GHC new build system megapatch

1 files changed, 46 insertions, 0 deletions

diff --git a/rules/hs-sources.mk b/rules/hs-sources.mk
new file mode 100644
index 0000000000..d8e6b4224a
--- /dev/null
+++ b/rules/hs-sources.mk
@@ -0,0 +1,46 @@
+
+define hs-sources # args: $1 = dir, $2 = distdir
+
+ifeq "$$($1_$2_HS_SRC_DIRS)" ""
+$1_$2_HS_SRC_DIRS = .
+endif
+
+# Here we collect all the .hs/.lhs source files that we can find.  If
+# we can't find a Haskell source file for a given module, then presumably
+# it can be generated by preprocessing something (.hsc, .y, .x etc.), so
+# we depend on dist/build/Foo.hs in anticipation that the implicit rules
+# will put the preprocessed source file there.
+#
+# NB. use :=, we only want this thing evaluated once.
+#
+$1_$2_HS_SRCS := $$(foreach file,$$($1_$2_SLASH_MODS),\
+		 $$(firstword \
+		   $$(wildcard \
+                     $$(foreach dir,$$($1_$2_HS_SRC_DIRS),\
+			$1/$$(dir)/$$(file).hs $1/$$(dir)/$$(file).lhs)) \
+	           $1/$2/build/$$(file).hs))
+
+# .hs-boot files must be in the same place as the .hs file they go
+# with (GHC assumes this).  When we preprocess a source file, and
+# that module has a .hs-boot or .lhs-boot file, we must arrange to
+# copy the file into the distdir so that it ends up alongside the
+# preprocessed .hs file.  This complicated macro figures out for which
+# files we need to do this, so we can add them as dependencies of the
+# .depend file rule.
+#
+# for each .hs file in the build dir,
+# if there is a .hs-boot or .lhs-boot file for it in a source dir,
+# we want that file in the build dir.
+#
+# NB. use :=, we only want this thing evaluated once.
+#
+$1_$2_HS_BOOT_SRCS := $$(foreach dir,$$($1_$2_HS_SRC_DIRS),\
+		       $$(subst $1/$$(dir),$1/$2/build,\
+		        $$(wildcard \
+	                 $$(subst $1/$2/build,$1/$$(dir),\
+		          $$(foreach file,\
+		           $$(filter $1/$2/build%,$$($1_$2_HS_SRCS)),\
+			   $$(patsubst %.hs,%.hs-boot,$$(file)) \
+			   $$(patsubst %.hs,%.lhs-boot,$$(file)))))))
+
+endef