#!/bin/bash
# SPDX-License-Identifier: GPL-2.0-only
# Generate tags or cscope files
# Usage tags.sh <mode>
#
# mode may be any of: tags, gtags, TAGS, cscope
#
# Uses the following environment variables:
# SUBARCH, SRCARCH, srctree

if [[ "$KBUILD_VERBOSE" =~ 1 ]]; then
	set -x
fi

# RCS_FIND_IGNORE has escaped ()s -- remove them.
ignore="$(echo "$RCS_FIND_IGNORE" | sed 's|\\||g' )"
# tags and cscope files should also ignore MODVERSION *.mod.c files
ignore="$ignore ( -name *.mod.c ) -prune -o"

# ignore arbitrary directories
if [ -n "${IGNORE_DIRS}" ]; then
	for i in ${IGNORE_DIRS}; do
		ignore="${ignore} ( -path $i ) -prune -o"
	done
fi

# Use make KBUILD_ABS_SRCTREE=1 {tags|cscope}
# to force full paths for a non-O= build
if [ "${srctree}" = "." -o -z "${srctree}" ]; then
	tree=
else
	tree=${srctree}/
fi

# gtags(1) refuses to index any file outside of its current working dir.
# If gtags indexing is requested and the build output directory is not
# the kernel source tree, index all files in absolute-path form.
if [[ "$1" == "gtags" && -n "${tree}" ]]; then
	tree=$(realpath "$tree")/
fi

# Detect if ALLSOURCE_ARCHS is set. If not, we assume SRCARCH
if [ "${ALLSOURCE_ARCHS}" = "" ]; then
	ALLSOURCE_ARCHS=${SRCARCH}
elif [ "${ALLSOURCE_ARCHS}" = "all" ]; then
	ALLSOURCE_ARCHS=$(find ${tree}arch/ -mindepth 1 -maxdepth 1 -type d -printf '%f ')
fi

# find sources in arch/$1
find_arch_sources()
{
	for i in $archincludedir; do
		local prune="$prune ( -path $i ) -prune -o"
	done
	find ${tree}arch/$1 $ignore $prune -name "$2" -not -type l -print;
}

# find sources in arch/$1/include
find_arch_include_sources()
{
	local include=$(find ${tree}arch/$1/ -name include -type d -print);
	if [ -n "$include" ]; then
		archincludedir="$archincludedir $include"
		find $include $ignore -name "$2" -not -type l -print;
	fi
}

# find sources in include/
find_include_sources()
{
	find ${tree}include $ignore -name config -prune -o -name "$1" \
		-not -type l -print;
}

# find sources in rest of tree
# we could benefit from a list of dirs to search in here
find_other_sources()
{
	find ${tree}* $ignore \
	     \( -path ${tree}include -o -path ${tree}arch -o -name '.tmp_*' \) -prune -o \
	       -name "$1" -not -type l -print;
}

all_sources()
{
	find_arch_include_sources ${SRCARCH} '*.[chS]'
	if [ -n "$archinclude" ]; then
		find_arch_include_sources $archinclude '*.[chS]'
	fi
	find_include_sources '*.[chS]'
	for arch in $ALLSOURCE_ARCHS
	do
		find_arch_sources $arch '*.[chS]'
	done
	find_other_sources '*.[chS]'
}

all_compiled_sources()
{
	{
		echo include/generated/autoconf.h
		find $ignore -name "*.cmd" -exec \
			grep -Poh '(?<=^  )\S+|(?<== )\S+[^\\](?=$)' {} \+ |
		awk '!a[$0]++'
	} | xargs realpath -esq $([ -z "$KBUILD_ABS_SRCTREE" ] && echo --relative-to=.) |
	sort -u
}

all_target_sources()
{
	if [ -n "$COMPILED_SOURCE" ]; then
		all_compiled_sources
	else
		all_sources
	fi
}

all_kconfigs()
{
	find ${tree}arch/ -maxdepth 1 $ignore \
	       -name "Kconfig*" -not -type l -print;
	for arch in $ALLSOURCE_ARCHS; do
		find_arch_sources $arch 'Kconfig*'
	done
	find_other_sources 'Kconfig*'
}

docscope()
{
	(echo \-k; echo \-q; all_target_sources) > cscope.files
	cscope -b -f cscope.out
}

