Arduino library detection works differently than "enableWiFiAtBootTime()" expects #7988
Description
PR #7902 suggests that only adding one call, enableWiFiAtBootTime(), is sufficient to restore previous behavior. This is underlined by the commit log:
- mv enableWiFiAtBootTime() to core_esp8266_features.h
suggesting that no additional includes from any library, in particular #include <ESP8266WiFi.h> is required for this to work.
Unfortunately, this is not how the Arduino library resolver works, at least in my installation.
MCVE does not pass the link phase:
void setup() { #ifdef WIFI_IS_OFF_AT_BOOT enableWiFiAtBootTime(); #endif } void loop() { } Result:
Compiling 'mcve' for 'LOLIN(WEMOS) D1 mini Pro' ld.exe: mcve.cpp.o:(.text.setup+0x0): undefined reference to enableWiFiAtBootTime ld.exe: mcve.cpp.o: in function setup mcve.ino:4: undefined reference to enableWiFiAtBootTime collect2.exe*: error: ld returned 1 exit status Error linking for board LOLIN(WEMOS) D1 mini Pro Build failed for project 'mcve' Adding #include <ESP8266WiFi.h> helps, but in that case please
--- a/cores/esp8266/core_esp8266_features.h +++ b/cores/esp8266/core_esp8266_features.h @@ -105,8 +105,6 @@ uint64_t micros64(void); void delay(unsigned long); void delayMicroseconds(unsigned int us); -void enableWiFiAtBootTime (void) __attribute__((noinline)); - #if defined(F_CPU) || defined(CORE_MOCK) #ifdef __cplusplus constexpr and
--- a/libraries/ESP8266WiFi/src/ESP8266WiFi.h +++ b/libraries/ESP8266WiFi/src/ESP8266WiFi.h @@ -53,6 +53,7 @@ extern "C" { #define DEBUG_WIFI(...) do { (void)0; } while (0) #endif +extern "C" void enableWiFiAtBootTime (void) __attribute__((noinline)); class ESP8266WiFiClass : public ESP8266WiFiGenericClass, public ESP8266WiFiSTAClass, public ESP8266WiFiScanClass, public ESP8266WiFiAPClass { public: because compiler errror messages are usually more easily understood by users than linker errors.
In the line of business finding: The #define WIFI_HAS_EVENT_CALLBACK from commit d9a7a81 seems to have no known use, as such, could it be (re)moved, because it intertwines ESP8266WiFi with the core without need?