synchronization example fails to build for SMP platforms

[abrodkin]

Initially reported by Shippable here https://app.shippable.com/github/zephyrproject-rtos/zephyr/runs/47829/3/console while reviewing #17992.

Yet could be reproduced for any other SMP platform, for example qemu_x86_64:

# mkdir build
# cd build
# cmake -DBOARD=qemu_x86_64 ../samples/synchronization/

Enable OpenOCD support (CONFIG_OPENOCD_SUPPORT=y).

# make
...
[ 60%] Built target app
In file included from .../include/kernel_includes.h:16,
                 from .../include/kernel.h:17,
                 from .../kernel/include/kernel_structs.h:10,
                 from .../subsys/debug/openocd.c:7:
.../subsys/debug/openocd.c:39:35: error: 'struct z_kernel' has no member named 'current'
  [OPENOCD_OFFSET_K_CURR_THREAD] = offsetof(struct z_kernel, current),
                                   ^~~~~~~~
.../subsys/debug/openocd.c:66:2: warning: #warning Please define OPENOCD_OFFSET_T_STACK_PTR for this architecture [-Wcpp]
 #warning Please define OPENOCD_OFFSET_T_STACK_PTR for this architecture
  ^~~~~~~

[ioannisg]

@abrodkin is this issue been taken care off?

[abrodkin]

@ioannisg sorry I was on ETO last 2 weeks with limited access to Internet, now I'm going to re-spin #18125 with fix in for of !SMP dependency of OPENOCD_SUPPORT in subsys/debug/Kconfig. Is that OK?

[galak]

there are 2 issues here, one is the SMP support, the other is building on X86_64.

So I think #18125 deals with the SMP issue.

@andrewboie does non-SMP on x86_64 make sense?

[abrodkin]

@galak what's the problem with building on X86_64? Maybe I missed some discussion last weeks so pls kindly point me to any relevant information and I'll take a look.

[galak]

@galak what's the problem with building on X86_64? Maybe I missed some discussion last weeks so pls kindly point me to any relevant information and I'll take a look.

The warning #warning Please define OPENOCD_OFFSET_T_STACK_PTR for this architecture is related to x86_64

[abrodkin]

@galak what's the problem with building on X86_64? Maybe I missed some discussion last weeks so pls kindly point me to any relevant information and I'll take a look.

The warning #warning Please define OPENOCD_OFFSET_T_STACK_PTR for this architecture is related to x86_64

Hm... but how can I reproduce it?
I don't see it with:

cmake -DBOARD=qemu_x86_64 ../samples/synchronization/
make

[abrodkin]

@galak what's the problem with building on X86_64? Maybe I missed some discussion last weeks so pls kindly point me to any relevant information and I'll take a look.

The warning #warning Please define OPENOCD_OFFSET_T_STACK_PTR for this architecture is related to x86_64

Hm... but how can I reproduce it?
I don't see it with:

cmake -DBOARD=qemu_x86_64 ../samples/synchronization/
make

Ooops, forgot to enable CONFIG_OPENOCD via menuconfig :(
Now I see it but again this has nothing to do with anything except x86_64 and CONFIG_OPENOCD.

So it looks like we'd need this then (since X86_64 seems to be quite incomplete, judging by contents of https://github.com/zephyrproject-rtos/zephyr/blob/master/arch/x86_64/include/kernel_arch_thread.h):

diff --git a/subsys/debug/Kconfig b/subsys/debug/Kconfig
index a5dff0ad4f..202d7f3f29 100644
--- a/subsys/debug/Kconfig
+++ b/subsys/debug/Kconfig
@@ -223,7 +223,7 @@ config EXCEPTION_STACK_TRACE

 config OPENOCD_SUPPORT
        bool "OpenOCD support [EXPERIMENTAL]"
-       depends on !SMP
+       depends on !SMP && !X86_64
        select THREAD_MONITOR
        select THREAD_NAME
        help

Does that look OK?