[PATCH v3 02/22] scripts: Support symlinks in s6-rc-compile inputs

[Demi Marie Obenour <demiobenour@gmail.com>]

Finish scripts can (and often will) be symbolic links to
/usr/bin/cgroup-setup.

This requires makefile changes, so take the opportunity to move some of
the make code to a new lib/targets.mk.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
---
 host/rootfs/Makefile     | 32 ++++----------------------------
 host/rootfs/default.nix  |  1 +
 host/rootfs/file-list.mk |  2 ++
 img/app/Makefile         | 23 +++--------------------
 img/app/default.nix      |  1 +
 img/app/file-list.mk     |  2 ++
 lib/targets.mk           | 30 ++++++++++++++++++++++++++++++
 release/live/Makefile    | 12 ++++--------
 release/live/default.nix |  1 +
 scripts/genfiles.awk     | 13 ++++++++++++-
 vm/sys/net/Makefile      | 19 ++++---------------
 vm/sys/net/default.nix   |  1 +
 vm/sys/net/file-list.mk  |  2 ++
 13 files changed, 67 insertions(+), 72 deletions(-)

diff --git a/host/rootfs/Makefile b/host/rootfs/Makefile
index 4f01e3ecce83558b786542ebbeedb7ff3b4c17a5..4c6233ba355ed7208de64df6c1b929aacfb52bbe 100644
--- a/host/rootfs/Makefile
+++ b/host/rootfs/Makefile
@@ -4,7 +4,8 @@
 
 .POSIX:
 
-include ../../lib/common.mk
+ROOT = ../..
+include $(ROOT)/lib/common.mk
 include file-list.mk
 
 ROOT_FS = build
@@ -85,33 +86,6 @@ build/etc/os-release:
 	mkdir -p build/etc
 	sed 's/@VERSION@/$(VERSION)/g' < os-release.in > build/etc/os-release
 
-build/fifo:
-	mkdir -p build
-	mkfifo -m 0600 $@
-
-build/empty:
-	mkdir -p $@
-
-# s6-rc-compile's input is a directory, but that doesn't play nice
-# with Make, because it won't know to update if some file in the
-# directory is changed, or a file is created or removed in a
-# subdirectory.  Using the whole source directory could also end up
-# including files that aren't intended to be part of the input, like
-# temporary editor files or .license files.  So for all these reasons,
-# only explicitly listed files are made available to s6-rc-compile.
-build/etc/s6-rc: $(S6_RC_FILES) file-list.mk
-	mkdir -p $$(dirname $@)
-	rm -rf $@
-	set -uo pipefail && dir=$$(mktemp -d) && \
-	    { tar -c $(S6_RC_FILES) | tar -C $$dir -x --strip-components 3; } && \
-	    s6-rc-compile $@ $$dir; \
-	    exit=$$?; rm -r $$dir; exit $$exit
-
-clean:
-	-chmod -Rf +w build
-	rm -rf build
-.PHONY: clean
-
 build/live.img: ../../scripts/format-uuid.sh ../../scripts/make-gpt.sh ../../scripts/sfdisk-field.awk build/verity-timestamp $(ROOT_FS_IMAGES)
 	../../scripts/make-gpt.sh $@.tmp \
 	    $(ROOT_FS_VERITY):verity:$$(../../scripts/format-uuid.sh "$$(dd if=$(ROOT_FS_VERITY_ROOTHASH) bs=32 skip=1 count=1 status=none)"):Spectrum_'$(VERSION).verity' \
@@ -155,3 +129,5 @@ run: build/empty build/live.img $(ROOTFS_VERITY_ROOTHASH)
 	    -vga none \
 	    -device vhost-vsock-pci,guest-cid=3
 .PHONY: run
+
+include $(ROOT)/lib/targets.mk
diff --git a/host/rootfs/default.nix b/host/rootfs/default.nix
index 6bfeefbe0a5f76c1538ccb40e5eb8f291f5d3592..4dcc10b9933cdfaf87f87417db1de0daa57b73f5 100644
--- a/host/rootfs/default.nix
+++ b/host/rootfs/default.nix
@@ -116,6 +116,7 @@ stdenvNoCC.mkDerivation {
     fileset = fileset.intersection src (fileset.unions [
       ./.
       ../../lib/common.mk
+      ../../lib/targets.mk
       ../../scripts/make-erofs.sh
     ]);
   };
diff --git a/host/rootfs/file-list.mk b/host/rootfs/file-list.mk
index 3899d620717fc97f42e669e5313c4100dcf5b1cd..7e44fc612a5a9ac8767be9148cdc71869ef16964 100644
--- a/host/rootfs/file-list.mk
+++ b/host/rootfs/file-list.mk
@@ -111,3 +111,5 @@ S6_RC_FILES = \
 	image/etc/s6-rc/weston/notification-fd \
 	image/etc/s6-rc/weston/run \
 	image/etc/s6-rc/weston/type
+
+S6_RC_LINKS =
diff --git a/img/app/Makefile b/img/app/Makefile
index 3996831120c1aa831e44a18579b1f5bbac7cb776..42793725f26af43605c5ae95a2dc78ca1c49efe9 100644
--- a/img/app/Makefile
+++ b/img/app/Makefile
@@ -4,7 +4,8 @@
 
