[Bug] Could not compile with the massdrop/ctrl keyboard: multiple definition of dmac_desc

[yu17]

The firmware could not be compiled with the massdrop/ctrl keyboard. The compilation exits with a bunch of multiple definition of 'dmac_desc' errors.

Describe the Bug

Steps to reproduce:

Cloning a fresh copy of QMK by:

qmk setup

Then compile the firmware with:

qmk compile -kb massdrop/ctrl -km default

And the following errors would occur:

Linking: .build/massdrop_ctrl_default.elf                                                           [ERRORS]
 | 
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/config_led.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: multiple definition of `dmac_desc_wb'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/config_led.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: multiple definition of `dmac_desc'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/keyboards/massdrop/ctrl/keymaps/default/keymap.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: multiple definition of `dmac_desc_wb'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/keyboards/massdrop/ctrl/keymaps/default/keymap.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: multiple definition of `dmac_desc'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/common/arm_atsam/suspend.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: multiple definition of `dmac_desc_wb'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/common/arm_atsam/suspend.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: multiple definition of `dmac_desc'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/common/magic.o:/home/($HOME)/QMK/qmk_firmware.test/quantum/keycode_config.h:44: multiple definition of `keymap_config'; .build/obj_massdrop_ctrl_default/keyboards/massdrop/ctrl/keymaps/default/keymap.o:(.bss+0x4): first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/adc.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: multiple definition of `dmac_desc_wb'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/adc.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: multiple definition of `dmac_desc'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/clks.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: multiple definition of `dmac_desc_wb'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/clks.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: multiple definition of `dmac_desc'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/i2c_master.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: multiple definition of `dmac_desc_wb'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/i2c_master.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: multiple definition of `dmac_desc'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/led_matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: multiple definition of `dmac_desc_wb'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/led_matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: multiple definition of `dmac_desc'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/main_arm_atsam.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: multiple definition of `dmac_desc_wb'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/main_arm_atsam.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: multiple definition of `dmac_desc'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/spi.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: multiple definition of `dmac_desc_wb'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/spi.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: multiple definition of `dmac_desc'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/usb/usb2422.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: multiple definition of `dmac_desc_wb'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:28: first defined here
 | /usr/lib/gcc/arm-none-eabi/10.1.0/../../../../arm-none-eabi/bin/ld: .build/obj_massdrop_ctrl_default/protocol/arm_atsam/usb/usb2422.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: multiple definition of `dmac_desc'; .build/obj_massdrop_ctrl_default/matrix.o:/home/($HOME)/QMK/qmk_firmware.test/tmk_core/protocol/arm_atsam/i2c_master.h:27: first defined here
 | collect2: error: ld returned 1 exit status
 | 
make[1]: *** [tmk_core/rules.mk:306: .build/massdrop_ctrl_default.elf] Error 1
Make finished with errors
make: *** [Makefile:584: massdrop/ctrl:default] Error 1

System Information

• Keyboard: massdrop/ctrl
  • Revision (if applicable):
• Operating system: Arch Linux 5.7.8-arch1-1
• AVR GCC version: 8.3.0

• ARM GCC version: 10.1.10

• QMK Firmware version: 0.9.38

• Any keyboard related software installed?
  • AutoHotKey
  • Karabiner
  • Other:

Additional Context

I had looked into this issue, and the problem is with these two files: tmk_core/protocol/arm_atsam/i2c_master.h and tmk_core/protocol/arm_atsam/i2c_master.c.

Since the issue is about duplicate definitions in the linking stage, it could actually be fixed by removing the following two lines:

__attribute__((__aligned__(16))) DmacDescriptor dmac_desc;
__attribute__((__aligned__(16))) DmacDescriptor dmac_desc_wb;

from tmk_core/protocol/arm_atsam/i2c_master.h and add them to tmk_core/protocol/arm_atsam/i2c_master.c.

However, I'm not quite familiar with the __attribute__ thing, and am not sure if this is a proper fix for this problem.

[fauxpark]

#9485

[zvecr]

Fixed by 9485

[chrisdonlan]

Recompiling for a keyboard that worked in 2017, and I am running into this bug again.

After checking #9485, it looks like the "fix" was immediately un-fixed.

The fix was not really a fix: more permissive compiler settings were added to tmk_core/rules.mk such that, project wide, the compiler no longer checked for duplicate definitions.

Instead, add CFLAGS += -fcommon to your massdrop rules.mk files to get things working again.