[PATCH v3 04/57] kbuild: Drop -Wdeclaration-after-statement

From: Peter Zijlstra
Date: Mon Jun 12 2023 - 05:55:56 EST


With the advent on scope-based resource management it comes really
tedious to abide by the contraints of -Wdeclaration-after-statement.

It will still be recommeneded to place declarations at the start of a
scope where possible, but it will no longer be enforced.

Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
Makefile | 6 +-----
arch/arm64/kernel/vdso32/Makefile | 2 --
2 files changed, 1 insertion(+), 7 deletions(-)

--- a/Makefile
+++ b/Makefile
@@ -447,8 +447,7 @@ HOSTRUSTC = rustc
HOSTPKG_CONFIG = pkg-config

KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
- -O2 -fomit-frame-pointer -std=gnu11 \
- -Wdeclaration-after-statement
+ -O2 -fomit-frame-pointer -std=gnu11
KBUILD_USERCFLAGS := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
KBUILD_USERLDFLAGS := $(USERLDFLAGS)

@@ -1012,9 +1011,6 @@ endif
# arch Makefile may override CC so keep this after arch Makefile is included
NOSTDINC_FLAGS += -nostdinc

-# warn about C99 declaration after statement
-KBUILD_CFLAGS += -Wdeclaration-after-statement
-
# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
KBUILD_CFLAGS += -Wvla

--- a/arch/arm64/kernel/vdso32/Makefile
+++ b/arch/arm64/kernel/vdso32/Makefile
@@ -65,11 +65,9 @@ VDSO_CFLAGS += -Wall -Wundef -Wstrict-pr
-fno-strict-aliasing -fno-common \
-Werror-implicit-function-declaration \
-Wno-format-security \
- -Wdeclaration-after-statement \
-std=gnu11
VDSO_CFLAGS += -O2
# Some useful compiler-dependent flags from top-level Makefile
-VDSO_CFLAGS += $(call cc32-option,-Wdeclaration-after-statement,)
VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign)
VDSO_CFLAGS += -fno-strict-overflow
VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes)