clang-14: unknown argument: '-gcc-toolchain'

[ayakael]

Description

During crossbuild of 7.0-preview7 with clang-14 on Alpine Linux, build fails with the following error on multiple files:

clang-14: error: unknown argument: '-gcc-toolchain'

This is due to clang-14 removing parsing of -gcc-toolchain in favor or --gcc-toolchain=

Reproduction Steps

Clone tag v7.0.0-preview.7.22375.6
Build using ROOTFS_DIR="$CBUILDROOT" ./build.sh -arch arm64 -c Release -cross -clang
where CBUILDROOT is your ROOTFS_DIR (in Alpine's case, $HOME/sysroot-arm64)

Expected behavior

--gcc-toolchain= should be used

Actual behavior

-gcc-toolchain used instead

Regression?

This also affects runtime v6.0.8

Known Workarounds

On v6.0.8, the following workaround was used:

1. let build fail
2. execute following to replace bad arguments

	_sedlist="
			pal/src/libunwind/src/CMakeFiles/libunwind.dir/build.make
			pal/src/CMakeFiles/coreclrpal.dir/build.make
			vm/wks/CMakeFiles/cee_wks_core.dir/build.make
			dlls/mscordac/CMakeFiles/mscordaccore.dir/build.make
			debug/di/CMakeFiles/cordbdi.dir/build.make
			debug/createdump/CMakeFiles/createdump.dir/build.make
			debug/ee/wks/CMakeFiles/cordbee_wks_obj.dir/build.make
			dlls/mscordbi/CMakeFiles/mscordbi.dir/build.make
		"
		for i in $_sedlist; do
			sed 's| -gcc-toolchain | --gcc-toolchain=|' -i artifacts/obj/coreclr/Linux.*.Release/$i || true
		done

3. start build again

Unfortunately, this does not work on version 7.0.0-preview.7, as build.make seems to be regenerated every build.

Configuration

Alpine Edge w/ clang 14 + cmake 3.23.1
Crossbuild x86_64 -» aarc64
Tested runtime versions 6.0.8 + 7.0.0-preview.7

Other information

I have not found the reason why some build.make files use the deprecated argument. Granted, I am a layman at clang + cmake.

[ghost]

Tagging subscribers to this area: @hoyosjs
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

During crossbuild of 7.0-preview7 with clang-14 on Alpine Linux, build fails with the following error on multiple files:

clang-14: error: unknown argument: '-gcc-toolchain'

This is due to clang-14 removing parsing of -gcc-toolchain in favor or --gcc-toolchain=

Reproduction Steps

Clone tag v7.0.0-preview.7.22375.6
Build using ROOTFS_DIR="$CBUILDROOT" ./build.sh -arch arm64 -c Release -cross -clang
where CBUILDROOT is your ROOTFS_DIR (in Alpine's case, $HOME/sysroot-arm64)

Expected behavior

--gcc-toolchain= should be used

Actual behavior

-gcc-toolchain used instead

Regression?

This also affects runtime v6.0.8

Known Workarounds

On v6.0.8, the following workaround was used:

1. let build fail
2. execute following to replace bad arguments

	_sedlist="
			pal/src/libunwind/src/CMakeFiles/libunwind.dir/build.make
			pal/src/CMakeFiles/coreclrpal.dir/build.make
			vm/wks/CMakeFiles/cee_wks_core.dir/build.make
			dlls/mscordac/CMakeFiles/mscordaccore.dir/build.make
			debug/di/CMakeFiles/cordbdi.dir/build.make
			debug/createdump/CMakeFiles/createdump.dir/build.make
			debug/ee/wks/CMakeFiles/cordbee_wks_obj.dir/build.make
			dlls/mscordbi/CMakeFiles/mscordbi.dir/build.make
		"
		for i in $_sedlist; do
			sed 's| -gcc-toolchain | --gcc-toolchain=|' -i artifacts/obj/coreclr/Linux.*.Release/$i || true
		done

3. start build again

Unfortunately, this does not work on version 7.0.0-preview.7, as build.make seems to be regenerated every build.

Configuration

Alpine Edge w/ clang 14 + cmake 3.23.1
Crossbuild x86_64 -» aarc64
Tested runtime versions 6.0.8 + 7.0.0-preview.7

Other information

I have not found the reason why some build.make files use the deprecated argument. Granted, I am a layman at clang + cmake.

Author:	ayakael
Assignees:	-
Labels:	area-Infrastructure-coreclr, untriaged
Milestone:	-

[jkotas]

Does applying this workaround fix the problem for you?

runtime/eng/native/configurecompiler.cmake

Lines 791 to 796 in cfd6cd1

	# This is a workaround for upstream issue: https://gitlab.kitware.com/cmake/cmake/-/issues/22995.
	#
	# In Clang.cmake, the decision to use single or double hyphen for target and gcc-toolchain
	# is made based on CMAKE_${LANG}_COMPILER_VERSION, but CMAKE_ASM_COMPILER_VERSION is empty
	# so it picks up single hyphen options, which new clang versions don't recognize.
	set (CMAKE_ASM_COMPILER_VERSION "${CMAKE_C_COMPILER_VERSION}")

[ayakael]

Does applying this workaround fix the problem for you?

runtime/eng/native/configurecompiler.cmake

Lines 791 to 796 in cfd6cd1

	# This is a workaround for upstream issue: https://gitlab.kitware.com/cmake/cmake/-/issues/22995.
	#
	# In Clang.cmake, the decision to use single or double hyphen for target and gcc-toolchain
	# is made based on CMAKE_${LANG}_COMPILER_VERSION, but CMAKE_ASM_COMPILER_VERSION is empty
	# so it picks up single hyphen options, which new clang versions don't recognize.
	set (CMAKE_ASM_COMPILER_VERSION "${CMAKE_C_COMPILER_VERSION}")

That did it, thanks!

[jkotas]

Let's keep this open for .NET 7 backport

[hoyosjs]

Fixed in 7.0 and 6.0.