From 50d1043a91db4343eb3a445e6f0611afc19c4032 Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Tue, 6 Sep 2022 13:40:32 +0930
Subject: [PATCH] external: build lowdown if not already found.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 .gitmodules       |  1 +
 configure         |  9 ++++++++-
 doc/Makefile      | 13 ++++++++++++-
 external/Makefile | 14 ++++++++++++++
 tools/md2man.sh   |  9 +++++----
 5 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/.gitmodules b/.gitmodules
index 8b8aa0660..6dae35a54 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -20,3 +20,4 @@
 [submodule "external/lowdown"]
 	path = external/lowdown
 	url = https://github.com/kristapsdz/lowdown.git
+	ignore = dirty
diff --git a/configure b/configure
index bd7aae297..a943baedf 100755
--- a/configure
+++ b/configure
@@ -105,7 +105,7 @@ check_command()
     shift 1
 
     echo -n "checking for $name... "
-    if "$@" >/dev/null 2>&1; then
+    if "$@" >/dev/null 2>&1 </dev/null; then
 	echo 'found'
 	return 0
     fi
@@ -425,6 +425,12 @@ else
     HAVE_PYTHON3_MAKO=0
 fi
 
+if check_command 'lowdown' lowdown; then
+    HAVE_LOWDOWN=1
+else
+    HAVE_LOWDOWN=0
+fi
+
 if echo | check_command sha256sum sha256sum; then
     SHA256SUM=sha256sum
 elif echo | check_command "shasum -a 256" shasum -a 256; then
@@ -463,6 +469,7 @@ add_var ASAN "$ASAN"
 add_var UBSAN "$UBSAN"
 add_var TEST_NETWORK "$TEST_NETWORK"
 add_var HAVE_PYTHON3_MAKO "$HAVE_PYTHON3_MAKO"
+add_var HAVE_LOWDOWN "$HAVE_LOWDOWN"
 add_var SHA256SUM "$SHA256SUM"
 add_var FUZZING "$FUZZING"
 add_var RUST "$RUST"
diff --git a/doc/Makefile b/doc/Makefile
index a9b0b61d1..a0665fd19 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -125,8 +125,19 @@ RBRACKET=)
 $(MARKDOWN_WITH_SCHEMA): doc/lightning-%.7.md: doc/schemas/%.schema.json tools/fromschema.py
 	@if $(call SHA256STAMP_CHANGED); then $(call VERBOSE, "fromschema $@", tools/fromschema.py --markdownfile=$@ doc/schemas/$*.schema.json > $@.tmp && grep -v SHA256STAMP: $@.tmp > $@ && rm -f $@.tmp && $(call SHA256STAMP,[comment]: # $(LBRACKET),$(RBRACKET))); else touch $@; fi
 
+# If we need to build lowdown, make tools/md2man.sh depend on it.
+# That way it's not used in SHA256STAMP (which only uses direct
+# dependencies), but make will be forced to build it.
+ifeq ($(HAVE_LOWDOWN),0)
+LOWDOWN := $(TARGET_DIR)/lowdown-build/bin/lowdown
+tools/md2man.sh: $(LOWDOWN)
+	touch $@
+else
+LOWDOWN := lowdown
+endif
+
 $(MANPAGES): doc/%: doc/%.md tools/md2man.sh version_gen.h
-	@if $(call SHA256STAMP_CHANGED); then $(call VERBOSE, "md2man $<", VERSION=$(VERSION) tools/md2man.sh $< > $@ && $(call SHA256STAMP,\\\",)); else touch $@; fi
+	@if $(call SHA256STAMP_CHANGED); then $(call VERBOSE, "md2man $<", VERSION=$(VERSION) tools/md2man.sh $(LOWDOWN) $< > $@ && $(call SHA256STAMP,\\\",)); else touch $@; fi
 
 $(MANPAGES): $(FORCE)
 $(MARKDOWN_WITH_SCHEMA): $(FORCE)
diff --git a/external/Makefile b/external/Makefile
index 92e976092..60b8068fe 100644
--- a/external/Makefile
+++ b/external/Makefile
@@ -6,6 +6,10 @@ SUBMODULES =					\
 	external/libbacktrace			\
 	external/lnprototest
 