dogtags()
{
	all_target_sources | gtags -i -C "${tree:-.}" -f - "$PWD"
}

# Basic regular expressions with an optional /kind-spec/ for ctags and
# the following limitations:
# - No regex modifiers
# - Use \{0,1\} instead of \?, because etags expects an unescaped ?
# - \s is not working with etags, use a space or [ \t]
# - \w works, but does not match underscores in etags
# - etags regular expressions have to match at the start of a line;
#   a ^[^#] is prepended by setup_regex unless an anchor is already present
regex_asm=(
	'/^\(ENTRY\|_GLOBAL\)([[:space:]]*\([[:alnum:]_\\]*\)).*/\2/'
)
regex_c=(
	'/^SYSCALL_DEFINE[0-9]([[:space:]]*\([[:alnum:]_]*\).*/sys_\1/'
	'/^BPF_CALL_[0-9]([[:space:]]*\([[:alnum:]_]*\).*/\1/'
	'/^COMPAT_SYSCALL_DEFINE[0-9]([[:space:]]*\([[:alnum:]_]*\).*/compat_sys_\1/'
	'/^TRACE_EVENT([[:space:]]*\([[:alnum:]_]*\).*/trace_\1/'
	'/^DEFINE_EVENT([^,)]*,[[:space:]]*\([[:alnum:]_]*\).*/trace_\1/'
	'/^DEFINE_INSN_CACHE_OPS([[:space:]]*\([[:alnum:]_]*\).*/get_\1_slot/'
	'/^DEFINE_INSN_CACHE_OPS([[:space:]]*\([[:alnum:]_]*\).*/free_\1_slot/'
	'/^PAGEFLAG([[:space:]]*\([[:alnum:]_]*\).*/Page\1/'
	'/^PAGEFLAG([[:space:]]*\([[:alnum:]_]*\).*/SetPage\1/'
	'/^PAGEFLAG([[:space:]]*\([[:alnum:]_]*\).*/ClearPage\1/'
	'/^TESTSETFLAG([[:space:]]*\([[:alnum:]_]*\).*/TestSetPage\1/'
	'/^TESTPAGEFLAG([[:space:]]*\([[:alnum:]_]*\).*/Page\1/'
	'/^SETPAGEFLAG([[:space:]]*\([[:alnum:]_]*\).*/SetPage\1/'
	'/\<__SETPAGEFLAG([[:space:]]*\([[:alnum:]_]*\).*/__SetPage\1/'
	'/\<TESTCLEARFLAG([[:space:]]*\([[:alnum:]_]*\).*/TestClearPage\1/'
	'/\<__TESTCLEARFLAG([[:space:]]*\([[:alnum:]_]*\).*/TestClearPage\1/'
	'/\<CLEARPAGEFLAG([[:space:]]*\([[:alnum:]_]*\).*/ClearPage\1/'
	'/\<__CLEARPAGEFLAG([[:space:]]*\([[:alnum:]_]*\).*/__ClearPage\1/'
	'/^__PAGEFLAG([[:space:]]*\([[:alnum:]_]*\).*/__SetPage\1/'
	'/^__PAGEFLAG([[:space:]]*\([[:alnum:]_]*\).*/__ClearPage\1/'
	'/^PAGEFLAG_FALSE([[:space:]]*\([[:alnum:]_]*\).*/Page\1/'
	'/\<TESTSCFLAG([[:space:]]*\([[:alnum:]_]*\).*/TestSetPage\1/'
	'/\<TESTSCFLAG([[:space:]]*\([[:alnum:]_]*\).*/TestClearPage\1/'
	'/\<SETPAGEFLAG_NOOP([[:space:]]*\([[:alnum:]_]*\).*/SetPage\1/'
	'/\<CLEARPAGEFLAG_NOOP([[:space:]]*\([[:alnum:]_]*\).*/ClearPage\1/'
	'/\<__CLEARPAGEFLAG_NOOP([[:space:]]*\([[:alnum:]_]*\).*/__ClearPage\1/'
	'/\<TESTCLEARFLAG_FALSE([[:space:]]*\([[:alnum:]_]*\).*/TestClearPage\1/'
	'/^PAGE_TYPE_OPS([[:space:]]*\([[:alnum:]_]*\).*/Page\1/'
	'/^PAGE_TYPE_OPS([[:space:]]*\([[:alnum:]_]*\).*/__SetPage\1/'
	'/^PAGE_TYPE_OPS([[:space:]]*\([[:alnum:]_]*\).*/__ClearPage\1/'
