Rework

Author: StanFromIreland

Lib/traceback.py

@@ -14,6 +14,11 @@
 
 from contextlib import suppress
 
+try:
+    from _stdlib_modules_info import MISSING_STDLIB_MODULE_MESSAGES
+except ImportError:
+    MISSING_STDLIB_MODULE_MESSAGES = None
+
 __all__ = ['extract_stack', 'extract_tb', 'format_exception',
            'format_exception_only', 'format_list', 'format_stack',
            'format_tb', 'print_exc', 'format_exc', 'print_exception',
@@ -1110,11 +1115,14 @@ def __init__(self, exc_type, exc_value, exc_traceback, *, limit=None,
         elif exc_type and issubclass(exc_type, ModuleNotFoundError):
             module_name = getattr(exc_value, "name", None)
             if module_name in sys.stdlib_module_names:
-                message = _missing_stdlib_module.get(
-                    module_name,
-                    f"Standard library module '{module_name}' was not found"
-                )
-                self._str = message
+                if MISSING_STDLIB_MODULE_MESSAGES is not None:
+                    message = MISSING_STDLIB_MODULE_MESSAGES.get(
+                        module_name,
+                        f"Standard library module '{module_name}' was not found"
+                    )
+                    self._str = message
+                else:
+                    self._str = f"Standard library module '{module_name}' was not found"
             elif sys.flags.no_site:
                 self._str += (". Site initialization is disabled, did you forget to "
                     + "add the site-packages directory to sys.path "
@@ -1798,12 +1806,3 @@ def _levenshtein_distance(a, b, max_cost):
             # Everything in this row is too big, so bail early.
             return max_cost + 1
     return result
-
-_windows_only_modules = ["winreg", "msvcrt", "winsound", "nt", "_winapi", "_msi"]
-
-_missing_stdlib_module = {
-    name: f"Windows-only standard library module '{name}' not found"
-    for name in _windows_only_modules
-} | {
-    # Distributors can patch this dictionary to provide installation suggestions.
-}

Makefile.pre.in

@@ -1601,6 +1601,7 @@ sharedmods: $(SHAREDMODS) pybuilddir.txt
 # dependency on BUILDPYTHON ensures that the target is run last
 .PHONY: checksharedmods
 checksharedmods: sharedmods $(PYTHON_FOR_BUILD_DEPS) $(BUILDPYTHON)
+	@$(RUNSHARED) $(PYTHON_FOR_BUILD) $(srcdir)/Tools/build/check_extension_modules.py --generate-stdlib-info
 	@$(RUNSHARED) $(PYTHON_FOR_BUILD) $(srcdir)/Tools/build/check_extension_modules.py
 
 .PHONY: rundsymutil
@@ -2815,6 +2816,7 @@ libinstall:	all $(srcdir)/Modules/xxmodule.c
 	$(INSTALL_DATA) `cat pybuilddir.txt`/_sysconfigdata_$(ABIFLAGS)_$(MACHDEP)_$(MULTIARCH).py $(DESTDIR)$(LIBDEST); \
 	$(INSTALL_DATA) `cat pybuilddir.txt`/_sysconfig_vars_$(ABIFLAGS)_$(MACHDEP)_$(MULTIARCH).json $(DESTDIR)$(LIBDEST); \
 	$(INSTALL_DATA) `cat pybuilddir.txt`/build-details.json $(DESTDIR)$(LIBDEST); \
+	$(INSTALL_DATA) `cat pybuilddir.txt`/_stdlib_modules_info.py $(DESTDIR)$(LIBDEST); \
 	$(INSTALL_DATA) $(srcdir)/LICENSE $(DESTDIR)$(LIBDEST)/LICENSE.txt
 	@ # If app store compliance has been configured, apply the patch to the
 	@ # installed library code. The patch has been previously validated against

Tools/build/check_extension_modules.py

@@ -116,6 +116,12 @@
     help="Print a list of module names to stdout and exit",
 )
 
+parser.add_argument(
+    "--generate-stdlib-info",
+    action="store_true",
+    help="Generate file with stdlib module info",
+)
+
 
 @enum.unique
 class ModuleState(enum.Enum):
@@ -281,6 +287,38 @@ def list_module_names(self, *, all: bool = False) -> set[str]:
             names.update(WINDOWS_MODULES)
         return names
 
+    def generate_stdlib_info(self) -> None:
+
+        disabled_modules = {modinfo.name for modinfo in self.modules
+                           if modinfo.state in (ModuleState.DISABLED, ModuleState.DISABLED_SETUP)}
+        missing_modules = {modinfo.name for modinfo in self.modules
+                          if modinfo.state == ModuleState.MISSING}
+        na_modules = {modinfo.name for modinfo in self.modules
+                     if modinfo.state == ModuleState.NA}
+
+        content = f'''\
+# Standard library information used by the traceback module for more informative
+# ModuleNotFound error messages.
+
+DISABLED_MODULES = {sorted(disabled_modules)!r}
+MISSING_MODULES = {sorted(missing_modules)!r}
+NOT_AVAILABLE_MODULES = {sorted(na_modules)!r}
+WINDOWS_ONLY_MODULES = {sorted(WINDOWS_MODULES)!r}
+
+MISSING_STDLIB_MODULE_MESSAGES = {{
+    **{{name: f"Windows-only standard library module '{{name}}' was not found"
+        for name in WINDOWS_ONLY_MODULES}},
+    **{{name: f"Standard library module disabled during build '{{name}}' was not found"
+        for name in DISABLED_MODULES}},
+    **{{name: f"Unsupported platform for standard library module '{{name}}'"
+        for name in NOT_AVAILABLE_MODULES}},
+}}
+'''
+
+        output_path = self.builddir / "_stdlib_modules_info.py"
+        with open(output_path, "w", encoding="utf-8") as f:
+            f.write(content)
+
     def get_builddir(self) -> pathlib.Path:
         try:
             with open(self.pybuilddir_txt, encoding="utf-8") as f:
@@ -499,6 +537,9 @@ def main() -> None:
         names = checker.list_module_names(all=True)
         for name in sorted(names):
             print(name)
+    elif args.generate_stdlib_info:
+        checker.check()
+        checker.generate_stdlib_info()
     else:
         checker.check()
         checker.summary(verbose=args.verbose)