After r232322, it turned out many people (and some ports) are building

kernel modules using their old installed /usr/share/mk/bsd.*.mk files,
instead of the updated ones in their source tree.  This leads to errors
like:

  "sys/conf/kmod.mk", line 111: Malformed conditional (${MK_CLANG_IS_CC} == "no" && ${CC:T:Mclang} != "clang")

Obviously, these errors will go away after a "make installworld", or
alternatively, by using "make buildenv" before attempting to manually
build modules.

However, since it is apparently an expected use case to build using old
.mk files, change the way we test for clang, so it also works when the
MK_CLANG_IS_CC macro doesn't exist.

Note the conditional expressions are becoming rather unreadable now, but
I will attempt to fix that on a followup commit.

MFC after:	2 weeks

3 files changed, 6 insertions, 6 deletions

diff --git a/sys/conf/kern.mk b/sys/conf/kern.mk
index d2ed68d..76042d2 100644
--- a/sys/conf/kern.mk
+++ b/sys/conf/kern.mk
@@ -15,7 +15,7 @@ CWARNFLAGS?=	-Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes \
 # Disable a few warnings for clang, since there are several places in the
 # kernel where fixing them is more trouble than it is worth, or where there is
 # a false positive.
-.if ${MK_CLANG_IS_CC} != "no" || ${CC:T:Mclang} == "clang"
+.if ${CC:T:Mclang} == "clang" || (defined(MK_CLANG_IS_CC) && ${MK_CLANG_IS_CC} != "no")
 NO_WCONSTANT_CONVERSION=	-Wno-constant-conversion
 NO_WARRAY_BOUNDS=		-Wno-array-bounds
 NO_WSHIFT_COUNT_NEGATIVE=	-Wno-shift-count-negative
@@ -50,7 +50,7 @@ CWARNEXTRA?=	-Wno-error-tautological-compare -Wno-error-empty-body \
 #                          -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42
 #
 .if ${MACHINE_CPUARCH} == "i386"
-.if ${MK_CLANG_IS_CC} == "no" && ${CC:T:Mclang} != "clang"
+.if ${CC:T:Mclang} != "clang" && (!defined(MK_CLANG_IS_CC) || ${MK_CLANG_IS_CC} == "no")
 CFLAGS+=	-mno-align-long-strings -mpreferred-stack-boundary=2 -mno-sse
 .else
 CFLAGS+=	-mno-aes -mno-avx
@@ -98,7 +98,7 @@ INLINE_LIMIT?=	15000
 # (-mfpmath= is not supported)
 #
 .if ${MACHINE_CPUARCH} == "amd64"
-.if ${MK_CLANG_IS_CC} == "no" && ${CC:T:Mclang} != "clang"
+.if ${CC:T:Mclang} != "clang" && (!defined(MK_CLANG_IS_CC) || ${MK_CLANG_IS_CC} == "no")
 CFLAGS+=	-mno-sse
 .else
 CFLAGS+=	-mno-aes -mno-avx
diff --git a/sys/conf/kern.pre.mk b/sys/conf/kern.pre.mk
index 07eaa38..fa4ef87 100644
--- a/sys/conf/kern.pre.mk
+++ b/sys/conf/kern.pre.mk
@@ -34,7 +34,7 @@ _MINUS_O=	-O2
 .endif
 .endif
 .if ${MACHINE_CPUARCH} == "amd64"
-.if ${MK_CLANG_IS_CC} == "no" && ${CC:T:Mclang} != "clang"
+.if ${CC:T:Mclang} != "clang" && (!defined(MK_CLANG_IS_CC) || ${MK_CLANG_IS_CC} == "no")
 COPTFLAGS?=-O2 -frename-registers -pipe
 .else
 COPTFLAGS?=-O2 -pipe
@@ -84,7 +84,7 @@ INCLUDES+= -I$S/dev/cxgb -I$S/dev/cxgbe
 
 CFLAGS=	${COPTFLAGS} ${C_DIALECT} ${DEBUG} ${CWARNFLAGS}
 CFLAGS+= ${INCLUDES} -D_KERNEL -DHAVE_KERNEL_OPTION_HEADERS -include opt_global.h
-.if ${MK_CLANG_IS_CC} == "no" && ${CC:T:Mclang} != "clang"
+.if ${CC:T:Mclang} != "clang" && (!defined(MK_CLANG_IS_CC) || ${MK_CLANG_IS_CC} == "no")
 CFLAGS+= -fno-common -finline-limit=${INLINE_LIMIT}
 .if ${MACHINE_CPUARCH} != "mips"
 CFLAGS+= --param inline-unit-growth=100
diff --git a/sys/conf/kmod.mk b/sys/conf/kmod.mk
index cb460ee..98437b3 100644
--- a/sys/conf/kmod.mk
+++ b/sys/conf/kmod.mk
@@ -108,7 +108,7 @@ CFLAGS+=	-I. -I@
 # for example.
 CFLAGS+=	-I@/contrib/altq
 
-.if ${MK_CLANG_IS_CC} == "no" && ${CC:T:Mclang} != "clang"
+.if ${CC:T:Mclang} != "clang" && (!defined(MK_CLANG_IS_CC) || ${MK_CLANG_IS_CC} == "no")
 CFLAGS+=	-finline-limit=${INLINE_LIMIT}
 CFLAGS+= --param inline-unit-growth=100
 CFLAGS+= --param large-function-growth=1000