From 80a2ce05a8e44ba9a3ee49dfa7d5c8e2b605b15c Mon Sep 17 00:00:00 2001
From: Samantaz Fox <coding@samantaz.fr>
Date: Sat, 16 Sep 2023 23:33:40 +0200
Subject: [PATCH] Makefile: Add cross-compilation targets

---
 Makefile | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 95 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index 9eb195df..a964e148 100644
--- a/Makefile
+++ b/Makefile
@@ -9,6 +9,7 @@ NO_DBG_SYMBOLS := 0
 
 
 FLAGS ?=
+LDFLAGS ?=
 
 
 ifeq ($(RELEASE), 1)
@@ -17,6 +18,7 @@ endif
 
 ifeq ($(STATIC), 1)
   FLAGS += --static
+  LDFLAGS += -static
 endif
 
 
@@ -31,6 +33,13 @@ ifeq ($(API_ONLY), 1)
 endif
 
 
+#FLAGS += --progress --stats --error-trace
+
+
+LIBS_SSL = $(shell command -v pkg-config > /dev/null && pkg-config --libs --silence-errors libssl || printf %s '-lssl -lcrypto')
+LIBS_CRYPTO = $(shell command -v pkg-config > /dev/null && pkg-config --libs --silence-errors libcrypto || printf %s '-lcrypto')
+
+
 # -----------------------
 #  Main
 # -----------------------
@@ -40,19 +49,80 @@ all: invidious
 get-libs:
 	shards install --production
 
-# TODO: add support for ARM64 via cross-compilation
 invidious: get-libs
-	crystal build src/invidious.cr $(FLAGS) --progress --stats --error-trace
-
+	crystal build src/invidious.cr $(FLAGS)
 
 run: invidious
 	./invidious
 
 
 # -----------------------
-#  Development
+#  Cross-compilation (Host)
 # -----------------------
 
+# Supported cross-sompilation targets:
+#  - amd64-glibc (x86_64-linux-gnu)
+#  - amd64-musl  (x86_64-linux-musl)
+#  - arm64-glibc (aarch64-linux-gnu)
+#  - arm64-musl  (aarch64-linux-musl)
+#  - armhf       (arm-linux-gnueabihf)
+
+invidious-cross-amd64-glibc:
+	crystal build src/invidious.cr $(FLAGS) -Dskip_videojs_download \
+		--cross-compile --target='x86_64-linux-gnu' -o invidious-amd64-glibc
+
+invidious-cross-amd64-musl:
+	crystal build src/invidious.cr $(FLAGS) -Dskip_videojs_download \
+		--cross-compile --target='x86_64-linux-musl' -o invidious-amd64-musl
+
+
+invidious-cross-arm64-glibc:
+	crystal build src/invidious.cr $(FLAGS) -Dskip_videojs_download \
+		--cross-compile --target='aarch64-linux-gnu' -o invidious-arm64-glibc
+
+invidious-cross-arm64-musl:
+	crystal build src/invidious.cr $(FLAGS) -Dskip_videojs_download \
+		--cross-compile --target='aarch64-linux-musl' -o invidious-arm64-musl
+
+
+invidious-cross-armhf:
+	crystal build src/invidious.cr $(FLAGS) -Dskip_videojs_download \
+		--cross-compile --target='arm-linux-gnueabihf' -o invidious-armhf
+
+
+# Build everything at once
+invidious-cross-all: invidious-cross-amd64-glibc
+invidious-cross-all: invidious-cross-amd64-musl
+invidious-cross-all: invidious-cross-arm64-glibc
+invidious-cross-all: invidious-cross-arm64-musl
+invidious-cross-all: invidious-cross-armhf
+
+
+# -----------------------
+#  Cross-compilation (Target)
+# -----------------------
+
+invidious-amd64-glibc:
+invidious-arm64-glibc:
+	cc "$@.o" -o "$@" -rdynamic $(LDFLAGS) \
+		-lyaml -lxml2 -lsqlite3 -lz -llzma $(LIBS_SSL) $(LIBS_CRYPTO) \
+		-lpcre -lm -lgc -lpthread -levent -lrt -lpthread -ldl
+
+invidious-amd64-musl:
+invidious-arm64-musl:
+	cc "$@.o" -o "$@" -rdynamic $(LDFLAGS) \
+		-lyaml -lxml2 -lsqlite3 -lz -llzma $(LIBS_SSL) $(LIBS_CRYPTO) \
+		-lpcre -lgc -levent
+
+invidious-armhf:
+	cc "$@.o" -o "$@" -rdynamic $(LDFLAGS) \
+		-lyaml -lxml2 -lsqlite3 -lz -llzma $(LIBS_SSL) $(LIBS_CRYPTO) \
+		-lpcre -lm -lgc -lpthread -levent -lpthread -ldl
+
+
+# -----------------------
+#  Development
+# -----------------------
 
 format:
 	crystal tool format
@@ -77,7 +147,7 @@ verify:
 # -----------------------
 
 clean:
-	rm invidious
+	rm -f invidious invidious-*
 
 distclean: clean
 	rm -rf libs
@@ -111,9 +181,28 @@ help:
 	@echo ""
 	@echo "  API_ONLY         Build invidious without a GUI   (Default: 0)"
 	@echo "  NO_DBG_SYMBOLS   Strip debug symbols             (Default: 0)"
-
+	@echo ""
+	@echo ""
+	@echo "Cross-compiling"
+	@echo ""
+	@echo "To cross compile, run 'make invidious-cross-{arch}' on the build host,"
+	@echo "then move the .o file to the target host and run 'make invidious-{arch}'"
+	@echo "on there (requires crystal and all the dependencies to be installed)"
+	@echo ""
+	@echo "Note: If 'STATIC=1' was used on the build host, then it MUST be used on"
+	@echo "      'the target host too!"
+	@echo ""
+	@echo "Supported cross-sompilation archs:"
+	@echo " - amd64-glibc (x86_64-linux-gnu)"
+	@echo " - amd64-musl  (x86_64-linux-musl)"
+	@echo " - arm64-glibc (aarch64-linux-gnu)"
+	@echo " - arm64-musl  (aarch64-linux-musl)"
+	@echo " - armhf       (arm-linux-gnueabihf)"
 
 
 # No targets generates an output named after themselves
 .PHONY: all get-libs build amd64 run
 .PHONY: format test verify clean distclean help
+.PHONY: invidious-cross-amd64-glibc invidious-cross-amd64-musl
+.PHONY: invidious-cross-arm64-glibc invidious-cross-arm64-musl
+.PHONY: invidious-cross-armhf