1 files changed, 97 insertions, 0 deletions
diff --git a/third_party/libwebrtc/build/rust/std/find_std_rlibs.py b/third_party/libwebrtc/build/rust/std/find_std_rlibs.py
new file mode 100755
index 0000000000..b8f775e438
--- /dev/null
+++ b/third_party/libwebrtc/build/rust/std/find_std_rlibs.py
@@ -0,0 +1,97 @@
+#!/usr/bin/env/python3
+
+# Copyright 2021 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# See BUILD.gn in this directory for an explanation of what this script is for.
+
+import argparse
+import os
+import sys
+import shutil
+import subprocess
+import re
+
+REMOVE_METADATA_SUFFIX_RE = re.compile(b"-[0-9a-f]*", re.I)
+
+
+def expand_name(concise_name):
+  return "lib%s.rlib" % concise_name
+
+
+def main():
+  parser = argparse.ArgumentParser("find_std_rlibs.py")
+  parser.add_argument("--rust-bin-dir",
+                      help="Path to Rust binaries",
+                      required=True),
+  parser.add_argument("--target", help="Rust target triple", required=False),
+  parser.add_argument("--output",
+                      help="Path to rlibs without suffixes",
+                      required=True)
+  parser.add_argument("--depfile", help="Path to write depfile", required=True)
+  parser.add_argument("--depfile-target",
+                      help="Target to key depfile around",
+                      required=True)
+  parser.add_argument("--stdlibs",
+                      help="Expected list of standard library libraries")
+  parser.add_argument("--skip-stdlibs",
+                      help="Standard library files to skip",
+                      default="")
+  args = parser.parse_args()
+  # Ensure we handle each rlib in the expected list exactly once.
+  if args.stdlibs:
+    rlibs_expected = [expand_name(x) for x in args.stdlibs.split(',')]
+  else:
+    rlibs_expected = None
+  rlibs_to_skip = [expand_name(x) for x in args.skip_stdlibs.split(',')]
+  # Ask rustc where to find the stdlib for this target.
+  rustc = os.path.join(args.rust_bin_dir, "rustc")
+  rustc_args = [rustc, "--print", "target-libdir"]
+  if args.target:
+    rustc_args.extend(["--target", args.target])
+  rustlib_dir = subprocess.check_output(rustc_args).rstrip()
+  # Copy the rlibs to a predictable location. Whilst we're doing so,
+  # also write a .d file so that ninja knows it doesn't need to do this
+  # again unless the source rlibs change.
+  # Format:
+  # <output path to>/lib<lib name.rlib>: <path to each Rust stlib rlib>
+  with open(args.depfile, 'w') as depfile:
+    # Ninja isn't versatile at understanding depfiles. We have to say that a
+    # single output depends on all the inputs. We choose any one of the
+    # output rlibs for that purpose. If any of the input rlibs change, ninja
+    # will run this script again and we'll copy them all afresh.
+    depfile.write("%s:" %
+                  (os.path.join(args.output, expand_name(args.depfile_target))))
+    for f in os.listdir(rustlib_dir):
+      if f.endswith(b'.rlib'):
+        # As standard Rust includes a hash on the end of each filename
+        # representing certain metadata, to ensure that clients will link
+        # against the correct version. As gn will be manually passing
+        # the correct file path to our linker invocations, we don't need
+        # that, and it would prevent us having the predictable filenames
+        # which we need for statically computable gn dependency rules.
+        (concise_name, count) = REMOVE_METADATA_SUFFIX_RE.subn(b"", f)
+        if count == 0:
+          raise Exception("Unable to remove suffix from %s" % f)
+        if concise_name.decode() in rlibs_to_skip:
+          continue
+        if rlibs_expected is not None:
+          if concise_name.decode() not in rlibs_expected:
+            raise Exception("Found stdlib rlib that wasn't expected: %s" %
+                            concise_name)
+          rlibs_expected.remove(concise_name.decode())
+        infile = os.path.join(rustlib_dir, f)
+        outfile = os.path.join(str.encode(args.output), concise_name)
+        depfile.write(" %s" % (infile.decode()))
+        if (not os.path.exists(outfile)
+            or os.stat(infile).st_mtime > os.stat(outfile).st_mtime):
+          shutil.copy(infile, outfile)
+    depfile.write("\n")
+    if rlibs_expected:
+      raise Exception("We failed to find all expected stdlib rlibs: %s" %
+                      ','.join(rlibs_expected))
+
+
+if __name__ == '__main__':
+  sys.exit(main())