1 files changed, 84 insertions, 0 deletions
diff --git a/pkgs/development/ocaml-modules/ocaml-freestanding/no-opam.patch b/pkgs/development/ocaml-modules/ocaml-freestanding/no-opam.patch
new file mode 100644
index 00000000000..43141b1472a
--- /dev/null
+++ b/pkgs/development/ocaml-modules/ocaml-freestanding/no-opam.patch
@@ -0,0 +1,84 @@
+commit 637b7ce639d54e617170433aa9596176b167d085
+Author: sternenseemann <0rpkxez4ksa01gb3typccl0i@systemli.org>
+Date:   Thu Mar 18 01:07:49 2021 +0100
+
+    Allow building without ocamlfind and opam
+    
+    This change is the result of my first go at packaging ocaml-freestanding
+    for NixOS. Our build infrastructure for ocaml there is completely
+    independent of opam at the moment, so depending on opam for the build
+    time is not an option, especially in this case where the information it
+    would give us would be garbage.
+    
+    Fortunately the build environment plays nicely with pkg-config which is
+    already heavily used by ocaml-freestanding. This patch leaves pkg-config
+    to its own devices if opam is not present (it can be assisted by a
+    manually set PKG_CONFIG_PATH environment variable).
+    
+    Additionally, in configure.sh we check if the target ocaml source
+    directory already exists. This allows for building ocaml-freestanding
+    without the ocaml-src package (which would be unnecessarily cumbersome
+    to package for NixOS) and ocamlfind (one less dependency is always a
+    nice bonus). The Makefile needs no fix since the target ocaml/Makefile
+    won't be built if it's already present.
+
+diff --git a/Makefile b/Makefile
+index b07b8c6..a68b31d 100644
+--- a/Makefile
++++ b/Makefile
+@@ -2,6 +2,12 @@
+ 
+ include Makeconf
+ 
++ifneq ($(shell command -v opam),)
++	# only set if opam is available and PKG_CONFIG_PATH isn't
++	# already set in the environment or on the command line
++	PKG_CONFIG_PATH ?= $(shell opam config var prefix)/lib/pkgconfig
++endif
++
+ FREESTANDING_LIBS=openlibm/libopenlibm.a \
+ 		  ocaml/runtime/libasmrun.a \
+ 		  nolibc/libnolibc.a
+@@ -73,8 +79,7 @@ flags/libs.tmp: flags/libs.tmp.in
+ 	opam config subst $@
+ 
+ flags/libs: flags/libs.tmp Makeconf
+-	env PKG_CONFIG_PATH="$(shell opam config var prefix)/lib/pkgconfig" \
+-	    pkg-config $(PKG_CONFIG_DEPS) --libs >> $<
++	pkg-config $(PKG_CONFIG_DEPS) --libs >> $<
+ 	awk -v RS= -- '{ \
+ 	    sub("@@PKG_CONFIG_EXTRA_LIBS@@", "$(PKG_CONFIG_EXTRA_LIBS)", $$0); \
+ 	    print "(", $$0, ")" \
+@@ -84,8 +89,7 @@ flags/cflags.tmp: flags/cflags.tmp.in
+ 	opam config subst $@
+ 
+ flags/cflags: flags/cflags.tmp Makeconf
+-	env PKG_CONFIG_PATH="$(shell opam config var prefix)/lib/pkgconfig" \
+-	    pkg-config $(PKG_CONFIG_DEPS) --cflags >> $<
++	pkg-config $(PKG_CONFIG_DEPS) --cflags >> $<
+ 	awk -v RS= -- '{ \
+ 	    print "(", $$0, ")" \
+ 	    }' $< >$@
+diff --git a/configure.sh b/configure.sh
+index 4d154ed..c254f7b 100755
+--- a/configure.sh
++++ b/configure.sh
+@@ -1,6 +1,8 @@
+ #!/bin/sh
+ 
+-export PKG_CONFIG_PATH=$(opam config var prefix)/lib/pkgconfig
++if command -v opam &> /dev/null; then
++    export PKG_CONFIG_PATH=$(opam config var prefix)/lib/pkgconfig
++fi
+ pkg_exists() {
+     pkg-config --exists "$@"
+ }
+@@ -21,7 +23,7 @@ if [ -z "${PKG_CONFIG_DEPS}" ]; then
+     echo "ERROR: solo5-bindings-hvt, solo5-bindings-spt, solo5-bindings-virtio, solo5-bindings-muen, solo5-bindings-genode or solo5-bindings-xen must be installed." 1>&2
+     exit 1
+ fi
+-ocamlfind query ocaml-src >/dev/null || exit 1
++[ -e "$(dirname "$0")/ocaml" ] || ocamlfind query ocaml-src >/dev/null || exit 1
+ 
+ FREESTANDING_CFLAGS="$(pkg-config --cflags ${PKG_CONFIG_DEPS})"
+ BUILD_ARCH="$(uname -m)"