Improve byte-compilation in packaging to be independent of -O or -B.

The code I fixed to comply with PEP 3147 still had one bug: When run
under python -O, some paths for pyc files would be pyo, because I called
imp.cache_from_source without explicit debug_override argument in some
places, and under -O that would return .pyo (this is well explained in
the imp docs).  Now all code (util.byte_compile, build_py, install_lib)
can create .pyo files according to options given by users,
without interference from the calling Python’s own optimize mode.

On a related topic, I also removed the code that prevented byte
compilation under python -B.  The rationale is that packaging gives
control over the creation of pyc files to the user with its own explicit
option, and the behavior should not be changed if the calling Python
happens to run with -B for whatever reason.  I will argue that this is a
bug fix and ask to be allowed to backport this change to distutils.

Finally, I moved one nugget of information about the --compile and
--optimize options from the source into the doc.  It clears up a
misunderstanding that I (and maybe other people) had.

2 files changed, 34 insertions, 53 deletions

diff --git a/Lib/packaging/command/build_py.py b/Lib/packaging/command/build_py.py
index 0248213..5faae39 100644
--- a/Lib/packaging/command/build_py.py
+++ b/Lib/packaging/command/build_py.py
@@ -2,7 +2,6 @@
 
 import os
 import imp
-import sys
 from glob import glob
 
 from packaging import logger
@@ -14,10 +13,14 @@ from packaging.compat import Mixin2to3
 # marking public APIs
 __all__ = ['build_py']
 
+
 class build_py(Command, Mixin2to3):
 
     description = "build pure Python modules (copy to build directory)"
 
+    # The options for controlling byte compilations are two independent sets;
+    # more info in install_lib or the reST docs
+
     user_options = [
         ('build-lib=', 'd', "directory to build (copy) to"),
         ('compile', 'c', "compile .py to .pyc"),
@@ -35,7 +38,8 @@ class build_py(Command, Mixin2to3):
         ]
 
     boolean_options = ['compile', 'force']
-    negative_opt = {'no-compile' : 'compile'}
+
+    negative_opt = {'no-compile': 'compile'}
 
     def initialize_options(self):
         self.build_lib = None
@@ -116,7 +120,7 @@ class build_py(Command, Mixin2to3):
     def get_data_files(self):
         """Generate list of '(package,src_dir,build_dir,filenames)' tuples.
 
-        Helper function for `finalize_options()`.
+        Helper function for finalize_options.
         """
         data = []
         if not self.packages:
@@ -131,7 +135,7 @@ class build_py(Command, Mixin2to3):
             # Length of path to strip from found files
             plen = 0
             if src_dir:
-                plen = len(src_dir)+1
+                plen = len(src_dir) + 1
 
             # Strip directory from globbed filenames
             filenames = [
@@ -143,7 +147,7 @@ class build_py(Command, Mixin2to3):
     def find_data_files(self, package, src_dir):
         """Return filenames for package's data files in 'src_dir'.
 
-        Helper function for `get_data_files()`.
+        Helper function for get_data_files.
         """
         globs = (self.package_data.get('', [])
                  + self.package_data.get(package, []))
@@ -158,7 +162,7 @@ class build_py(Command, Mixin2to3):
     def build_package_data(self):
         """Copy data files into build directory.
 
-        Helper function for `run()`.
+        Helper function for run.
         """
         # FIXME add tests for this method
         for package, src_dir, build_dir, filenames in self.data_files:
@@ -168,16 +172,17 @@ class build_py(Command, Mixin2to3):
                 self.mkpath(os.path.dirname(target))
                 outf, copied = self.copy_file(srcfile,
                                target, preserve_mode=False)
-                if copied and srcfile in self.distribution.convert_2to3.doctests:
+                doctests = self.distribution.convert_2to3_doctests
+                if copied and srcfile in doctests:
                     self._doctests_2to3.append(outf)
 
