git: 31f9f7037bc7 - stable/13 - Properly conditionalize clang 15-only flags

The branch stable/13 has been updated by dim:

URL: https://cgit.FreeBSD.org/src/commit/?id=31f9f7037bc786afd40fe204b0eefedfbcec4915

commit 31f9f7037bc786afd40fe204b0eefedfbcec4915
Author:     Warner Losh <imp@FreeBSD.org>
AuthorDate: 2023-02-13 15:19:00 +0000
Commit:     Dimitry Andric <dim@FreeBSD.org>
CommitDate: 2023-04-09 14:56:23 +0000

    Properly conditionalize clang 15-only flags
    
    Sponsored by:           Netflix
    Reviewed by:            emaste
    Differential Revision:  https://reviews.freebsd.org/D38550
    
    (cherry picked from commit b9f235ba3178e5315cc1c77c87febd033cf69b3e)
---
 sys/conf/files       | 20 ++++++++++----------
 sys/conf/kern.pre.mk |  5 +++++
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/sys/conf/files b/sys/conf/files
index d1024ae8b8bb..2258acd4c9e7 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -4142,34 +4142,34 @@ libkern/strvalid.c		standard
 libkern/timingsafe_bcmp.c	standard
 contrib/zlib/adler32.c		optional crypto | geom_uzip | \
 	mxge | ddb_ctf | gzio | zfs | zlib \
-	compile-with "${NORMAL_C} -Wno-deprecated-non-prototype"
+	compile-with "${ZLIB_C}"
 contrib/zlib/compress.c		optional crypto | geom_uzip | \
 	mxge | ddb_ctf | gzio | zfs | zlib \
-	compile-with "${NORMAL_C} -Wno-cast-qual -Wno-deprecated-non-prototype"
+	compile-with "${ZLIB_C}"
 contrib/zlib/crc32.c		optional crypto | geom_uzip | \
 	mxge | ddb_ctf | gzio | zfs | zlib \
-	compile-with "${NORMAL_C} ${NO_WSTRICT_PROTOTYPES}"
+	compile-with "${ZLIB_C}"
 contrib/zlib/deflate.c		optional crypto | geom_uzip | \
 	mxge | ddb_ctf | gzio | zfs | zlib \
-	compile-with "${NORMAL_C} -Wno-cast-qual -Wno-deprecated-non-prototype"
+	compile-with "${ZLIB_C}"
 contrib/zlib/inffast.c		optional crypto | geom_uzip | \
 	mxge | ddb_ctf | gzio | zfs | zlib \
-	compile-with "${NORMAL_C} -Wno-deprecated-non-prototype"
+	compile-with "${ZLIB_C}"
 contrib/zlib/inflate.c		optional crypto | geom_uzip | \
 	mxge | ddb_ctf | gzio | zfs | zlib \
-	compile-with "${NORMAL_C} -Wno-deprecated-non-prototype"
+	compile-with "${ZLIB_C}"
 contrib/zlib/inftrees.c		optional crypto | geom_uzip | \
 	mxge | ddb_ctf | gzio | zfs | zlib \
-	compile-with "${NORMAL_C} -Wno-deprecated-non-prototype"
+	compile-with "${ZLIB_C}"
 contrib/zlib/trees.c		optional crypto | geom_uzip | \
 	mxge | ddb_ctf | gzio | zfs | zlib \
-	compile-with "${NORMAL_C} ${NO_WSTRICT_PROTOTYPES}"
+	compile-with "${ZLIB_C}"
 contrib/zlib/uncompr.c		optional crypto | geom_uzip | \
 	mxge | ddb_ctf | gzio | zfs | zlib \
-	compile-with "${NORMAL_C} -Wno-cast-qual -Wno-deprecated-non-prototype"
+	compile-with "${ZLIB_C}"
 contrib/zlib/zutil.c		optional crypto | geom_uzip | \
 	mxge | ddb_ctf | gzio | zfs | zlib \
-	compile-with "${NORMAL_C} ${NO_WSTRICT_PROTOTYPES}"
+	compile-with "${ZLIB_C}"
 dev/zlib/zlib_mod.c		optional crypto | geom_uzip | \
 	mxge | ddb_ctf | gzio | zfs | zlib
 dev/zlib/zcalloc.c		optional crypto | geom_uzip | \
diff --git a/sys/conf/kern.pre.mk b/sys/conf/kern.pre.mk
index 5fba3e58295b..a12aff2c2816 100644
--- a/sys/conf/kern.pre.mk
+++ b/sys/conf/kern.pre.mk
@@ -296,6 +296,11 @@ DTRACE_ASM_CFLAGS=	-x assembler-with-cpp -DLOCORE ${DTRACE_CFLAGS}
 DTRACE_C=	${CC} -c ${DTRACE_CFLAGS}	${WERROR} ${PROF} ${.IMPSRC}
 DTRACE_S=	${CC} -c ${DTRACE_ASM_CFLAGS}	${WERROR} ${.IMPSRC}
 
+# zlib code supports systems that are quite old, but will fix this issue once C2x gets radified.
+# see https://github.com/madler/zlib/issues/633 for details
+ZLIB_CFLAGS=	-Wno-cast-qual ${NO_WDEPRECATED_NON_PROTOTYPE} -Wno-strict-prototypes
+ZLIB_C=		${CC} -c ${CFLAGS} ${WERROR} ${ZLIB_CFLAGS} ${.IMPSRC}
+
 # Special flags for managing the compat compiles for DTrace/FBT
 FBT_CFLAGS=	-DBUILDING_DTRACE -nostdinc -I$S/cddl/dev/fbt/${MACHINE_CPUARCH} -I$S/cddl/dev/fbt ${CDDL_CFLAGS} -I$S/cddl/compat/opensolaris -I$S/cddl/contrib/opensolaris/uts/common  
 .if ${MACHINE_CPUARCH} == "amd64" || ${MACHINE_CPUARCH} == "i386"