Use tools framework for Haskell source preprocessors

4 files changed, 59 insertions, 1 deletions

diff --git a/mk/haskell.mk b/mk/haskell.mk
index 29511c3008b..e467a936758 100644
--- a/mk/haskell.mk
+++ b/mk/haskell.mk
@@ -1,4 +1,4 @@
-# $NetBSD: haskell.mk,v 1.32 2021/05/01 15:06:26 pho Exp $
+# $NetBSD: haskell.mk,v 1.33 2021/05/01 16:14:19 pho Exp $
 #
 # This Makefile fragment handles Haskell Cabal packages.
 # Package configuration, building, installation, registration and
@@ -111,6 +111,13 @@ HASKELL_ENABLE_HADDOCK_DOCUMENTATION?=	yes
 
 .include "../../lang/ghc88/buildlink3.mk"
 
+# Some Cabal packages requires preprocessors to build, and we don't
+# want them to implicitly depend on such tools. Place dummy scripts by
+# default.
+.include "../../mk/haskell/tools/alex.mk"
+.include "../../mk/haskell/tools/cpphs.mk"
+.include "../../mk/haskell/tools/happy.mk"
+
 # Tools
 _HASKELL_BIN=		${BUILDLINK_PREFIX.ghc:U${PREFIX}}/bin/ghc
 _HASKELL_PKG_BIN=	${BUILDLINK_PREFIX.ghc:U${PREFIX}}/bin/ghc-pkg
diff --git a/mk/haskell/tools/alex.mk b/mk/haskell/tools/alex.mk
new file mode 100644
index 00000000000..8ba7b2900db
--- /dev/null
+++ b/mk/haskell/tools/alex.mk
@@ -0,0 +1,17 @@
+# $NetBSD: alex.mk,v 1.1 2021/05/01 16:14:19 pho Exp $
+#
+# Usage: USE_TOOLS+= alex
+#
+
+ALEX_REQD?=	0
+TOOLS_CREATE+=	alex
+
+.if !empty(USE_TOOLS:Malex)
+TOOLS_DEPENDS.alex?=	alex>=${ALEX_REQD}:../../devel/alex
+TOOLS_PATH.alex=	${PREFIX}/bin/alex
+.else
+# We can't use TOOLS_FAIL because Cabal tries to invoke all of
+# relevant tools regardless of whether they are actually required.
+TOOLS_SCRIPT.alex=	\
+	${FAIL_MSG} "To use this tool, add USE_TOOLS+=alex to the package Makefile."
+.endif
diff --git a/mk/haskell/tools/cpphs.mk b/mk/haskell/tools/cpphs.mk
new file mode 100644
index 00000000000..4c9ec8581c6
--- /dev/null
+++ b/mk/haskell/tools/cpphs.mk
@@ -0,0 +1,17 @@
+# $NetBSD: cpphs.mk,v 1.1 2021/05/01 16:14:19 pho Exp $
+#
+# Usage: USE_TOOLS+= cpphs
+#
+
+CPPHS_REQD?=	0
+TOOLS_CREATE+=		cpphs
+
+.if !empty(USE_TOOLS:Mcpphs)
+TOOLS_DEPENDS.cpphs?=	hs-cpphs>=${CPPHS_REQD}:../../devel/hs-cpphs
+TOOLS_PATH.cpphs=	${PREFIX}/bin/cpphs
+.else
+# We can't use TOOLS_FAIL because Cabal tries to invoke all of
+# relevant tools regardless of whether they are actually required.
+TOOLS_SCRIPT.cpphs=	\
+	${FAIL_MSG} "To use this tool, add USE_TOOLS+=cpphs to the package Makefile."
+.endif
diff --git a/mk/haskell/tools/happy.mk b/mk/haskell/tools/happy.mk
new file mode 100644
index 00000000000..22a9a61827b
--- /dev/null
+++ b/mk/haskell/tools/happy.mk
@@ -0,0 +1,17 @@
+# $NetBSD: happy.mk,v 1.1 2021/05/01 16:14:19 pho Exp $
+#
+# Usage: USE_TOOLS+= happy
+#
+
+HAPPY_REQD?=	0
+TOOLS_CREATE+=	happy
+
+.if !empty(USE_TOOLS:Mhappy)
+TOOLS_DEPENDS.happy?=	happy>=${HAPPY_REQD}:../../devel/happy
+TOOLS_PATH.happy=	${PREFIX}/bin/happy
+.else
+# We can't use TOOLS_FAIL because Cabal tries to invoke all of
+# relevant tools regardless of whether they are actually required.
+TOOLS_SCRIPT.happy=	\
+	${FAIL_MSG} "To use this tool, add USE_TOOLS+=happy to the package Makefile."
+.endif