From 0fda5a87da428601e05cb5a0b1f46960e62f2193 Mon Sep 17 00:00:00 2001
From: David Allsopp <david.allsopp@metastack.com>
Date: Fri, 17 Jun 2022 12:03:19 +0100
Subject: [PATCH] Generate .install files for opam installations

---
 .gitignore   |  2 +-
 Makefile     |  5 +++++
 num.opam     |  8 +-------
 src/Makefile | 45 +++++++++++++++++++++++++++++++++++++++++++--
 4 files changed, 50 insertions(+), 10 deletions(-)

diff --git a/.gitignore b/.gitignore
index 885225b..bca155d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -17,4 +17,4 @@ test/test.byt
 test/test.exe
 .merlin
 _build/
-num.install
+*.install
diff --git a/Makefile b/Makefile
index f7bb96d..c69ace6 100644
--- a/Makefile
+++ b/Makefile
@@ -7,6 +7,7 @@ test:
 clean:
 	$(MAKE) -C src clean
 	$(MAKE) -C test clean
+	rm -f num.install
 
 install:
 	$(MAKE) -C src install
@@ -20,4 +21,8 @@ uninstall:
 findlib-uninstall:
 	$(MAKE) -C src findlib-uninstall
 
+.PHONY: opam-%
+opam-%: all
+	cp src/num-$*.install num.install
+
 .PHONY: all test clean install uninstall findlib-install findlib-uninstall
diff --git a/num.opam b/num.opam
index c26d87f..cd4479c 100644
--- a/num.opam
+++ b/num.opam
@@ -11,17 +11,11 @@ homepage: "https://github.com/ocaml/num/"
 bug-reports: "https://github.com/ocaml/num/issues"
 dev-repo: "git+https://github.com/ocaml/num.git"
 build: [
-  [make]
+  [make "opam-legacy" {!ocaml:preinstalled} "opam-modern" {ocaml:preinstalled | ocaml:version >= "5.0.0~~"}]
   [make "test"] {with-test}
 ]
-install: [
-  make
-  "install" {!ocaml:preinstalled}
-  "findlib-install" {ocaml:preinstalled}
-]
 depends: [
   "ocaml" {>= "4.06.0"}
-  "ocamlfind" {build & >= "1.7.3"}
 ]
 conflicts: [ "base-num" ]
 synopsis:
diff --git a/src/Makefile b/src/Makefile
index 1db0ca8..1316b5c 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -27,7 +27,8 @@ SOURCES_NUM_TOP=\
   $(addsuffix .mli,$(MODULES_NUM_TOP)) $(addsuffix .ml,$(MODULES_NUM_TOP))
 CMOS_NUM_TOP=$(addsuffix .cmo,$(MODULES_NUM_TOP))
 
-all:: libnums.$(A) nums.cma num_top.cma META.legacy META.modern META.top
+all:: libnums.$(A) nums.cma num_top.cma META.legacy META.modern META.top \
+      num-legacy.install num-modern.install
 
 ifeq "$(NATIVE_COMPILER)" "true"
 all:: nums.cmxa
@@ -109,6 +110,45 @@ TOINSTALL_STUBS=
 endif
 TOINSTALL_NUM_TOP=num_top.cma $(addsuffix .cmi,$(MODULES_NUM_TOP))
 
+# Generate opam .install files for both installation modes:
+# lib_root section
+#   - num-top files (legacy and modern)
+#   - num artefacts to ocaml/ (legacy only)
+#   - dllnums.so to ocaml/stublibs/ (legacy only)
+# lib section:
+#   - num META file
+#   - num artefacts (modern only)
+# stublibs section:
+#   - dllnums.so (modern only)
+define GENERATE_INSTALL_FILE
+num-$1.install:
+	@echo 'lib_root: [' > $$@
+	@echo '  "src/META.top" {"num-top/META"}' >> $$@
+$(foreach file,$(TOINSTALL_NUM_TOP),
+	@echo '  "src/$(file)" {"num-top/$(file)"}' >> $$@)
+ifeq "$(1)" "legacy"
+$(foreach file,$(TOINSTALL),
+	@echo '  "src/$(file)" {"ocaml/$(file)"}' >> $$@)
+$(foreach file,$(TOINSTALL_STUBS),
+	@echo '  "src/$(file)" {"ocaml/stublibs/$(file)"}' >> $$@)
+endif
+	@echo ']' >> $$@
+	@echo 'lib: [' >> $$@
+	@echo '  "src/META.$(1)" {"META"}' >> $$@
+ifeq "$(1)" "modern"
+$(foreach file,$(TOINSTALL),
+	@echo '  "src/$(file)"' >> $$@)
+	@echo ']' >> $$@
+	@echo 'stublibs: [' >> $$@
+$(foreach file,$(TOINSTALL_STUBS),
+	@echo '  "src/$(file)"' >> $$@)
+endif
+	@echo ']' >> $$@
+endef
+
+$(eval $(call GENERATE_INSTALL_FILE,legacy))
+$(eval $(call GENERATE_INSTALL_FILE,modern))
+
 install: num-top-install
 	$(INSTALL_DIR) $(DESTDIR)$(STDLIBDIR)
 	cp META.legacy META
@@ -144,7 +184,8 @@ endif
 
 clean:
 	rm -f *.cm[ioxta] *.cmx[as] *.cmti *.$(O) *.$(A) *$(EXT_DLL) \
-        META.top META.legacy META.modern $(SOURCES_NUM_TOP)
+        META.top META.legacy META.modern $(SOURCES_NUM_TOP) \
+        num-legacy.install num-modern.install
 
 $(SOURCES_NUM_TOP:num_=%): $(addprefix ../toplevel/,$(SOURCES_NUM_TOP))
 	cp $^ .