Merge tag 'kbuild-v5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull more Kbuild updates from Masahiro Yamada:

 - raise minimum supported binutils version to 2.23

 - remove old CONFIG_AS_* macros that we know binutils >= 2.23 supports

 - move remaining CONFIG_AS_* tests to Kconfig from Makefile

 - enable -Wtautological-compare warnings to catch more issues

 - do not support GCC plugins for GCC <= 4.7

 - fix various breakages of 'make xconfig'

 - include the linker version used for linking the kernel into
   LINUX_COMPILER, which is used for the banner, and also exposed to
   /proc/version

 - link lib-y objects to vmlinux forcibly when CONFIG_MODULES=y, which
   allows us to remove the lib-ksyms.o workaround, and to solve the last
   known issue of the LLVM linker

 - add dummy tools in scripts/dummy-tools/ to enable all compiler tests
   in Kconfig, which will be useful for distro maintainers

 - support the single switch, LLVM=1 to use Clang and all LLVM utilities
   instead of GCC and Binutils.

 - support LLVM_IAS=1 to enable the integrated assembler, which is still
   experimental

* tag 'kbuild-v5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (36 commits)
  kbuild: fix comment about missing include guard detection
  kbuild: support LLVM=1 to switch the default tools to Clang/LLVM
  kbuild: replace AS=clang with LLVM_IAS=1
  kbuild: add dummy toolchains to enable all cc-option etc. in Kconfig
  kbuild: link lib-y objects to vmlinux forcibly when CONFIG_MODULES=y
  MIPS: fw: arc: add __weak to prom_meminit and prom_free_prom_memory
  kbuild: remove -I$(srctree)/tools/include from scripts/Makefile
  kbuild: do not pass $(KBUILD_CFLAGS) to scripts/mkcompile_h
  Documentation/llvm: fix the name of llvm-size
  kbuild: mkcompile_h: Include $LD version in /proc/version
  kconfig: qconf: Fix a few alignment issues
  kconfig: qconf: remove some old bogus TODOs
  kconfig: qconf: fix support for the split view mode
  kconfig: qconf: fix the content of the main widget
  kconfig: qconf: Change title for the item window
  kconfig: qconf: clean deprecated warnings
  gcc-plugins: drop support for GCC <= 4.7
  kbuild: Enable -Wtautological-compare
  x86: update AS_* macros to binutils >=2.23, supporting ADX and AVX2
  crypto: x86 - clean up poly1305-x86_64-cryptogams.S by 'make clean'
  ...

4 files changed, 123 insertions, 0 deletions

diff --git a/scripts/dummy-tools/gcc b/scripts/dummy-tools/gcc
new file mode 100755
index 000000000000..33487e99d83e
--- /dev/null
+++ b/scripts/dummy-tools/gcc
@@ -0,0 +1,91 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Staring v4.18, Kconfig evaluates compiler capabilities, and hides CONFIG
+# options your compiler does not support. This works well if you configure and
+# build the kernel on the same host machine.
+#
+# It is inconvenient if you prepare the .config that is carried to a different
+# build environment (typically this happens when you package the kernel for
+# distros) because using a different compiler potentially produces different
+# CONFIG options than the real build environment. So, you probably want to make
+# as many options visible as possible. In other words, you need to create a
+# super-set of CONFIG options that cover any build environment. If some of the
+# CONFIG options turned out to be unsupported on the build machine, they are
+# automatically disabled by the nature of Kconfig.
+#
+# However, it is not feasible to get a full-featured compiler for every arch.
+# Hence these dummy toolchains to make all compiler tests pass.
+#
+# Usage:
+#
+# From the top directory of the source tree, run
+#
+#   $ make CROSS_COMPILE=scripts/dummy-tools/ oldconfig
+#
+# Most of compiler features are tested by cc-option, which simply checks the
+# exit code of $(CC). This script does nothing and just exits with 0 in most
+# cases. So, $(cc-option, ...) is evaluated as 'y'.
+#
+# This scripts caters to more checks; handle --version and pre-process __GNUC__
+# etc. to pretend to be GCC, and also do right things to satisfy some scripts.
+
+# Check if the first parameter appears in the rest. Succeeds if found.
+# This helper is useful if a particular option was passed to this script.
+# Typically used like this:
+#   arg_contain <word-you-are-searching-for> "$@"
+arg_contain ()
+{
+	search="$1"
+	shift
+
+	while [ $# -gt 0 ]
+	do
+		if [ "$search" = "$1" ]; then
+			return 0
+		fi
+		shift
+	done
+
+	return 1
+}
+
+# To set CONFIG_CC_IS_GCC=y
+if arg_contain --version "$@"; then
+	echo "gcc (scripts/dummy-tools/gcc)"
+	exit 0
+fi
+
+if arg_contain -E "$@"; then
+	# For scripts/gcc-version.sh; This emulates GCC 20.0.0
+	if arg_contain - "$@"; then
+		sed 's/^__GNUC__$/20/; s/^__GNUC_MINOR__$/0/; s/^__GNUC_PATCHLEVEL__$/0/'
+		exit 0
+	else
+		echo "no input files" >&2
+		exit 1
+	fi
+fi
+
+if arg_contain -S "$@"; then
+	# For scripts/gcc-x86-*-has-stack-protector.sh
+	if arg_contain -fstack-protector "$@"; then
+		echo "%gs"
+		exit 0
+	fi
+fi
+
+# For scripts/gcc-plugin.sh
+if arg_contain -print-file-name=plugin "$@"; then
+	plugin_dir=$(mktemp -d)
+
+	sed -n 's/.*#include "\(.*\)"/\1/p' $(dirname $0)/../gcc-plugins/gcc-common.h |
+	while read header
+	do
+		mkdir -p $plugin_dir/include/$(dirname $header)
+		touch $plugin_dir/include/$header
+	done
+
+	echo $plugin_dir
+	exit 0
+fi
diff --git a/scripts/dummy-tools/ld b/scripts/dummy-tools/ld
new file mode 100755
index 000000000000..f68233050405
--- /dev/null
+++ b/scripts/dummy-tools/ld
@@ -0,0 +1,30 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-only
+
+# Dummy script that always succeeds.
+
+# Check if the first parameter appears in the rest. Succeeds if found.
+# This helper is useful if a particular option was passed to this script.
+# Typically used like this:
+#   arg_contain <word-you-are-searching-for> "$@"
+arg_contain ()
+{
+	search="$1"
+	shift
+
+	while [ $# -gt 0 ]
+	do
+		if [ "$search" = "$1" ]; then
+			return 0
+		fi
+		shift
+	done
+
+	return 1
+}
+
+if arg_contain --version "$@" || arg_contain -v "$@"; then
+	progname=$(basename $0)
+	echo "GNU $progname (scripts/dummy-tools/$progname) 2.50"
+	exit 0
+fi
diff --git a/scripts/dummy-tools/nm b/scripts/dummy-tools/nm
new file mode 120000
index 000000000000..c0648b38dd42
--- /dev/null
+++ b/scripts/dummy-tools/nm
@@ -0,0 +1 @@
+ld
\ No newline at end of file
diff --git a/scripts/dummy-tools/objcopy b/scripts/dummy-tools/objcopy
new file mode 120000
index 000000000000..c0648b38dd42
--- /dev/null
+++ b/scripts/dummy-tools/objcopy
@@ -0,0 +1 @@
+ld
\ No newline at end of file