Compilation Bug with C++ in os.h

[Francois-Belanger]

/.espressif/tools/xtensa-esp32-elf/esp-2020r3-8.4.0/xtensa-esp32-elf/xtensa-esp32-elf/include/c++/8.4.0/bits/sstream.tcc: In member function 'virtual std::__cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>::int_type std::cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>::overflow(std::cxx11::basic_stringbuf<_CharT, _Traits, _Alloc>::int_type)': /esp/esp-idf/components/bt/host/nimble/nimble/porting/nimble/include/os/os.h:34:19: error: expected unqualified-id before '(' token

define max(a, b) ((a)>(b)?(a):(b))

               ^

/esp/esp-idf/components/bt/host/nimble/nimble/porting/nimble/include/os/os.h:30:19: error: expected unqualified-id before '(' token

define min(a, b) ((a)<(b)?(a):(b))

Found this: https://stackoverflow.com/questions/6379716/c-compilation-what-did-i-do-wrong

[prasad-alatkar]

Hi @Francois-Belanger recently I had also encountered this problem, #define min & #define max before including NimBLE header files (in CPP source/header files) and then undefine them might help you resolve the issue. For example,

#define min
#define max
#include "host/ble_hs.h"
#undef min
#undef max

[Francois-Belanger]

Ok, I will do that, but will this be fixed ?

Also, can you please look again at the log for issue: Nimble BLE Cached access crash (IDFGH-4052) #5923

It's nasty :-). I'm wondering if it's a setting.. I don't know where to look.

Thanks

[prasad-alatkar]

Hi @Francois-Belanger I had attempted to fix this issue upstream here: min-max-macro, however it won't be accepted upstream for valid reasons. So I may need to spend some time to understand and fix this issue in acceptable manner, and it may take some time :sweat_smile: . Did the above mentioned hackish suggestions help you resolve the issue ?

P.S.: Just FYI, I could find a research paper from 1995 on this "min max macro" thing, here is the link : min max and more

[Francois-Belanger]

Hi @prasad-alatkar , yes changing includes order did fix the issue. I hope you can fix this :-). I must say that I prefer C++ now for ESP32, much simpler to create complex app ! Thanks for the time.

[okaestne]

Also had loong gcc error messages in the Pinetime (c++) project because of these. I would suggest renaming the macros to be in CAPS, so they don't collide with c++'s

[rahult-github]

Hi @okaestne , the min / max defination conflicts with other open source library also, since it is a very common name. So recently a change was done to handle the same. Can you please confirm if you observe issue even with latest IDF code ?

[rahult-github]

Closing issue. Please feel to reopen, if issue still seen.