GCC 7.3.1 compiler error in SEGGER_RTT_Syscalls_GCC.c

[Steve H]

A makefile project using SDK 15.0.0 that compiled under GCC 7.2.1 no longer compiles under 7.3.1 with these errors:

../../../../../../external/segger_rtt/SEGGER_RTT_Syscalls_GCC.c:94:19: error: expected '=', ',', ';', 'asm' or '__attribute__' before '_PARAMS'
_ssize_t _write_r _PARAMS ((struct _reent *, int, const void *, size_t));
^~~~~~~
../../../../../../external/segger_rtt/SEGGER_RTT_Syscalls_GCC.c:129:19: error: expected '=', ',', ';', 'asm' or '__attribute__' before '_PARAMS'
_ssize_t _write_r _PARAMS((struct _reent *r, int file, const void *ptr, size_t len)) {
^~~~~~~

[Michael]

This also happens with SDK v15.3.0

Note that the default compiler, as is configured in Makefile.windows is 7.3.1 and it exhibits the exact same compilation error as the OP found.

With GCC 6.3 2017q2-update (6.3.1) it compiles fine.

Is 6.3.1 fine to use with SDK v15.3.0?

[Vidar Berg]

Strange, I'm not getting any build errors here. I tried building the ble_app_uart example which uses RTT for logging. 

Are you using the "7 2018-q2 update" from ARM?  Link: https://developer.arm.com/tools-and-software/open-source-software/gnu-toolchain/gnu-rm/downloads#panel2a. 

Edit: It shouldn't be a problem to use v.6.3.1. We used this for SDK 15.2.0

[Michael]

Perhaps there's something wrong with my environment variables?
I didn't install the .exe file, but used the zip, because I have to use several gcc versions for different projects.
When I track the definition for the _PARAMS macro, it points to the 5.4.1 include folder, but I can't seem to point it to the 7.3.1 include path

[Vidar Berg]

I'm not sure how this works, to be honest, maybe there are some registry settings that tell the toolchain which include paths to use? When you run the installer it is optional to set the PATH variable (checkbox for setting the PATH variable). Could you try installing the toolchain without updating PATH?