in the meantime.

[tobozo]

not sure if it's related but memrchr is gone too and the __GNU_VISIBLE macros seems involved

adding this to my sketch solved the issue:

extern "C" void *memrchr (const void *__restrict, int __restrict, size_t __restrict);

[d-a-v]

It seems that defining _GNU_SOURCE would make these two functions visible.

diff --git a/platform.txt b/platform.txt
index 5b4a1442..88d9c82b 100644
--- a/platform.txt
+++ b/platform.txt
@@ -56,7 +56,7 @@ compiler.path={runtime.tools.xtensa-lx106-elf-gcc.path}/bin/
 compiler.sdk.path={runtime.platform.path}/tools/sdk
 
 compiler.libc.path={runtime.platform.path}/tools/sdk/libc/xtensa-lx106-elf
-compiler.cpreprocessor.flags=-D__ets__ -DICACHE_FLASH -U__STRICT_ANSI__ "-I{compiler.sdk.path}/include" "-I{compiler.sdk.path}/{build.lwip_include}" "-I{compiler.libc.path}/include" "-I{build.path}/core"
+compiler.cpreprocessor.flags=-D__ets__ -DICACHE_FLASH -U__STRICT_ANSI__ -D_GNU_SOURCE "-I{compiler.sdk.path}/include" "-I{compiler.sdk.path}/{build.lwip_include}" "-I{compiler.libc.path}/include" "-I{build.path}/core"
 
 compiler.c.cmd=xtensa-lx106-elf-gcc
 compiler.c.flags=-c {compiler.warning_flags} -std=gnu17 {build.stacksmash_flags} -Os -g -free -fipa-pta -Wpointer-arith -Wno-implicit-function-declaration -Wl,-EL -fno-inline-functions -nostdlib -mlongcalls -mtext-section-literals -falign-functions=4 -MMD -ffunction-sections -fdata-sections {build.exception_flags} {build.sslflags} {build.mmuflags} {build.non32xferflags}

diff --git a/tools/platformio-build.py b/tools/platformio-build.py
index d8a97982..35a88fe4 100644
--- a/tools/platformio-build.py
+++ b/tools/platformio-build.py
@@ -73,6 +73,7 @@ env.Append(
         "-mtext-section-literals",
         "-falign-functions=4",
         "-U__STRICT_ANSI__",
+        "-D_GNU_SOURCE",
         "-ffunction-sections",
         "-fdata-sections",
         "-Wall",

[earlephilhower]

@tobozo @asturcon3 @dok-net can you please give #8147 a try and report back? Simple tests look good to me w/it.