gh-141692: Add a slice-specific lib folder to iOS XCframeworks. (#141693)

Modifies the iOS XCframework to include a lib folder for each slice that
contains a symlinked version of the libPython dynamic library.

Author: freakboy3742

Apple/__main__.py

@@ -477,6 +477,12 @@ def lib_platform_files(dirname, names):
                 or name == "build-details.json"
             )
         }
+    elif path.parts[-1] == "lib":
+        ignored_names = {
+            name
+            for name in names
+            if name.startswith("libpython") and name.endswith(".dylib")
+        }
     else:
         ignored_names = set()
 
@@ -614,6 +620,12 @@ def create_xcframework(platform: str) -> str:
             slice_framework / "Headers/pyconfig.h",
         )
 
+        print(f" - {slice_name} shared library")
+        # Create a simlink for the fat library
+        shared_lib = slice_path / f"lib/libpython{version_tag}.dylib"
+        shared_lib.parent.mkdir()
+        shared_lib.symlink_to("../Python.framework/Python")
+
         print(f" - {slice_name} architecture-specific files")
         for host_triple, multiarch in slice_parts.items():
             print(f"   - {multiarch} standard library")
@@ -625,13 +637,15 @@ def create_xcframework(platform: str) -> str:
                     framework_path(host_triple, multiarch) / "lib",
                     package_path / "Python.xcframework/lib",
                     ignore=lib_platform_files,
+                    symlinks=True,
                 )
                 has_common_stdlib = True
 
             shutil.copytree(
                 framework_path(host_triple, multiarch) / "lib",
                 slice_path / f"lib-{arch}",
                 ignore=lib_non_platform_files,
+                symlinks=True,
             )
 
             # Copy the host's pyconfig.h to an architecture-specific name.

Apple/testbed/Python.xcframework/build/utils.sh

@@ -46,7 +46,8 @@ install_stdlib() {
         rsync -au --delete "$PROJECT_DIR/$PYTHON_XCFRAMEWORK_PATH/lib/" "$CODESIGNING_FOLDER_PATH/python/lib/"
         rsync -au "$PROJECT_DIR/$PYTHON_XCFRAMEWORK_PATH/$SLICE_FOLDER/lib-$ARCHS/" "$CODESIGNING_FOLDER_PATH/python/lib/"
     else
-        rsync -au --delete "$PROJECT_DIR/$PYTHON_XCFRAMEWORK_PATH/$SLICE_FOLDER/lib/" "$CODESIGNING_FOLDER_PATH/python/lib/"
+        # A single-arch framework will have a libpython symlink; that can't be included at runtime
+        rsync -au --delete "$PROJECT_DIR/$PYTHON_XCFRAMEWORK_PATH/$SLICE_FOLDER/lib/" "$CODESIGNING_FOLDER_PATH/python/lib/" --exclude 'libpython*.dylib'
     fi
 }
 

Makefile.pre.in

@@ -3050,6 +3050,9 @@ frameworkinstallunversionedstructure:	$(LDLIBRARY)
 	$(INSTALL) -d -m $(DIRMODE) $(DESTDIR)$(PYTHONFRAMEWORKINSTALLDIR)
 	sed 's/%VERSION%/'"`$(RUNSHARED) $(PYTHON_FOR_BUILD) -c 'import platform; print(platform.python_version())'`"'/g' < $(RESSRCDIR)/Info.plist > $(DESTDIR)$(PYTHONFRAMEWORKINSTALLDIR)/Info.plist
 	$(INSTALL_SHARED) $(LDLIBRARY) $(DESTDIR)$(PYTHONFRAMEWORKPREFIX)/$(LDLIBRARY)
+	$(INSTALL) -d -m $(DIRMODE) $(DESTDIR)$(LIBDIR)
+	$(LN) -fs "../$(LDLIBRARY)" "$(DESTDIR)$(prefix)/lib/libpython$(LDVERSION).dylib"
+	$(LN) -fs "../$(LDLIBRARY)" "$(DESTDIR)$(prefix)/lib/libpython$(VERSION).dylib"
 	$(INSTALL) -d -m $(DIRMODE) $(DESTDIR)$(BINDIR)
 	for file in $(srcdir)/$(RESSRCDIR)/bin/* ; do \
 		$(INSTALL) -m $(EXEMODE) $$file $(DESTDIR)$(BINDIR); \

Misc/NEWS.d/next/Tools-Demos/2025-11-18-13-55-47.gh-issue-141692.tud9if.rst

@@ -0,0 +1,3 @@
+Each slice of an iOS XCframework now contains a ``lib`` folder that contains
+a symlink to the libpython dylib. This allows binary modules to be compiled
+for iOS using dynamic libreary linking, rather than Framework linking.