From 6f859910070556a0cf07fef17632ec6f18a39984 Mon Sep 17 00:00:00 2001
From: Ian Lynagh <igloo@earth.li>
Date: Tue, 15 Dec 2009 13:53:50 +0000
Subject: [PATCH] Just make C dependencies once, rather than each way This
 makes generating C dependencies for the RTS take 3 seconds,
 rather than 30.

---
 rts/ghc.mk                  |    7 +++++++
 rules/build-dependencies.mk |   13 ++++++++-----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/rts/ghc.mk b/rts/ghc.mk
index bffdaae..aee3369 100644
--- a/rts/ghc.mk
+++ b/rts/ghc.mk
@@ -367,6 +367,13 @@ rts_dist_C_SRCS  = $(rts_C_SRCS) $(rts_thr_EXTRA_C_SRCS)
 rts_dist_S_SRCS =  $(rts_S_SRCS)
 rts_dist_C_FILES = $(rts_C_SRCS) $(rts_thr_EXTRA_C_SRCS) $(rts_S_SRCS)
 
+# Hack: we define every way-related option here, so that we get (hopefully)
+# a superset of the dependencies.  To do this properly, we should generate
+# a different set of dependencies for each way.  Further hack: PROFILING an
+
+# TICKY_TICKY can't be used together, so we omit TICKY_TICKY for now.
+rts_dist_MKDEPENDC_OPTS += -DPROFILING -DTHREADED_RTS -DDEBUG
+
 ifeq "$(HaveDtrace)" "YES"
 
 rts_dist_MKDEPENDC_OPTS += -Irts/dist/build
diff --git a/rules/build-dependencies.mk b/rules/build-dependencies.mk
index d6cf33e..2f8b607 100644
--- a/rules/build-dependencies.mk
+++ b/rules/build-dependencies.mk
@@ -45,9 +45,12 @@ $$($1_$2_depfile_c_asm) : $$($1_$2_C_FILES_DEPS) $$($1_$2_S_FILES) | $$$$(dir $$
 	"$$(RM)" $$(RM_OPTS) $$@.tmp
 	touch $$@.tmp
 ifneq "$$(strip $$($1_$2_C_FILES_DEPS)$$($1_$2_S_FILES))" ""
+# We ought to actually do this for each way in $$($1_$2_WAYS), but then
+# it takes a long time to make the C deps for the RTS (30 seconds rather
+# than 3), so instead we just pass the list of ways in and let addCFileDeps
+# copy the deps for each way on the assumption that they are the same
 	$$(foreach f,$$($1_$2_C_FILES_DEPS) $$($1_$2_S_FILES), \
-	  $$(foreach w,$$($1_$2_WAYS), \
-	    $$(call addCFileDeps,$1,$2,$$($1_$2_depfile_c_asm),$$f,$$w)))
+	    $$(call addCFileDeps,$1,$2,$$($1_$2_depfile_c_asm),$$f,$$($1_$2_WAYS)))
 	"$$(RM)" $$(RM_OPTS) $$@.bit
 endif
 	echo "$1_$2_depfile_c_asm_EXISTS = YES" >> $$@.tmp
@@ -79,12 +82,12 @@ endef
 # $2 = distdir
 # $3 = depfile
 # $4 = file
-# $5 = way
+# $5 = ways
 # The formatting of this definition (e.g. the blank line above) is
 # important, in order to get make to generate the right makefile code.
 define addCFileDeps
 
-	$(CPP) $($1_$2_MKDEPENDC_OPTS) $($1_$2_$5_ALL_CC_OPTS) $($(basename $4)_CC_OPTS) -MM $4 -MF $3.bit
-	sed -e "1s|\.o|\.$($5_osuf)|" -e "1s|^|$(dir $4)|" -e "1s|$1/|$1/$2/build/|" -e "s|$(TOP)/||g" -e "s|$2/build/$2/build|$2/build|g" $3.bit >> $3.tmp
+	$(CPP) $($1_$2_MKDEPENDC_OPTS) $($1_$2_v_ALL_CC_OPTS) $($(basename $4)_CC_OPTS) -MM $4 -MF $3.bit
+	$(foreach w,$5,sed -e "1s|\.o|\.$($w_osuf)|" -e "1s|^|$(dir $4)|" -e "1s|$1/|$1/$2/build/|" -e "s|$(TOP)/||g" -e "s|$2/build/$2/build|$2/build|g" $3.bit >> $3.tmp &&) true
 endef
 
-- 
1.7.10.4