svn commit: r338096 - head/tools/build/mk

[Alex Richardson]

Author: arichardson
Date: Mon Aug 20 10:39:42 2018
New Revision: 338096
URL: https://svnweb.freebsd.org/changeset/base/338096

Log:
  Avoid depending on system headers from the source tree during bootstrap
  
  This can cause surprising errors if the build tools is built against
  headers that don't match the host system. It is also required in order
  to allow building on non-FreeBSD systems where the headers in
  /usr/include/sys are usually completely incompatible with those in the
  source tree.
  
  I added an error to Makefile.boot if this is done and found this was
  only the case in libnv. With this error in the Makefile ABI breakages
  such as r336019 should no longer be possible.
  
  Reviewed By:	bdrewery, kevans
  Approved By:	jhb (mentor)
  Differential Revision: https://reviews.freebsd.org/D16186

Modified:
  head/tools/build/mk/Makefile.boot

Modified: head/tools/build/mk/Makefile.boot
==============================================================================
--- head/tools/build/mk/Makefile.boot	Mon Aug 20 10:39:37 2018	(r338095)
+++ head/tools/build/mk/Makefile.boot	Mon Aug 20 10:39:42 2018	(r338096)
@@ -7,3 +7,20 @@ LDFLAGS+=	-L${WORLDTMP}/legacy/usr/lib
 
 # we do not want to capture dependencies referring to the above
 UPDATE_DEPENDFILE= no
+
+# When building host tools we should never pull in headers from the source sys
+# directory to avoid any ABI issues that might cause the built binary to crash.
+# The only exceptions to this are sys/cddl/compat for dtrace bootstrap tools and
+# sys/crypto for libmd bootstrap.
+.if !empty(CFLAGS:M*${SRCTOP}/sys*:N*${SRCTOP}/sys/cddl/compat*:N*${SRCTOP}/sys/crypto*)
+.error Do not include $${SRCTOP}/sys when building bootstrap tools. \
+    Copy the header to $${WORLDTMP}/legacy in tools/build/Makefile instead. \
+    Error was caused by Makefile in ${.CURDIR}
+.endif
+
+# ${SRCTOP}/include should also never be used to avoid ABI issues
+.if !empty(CFLAGS:M*${SRCTOP}/include*)
+.error Do not include $${SRCTOP}/include when building bootstrap tools. \
+    Copy the header to $${WORLDTMP}/legacy in tools/build/Makefile instead. \
+    Error was caused by Makefile in ${.CURDIR}
+.endif