From c718f34d435a913d462e90c74adff03c6252dc7b Mon Sep 17 00:00:00 2001
From: Colin Walters <walters@verbum.org>
Date: Fri, 11 Dec 2020 15:09:57 +0000
Subject: [PATCH] Fix and improve support for rpmostree-rust.h being
 pre-generated

First, we now need the `vendor/` directory at the toplevel because
that's where `Cargo.toml` is.

Now this triggers another bug introduced in the build system
with how we're handling the `rpmostree-rust.h` header.
We ended up vendoring a pre-generated one in the tarball
mainly because RHEL doesn't include cbindgen.
Now probably in the future I'd like to fix that.

But let's clean this up - the tarball generation process copies
the file into `rpmostree-rust-prebuilt.h`, and build machinery
detects that and entirely skips looking for or trying to build
our internal cbindgen.
---
 Makefile-rpm-ostree.am         | 7 ++++++-
 configure.ac                   | 8 ++++++--
 packaging/make-git-snapshot.sh | 4 ++--
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/Makefile-rpm-ostree.am b/Makefile-rpm-ostree.am
index b1cfdb12..713d4b00 100644
--- a/Makefile-rpm-ostree.am
+++ b/Makefile-rpm-ostree.am
@@ -106,6 +106,10 @@ $(librpmostree_rust_path): Makefile $(LIBRPMOSTREE_RUST_SRCS)
 EXTRA_DIST += $(LIBRPMOSTREE_RUST_SRCS)
 
 # Generate bindings from Rust to C
+if BUILDOPT_PREBUILT_BINDINGS
+rpmostree-rust.h:
+	ln -sfr rpmostree-rust-prebuilt.h $@
+else
 if !HAVE_PREBUILT_CBINDGEN
 if HAVE_EXTERNAL_CBINDGEN
 rpmostree-rust.h:
@@ -114,8 +118,9 @@ else
 rpmostree-rust.h: rpmostree-bindgen
 	$(AM_V_GEN) ./rpmostree-bindgen $(top_srcdir)
 endif
-BUILT_SOURCES += rpmostree-rust.h
 endif
+endif
+BUILT_SOURCES += rpmostree-rust.h
 
 rpm_ostree_CFLAGS += $(PKGDEP_RPMOSTREE_RS_CFLAGS)
 rpm_ostree_LDADD += $(librpmostree_rust_path) $(PKGDEP_RPMOSTREE_RS_LIBS) -lstdc++
diff --git a/configure.ac b/configure.ac
index d319e2fe..e1d2d205 100644
--- a/configure.ac
+++ b/configure.ac
@@ -195,14 +195,18 @@ AS_IF([test -z "$cargo"], [AC_MSG_ERROR([cargo is required for --enable-rust])])
 AC_PATH_PROG([rustc], [rustc])
 AS_IF([test -z "$rustc"], [AC_MSG_ERROR([rustc is required for --enable-rust])])
 
+dnl this is true effectively iff we used make-git-snapshot.sh
+AM_CONDITIONAL(BUILDOPT_PREBUILT_BINDINGS, [test -f rpmostree-rust-prebuilt.h])
+
+AM_COND_IF([BUILDOPT_PREBUILT_BINDINGS], [cbindgen=prebuilt], [
 dnl https://github.com/projectatomic/rpm-ostree/pull/1573
-dnl We support 3 modes for bindgen:
+dnl We support 2 modes for bindgen:
 dnl  - External /usr/bin/cbindgen (Fedora + CI)
 dnl  - Downloading it from crates.io (CentOS + CI builds)
-dnl  - Not running it at all, and using a pre-built rpmostree-rust.h (Koji)
 AS_IF([test -d "${srcdir}"/rust/vendor],
       [cbindgen=dist],
       [AC_PATH_PROG([cbindgen], [cbindgen])])
+])
 AM_CONDITIONAL(HAVE_PREBUILT_CBINDGEN, [test "${cbindgen}" = "dist"])
 AM_CONDITIONAL(HAVE_EXTERNAL_CBINDGEN, [test -n "${cbindgen}" && test "${cbindgen}" != dist])
 
diff --git a/packaging/make-git-snapshot.sh b/packaging/make-git-snapshot.sh
index fb69c907..d9102609 100755
--- a/packaging/make-git-snapshot.sh
+++ b/packaging/make-git-snapshot.sh
@@ -57,13 +57,13 @@ j = json.load(open(checksum_file))
 j["files"] = {f:c for f, c in j["files"].items() if not f.startswith(subdir)}
 open(checksum_file, "w").write(json.dumps(j))' $crate_subdir
  done
- tar --transform="s,^,${PKG_VER}/rust/," -rf ${TARFILE_TMP} * .cargo/
+ tar --transform="s,^,${PKG_VER}/," -rf ${TARFILE_TMP} * .cargo/
  )
 
 # And finally, vendor rpmostree-rust.h; it's generated by cbindgen,
 # and it's easier than vendoring all of the source for that too.
 # This is currently the *only* generated file we treat this way. See also
 # https://github.com/projectatomic/rpm-ostree/pull/1573
-(cd ${srcdir} && tar --transform "s,^,${PKG_VER}/," -rf ${TARFILE_TMP} rpmostree-rust.h)
+(cd ${srcdir} && cp rpmostree-rust{,-prebuilt}.h && tar --transform "s,^,${PKG_VER}/," -rf ${TARFILE_TMP} rpmostree-rust-prebuilt.h)
 
 mv ${TARFILE_TMP} ${TARFILE}