util/lint: Unify checks for git worktree

Linters try to determine whether they are running in a git worktree so
that `git grep` can be used instead of `grep`. These checks are done in
different not truly correct ways and thus the linters don't use `git
grep` when running from a worktree subdirectory, e.g. in a git subtree
environment.

Unify checks using `git rev-parse --is-inside-work-tree`.

Change-Id: I3f54afc99ad0f0e3052cffdd32bdd9649cf3d720
Signed-off-by: Alex Thiessen <alex.thiessen.de+coreboot@gmail.com>
Reviewed-on: https://review.coreboot.org/23297
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

util/lint/lint-008-kconfig

@@ -23,7 +23,9 @@ fi
 
 # If coreboot is in a git repo, use git grep to check as it will ignore any
 # files in the tree that aren't checked into git
-if [ -n "$(command -v git)" ] && [ -e ".git" ]; then
+if [ -n "$(command -v git)" ] && \
+	[ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]
+then
 	env perl util/lint/kconfig_lint
 else
 	env perl util/lint/kconfig_lint --no_git_grep

util/lint/lint-014-qualified-types

@@ -21,7 +21,9 @@ EXCLUDED_DIRS='^src/vendorcode\|^util/romcc\|cbfstool/lzma\|cbfstool/lz4'
 INCLUDED_FILES='\.[ch]:'
 
 # Use git grep if the code is in a git repo, otherwise use grep.
-if [ -n "$(command -v git)" ] && [ -d .git ]; then
+if [ -n "$(command -v git)" ] && \
+	[ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]
+then
 	GREP_FILES="git grep -n"
 else
 	GREP_FILES="grep -rn"

util/lint/lint-016-non-ascii

@@ -22,7 +22,9 @@ EXCLUDED_FILES='to-wiki/towiki\.sh$\|vga/vga_font\|video/font\|PDCurses.*x11'
 EXCLUDED_PHRASES='Copyright\|Ported to\|Intel®\|°C\|°F\|Athlon™\|Copyright.*©\|A-Za-zÀ-ÿ'
 
 # Use git ls-files if the code is in a git repo, otherwise use find.
-if [ -n "$(command -v git)" ] && [ -d .git ]; then
+if [ -n "$(command -v git)" ] && \
+	[ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]
+then
 	FIND_FILES="git ls-files"
 else
 	FIND_FILES="find . "

util/lint/lint-extended-015-final-newlines

@@ -20,7 +20,9 @@ EXCLUDED_DIRS='src/vendorcode/\|util/romcc/\|cbfstool/lzma/\|cbfstool/lz4/\|Docu
 EXCLUDED_FILES='\.jpg$\|\.cksum$\|\.bin$\|\.hex$\|\.ico$\|\.o$\|\.bz2$\|\.xz$\|^.tmpconfig\|\.pyc$\|_shipped$\|sha256$\|\.png$\|\.patch$'
 
 # Use git ls-files if the code is in a git repo, otherwise use find.
-if [ -n "$(command -v git)" ] && [ -d .git ]; then
+if [ -n "$(command -v git)" ] && \
+	[ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]
+then
 	FIND_FILES="git ls-files"
 else
 	FIND_FILES="find . "

util/lint/lint-extended-020-signed-off-by

@@ -16,7 +16,9 @@
 # DESCR: Check for a signed-off-by line on the latest git commit
 
 # This test is mainly for the jenkins server
-if [ -n "$(command -v git)" ] && [ -d .git ]; then
+if [ -n "$(command -v git)" ] && \
+	[ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]
+then
 	if [ -z "$(git log -n 1 | grep '[[:space:]]\+Signed-off-by: ')" ]; then
 		echo "No Signed-off-by line in commit message"
 	fi

util/lint/lint-stable-004-style-labels

@@ -18,7 +18,9 @@
 LC_ALL=C export LC_ALL
 
 # Use git ls-files if the code is in a git repo, otherwise use find.
-if [ -n "$(command -v git)" ] && [ -d .git ]; then
+if [ -n "$(command -v git)" ] && \
+	[ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]
+then
 	FIND_FILES="git ls-files"
 else
 	FIND_FILES="find src"

util/lint/lint-stable-008-kconfig

@@ -23,7 +23,9 @@ fi
 
 # If coreboot is in a git repo, use git grep to check as it will ignore any
 # files in the tree that aren't checked into git
-if [ -n "$(command -v git)" ] && [ -e ".git" ]; then
+if [ -n "$(command -v git)" ] && \
+	[ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]
+then
 	env perl util/lint/kconfig_lint --warnings_off 2>&1
 else
 	env perl util/lint/kconfig_lint --no_git_grep --warnings_off 2>&1

util/lint/lint-stable-013-site-local

@@ -22,7 +22,9 @@
 
 LC_ALL=C export LC_ALL
 
-if [ -n "$(command -v git)" ]  && [ -e ".git" ]; then
+if [ -n "$(command -v git)" ] && \
+	[ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]
+then
 	if [ -n "$(git ls-files site-local/*)" ]; then
 		echo "Error: site-local must be kept separate from the coreboot repository."
 	fi

util/lint/lint-stable-017-configs

@@ -19,7 +19,9 @@ LC_ALL=C export LC_ALL
 SYMBOLS='CONFIG_ARCH_\|CONFIG_MAINBOARD_HAS_'
 
 # Use git grep if the code is in a git repo, otherwise use grep.
-if [ -n "$(command -v git)" ] && [ -d .git ]; then
+if [ -n "$(command -v git)" ] && \
+	[ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]
+then
 	GREP="git grep -l"
 else
 	GREP="grep -rl"

util/lint/lint-stable-018-symlinks

@@ -19,7 +19,9 @@ LC_ALL=C export LC_ALL
 EXCLUDED_DIRS='^3rdparty\|^site-local'
 
 # If the code is in a git repo, only print files that are checked in
-if [ -n "$(command -v git)" ] && [ -d .git ]; then
+if [ -n "$(command -v git)" ] && \
+	[ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]
+then
 	git ls-tree -r HEAD | \
 		grep ^120000 | \
 		cut -f2 | \

util/lint/lint-stable-019-header-files

@@ -23,7 +23,9 @@ EXCLUDED_FILES='src/include/kconfig.h'
 HEADER_FILES="k*config"
 
 # Use git grep if the code is in a git repo, otherwise use grep.
-if [ -n "$(command -v git)" ] && [ -d .git ]; then
+if [ -n "$(command -v git)" ] && \
+	[ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]
+then
 	GREP_FILES="git grep -n"
 else
 	GREP_FILES="grep -rn"

util/lint/lint-stable-021-coreboot-lowercase

@@ -19,7 +19,9 @@ LC_ALL=C export LC_ALL
 EXCLUDE='^3rdparty/\|util/crossgcc/xgcc\|Binary file\|coreboot\|COREBOOT\|CorebootPayload\|CorebootModule\|minnowboard.org/Coreboot\|.*\.patch$\|CorebootBdsLib\|^payloads/external'
 
 # Use git grep if the code is in a git repo, otherwise use grep.
-if [ -n "$(command -v git)" ] && [ -d .git ]; then
+if [ -n "$(command -v git)" ] && \
+	[ "$(git rev-parse --is-inside-work-tree 2>/dev/null)" = "true" ]
+then
 	GREP_FILES="git grep -in"
 
 	# Check last commit message