Merge tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - add modpost warn exported symbols marked as 'static' because 'static'
   and EXPORT_SYMBOL is an odd combination

 - break the build early if gold linker is used

 - optimize the Bison rule to produce .c and .h files by a single
   pattern rule

 - handle PREEMPT_RT in the module vermagic and UTS_VERSION

 - warn CONFIG options leaked to the user-space except existing ones

 - make single targets work properly

 - rebuild modules when module linker scripts are updated

 - split the module final link stage into scripts/Makefile.modfinal

 - fix the missed error code in merge_config.sh

 - improve the error message displayed on the attempt of the O= build in
   unclean source tree

 - remove 'clean-dirs' syntax

 - disable -Wimplicit-fallthrough warning for Clang

 - add CONFIG_CC_OPTIMIZE_FOR_SIZE_O3 for ARC

 - remove ARCH_{CPP,A,C}FLAGS variables

 - add $(BASH) to run bash scripts

 - change *CFLAGS_<basetarget>.o to take the relative path to $(obj)
   instead of the basename

 - stop suppressing Clang's -Wunused-function warnings when W=1

 - fix linux/export.h to avoid genksyms calculating CRC of trimmed
   exported symbols

 - misc cleanups

* tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (63 commits)
  genksyms: convert to SPDX License Identifier for lex.l and parse.y
  modpost: use __section in the output to *.mod.c
  modpost: use MODULE_INFO() for __module_depends
  export.h, genksyms: do not make genksyms calculate CRC of trimmed symbols
  export.h: remove defined(__KERNEL__), which is no longer needed
  kbuild: allow Clang to find unused static inline functions for W=1 build
  kbuild: rename KBUILD_ENABLE_EXTRA_GCC_CHECKS to KBUILD_EXTRA_WARN
  kbuild: refactor scripts/Makefile.extrawarn
  merge_config.sh: ignore unwanted grep errors
  kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)
  modpost: add NOFAIL to strndup
  modpost: add guid_t type definition
  kbuild: add $(BASH) to run scripts with bash-extension
  kbuild: remove ARCH_{CPP,A,C}FLAGS
  kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC
  kbuild: Do not enable -Wimplicit-fallthrough for clang for now
  kbuild: clean up subdir-ymn calculation in Makefile.clean
  kbuild: remove unneeded '+' marker from cmd_clean
  kbuild: remove clean-dirs syntax
  kbuild: check clean srctree even earlier
  ...

1 files changed, 14 insertions, 6 deletions

diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 599c27b56c29..b056a40116da 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -130,10 +130,6 @@ struct ftrace_likely_data {
 
 /*
  * Force always-inline if the user requests it so via the .config.
- * GCC does not warn about unused static inline functions for
- * -Wunused-function.  This turns out to avoid the need for complex #ifdef
- * directives.  Suppress the warning in clang as well by using "unused"
- * function attribute, which is redundant but not harmful for gcc.
  * Prefer gnu_inline, so that extern inline functions do not emit an
  * externally visible function. This makes extern inline behave as per gnu89
  * semantics rather than c99. This prevents multiple symbol definition errors
@@ -144,16 +140,28 @@ struct ftrace_likely_data {
  */
 #if !defined(CONFIG_OPTIMIZE_INLINING)
 #define inline inline __attribute__((__always_inline__)) __gnu_inline \
-	__maybe_unused notrace
+	__inline_maybe_unused notrace
 #else
 #define inline inline                                    __gnu_inline \
-	__maybe_unused notrace
+	__inline_maybe_unused notrace
 #endif
 
 #define __inline__ inline
 #define __inline   inline
 
 /*
+ * GCC does not warn about unused static inline functions for -Wunused-function.
+ * Suppress the warning in clang as well by using __maybe_unused, but enable it
+ * for W=1 build. This will allow clang to find unused functions. Remove the
+ * __inline_maybe_unused entirely after fixing most of -Wunused-function warnings.
+ */
+#ifdef KBUILD_EXTRA_WARN1
+#define __inline_maybe_unused
+#else
+#define __inline_maybe_unused __maybe_unused
+#endif
+
+/*
  * Rather then using noinline to prevent stack consumption, use
  * noinline_for_stack instead.  For documentation reasons.
  */