chore(pkg/driverbuiler): avoid overriding CC at build time.

[FedeDP]

What type of PR is this?

/kind cleanup

Any specific area of the project related to this PR?

/area pkg

What this PR does / why we need it:

Instead, set CMAKE_C_COMPILER variable at cmake configure step.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

NONE

[poiana]

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[FedeDP]

We don't need the templated GCCVersion anymore since we already pass a correctly formatted cmake command to builders.

[FedeDP]

When building through dkms, cmake is not involved, therefore for local script, it must still be passed somehow.

[FedeDP]

Uh it seems like debian for example (but possible other builders) overriddes CC in the kernel sources makefiles, using the gcc it was built with; in Debian, we set CMAKE_C_COMPILER to /usr/bin/gcc-11.0.0 but then it tries to build it using gcc-10:

level=DEBUG msg="+ cmake -Wno-dev -DUSE_BUNDLED_DEPS=On -DCREATE_TEST_TARGETS=Off -DBUILD_LIBSCAP_GVISOR=Off -DBUILD_LIBSCAP_MODERN_BPF=Off -DENABLE_DRIVERS_TESTS=Off -DDRIVER_NAME=falco -DPROBE_NAME=falco -DBUILD_BPF=On -DDRIVER_VERSION=17f5df52a7d9ed6bb12d3b1768460def8439936d -DPROBE_VERSION=17f5df52a7d9ed6bb12d3b1768460def8439936d -DGIT_COMMIT=17f5df52a7d9ed6bb12d3b1768460def8439936d -DDRIVER_DEVICE_NAME=falco -DPROBE_DEVICE_NAME=falco -DCMAKE_C_COMPILER=/usr/bin/gcc-11.0.0 .."

...

level=DEBUG msg="make[6]: gcc-10: No such file or directory"

and indeed:

level=DEBUG msg="+ grep -R CC_VERSION /usr/src/linux-headers-5.10.0-10-amd64"
level=DEBUG msg="/usr/src/linux-headers-5.10.0-10-amd64/scripts/Kbuild.include:cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] && echo $(3) || echo $(4))"
level=DEBUG msg="/usr/src/linux-headers-5.10.0-10-amd64/.config:CONFIG_CC_VERSION_TEXT="gcc-10 (Debian 10.2.1-6) 10.2.1 20210110""
level=DEBUG msg="/usr/src/linux-headers-5.10.0-10-amd64/.config:CONFIG_GCC_VERSION=100201"
level=DEBUG msg="/usr/src/linux-headers-5.10.0-10-amd64/include/generated/autoconf.h:#define CONFIG_CC_VERSION_TEXT "gcc-10 (Debian 10.2.1-6) 10.2.1 20210110""
level=DEBUG msg="/usr/src/linux-headers-5.10.0-10-amd64/include/generated/autoconf.h:#define CONFIG_GCC_VERSION 100201"
level=DEBUG msg="/usr/src/linux-headers-5.10.0-10-amd64/include/config/auto.conf:CONFIG_CC_VERSION_TEXT="gcc-10 (Debian 10.2.1-6) 10.2.1 20210110""
level=DEBUG msg="/usr/src/linux-headers-5.10.0-10-amd64/include/config/auto.conf:CONFIG_GCC_VERSION=100201"

[FedeDP]

/close

[poiana]

@FedeDP: Closed this PR.

In response to this:

/close

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