     # XXX - this should be moved to the Distribution class as it is not
     # only needed for build_py. It also has no dependencies on this class.
     def get_package_dir(self, package):
         """Return the directory, relative to the top of the source
-           distribution, where package 'package' should be found
-           (at least according to the 'package_dir' option, if any)."""
-
+        distribution, where package 'package' should be found
+        (at least according to the 'package_dir' option, if any).
+        """
         path = package.split('.')
         if self.package_dir is not None:
             path.insert(0, self.package_dir)
@@ -188,8 +193,7 @@ class build_py(Command, Mixin2to3):
         return ''
 
     def check_package(self, package, package_dir):
-        """Helper function for `find_package_modules()` and `find_modules()'.
-        """
+        """Helper function for find_package_modules and find_modules."""
         # Empty dir name means current directory, which we can probably
         # assume exists.  Also, os.path.exists and isdir don't know about
         # my "empty string means current dir" convention, so we have to
@@ -209,8 +213,8 @@ class build_py(Command, Mixin2to3):
             if os.path.isfile(init_py):
                 return init_py
             else:
-                logger.warning(("package init file '%s' not found " +
-                                "(or not a regular file)"), init_py)
+                logger.warning("package init file %r not found "
+                               "(or not a regular file)", init_py)
 
         # Either not in a package at all (__init__.py not expected), or
         # __init__.py doesn't exist -- so don't return the filename.
@@ -218,7 +222,7 @@ class build_py(Command, Mixin2to3):
 
     def check_module(self, module, module_file):
         if not os.path.isfile(module_file):
-            logger.warning("file %s (for module %s) not found",
+            logger.warning("file %r (for module %r) not found",
                            module_file, module)
             return False
         else:
@@ -239,7 +243,7 @@ class build_py(Command, Mixin2to3):
                 module = os.path.splitext(os.path.basename(f))[0]
                 modules.append((package, module, f))
             else:
-                logger.debug("excluding %s", setup_script)
+                logger.debug("excluding %r", setup_script)
         return modules
 
     def find_modules(self):
@@ -331,7 +335,8 @@ class build_py(Command, Mixin2to3):
             outputs.append(filename)
             if include_bytecode:
                 if self.compile:
-                    outputs.append(imp.cache_from_source(filename))
+                    outputs.append(imp.cache_from_source(filename,
+                                                         debug_override=True))
                 if self.optimize > 0:
                     outputs.append(imp.cache_from_source(filename,
                                                          debug_override=False))
@@ -361,7 +366,6 @@ class build_py(Command, Mixin2to3):
     def build_modules(self):
         modules = self.find_modules()
         for package, module, module_file in modules:
-
             # Now "build" the module -- ie. copy the source file to
             # self.build_lib (the build directory for Python source).
             # (Actually, it gets copied to the directory for this package
@@ -370,7 +374,6 @@ class build_py(Command, Mixin2to3):
 
     def build_packages(self):
         for package in self.packages:
-
             # Get list of (package, module, module_file) tuples based on
             # scanning the package directory.  'package' is only included
             # in the tuple so that 'find_modules()' and
@@ -390,11 +393,6 @@ class build_py(Command, Mixin2to3):
                 self.build_module(module, module_file, package)
 
     def byte_compile(self, files):
-        if sys.dont_write_bytecode:
-            logger.warning('%s: byte-compiling is disabled, skipping.',
-                           self.get_command_name())
-            return
-
         from packaging.util import byte_compile  # FIXME use compileall
         prefix = self.build_lib
         if prefix[-1] != os.sep:
@@ -403,7 +401,6 @@ class build_py(Command, Mixin2to3):
         # XXX this code is essentially the same as the 'byte_compile()
         # method of the "install_lib" command, except for the determination
         # of the 'prefix' string.  Hmmm.
-
         if self.compile:
             byte_compile(files, optimize=0,
                          force=self.force, prefix=prefix, dry_run=self.dry_run)
diff --git a/Lib/packaging/command/install_lib.py b/Lib/packaging/command/install_lib.py
index 558966d..f6c785f 100644
--- a/Lib/packaging/command/install_lib.py
+++ b/Lib/packaging/command/install_lib.py
@@ -2,7 +2,6 @@
 
 import os
 import imp
-import sys
 import logging
 
 from packaging import logger
@@ -11,25 +10,18 @@ from packaging.errors import PackagingOptionError
 