	'/^TASK_PFA_TEST([^,]*,[[:space:]]*\([[:alnum:]_]*\))/task_\1/'
	'/^TASK_PFA_SET([^,]*,[[:space:]]*\([[:alnum:]_]*\))/task_set_\1/'
	'/^TASK_PFA_CLEAR([^,]*,[[:space:]]*\([[:alnum:]_]*\))/task_clear_\1/'
	'/^DEF_MMIO_\(IN\|OUT\)_[XD]([[:space:]]*\([[:alnum:]_]*\),[^)]*)/\2/'
	'/^DEBUGGER_BOILERPLATE([[:space:]]*\([[:alnum:]_]*\))/\1/'
	'/^DEF_PCI_AC_\(\|NO\)RET([[:space:]]*\([[:alnum:]_]*\).*/\2/'
	'/^PCI_OP_READ([[:space:]]*\(\w*\).*[1-4])/pci_bus_read_config_\1/'
	'/^PCI_OP_WRITE([[:space:]]*\(\w*\).*[1-4])/pci_bus_write_config_\1/'
	'/\<DEFINE_\(RT_MUTEX\|MUTEX\|SEMAPHORE\|SPINLOCK\)([[:space:]]*\([[:alnum:]_]*\)/\2/v/'
	'/\<DEFINE_\(RAW_SPINLOCK\|RWLOCK\|SEQLOCK\)([[:space:]]*\([[:alnum:]_]*\)/\2/v/'
	'/\<DECLARE_\(RWSEM\|COMPLETION\)([[:space:]]*\([[:alnum:]_]\+\)/\2/v/'
	'/\<DECLARE_BITMAP([[:space:]]*\([[:alnum:]_]\+\)/\1/v/'
	'/\(^\|\s\)\(\|L\|H\)LIST_HEAD([[:space:]]*\([[:alnum:]_]*\)/\3/v/'
	'/\(^\|\s\)RADIX_TREE([[:space:]]*\([[:alnum:]_]*\)/\2/v/'
	'/\<DEFINE_PER_CPU([^,]*,[[:space:]]*\([[:alnum:]_]*\)/\1/v/'
	'/\<DEFINE_PER_CPU_SHARED_ALIGNED([^,]*,[[:space:]]*\([[:alnum:]_]*\)/\1/v/'
	'/\<DECLARE_WAIT_QUEUE_HEAD([[:space:]]*\([[:alnum:]_]*\)/\1/v/'
	'/\<DECLARE_\(TASKLET\|WORK\|DELAYED_WORK\)([[:space:]]*\([[:alnum:]_]*\)/\2/v/'
	'/\(^\s\)OFFSET([[:space:]]*\([[:alnum:]_]*\)/\2/v/'
	'/\(^\s\)DEFINE([[:space:]]*\([[:alnum:]_]*\)/\2/v/'
	'/\<\(DEFINE\|DECLARE\)_HASHTABLE([[:space:]]*\([[:alnum:]_]*\)/\2/v/'
	'/\<DEFINE_ID\(R\|A\)([[:space:]]*\([[:alnum:]_]\+\)/\2/'
	'/\<DEFINE_WD_CLASS([[:space:]]*\([[:alnum:]_]\+\)/\1/'
	'/\<ATOMIC_NOTIFIER_HEAD([[:space:]]*\([[:alnum:]_]\+\)/\1/'
	'/\<RAW_NOTIFIER_HEAD([[:space:]]*\([[:alnum:]_]\+\)/\1/'
	'/\<DECLARE_FAULT_ATTR([[:space:]]*\([[:alnum:]_]\+\)/\1/'
	'/\<BLOCKING_NOTIFIER_HEAD([[:space:]]*\([[:alnum:]_]\+\)/\1/'
	'/\<DEVICE_ATTR_\(RW\|RO\|WO\)([[:space:]]*\([[:alnum:]_]\+\)/dev_attr_\2/'
	'/\<DRIVER_ATTR_\(RW\|RO\|WO\)([[:space:]]*\([[:alnum:]_]\+\)/driver_attr_\2/'
	'/\<\(DEFINE\|DECLARE\)_STATIC_KEY_\(TRUE\|FALSE\)\(\|_RO\)([[:space:]]*\([[:alnum:]_]\+\)/\4/'
	'/^SEQCOUNT_LOCKTYPE(\([^,]*\),[[:space:]]*\([^,]*\),[^)]*)/seqcount_\2_t/'
	'/^SEQCOUNT_LOCKTYPE(\([^,]*\),[[:space:]]*\([^,]*\),[^)]*)/seqcount_\2_init/'
	'/^\<DECLARE_IDTENTRY[[:alnum:]_]*([^,)]*,[[:space:]]*\([[:alnum:]_]\+\)/\1/'
	'/^\<DEFINE_IDTENTRY[[:alnum:]_]*([[:space:]]*\([[:alnum:]_]\+\)/\1/'
)
regex_kconfig=(
	'/^[[:blank:]]*\(menu\|\)config[[:blank:]]\+\([[:alnum:]_]\+\)/\2/'
	'/^[[:blank:]]*\(menu\|\)config[[:blank:]]\+\([[:alnum:]_]\+\)/CONFIG_\2/'
)
setup_regex()
{
	local mode=$1 lang tmp=() r
	shift

