1 files changed, 79 insertions, 0 deletions
diff --git a/python/mozbuild/mozbuild/action/wrap_rustc.py b/python/mozbuild/mozbuild/action/wrap_rustc.py
new file mode 100644
index 0000000000..d865438c47
--- /dev/null
+++ b/python/mozbuild/mozbuild/action/wrap_rustc.py
@@ -0,0 +1,79 @@
+# 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/.
+
+import argparse
+import os
+import subprocess
+import sys
+
+
+def parse_outputs(crate_output, dep_outputs, pass_l_flag):
+    env = {}
+    args = []
+
+    def parse_line(line):
+        if line.startswith("cargo:"):
+            return line[len("cargo:") :].split("=", 1)
+
+    def parse_file(f):
+        with open(f) as fh:
+            return [parse_line(line.rstrip()) for line in fh.readlines()]
+
+    for f in dep_outputs:
+        for entry in parse_file(f):
+            if not entry:
+                continue
+            key, value = entry
+            if key == "rustc-link-search":
+                args += ["-L", value]
+            elif key == "rustc-flags":
+                flags = value.split()
+                for flag, val in zip(flags[0::2], flags[1::2]):
+                    if flag == "-l" and f == crate_output:
+                        args += ["-l", val]
+                    elif flag == "-L":
+                        args += ["-L", val]
+                    else:
+                        raise Exception(
+                            "Unknown flag passed through "
+                            '"cargo:rustc-flags": "%s"' % flag
+                        )
+            elif key == "rustc-link-lib" and f == crate_output:
+                args += ["-l", value]
+            elif key == "rustc-cfg" and f == crate_output:
+                args += ["--cfg", value]
+            elif key == "rustc-env" and f == crate_output:
+                env_key, env_value = value.split("=", 1)
+                env[env_key] = env_value
+            elif key == "rerun-if-changed":
+                pass
+            elif key == "rerun-if-env-changed":
+                pass
+            elif key == "warning":
+                pass
+            elif key:
+                # Todo: Distinguish between direct and transitive
+                # dependencies so we can pass metadata environment
+                # variables correctly.
+                pass
+
+    return env, args
+
+
+def wrap_rustc(args):
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--crate-out", nargs="?")
+    parser.add_argument("--deps-out", nargs="*")
+    parser.add_argument("--cwd")
+    parser.add_argument("--pass-l-flag", action="store_true")
+    parser.add_argument("--cmd", nargs=argparse.REMAINDER)
+    args = parser.parse_args(args)
+
+    new_env, new_args = parse_outputs(args.crate_out, args.deps_out, args.pass_l_flag)
+    os.environ.update(new_env)
+    return subprocess.Popen(args.cmd + new_args, cwd=args.cwd).wait()
+
+
+if __name__ == "__main__":
+    sys.exit(wrap_rustc(sys.argv[1:]))