Rust: Split glean-ffi up into 2 crates

glean-ffi carries all the no_mangle extern "C" definitions of our FFI
layer. This is getting included in mozilla-central soon.
However we can't have crates that are build as a `cdylib` as
dependencies in mozilla-central, as this will then produce said `cdylib`
during the build, which breaks at least on one build target.

We don't need that `cdylib` published, we only need it for builds we
ship ourselves: Kotlin, Swift & Python.

Therefore we split this part into a `glean-bundle` crate which itself
will generate a `cdylib` by the name `libglean_ffi`.
Our builds only need to reference that other workspace member, but don't
need to change what library they are loading.
Now `glean-ffi` is a plain ol' Rust crate and we can use that in
mozilla-central.

Author: badboy

Cargo.lock

@@ -4,6 +4,13 @@ members = [
   "glean-core",
   "glean-core/ffi",
   "glean-core/rlb",
+  "glean-core/bundle",
+]
+
+default-members = [
+  "glean-core",
+  "glean-core/ffi",
+  "glean-core/rlb",
 ]
 
 exclude = [

Cargo.toml

@@ -140,7 +140,7 @@ afterEvaluate {
 
 cargo {
     // The directory of the Cargo.toml to build.
-    module = '../ffi'
+    module = '../bundle'
 
     // The Android NDK API level to target.
     apiLevel = 21

glean-core/android/build.gradle

@@ -0,0 +1,26 @@
+[package]
+name = "glean-bundle"
+# No need to ever change this version
+version = "1.0.0"
+authors = ["Jan-Erik Rediger <[email protected]>"]
+edition = "2018"
+description = "Static/Dynamic library build of glean-ffi, for use in mobile builds"
+repository = "https://github.com/mozilla/glean"
+license = "MPL-2.0"
+
+# This crate is never published to crates.io
+publish = false
+
+# We use the same name as glean-ffi.
+# The Kotlin/Swift/Python bindings will use this name.
+[lib]
+name = "glean_ffi"
+crate-type = ["staticlib", "cdylib"]
+
+[dependencies.glean-ffi]
+# No version specified, we build against what's available here.
+path = "../ffi"
+
+[features]
+# Enable the "safe-mode" Rust storage backend instead of the default LMDB one.
+rkv-safe-mode = ["glean-ffi/rkv-safe-mode"]

glean-core/bundle/Cargo.toml

@@ -0,0 +1,5 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+pub use glean_ffi;

glean-core/bundle/src/lib.rs

@@ -24,7 +24,7 @@ maintenance = { status = "actively-developed" }
 
 [lib]
 name = "glean_ffi"
-crate-type = ["lib", "staticlib", "cdylib"]
+crate-type = ["lib"]
 
 [dependencies]
 ffi-support = "0.4.0"

glean-core/ffi/Cargo.toml

@@ -523,7 +523,7 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
-			shellScript = "bash $PWD/../../build-scripts/xc-universal-binary.sh glean-ffi $PWD/../.. $buildvariant\n";
+			shellScript = "bash $PWD/../../build-scripts/xc-universal-binary.sh glean-bundle $PWD/../.. $buildvariant\n";
 		};
 		BFB59A9723429FC000F40CA8 /* Run Glean SDK generator */ = {
 			isa = PBXShellScriptBuildPhase;

glean-core/ios/Glean.xcodeproj/project.pbxproj

@@ -183,7 +183,7 @@ def run(self):
             "cargo",
             "build",
             "--package",
-            "glean-ffi",
+            "glean-bundle",
             "--target",
             target,
             "--features",