iwlwifi: fix the gcc build

[ngie]

Summary

• Only apply the previously added CWARNFLAGS to drv.c instead of the whole module.
• Only apply -Wno-initializer-overrides to CWARNFLAGS in the clang scenario for drv.c as the flag is clang-specific.

This fixes building the module with gcc and avoids accidentally
introducing tech debt with the module, in the event other issues are
accidentally introduced.

MFC after: 3 days
Fixes: 6b627f8858 ("iwlwifi: update Intel's mvm/mld drivers")

Test Plan

Basic check to ensure the flag was being passed properly

% CC=gcc14 make -n all | grep 'pcie/drv\.c' | egrep -o 'Wno-override-init|Wno-initializer-overrides'
Wno-override-init
% CC=clang make -n all | grep 'pcie/drv\.c' | egrep -o 'Wno-override-init|Wno-initializer-overrides'
Wno-override-init
Wno-initializer-overrides

Build spot checks

The build passed in the following scenarios:

• clang from base: make all CC=cc -j$(nproc)
• devel/freebsd-gcc14 with TARGET=amd64/TARGET_ARCH=amd64: make all CC=x86_64-unknown-freebsd14.3-gcc14 -j$(nproc)

[delphij]

I think what bz@ really wanted is something like:

.if ${COMPILER_TYPE} == "clang"
CWARNFLAGS.drv.c += -Wno-override-init -Wno-initializer-overrides
.endif

but your change should be sufficient to fix gcc build.

[bz]

Give me a day; I think I actually had a proper solution for this for the never happened v6.16 import.
Otherwise be my guest and put this in and I'll follow-up again.

Also -Wno-override-init is for gcc, isn't it?

[ngie]

In D53591#1223568, @delphij wrote:

I think what bz@ really wanted is something like:

.if ${COMPILER_TYPE} == "clang"
CWARNFLAGS.drv.c += -Wno-override-init -Wno-initializer-overrides
.endif

but your change should be sufficient to fix gcc build.

Ah, yes -- that's the best way to handle it.. I'll wait for @bz to do what he plans on doing before landing a similar change.

@bz: Give me a day; I think I actually had a proper solution for this for the never happened v6.16 import.
Otherwise be my guest and put this in and I'll follow-up again.

Also -Wno-override-init is for gcc, isn't it?

Odd. It shows up in the manpage. Ah, wait... -Wno-initializer-overrides is the one that isn't present in gcc13--so technically my proposed change was incorrect.

[ngie]

Incorporate corrections/suggestions from @delphij

[bz]

sys/modules/iwlwifi/Makefile

99

Missing -

[bz]

You do not need the .if if you do it as suggested here:
https://lists.freebsd.org/archives/freebsd-hackers/2025-August/004872.html

[ngie]

Fix typo spotted by @bz.

[ngie]

In D53591#1223710, @bz wrote:

You do not need the .if if you do it as suggested here:
https://lists.freebsd.org/archives/freebsd-hackers/2025-August/004872.html

That line/logic doesn't exist on main. That requires a change to bsd.sys.mk.

[bz]

I cannot test gcc currently but if the above logic is correct you can simplify it to

% git diff .
diff --git sys/modules/iwlwifi/Makefile sys/modules/iwlwifi/Makefile
index 5d4830537a0b..f880536d5885 100644
--- sys/modules/iwlwifi/Makefile
+++ sys/modules/iwlwifi/Makefile
@@ -91,7 +91,6 @@ CFLAGS+=      -DCONFIG_IWLWIFI_DEVICE_TRACING=1
 #CFLAGS+=      -DCONFIG_THERMAL=1
 #CFLAGS+=      -DCONFIG_EFI=1
 
-# XXX-BZ how to do this just for pcie/drv.c (and gcc vs. clang)?
-CFLAGS += -Wno-override-init -Wno-initializer-overrides
+CWARNFLAGS.drv.c+=         -Wno-override-init
 
 .include <bsd.kmod.mk>

which seems to work on main currently with clang (please make sure to test both before commit).

My initial version was to do something like:

diff --git sys/modules/iwlwifi/Makefile sys/modules/iwlwifi/Makefile
index 5d4830537a0b..1a99e3c0b74a 100644
--- sys/modules/iwlwifi/Makefile
+++ sys/modules/iwlwifi/Makefile
@@ -91,7 +91,8 @@ CFLAGS+=      -DCONFIG_IWLWIFI_DEVICE_TRACING=1
 #CFLAGS+=      -DCONFIG_THERMAL=1
 #CFLAGS+=      -DCONFIG_EFI=1
 
-# XXX-BZ how to do this just for pcie/drv.c (and gcc vs. clang)?
-CFLAGS += -Wno-override-init -Wno-initializer-overrides
+CWARNFLAGS.gcc.drv.c+=         -Wno-override-init
+CWARNFLAGS.clang.drv.c+=       -Wno-initializer-overrides
+CWARNFLAGS.drv.c+=             ${CWARNFLAGS.${COMPILER_TYPE}.${.IMPSRC:T}}
 
 .include <bsd.kmod.mk>

[ngie]

Incorporate feedback from @bz

[ngie]

I still think it's a good idea to push ${CWARNFLAGS.${COMPILER_TYPE}.${.IMPSRC:T}} into bsd.sys.mk, but this is ok too.

[bz]

In D53591#1224260, @ngie wrote:

I still think it's a good idea to push ${CWARNFLAGS.${COMPILER_TYPE}.${.IMPSRC:T}} into bsd.sys.mk, but this is ok too.

If you want to do this I think it needs to be consistent between user land and kernel and modules and thus should be a totally different change and then some of the current "hacks" would need to be undone at the same time. I'd be happy if someone would persue this but it's clearly not my area of expertise.

[bz]

sys/modules/iwlwifi/Makefile

95

In Phabricator on the web this looks like a space issue but seems to be clean in the patch.

Also, again, the original reason to set both options was that one was sufficient for each compiler. I wonder how -Wno-override-init is implemented in clang?

contrib/llvm-project/clang/include/clang/Basic/DiagnosticGroups.td:// For compatibility with GCC; -Woverride-init = -Winitializer-overrides

I'd still feel it'd be cleaner to either only set one or set one per compiler.

But let's get this in and then if we get proper per-compiler, per-file support then we can still have a .clang. and a .gcc. with the different options or we migrate the "alias" into a central place.

[ngie]

sys/modules/iwlwifi/Makefile

95

Oof -- it is kind of silly to specify both for clang... oh well.
I'll look at what's needed for share/mk to generalize this pattern and unwind this a bit later.