+
+# This comment is outside the "define addCFileDeps" as that definition
+# is a list of command lines, and if it is inside it then we pass this
+# comment to the shell every time we call the definition.
+# $1 = dir
+# $2 = distdir
+# $3 = depfile
+# $4 = file
+# $5 = ways
+#
+# The formatting of this definition (e.g. the blank line above) is
+# important, in order to get make to generate the right makefile code.
+#
+# "1s|\.o|\.$($w_osuf)|"
+# We will have dependencies for .o files, so we need to fix them up
+# for the right object suffix for the way we're doing
+# "1s|^|$(dir $4)|"
+# We always get deps for just foo.o when the file we're making is
+# a/b/c/foo.o, so we need to prepend the directory of the source file
+# "1s|$1/|$1/$2/build/|"
+# Well, almost. We actually need to insert e.g. "dist/build" in the
+# middle of that directory
+# "1s|$2/build/$2/build|$2/build|g"
+# But some source files, e.g. sm/Evac_thr.c, are also inside the
+# "dist/build" directory, so now we've just made
+# "dist/build/dist/build", so we need to remove the duplication
+# again
+# "s|$(TOP)/||g$(CASE_INSENSITIVE_SED)"
+# Finally, when making deps for packages like ghc stage2, we have
+# some include paths for packages registered in the in-tree package
+# database. These include paths are full (i.e. not relative) paths,
+# which means that the "cpp -MM" output uses full paths in some cases.
+# This causes 2 problems:
+# * they don't match up with the rules to rebuild the files, where
+# appropriate.
+# * on Windows, make interprets the colon in c:/foo/bar.h as make
+# syntax.
+# So we sed off $(TOP). Unfortunately, on Windows, the case for the
+# drive letter is sometimes different in what $(TOP) starts with, and
+# what the path in the package database starts with. We therefore
+# need to do the substitution case-insensitively on Windows. But
+# the s///i modifier isn't portable, so we set CASE_INSENSITIVE_SED
+# to "i" on Windows and "" on any other platform.
+define addCFileDeps
+
+ $(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 "1s|$2/build/$2/build|$2/build|g" -e "s|$(TOP)/||g$(CASE_INSENSITIVE_SED)" $3.bit >> $3.tmp &&) true
+endef
+
+ifeq "$(Windows)" "YES"
+CASE_INSENSITIVE_SED = i
+else
+CASE_INSENSITIVE_SED =
+endif
+