WIP: replace develop command

src/setuptools_dso/__init__.py

@@ -6,6 +6,7 @@
 import os
 from setuptools import setup as _setup
 from .dsocmd import DSO, Extension, build_dso, build_ext, bdist_egg
+from .develop import develop
 from .runtime import dylink_prepare_dso, find_dso
 from .probe import ProbeToolchain
 
@@ -48,6 +49,7 @@ def cmdclass_setdefault(name, klass, error=True):
     cmdclass_setdefault('bdist_egg', bdist_egg)
     cmdclass_setdefault('build_dso', build_dso)
     cmdclass_setdefault('build_ext', build_ext)
+    cmdclass_setdefault('develop', develop, error=False)
     try:
         from .dsocmd import bdist_wheel
     except ImportError:

src/setuptools_dso/develop.py

@@ -0,0 +1,113 @@
+# Copyright 2022  Michael Davidsaver
+# SPDX-License-Identifier: BSD
+# See LICENSE
+
+import sys
+import os
+from distutils import log
+from distutils.dir_util import mkpath
+
+from setuptools import Command
+from setuptools.command.develop import develop as _develop
+
+class link_develop(Command):
+    """
+    Use of .egg-link (really 'easy-install.pth') doesn't work in conjunction with RPATH.
+    Further, simply sym-linking directories into the install tree doesn't work as path
+    traversal follows sym-links.  eg. "adir/link2dir/../other/lib" does not reach "adir/other/lib".
+
+    So instead, we hijack the develop command entirely to install sym-links for each individual
+    file (.py and .so/dylib).  This is not 100% as 'develop' must be re-run each time new files
+    are created in the source tree.
+    """
+
+    description = _develop.description
+
+    # pull in the full set of options as we don't know which ones
+    # pip can/will use.
+
+    user_options = _develop.user_options
+    boolean_options = _develop.boolean_options
+
+    def initialize_options(self):
+        _develop.initialize_options(self) # evil!
+        self.uninstall = None
+        self.no_deps = None
+
+    def finalize_options(self):
+        pass
+
+    def run(self):
+        if self.uninstall:
+            self.run_uninstall()
+        else:
+            self.run_install()
+
+    def run_install(self):
+        log.info('setuptools_dso develop mode')
+
+        install_lib = self.get_finalized_command('install_lib')
+
+        # note: doc comment on get_inputs() claims the returned list is one-to-one
+        #       with get_outputs().   However, this is only true if compile=False,
+        #       otherwise get_outputs() emits bytecode files between .py and .so
+        install_lib.compile = False
+
+        install_lib.build()
+
+        for inp, out in zip(install_lib.get_inputs(), install_lib.get_outputs()):
+            assert os.path.basename(inp)==os.path.basename(out), (inp, out)
+
+            outdir = os.path.dirname(out)
+            inp = os.path.relpath(inp, outdir)
+
+            mkpath(outdir, verbose=self.verbose, dry_run=self.dry_run)
+
+            log.info('ln -s %s %s', inp, out)
+
+            # note: samefile() follows symlinks by default
+            if not (os.path.exists(out) and os.path.samefile(inp, out)) and not self.dry_run:
+                os.symlink(inp, out)
+
+        # TODO: need to create/install *.dist_info for "pip uninstall ..."
+        #dist_info = self.get_finalized_command('dist_info')
+        #dist_info.run()
+
+    def run_uninstall(self):
+        log.info('setuptools_dso develop mode, uninstall')
+
+        install_lib = self.get_finalized_command('install_lib')
+        # leave install_lib.compile (maybe) set so that bytecode is also removed
+
+        # From an abundance of caution, only removing known output files
+        # and empty directories containing them.
+
+        pkgdirs = set()
+        for out in install_lib.get_outputs():
+            pkgdirs.add(os.path.dirname(out))
+            if os.path.isfile(out):
+                log.info('rm %s', out)
+                if not self.dry_run:
+                    os.remove(out)
+
+        # delete (longer) sub-directories first
+        pkgdirs = list(pkgdirs)
+        pkgdirs.sort()
+        pkgdirs.reverse()
+
+        for odir in pkgdirs:
+            if os.path.isdir(odir):
+                try:
+                    if not self.dry_run:
+                        os.rmdir(odir)
+                except OSError as e:
+                    log.warn('Unable to remove directory: %s : %s', odir, e.args)
+                else:
+                    log.info('rmdir %s', odir)
+
+
+if sys.platform=='win32':
+    develop = _develop
+
+else:
+    develop = link_develop