undefined reference to app_main' OR undefined reference to setup'

[TLINDEN]

Hardware:

Board: Lolin esp32
Core Installation version: n/a
IDE name: emacs
Flash Frequency: 40Mhz
PSRAM enabled: n/a
Upload Speed: n/a
Computer OS: Ubuntu

Description:

I have a fresh installation and haven't done anything with esp32 before. I want to write my code with emacs and just use make flash to install firmwares.

I've installed
Toolchain version: crosstool-ng-1.22.0-80-g6c4433a Compiler version: 5.2.0
I followed these insttructions: https://docs.espressif.com/projects/esp-idf/en/stable/get-started/linux-setup.html. I had to use the the release/v3.2.3 branch of esp-idf though because otherwise I couldn't get the whole thing to work.

Then I followed issue #1409. I created a new project folder with main/test.cpp containing the code posted in this issue. My Makefile has test set as project name.

When I compile with arduino autostart disabled I get:

LD build/test.elf
/home/scip/D/github/buswetter/esptest/build/esp32/libesp32.a(cpu_start.o):(.literal.main_task+0x18): undefined reference to `app_main'
/home/scip/D/github/buswetter/esptest/build/esp32/libesp32.a(cpu_start.o): In function `main_task':
/usr/local/esp32/esp-idf/components/esp32/cpu_start.c:512: undefined reference to `app_main'
collect2: error: ld returned 1 exit status

When I enable it, I get the same error as in #1409 (setup and loop undefined):

LD build/test.elf
/home/scip/D/github/buswetter/esptest/build/arduino/libarduino.a(main.o):(.literal._Z8loopTaskPv+0x8): undefined reference to `setup()'
/home/scip/D/github/buswetter/esptest/build/arduino/libarduino.a(main.o):(.literal._Z8loopTaskPv+0xc): undefined reference to `loop()'
/home/scip/D/github/buswetter/esptest/build/arduino/libarduino.a(main.o): In function `loopTask(void*)':
/home/scip/D/github/buswetter/esptest/components/arduino/cores/esp32/main.cpp:14: undefined reference to `setup()'
/home/scip/D/github/buswetter/esptest/components/arduino/cores/esp32/main.cpp:17: undefined reference to `loop()'
collect2: error: ld returned 1 exit status

It looks like the toolchain doesn't build main/test.cpp at all. In fact, I can even add any non-cpp rubbish in there and I get the same message as above, no syntax errors or the like.

What can I do to fix this weird behavior?

[TLINDEN]

Ok, my bad. I had no main/CMakeLists.txt AND the sample code posted in #1409 is wrong (macros wrong). So, it works now.

[Jobui21]

Hello I hope you are well. look I am also presenting this problem. since I had been working well with the Esp32 card for months and I even get those problems. Can you advise me how did you solve that?

[lbernstone]

This is very outdated. You can now use lib-builder to get everything laid out properly, and then just add your main code. Choose either app_main or setup by adjusting the arduino settings in make menuconfig.

[Sergio-Navarro-M]

Ok, my bad. I had no main/CMakeLists.txt AND the sample code posted in #1409 is wrong (macros wrong). So, it works now.
Hello @TLINDEN ,

can you please share the code that did work for you? I am having the same issues while compiling test code.

Thanks in advance!
Sergio