commit e79c58a03f5099692774fc17c2e0450652a0d13c
Author: Bryan Drewery <bdrewery@FreeBSD.org>
Date:   Tue Mar 21 17:26:41 2017 -0700

    stash compiler metadata cache
    
    PR:             212877

diff --git Makefile Makefile
index 8b02703bda5d..0f6164b46d0e 100644
--- Makefile
+++ Makefile
@@ -101,6 +101,12 @@
 # For more information, see the build(7) manual page.
 #
 
+# Suck in compiler metadata from buildworld/toolchain if possible to avoid
+# running CC from bsd.compiler.mk.
+.if make(installworld) || make(install)
+.-include "compiler-metadata.mk"
+.endif
+
 # This is included so CC is set to ccache for -V, and COMPILER_TYPE/VERSION
 # can be cached for sub-makes.
 .if ${MAKE_VERSION} >= 20140620 && defined(.PARSEDIR)
diff --git Makefile.inc1 Makefile.inc1
index 415755d565c3..5257371624c8 100644
--- Makefile.inc1
+++ Makefile.inc1
@@ -160,6 +160,19 @@ CROSSENV+=	COMPILER_VERSION=${X_COMPILER_VERSION} \
 		COMPILER_FREEBSD_VERSION=${X_COMPILER_FREEBSD_VERSION}
 .endif
 .endif
+# Store some compiler metadata for use in installworld where we don't
+# want to invoke CC at all.
+_COMPILER_METADATA_VARS=	COMPILER_VERSION \
+				COMPILER_TYPE \
+				COMPILER_FREEBSD_VERSION
+compiler-metadata: .PHONY
+	@: > ${.TARGET}.mk
+	@echo ".info Using cached compiler metadata from build on $$(hostname) at $$(date)" \
+	    > ${.TARGET}.mk
+.for v in ${_COMPILER_METADATA_VARS}
+	@echo "${v}=${${v}}" >> ${.TARGET}.mk
+.endfor
+	@echo ".export ${_COMPILER_METADATA_VARS}" >> ${.TARGET}.mk
 
 # Handle external binutils.
 .if defined(CROSS_TOOLCHAIN_PREFIX)
@@ -764,6 +777,12 @@ _cross-tools:
 	@echo "--------------------------------------------------------------"
 	${_+_}cd ${.CURDIR}; ${XMAKE} cross-tools
 	${_+_}cd ${.CURDIR}; ${XMAKE} kernel-tools
+_compiler_metadata:
+	@echo
+	@echo "--------------------------------------------------------------"
+	@echo ">>> stage 3.1: recording compiler metadata for install"
+	@echo "--------------------------------------------------------------"
+	${_+_}cd ${.CURDIR}; ${XMAKE} compiler-metadata
 _includes:
 	@echo
 	@echo "--------------------------------------------------------------"
@@ -797,6 +816,7 @@ WMAKE_TGTS+=	_worldtmp _legacy
 WMAKE_TGTS+=	_bootstrap-tools
 .endif
 WMAKE_TGTS+=	_cleanobj _obj _build-tools _cross-tools
+WMAKE_TGTS+=	_compiler_metadata
 WMAKE_TGTS+=	_includes _libraries
 WMAKE_TGTS+=	everything
 .if defined(LIBCOMPAT) && empty(SUBDIR_OVERRIDE)