Further gn/rust cleanups

Move rust.gni and deno.gni into build_extra/

Removes rust_library which was only an action. This instead defines
rust_component, which is an action plus a gn "component" target
to expose the resulting object file. This simplifies link code in
rust.gni.

Support rust modules that can be linked into C++.

1 files changed, 15 insertions, 0 deletions

diff --git a/build_extra/rust/BUILD.gn b/build_extra/rust/BUILD.gn
new file mode 100644
index 000000000..e5a4fec16
--- /dev/null
+++ b/build_extra/rust/BUILD.gn
@@ -0,0 +1,15 @@
+import("rust.gni")
+
+# By compiling an empty file as crate-type=staticlib we get all the code
+# for the rust stdlib, which are not included in the object file outputs
+# of other libs.
+rust_component("stdlib") {
+  crate_type = "staticlib"
+  source_root = "empty.rs"
+  if (current_os == "mac") {
+    libs = [ "resolv" ]
+  }
+  if (current_os == "win") {
+    libs = [ "userenv.lib" ]
+  }
+}