Require HsColour by default

This should stop us ending up without HsColour'ed sources on some
platforms.

We also now tell Cabal where to find HsColour, rather than it finding
it itself.

Makefile

@@ -74,7 +74,7 @@ endif
 
 SUBDIRS = gmp libffi includes utils docs rts compiler ghc driver libraries libraries/Cabal/doc
 
-check-all: check-packages
+check-all: check-packages check-tools
 
 # Sanity check that all the boot libraries are in the tree, to catch
 # failure to run darcs-all.
@@ -93,6 +93,14 @@ check-packages :
 	    exit 1; \
 	fi
 
+check-tools:
+ifeq "$(HSCOLOUR_SRCS) $(HSCOLOUR)" "YES "
+	@echo "HsColour needed but wasn't found."
+	@echo "Set HSCOLOUR_SRCS=NO if you don't want to use it"
+	exit 1
+endif
+	@:
+
 ifeq "$(TARGETPLATFORM)" "i386-unknown-mingw32"
 ifneq "$(WhatGccIsCalled)" ""
 GCC_LIB_DEP = stamp.inplace-gcc-lib

libraries/Makefile

@@ -108,6 +108,10 @@ CONFIGURE_OPTS += --enable-split-objs
 CONFIGURE_STAMP_EXTRAS := $(CONFIGURE_STAMP_EXTRAS)-splitting
 endif
 
+ifeq "$(HSCOLOUR_SRCS)" "YES"
+CONFIGURE_OPTS += --with-hscolour="$(HSCOLOUR)"
+endif
+
 .PHONY: subdirs
 
 subdirs:
@@ -253,7 +257,7 @@ doc: $(foreach SUBDIR,$(DOC_SUBDIRS),doc.library.$(SUBDIR))
 	sh gen_contents_index --inplace
 
 # Making hyperlinked source only works if we have hscolour
-ifneq "$(HSCOLOUR)" ""
+ifeq "$(HSCOLOUR_SRCS)" "YES"
 CABAL_HADDOCK_FLAGS += --hyperlink-source
 endif
 CABAL_HADDOCK_FLAGS += --with-haddock=$(FPTOOLS_TOP_ABS)/utils/haddock/install-inplace/bin/haddock

mk/config.mk.in

@@ -187,6 +187,8 @@ XMLDocWays=
 
 # Should we build haddock docs?
 HADDOCK_DOCS = YES
+# And HsColour the sources?
+HSCOLOUR_SRCS = YES
 
 # Should we build latex docs?
 LATEX_DOCS = NO

mk/validate-settings.mk

@@ -2,6 +2,7 @@
 WERROR          = -Werror
 
 HADDOCK_DOCS    = YES
+HSCOLOUR_SRCS   = YES
 SRC_CC_OPTS     = $(WERROR)
 SRC_HC_OPTS     = $(WERROR) -H64m -O0 -fasm
 GhcStage1HcOpts = -O -fasm