 .POSIX:
 
-include ../../lib/common.mk
+ROOT = ../..
+include $(ROOT)/lib/common.mk
 include file-list.mk
 
 prefix = build/host
@@ -39,13 +40,6 @@ FIFOS = etc/s6-linux-init/run-image/service/s6-linux-init-shutdownd/fifo
 
 BUILD_FILES = build/etc/s6-rc
 
-build/fifo:
-	mkdir -p build
-	mkfifo -m 0600 $@
-
-build/empty:
-	mkdir -p $@
-
 build/rootfs.erofs: ../../scripts/make-erofs.sh $(PACKAGES_FILE) $(FILES) $(BUILD_FILES) build/empty build/fifo file-list.mk
 	set -euo pipefail; \
 	{ \
@@ -56,15 +50,6 @@ build/rootfs.erofs: ../../scripts/make-erofs.sh $(PACKAGES_FILE) $(FILES) $(BUIL
 	    printf 'build/fifo\n%s\n' $(FIFOS) ;\
 	} | ../../scripts/make-erofs.sh $@
 
-
-build/etc/s6-rc: $(S6_RC_FILES) file-list.mk
-	mkdir -p $$(dirname $@)
-	rm -rf $@
-	set -uo pipefail && dir=$$(mktemp -d) && \
-	    { tar -c $(S6_RC_FILES) | tar -C $$dir -x --strip-components 3; } && \
-	    s6-rc-compile $@ $$dir; \
-	    exit=$$?; rm -r $$dir; exit $$exit
-
 debug:
 	$(GDB) -q \
 	    -ex 'set substitute-path .. $(LINUX_SRC)' \
@@ -144,6 +129,4 @@ run-crosvm: $(imgdir)/appvm/blk/root.img start-vhost-user-gpu start-virtiofsd
 run: run-$(VMM)
 .PHONY: run
 
