SERVER-50689 Support ABI driven linking on macOS with tapi

1 files changed, 108 insertions, 0 deletions

diff --git a/site_scons/site_tools/tapilink.py b/site_scons/site_tools/tapilink.py
new file mode 100644
index 00000000000..0521767fc06
--- /dev/null
+++ b/site_scons/site_tools/tapilink.py
@@ -0,0 +1,108 @@
+# Copyright 2020 MongoDB Inc.
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
+# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+#
+
+import SCons
+import subprocess
+
+# TODO: DRY this with abilink.py by moving duplicated code out to a common
+# support module.
+
+def _detect(env):
+    try:
+        tapi = env["TAPI"]
+        if not tapi:
+            return None
+        return tapi
+    except KeyError:
+        pass
+
+    return env.WhereIs("tapi")
+
+
+def _add_emitter(builder):
+    base_emitter = builder.emitter
+
+    def new_emitter(target, source, env):
+        new_targets = []
+        for t in target:
+            base, ext = SCons.Util.splitext(str(t))
+            if not ext == env['SHLIBSUFFIX']:
+                continue
+
+            tbd_target = (t.builder.target_factory or env.File)(base + ".tbd")
+            new_targets.append(tbd_target)
+
+            tbd_no_uuid_target = (t.builder.target_factory or env.File)(base + ".tbd.no_uuid")
+            new_targets.append(tbd_no_uuid_target)
+
+            setattr(t.attributes, "tbd", tbd_no_uuid_target)
+        targets = target + new_targets
+        return (targets, source)
+
+    new_emitter = SCons.Builder.ListEmitter([base_emitter, new_emitter])
+    builder.emitter = new_emitter
+
+
+def _add_scanner(builder):
+    old_scanner = builder.target_scanner
+    path_function = old_scanner.path_function
+
+    def new_scanner(node, env, path):
+        return (getattr(env.Entry(o).attributes, "tbd", o) for o in old_scanner(node, env, path))
+
+    builder.target_scanner = SCons.Scanner.Scanner(
+        function=new_scanner, path_function=path_function
+    )
+
+def _add_action(builder):
+    actions = builder.action
+
+    # The first inbocation of TAPI is to make the tbd file that the
+    # linker will actually use when linking. This must contain the
+    # dylib UUID or the link will fail. The second creates a version
+    # that does not contain the UUID. We use that as the ABI file. If
+    # invoking TAPI proves to be expensive, we could address this by
+    # instead post-processing the "real" .tbd file to strip out the
+    # UUID, and then potentially even feed it into a hash algorithm.
+    builder.action = actions + SCons.Action.Action(
+        [
+            "$TAPI stubify -o ${TARGET.base}.tbd ${TARGET}",
+            "$TAPI stubify --no-uuids -o ${TARGET.base}.tbd.no_uuid ${TARGET}"
+        ]
+    )
+
+def exists(env):
+    result = _detect(env) != None
+    return result
+
+
+def generate(env):
+
+    if not exists(env):
+        return
+
+    builder = env["BUILDERS"]["SharedLibrary"]
+    _add_emitter(builder)
+    _add_action(builder)
+    _add_scanner(builder)
+    _add_scanner(env["BUILDERS"]["Program"])
+    _add_scanner(env["BUILDERS"]["LoadableModule"])