 
 # Extension for Python source files.
+# XXX dead code?  most of the codebase checks for literal '.py'
 if hasattr(os, 'extsep'):
     PYTHON_SOURCE_EXTENSION = os.extsep + "py"
 else:
     PYTHON_SOURCE_EXTENSION = ".py"
 
+
 class install_lib(Command):
 
     description = "install all modules (extensions and pure Python)"
 
-    # The byte-compilation options are a tad confusing.  Here are the
-    # possible scenarios:
-    #   1) no compilation at all (--no-compile --no-optimize)
-    #   2) compile .pyc only (--compile --no-optimize; default)
-    #   3) compile .pyc and "level 1" .pyo (--compile --optimize)
-    #   4) compile "level 1" .pyo only (--no-compile --optimize)
-    #   5) compile .pyc and "level 2" .pyo (--compile --optimize-more)
-    #   6) compile "level 2" .pyo only (--no-compile --optimize-more)
-    #
-    # The UI for this is two option, 'compile' and 'optimize'.
+    # The options for controlling byte compilations are two independent sets:
     # 'compile' is strictly boolean, and only decides whether to
     # generate .pyc files.  'optimize' is three-way (0, 1, or 2), and
     # decides both whether to generate .pyo files and what level of
@@ -37,7 +29,7 @@ class install_lib(Command):
 
     user_options = [
         ('install-dir=', 'd', "directory to install to"),
-        ('build-dir=','b', "build directory (where to install from)"),
+        ('build-dir=', 'b', "build directory (where to install from)"),
         ('force', 'f', "force installation (overwrite existing files)"),
         ('compile', 'c', "compile .py to .pyc [default]"),
         ('no-compile', None, "don't compile .py files"),
@@ -48,7 +40,8 @@ class install_lib(Command):
         ]
 
     boolean_options = ['force', 'compile', 'skip-build']
-    negative_opt = {'no-compile' : 'compile'}
+
+    negative_opt = {'no-compile': 'compile'}
 
     def initialize_options(self):
         # let the 'install_dist' command dictate our installation directory
@@ -66,7 +59,8 @@ class install_lib(Command):
         self.set_undefined_options('install_dist',
                                    ('build_lib', 'build_dir'),
                                    ('install_lib', 'install_dir'),
-                                   'force', 'compile', 'optimize', 'skip_build')
+                                   'force', 'compile', 'optimize',
+                                   'skip_build')
 
         if self.compile is None:
             self.compile = True
@@ -115,14 +109,6 @@ class install_lib(Command):
         return outfiles
 
     def byte_compile(self, files):
-        if sys.dont_write_bytecode:
-            # XXX do we want this?  because a Python runs without bytecode
-            # doesn't mean that the *dists should not contain bytecode
-            #--or does it?
-            logger.warning('%s: byte-compiling is disabled, skipping.',
-                           self.get_command_name())
-            return
-
         from packaging.util import byte_compile  # FIXME use compileall
 
         # Get the "--root" directory supplied to the "install_dist" command,
@@ -138,13 +124,11 @@ class install_lib(Command):
         if self.compile:
             byte_compile(files, optimize=0,
                          force=self.force, prefix=install_root,
-                         dry_run=self.dry_run)
+                         verbose=verbose, dry_run=self.dry_run)
         if self.optimize > 0:
             byte_compile(files, optimize=self.optimize,
                          force=self.force, prefix=install_root,
-                         verbose=verbose,
-                         dry_run=self.dry_run)
-
+                         verbose=verbose, dry_run=self.dry_run)
 
     # -- Utility methods -----------------------------------------------
 
@@ -173,14 +157,14 @@ class install_lib(Command):
             if ext != PYTHON_SOURCE_EXTENSION:
                 continue
             if self.compile:
-                bytecode_files.append(imp.cache_from_source(py_file))
+                bytecode_files.append(imp.cache_from_source(
+                    py_file, debug_override=True))
             if self.optimize > 0:
                 bytecode_files.append(imp.cache_from_source(
                     py_file, debug_override=False))
 
         return bytecode_files
 
-
     # -- External interface --------------------------------------------
     # (called by outsiders)