+ifeq ($(HAVE_LOWDOWN),0)
+SUBMODULES += external/lowdown
+endif
+
 TOP := ../..
 ifdef BUILD
 CROSSCOMPILE_OPTS := --host="$(MAKE_HOST)" --build="$(BUILD)"
@@ -29,6 +33,10 @@ LIBBACKTRACE_HEADERS := external/libbacktrace/backtrace.h
 EXTERNAL_HEADERS := $(LIBSODIUM_HEADERS) $(LIBWALLY_HEADERS) $(LIBSECP_HEADERS) $(JSMN_HEADERS) $(GHEAP_HEADERS) $(LIBBACKTRACE_HEADERS)
 EXTERNAL_LIBS := ${TARGET_DIR}/libwallycore.a ${TARGET_DIR}/libsecp256k1.a ${TARGET_DIR}/libjsmn.a ${TARGET_DIR}/libbacktrace.a
 
+ifeq ($(HAVE_LOWDOWN),0)
+EXTERNAL_HEADERS += external/lowdown/lowdown.h
+endif
+
 EXTERNAL_INCLUDE_FLAGS :=					\
 	-I external/libwally-core/include/			\
 	-I external/libwally-core/src/secp256k1/include/	\
@@ -106,6 +114,10 @@ $(TARGET_DIR)/libbacktrace.a: external/libbacktrace/backtrace.h
 	cd $(TARGET_DIR)/libbacktrace-build && $(TOP)/libbacktrace/configure CC="$(CC)" --enable-static=yes $(CROSSCOMPILE_OPTS) --enable-shared=no --prefix=/ --libdir=/ && $(MAKE)
 	$(MAKE) -C $(TARGET_DIR)/libbacktrace-build DESTDIR=$$(pwd)/$(TARGET_DIR) install-exec
 
+$(TARGET_DIR)/lowdown-build/bin/lowdown: external/lowdown/lowdown.h
+	cd external/lowdown && CC="$(CC)" ./configure PREFIX=`pwd`/$(TOP)/$(TARGET_DIR)/lowdown-build/
+	$(MAKE) -C external/lowdown install
+
 distclean: external-distclean
 clean: external-clean
 
@@ -116,8 +128,10 @@ external-clean:
 	if [ -f ${TARGET_DIR}/libwally-core-build/Makefile ]; then make -C ${TARGET_DIR}/libwally-core-build clean; fi
 	if [ -f ${TARGET_DIR}/libwally-core-build/src/Makefile ]; then make -C ${TARGET_DIR}/libwally-core-build/src clean; fi
 	if [ -f ${TARGET_DIR}/libbacktrace-build/Makefile ]; then make -C ${TARGET_DIR}/libbacktrace-build clean; fi
+	[ -f external/lowdown/Makefile.configure ] && $(MAKE) -C external/lowdown clean
 
 external-distclean:
 	make -C external/libsodium distclean || true
+	[ -f external/lowdown/Makefile.configure ] && $(MAKE) -C external/lowdown distclean
 	$(RM) -rf ${TARGET_DIR}/libbacktrace-build ${TARGET_DIR}/libsodium-build ${TARGET_DIR}/libwally-core-build ${TARGET_DIR}/jsmn-build
 	$(RM) -r `git status --ignored --porcelain external/libwally-core | grep '^!! ' | cut -c3-`
diff --git a/tools/md2man.sh b/tools/md2man.sh
index 7dea4cb70..5052459eb 100755
--- a/tools/md2man.sh
+++ b/tools/md2man.sh
@@ -1,10 +1,11 @@
 #! /bin/sh
 
-if [ $# != 1 ]; then
-    echo "Usage: $0 <markdownpage>" >&2
+if [ $# != 2 ]; then
+    echo "Usage: $0 <lowdown> <markdownpage>" >&2
     exit 1
 fi
-SOURCE=$1
+LOWDOWN="$1"
+SOURCE="$2"
 SECTION="$(basename "$SOURCE" .md | cut -d. -f2-)"
 TITLE="$(basename "$(basename "$SOURCE" .md)" ."$SECTION" | tr '[:lower:]' '[:upper:]')"
 
@@ -12,4 +13,4 @@ TITLE="$(basename "$(basename "$SOURCE" .md)" ."$SECTION" | tr '[:lower:]' '[:up
 # format.  mrkd used to do this for us, lowdown(1) doesn't.
 TITLELINE="$(head -n1 "$SOURCE")"
 
-(echo "NAME"; echo "----"; echo "$TITLELINE"; tail -n +3 "$SOURCE") | lowdown -s --out-no-smarty -Tman -m "title:$TITLE" -m "section:$SECTION" -m "source:Core Lightning $VERSION" -m "shiftheadinglevelby:-1"
+(echo "NAME"; echo "----"; echo "$TITLELINE"; tail -n +3 "$SOURCE") | $LOWDOWN -s --out-no-smarty -Tman -m "title:$TITLE" -m "section:$SECTION" -m "source:Core Lightning $VERSION" -m "shiftheadinglevelby:-1"