	regex=()
	for lang; do
		case "$lang" in
		asm)       tmp=("${regex_asm[@]}") ;;
		c)         tmp=("${regex_c[@]}") ;;
		kconfig)   tmp=("${regex_kconfig[@]}") ;;
		esac
		for r in "${tmp[@]}"; do
			if test "$mode" = "exuberant"; then
				regex[${#regex[@]}]="--regex-$lang=${r}b"
			else
				# Remove ctags /kind-spec/
				case "$r" in
				/*/*/?/)
					r=${r%?/}
				esac
				# Prepend ^[^#] unless already anchored
				case "$r" in
				/^*) ;;
				*)
					r="/^[^#]*${r#/}"
				esac
				regex[${#regex[@]}]="--regex=$r"
			fi
		done
	done
}

exuberant()
{
	CTAGS_EXTRA="extra"
	if $1 --version 2>&1 | grep -iq universal; then
	    CTAGS_EXTRA="extras"
	fi
	setup_regex exuberant asm c
	# identifiers to ignore by ctags
	local ign=(
		ACPI_EXPORT_SYMBOL
		DEFINE_{TRACE,MUTEX}
		EXPORT_SYMBOL EXPORT_SYMBOL_GPL
		EXPORT_TRACEPOINT_SYMBOL EXPORT_TRACEPOINT_SYMBOL_GPL
		____cacheline_aligned ____cacheline_aligned_in_smp
		____cacheline_internodealigned_in_smp
		__acquires __aligned __always_inline __always_unused
		__attribute
		__cacheline_aligned __cacheline_aligned_in_smp
		__deprecated
		__exitdata
		__initconst __initdata __initdata_memblock
		__maybe_unused __must_check __must_hold
		__packed __packed2__
		__read_mostly __refdata __releases __ro_after_init
		__used
		const
		static
	)
	all_target_sources | \
	xargs $1 -a -I "$(IFS=','; echo "${ign[*]}")" \
	--$CTAGS_EXTRA=+fq --c-kinds=+px --fields=+iaS --langmap=c:+.h \
	"${regex[@]}"

	KCONFIG_ARGS=()
	if ! $1 --list-languages | grep -iq kconfig; then
		setup_regex exuberant kconfig
		KCONFIG_ARGS=(--langdef=kconfig --language-force=kconfig "${regex[@]}")
	fi
	all_kconfigs | xargs $1 -a "${KCONFIG_ARGS[@]}"
}

emacs()
{
	setup_regex emacs asm c
	all_target_sources | xargs $1 -a "${regex[@]}"

	setup_regex emacs kconfig
	all_kconfigs | xargs $1 -a "${regex[@]}"
}

xtags()
{
	if $1 --version 2>&1 | grep -iq exuberant; then
		exuberant $1
	elif $1 --version 2>&1 | grep -iq emacs; then
		emacs $1
	else
		all_target_sources | xargs $1 -a
	fi
}

# Support um (which uses SUBARCH)
if [ "${ARCH}" = "um" ]; then
	if [ "$SUBARCH" = "i386" ]; then
		archinclude=x86
	elif [ "$SUBARCH" = "x86_64" ]; then
		archinclude=x86
	else
		archinclude=${SUBARCH}
	fi
fi

remove_structs=
case "$1" in
	"cscope")
		docscope
		;;

	"gtags")
		dogtags
		;;

	"tags")
		rm -f tags
		xtags ctags
		remove_structs=y
		;;

	"TAGS")
		rm -f TAGS
		xtags etags
		remove_structs=y
		;;
esac

# Remove structure forward declarations.
if [ -n "$remove_structs" ]; then
    LC_ALL=C sed -i -e '/^\([a-zA-Z_][a-zA-Z0-9_]*\)\t.*\t\/\^struct \1;.*\$\/;"\tx$/d' $1
fi