svn commit: r296696 - head/share/mk

[Bryan Drewery]

Author: bdrewery
Date: Fri Mar 11 23:45:13 2016
New Revision: 296696
URL: https://svnweb.freebsd.org/changeset/base/296696

Log:
  DIRDEPS_BUILD: Avoid rebuilds due to changed build commands with newly staged tools.
  
  This is a follow-up to r291561 which reworked the bootstrap tool PATH
  handling.
  
  An example of this is when building lib/clang/libclangedit.  At first
  clang-tblgen will not be staged in the host tree so it will have
  CLANG_TBLGEN=clang-tblgen set and exported.  During the build though it
  will stage clang-tblgen and then find it via the PATH.  On the next
  build it finds clang-tblgen in the stage directory and would set
  CLANG_TBLGEN=<stagedir/usr/bin>/clang-tblgen thus causing the build
  command to change.  In both cases the same exact tool was used though so
  there is no need to rebuild.  If the tool did change the normal
  meta/filemon handling would pick that up via timestamp comparisons and
  rebuild.
  
  Sponsored by:	EMC / Isilon Storage Division

Modified:
  head/share/mk/local.meta.sys.mk

Modified: head/share/mk/local.meta.sys.mk
==============================================================================
--- head/share/mk/local.meta.sys.mk	Fri Mar 11 23:45:09 2016	(r296695)
+++ head/share/mk/local.meta.sys.mk	Fri Mar 11 23:45:13 2016	(r296696)
@@ -236,8 +236,7 @@ PATH:= ${TOOLSDIR}${dir}:${PATH}
 _toolchain_bin.${var}=	${TOOLSDIR}${_toolchain_bin_${var}:U/usr/bin/${var:tl}}
 .if exists(${_toolchain_bin.${var}})
 HOST_${var}?=	${_toolchain_bin.${var}}
-${var}?=	${HOST_${var}}
-.export		HOST_${var} ${var}
+.export		HOST_${var}
 .endif
 .endfor
 .endif