-clean:
-	rm -rf build
-.PHONY: clean
+include $(ROOT)/lib/targets.mk
diff --git a/img/app/default.nix b/img/app/default.nix
index 71e6fa02e78553d027d59f5b2ff728830276d480..97f4cc75d620c93c6f5a6de7c7069cf3d39f25b5 100644
--- a/img/app/default.nix
+++ b/img/app/default.nix
@@ -104,6 +104,7 @@ stdenvNoCC.mkDerivation {
     fileset = lib.fileset.intersection src (lib.fileset.unions [
       ./.
       ../../lib/common.mk
+      ../../lib/targets.mk
       ../../scripts/make-erofs.sh
       ../../scripts/make-gpt.sh
       ../../scripts/sfdisk-field.awk
diff --git a/img/app/file-list.mk b/img/app/file-list.mk
index 815b63ab2a4f2d11f63ce5593fecefa979c13eba..6312c361b629430629661be30332fac38ca0be73 100644
--- a/img/app/file-list.mk
+++ b/img/app/file-list.mk
@@ -71,3 +71,5 @@ S6_RC_FILES = \
 	image/etc/s6-rc/wireplumber/dependencies.d/pipewire \
 	image/etc/s6-rc/wireplumber/run \
 	image/etc/s6-rc/wireplumber/type
+
+S6_RC_LINKS =
diff --git a/lib/targets.mk b/lib/targets.mk
new file mode 100644
index 0000000000000000000000000000000000000000..2d6d2682df2ed070b3f6075913fcfc0e6a803bbb
--- /dev/null
+++ b/lib/targets.mk
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2021, 2023, 2024, 2025 Alyssa Ross <hi@alyssa.is>
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+build/fifo:
+	mkdir -p build
+	mkfifo -m 0600 $@
+
+build/empty:
+	mkdir -p $@
+
+# s6-rc-compile's input is a directory, but that doesn't play nice
+# with Make, because it won't know to update if some file in the
+# directory is changed, or a file is created or removed in a
+# subdirectory.  Using the whole source directory could also end up
+# including files that aren't intended to be part of the input, like
+# temporary editor files or .license files.  So for all these reasons,
+# only explicitly listed files are made available to s6-rc-compile.
+build/etc/s6-rc: $(S6_RC_FILES) file-list.mk
+	mkdir -p $$(dirname $@)
+	rm -rf $@
+	set -uo pipefail && dir=$$(mktemp -d) && \
+	    { tar -c $(S6_RC_FILES) $(S6_RC_LINKS) | tar -C $$dir -x --strip-components 3; } && \
+	    s6-rc-compile $@ $$dir; \
+	    exit=$$?; rm -r $$dir; exit $$exit
+
+clean:
+	-chmod -Rf +w build
+	rm -rf build
+.PHONY: clean
diff --git a/release/live/Makefile b/release/live/Makefile
index 85319d0eec06df4e7ab1e28030e3bb78608194df..f984bc8d5a93733a246ccc901674be06bbcbb69e 100644
--- a/release/live/Makefile
+++ b/release/live/Makefile
@@ -3,7 +3,8 @@
 
 .POSIX:
 
-include ../../lib/common.mk
+ROOT = ../..
+include $(ROOT)/lib/common.mk
 
 dest = build/live.img
 
@@ -24,13 +25,6 @@ build/boot.fat: $(SYSTEMD_BOOT_EFI) $(SPECTRUM_EFI)
 	$(MCOPY) -i $@ $(SPECTRUM_EFI) ::/EFI/Linux/'Spectrum_$(VERSION).efi'
 	$(MCOPY) -i $@ $(SYSTEMD_BOOT_EFI) ::/EFI/BOOT/$(EFINAME)
 
-build/empty:
-	mkdir -p $@
-
-clean:
-	rm -rf build
-.PHONY: clean
-
 run: build/empty $(dest)
 	@set -xueo pipefail && \
 	img="$$(mktemp build/spectrum-rootfs.XXXXXXXXX.img)" && \
@@ -61,3 +55,5 @@ run: build/empty $(dest)
 	    -drive file=/proc/self/fd/3,id=drive1,format=raw,if=none \
 	    -drive file=/proc/self/fd/4,if=virtio,format=raw
 .PHONY: run
+
+include $(ROOT)/lib/targets.mk
diff --git a/release/live/default.nix b/release/live/default.nix
index aa8dddd68497ced322961a6b551b73fe5ab4c475..403183226570ec318fbf7fddecfd52fd7c133c7e 100644
--- a/release/live/default.nix
+++ b/release/live/default.nix
@@ -28,6 +28,7 @@ stdenv.mkDerivation {
     fileset = lib.fileset.intersection src (lib.fileset.unions [
       ./.
       ../../lib/common.mk
+      ../../lib/targets.mk
       ../../scripts/format-uuid.sh
       ../../scripts/make-gpt.sh
       ../../scripts/sfdisk-field.awk
diff --git a/scripts/genfiles.awk b/scripts/genfiles.awk
index 2d32016b5e6d6773685b71cc04e49cf24e842ba9..35e8538e75cc67f0a2ec8bc7b1be403a3f6604f0 100644
--- a/scripts/genfiles.awk
+++ b/scripts/genfiles.awk
@@ -6,6 +6,7 @@ BEGIN {
 	modes["120000"] = "symlink";
 	modes["100644"] = "regular";
 	modes["100755"] = "regular";
+	rc_count = rc_link_count = file_count = symlink_count = 0;
 }
 
 function fail(msg) {
@@ -34,6 +35,10 @@ filename !~ /^[[:alnum:]_./-]+$/ {
 filename ~ /\.license$/ { next }
 
