lib/clan/llvm.build.mk: Shouldn't BUILD_TRIPLE definition rely host 'cc -dumpmachine'?

[Eddy Petrișor]

Hello,

I am trying to make the FreeBSD code base build from a Linux host and
found this bit which defines BUILD_TRIPLE in a way which to my
untrained eyes look like overengineering.

 .if ${TARGET_ARCH:Marmv6*} && (!defined(CPUTYPE) || ${CPUTYPE:M*soft*} == "")
 TARGET_ABI=    -gnueabihf
 .elif ${TARGET_ARCH:Marm*}
 TARGET_ABI=    -gnueabi
 .else
 TARGET_ABI=
 .endif
 VENDOR=        unknown
 OS_VERSION=    freebsd12.0

 TARGET_TRIPLE?=
${TARGET_ARCH:C/amd64/x86_64/:C/arm64/aarch64/}-${VENDOR}-${OS_VERSION}${TARGET_ABI}
 BUILD_TRIPLE?=
${BUILD_ARCH:C/amd64/x86_64/:C/arm64/aarch64/}-${VENDOR}-${OS_VERSION}


To support a Linux host I made these changes that is using 'cc
-dumpmachine' to get the correct BUILD_TRIPLE, but I am wondering if
it shouldn't be OK for building on a FreeBSD host

 .if ${TARGET_ARCH:Marmv6*} && (!defined(CPUTYPE) || ${CPUTYPE:M*soft*} == "")
 TARGET_ABI=    -gnueabihf
 .elif ${TARGET_ARCH:Marm*}
 TARGET_ABI=    -gnueabi
 .else
 TARGET_ABI=
 .endif
 VENDOR=        unknown
 OS_VERSION=    freebsd12.0
+BUILD_OS!=    uname -s
+

 TARGET_TRIPLE?=
${TARGET_ARCH:C/amd64/x86_64/:C/arm64/aarch64/}-${VENDOR}-${OS_VERSION}${TARGET_ABI}
+.if ${BUILD_OS} == FreeBSD
 BUILD_TRIPLE?=
${BUILD_ARCH:C/amd64/x86_64/:C/arm64/aarch64/}-${VENDOR}-${OS_VERSION}
+.else
+HOST_CC_DUMPMACHINE!=    cc -dumpmachine
+BUILD_TRIPLE?=    ${HOST_CC_DUMPMACHINE}
+.endif

What do you think, should the code be instead:

 .if ${TARGET_ARCH:Marmv6*} && (!defined(CPUTYPE) || ${CPUTYPE:M*soft*} == "")
 TARGET_ABI=    -gnueabihf
 .elif ${TARGET_ARCH:Marm*}
 TARGET_ABI=    -gnueabi
 .else
 TARGET_ABI=
 .endif
 VENDOR=        unknown
 OS_VERSION=    freebsd12.0

 TARGET_TRIPLE?=
${TARGET_ARCH:C/amd64/x86_64/:C/arm64/aarch64/}-${VENDOR}-${OS_VERSION}${TARGET_ABI}
+HOST_CC_DUMPMACHINE!=    cc -dumpmachine
+BUILD_TRIPLE?=    ${HOST_CC_DUMPMACHINE}


-- 
Eddy Petrișor