Commit 0bde1150 authored by Simon Marlow's avatar Simon Marlow
Browse files

Avoid unnecessary recompilation after ./configure (helps #3228)

We cache the old versions of files generated by configure, so that if
configure touches the file without changing it, we can detect that and
restore the timestamp.
parent a6ce3525
......@@ -51,10 +51,39 @@ include mk/
# No need to update makefiles for these targets:
REALGOALS=$(filter-out bootstrapping-files framework-pkg clean clean_% distclean maintainer-clean show help,$(MAKECMDGOALS))
# configure touches certain files even if they haven't changed. This
# can mean a lot of unnecessary recompilation after a re-configure, so
# here we cache the old versions of these files so we can restore the
# timestamps.
define check-configure-file
# $1 = file
if ! test -f $1.old; then \
echo "backing up $1"; \
cp $1 $1.old; \
touch -r $1 $1.old; \
else \
if test $1 -nt $1.old; then \
if cmp $1 $1.old; then \
echo "$1 has been touched, but has not changed"; \
touch -r $1.old $1; \
else \
echo "$1 has changed"; \
cp $1 $1.old; \
touch -r $1 $1.old; \
fi \
fi \
# NB. not the same as saying '%: ...', which doesn't do the right thing:
# it does nothing if we specify a target that already exists.
@$(call check-configure-file,mk/
@$(call check-configure-file,mk/
@$(call check-configure-file,compiler/ghc.cabal)
@echo "===--- updating makefiles phase 0"
$(MAKE) -r --no-print-directory -f phase=0 just-makefiles
ifneq "$(OMIT_PHASE_1)" "YES"
......@@ -922,8 +922,10 @@ endif
distclean : clean
"$(RM)" $(RM_OPTS) config.cache config.status config.log mk/config.h mk/stamp-h
"$(RM)" $(RM_OPTS) mk/ mk/ mk/
"$(RM)" $(RM_OPTS) mk/ mk/
"$(RM)" $(RM_OPTS) extra-gcc-opts docs/users_guide/ug-book.xml
"$(RM)" $(RM_OPTS) compiler/ghc.cabal ghc/ghc-bin.cabal
"$(RM)" $(RM_OPTS) compiler/ghc.cabal compiler/ghc.cabal.old
"$(RM)" $(RM_OPTS) ghc/ghc-bin.cabal
"$(RM)" $(RM_OPTS) libraries/base/include/HsBaseConfig.h
"$(RM)" $(RM_OPTS) libraries/directory/include/HsDirectoryConfig.h
"$(RM)" $(RM_OPTS) libraries/process/include/HsProcessConfig.h
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