 filename ~ /^image\/etc\/s6-rc\// {
+	if (mode == "symlink") {
+		rc_links[rc_link_count++] = filename;
+		next;
+	}
 	if (mode != "regular") {
 		fail("s6-rc-compile input '" filename "' isn't a regular file");
 	}
@@ -77,9 +82,15 @@ END {
 	for (array_index = 0; array_index < symlink_count; array_index += 1) {
 		printf " \\\n\t%s", symlinks[array_index];
 	}
-	printf "\n\nS6_RC_FILES =";
+	printf "\n\n" \
+"S6_RC_FILES =";
 	for (array_index = 0; array_index < rc_count; array_index += 1) {
 		printf " \\\n\t%s", rc_files[array_index];
 	}
+	printf "\n\n" \
+"S6_RC_LINKS =";
+	for (array_index = 0; array_index < rc_link_count; array_index += 1) {
+		printf " \\\n\t%s", rc_links[array_index];
+	}
 	print "";
 }
diff --git a/vm/sys/net/Makefile b/vm/sys/net/Makefile
index e37fe8ca161106f9c6492b2f8b5d68d48ae945de..a1258432b39175839b7f2f6c2535e75197910679 100644
--- a/vm/sys/net/Makefile
+++ b/vm/sys/net/Makefile
@@ -3,7 +3,9 @@
 
 .POSIX:
 
-include ../../../lib/common.mk
+ROOT = ../../..
+ROOT_FS = build
+include $(ROOT)/lib/common.mk
 include file-list.mk
 
 prefix = build/host
@@ -33,9 +35,6 @@ DIRS = dev etc/s6-linux-init/env proc run sys
 
 BUILD_FILES = build/etc/s6-rc
 
-build/empty:
-	mkdir -p $@
-
 build/rootfs.erofs: ../../../scripts/make-erofs.sh $(PACKAGES_FILE) $(FILES) $(BUILD_FILES) build/empty file-list.mk
 	set -euo pipefail; \
 	{ \
@@ -45,14 +44,6 @@ build/rootfs.erofs: ../../../scripts/make-erofs.sh $(PACKAGES_FILE) $(FILES) $(B
 	    printf 'build/empty\n%s\n' $(DIRS) ;\
 	} | ../../../scripts/make-erofs.sh $@
 
-build/etc/s6-rc: $(S6_RC_FILES) file-list.mk
-	mkdir -p $$(dirname $@)
-	rm -rf $@
-	set -uo pipefail && dir=$$(mktemp -d) && \
-	    { tar -c $(S6_RC_FILES) | tar -C $$dir -x --strip-components 3; } && \
-	    s6-rc-compile $@ $$dir; \
-	    exit=$$?; rm -r $$dir; exit $$exit
-
 debug:
 	$(GDB) -q \
 	    -ex 'set substitute-path .. $(LINUX_SRC)' \
@@ -108,6 +99,4 @@ run-crosvm: $(vmdir)/netvm/blk/root.img start-vhost-user-net
 run: run-$(VMM)
 .PHONY: run
 
-clean:
-	rm -rf build
-.PHONY: clean
+include $(ROOT)/lib/targets.mk
diff --git a/vm/sys/net/default.nix b/vm/sys/net/default.nix
index a722b021dc30f80e01dc626393a2f0311a75dc9d..df5fe7b1aa370c8b620dc18e565ca7fabde25f38 100644
--- a/vm/sys/net/default.nix
+++ b/vm/sys/net/default.nix
@@ -110,6 +110,7 @@ stdenvNoCC.mkDerivation {
     fileset = lib.fileset.intersection src (lib.fileset.unions [
       ./.
       ../../../lib/common.mk
+      ../../../lib/targets.mk
       ../../../scripts/make-erofs.sh
       ../../../scripts/make-gpt.sh
       ../../../scripts/sfdisk-field.awk
diff --git a/vm/sys/net/file-list.mk b/vm/sys/net/file-list.mk
index c8d6d8ccb569c988f5de804244d800fe05784d05..e13bf1c32a290e6d0a9465d14bed8da2049a65f7 100644
--- a/vm/sys/net/file-list.mk
+++ b/vm/sys/net/file-list.mk
@@ -33,3 +33,5 @@ S6_RC_FILES = \
 	image/etc/s6-rc/nftables/up \
 	image/etc/s6-rc/ok-all/contents.d/mdevd-coldplug \
 	image/etc/s6-rc/ok-all/type
+
+S6_RC_LINKS =

-- 
2.55.0