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authorMasahiro Yamada <yamada.masahiro@socionext.com>2018-11-30 04:05:26 +0300
committerMasahiro Yamada <yamada.masahiro@socionext.com>2018-12-01 17:13:14 +0300
commitbbda5ec671d3fe62faefa1cab7270aa586042a4b (patch)
treea1d375f74ad25efd2797bffaadfb0dc5fc1f65fe /scripts/gen_ksymdeps.sh
parentee3e46b7efd2954479f87030d31fda3c22bbc763 (diff)
downloadlinux-bbda5ec671d3fe62faefa1cab7270aa586042a4b.tar.xz
kbuild: simplify dependency generation for CONFIG_TRIM_UNUSED_KSYMS
My main motivation of this commit is to clean up scripts/Kbuild.include and scripts/Makefile.build. Currently, CONFIG_TRIM_UNUSED_KSYMS works with a tricky gimmick; possibly exported symbols are detected by letting $(CPP) replace EXPORT_SYMBOL* with a special string '=== __KSYM_*===', which is post-processed by sed, and passed to fixdep. The extra preprocessing is costly, and hacking cmd_and_fixdep is ugly. I came up with a new way to find exported symbols; insert a dummy symbol __ksym_marker_* to each potentially exported symbol. Those dummy symbols are picked up by $(NM), post-processed by sed, then appended to .*.cmd files. I collected the post-process part to a new shell script scripts/gen_ksymdeps.sh for readability. The dummy symbols are put into the .discard.* section so that the linker script rips them off the final vmlinux or modules. A nice side-effect is building with CONFIG_TRIM_UNUSED_KSYMS will be much faster. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nicolas Pitre <nico@linaro.org>
Diffstat (limited to 'scripts/gen_ksymdeps.sh')
-rwxr-xr-xscripts/gen_ksymdeps.sh25
1 files changed, 25 insertions, 0 deletions
diff --git a/scripts/gen_ksymdeps.sh b/scripts/gen_ksymdeps.sh
new file mode 100755
index 000000000000..1324986e1362
--- /dev/null
+++ b/scripts/gen_ksymdeps.sh
@@ -0,0 +1,25 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+set -e
+
+# List of exported symbols
+ksyms=$($NM $1 | sed -n 's/.*__ksym_marker_\(.*\)/\1/p' | tr A-Z a-z)
+
+if [ -z "$ksyms" ]; then
+ exit 0
+fi
+
+echo
+echo "ksymdeps_$1 := \\"
+
+for s in $ksyms
+do
+ echo $s | sed -e 's:^_*: $(wildcard include/ksym/:' \
+ -e 's:__*:/:g' -e 's/$/.h) \\/'
+done
+
+echo
+echo "$1: \$(ksymdeps_$1)"
+echo
+echo "\$(ksymdeps_$1):"