bpo-36876: Small adjustments to the C-analyzer tool. (GH-23045)

This is a little bit of clean-up, small fixes, and additional helpers prior to building an updated & accurate list of globals to eliminate.

Tools/c-analyzer/c_analyzer/match.py

@@ -0,0 +1,212 @@
+import os.path
+
+from c_parser import (
+    info as _info,
+    match as _match,
+)
+
+
+_KIND = _info.KIND
+
+
+# XXX Use known.tsv for these?
+SYSTEM_TYPES = {
+    'int8_t',
+    'uint8_t',
+    'int16_t',
+    'uint16_t',
+    'int32_t',
+    'uint32_t',
+    'int64_t',
+    'uint64_t',
+    'size_t',
+    'ssize_t',
+    'intptr_t',
+    'uintptr_t',
+    'wchar_t',
+    '',
+    # OS-specific
+    'pthread_cond_t',
+    'pthread_mutex_t',
+    'pthread_key_t',
+    'atomic_int',
+    'atomic_uintptr_t',
+    '',
+    # lib-specific
+    'WINDOW',  # curses
+    'XML_LChar',
+    'XML_Size',
+    'XML_Parser',
+    'enum XML_Error',
+    'enum XML_Status',
+    '',
+}
+
+
+def is_system_type(typespec):
+    return typespec in SYSTEM_TYPES
+
+
+##################################
+# decl matchers
+
+def is_public(decl):
+    if not decl.filename.endswith('.h'):
+        return False
+    if 'Include' not in decl.filename.split(os.path.sep):
+        return False
+    return True
+
+
+def is_process_global(vardecl):
+    kind, storage, _, _, _ = _info.get_parsed_vartype(vardecl)
+    if kind is not _KIND.VARIABLE:
+        raise NotImplementedError(vardecl)
+    if 'static' in (storage or ''):
+        return True
+
+    if hasattr(vardecl, 'parent'):
+        parent = vardecl.parent
+    else:
+        parent = vardecl.get('parent')
+    return not parent
+
+
+def is_fixed_type(vardecl):
+    if not vardecl:
+        return None
+    _, _, _, typespec, abstract = _info.get_parsed_vartype(vardecl)
+    if 'typeof' in typespec:
+        raise NotImplementedError(vardecl)
+    elif not abstract:
+        return True
+
+    if '*' not in abstract:
+        # XXX What about []?
+        return True
+    elif _match._is_funcptr(abstract):
+        return True
+    else:
+        for after in abstract.split('*')[1:]:
+            if not after.lstrip().startswith('const'):
+                return False
+        else:
+            return True
+
+
+def is_immutable(vardecl):
+    if not vardecl:
+        return None
+    if not is_fixed_type(vardecl):
+        return False
+    _, _, typequal, _, _ = _info.get_parsed_vartype(vardecl)
+    # If there, it can only be "const" or "volatile".
+    return typequal == 'const'
+
+
+def is_public_api(decl):
+    if not is_public(decl):
+        return False
+    if decl.kind is _KIND.TYPEDEF:
+        return True
+    elif _match.is_type_decl(decl):
+        return not _match.is_forward_decl(decl)
+    else:
+        return _match.is_external_reference(decl)
+
+
+def is_public_declaration(decl):
+    if not is_public(decl):
+        return False
+    if decl.kind is _KIND.TYPEDEF:
+        return True
+    elif _match.is_type_decl(decl):
+        return _match.is_forward_decl(decl)
+    else:
+        return _match.is_external_reference(decl)
+
+
+def is_public_definition(decl):
+    if not is_public(decl):
+        return False
+    if decl.kind is _KIND.TYPEDEF:
+        return True
+    elif _match.is_type_decl(decl):
+        return not _match.is_forward_decl(decl)
+    else:
+        return not _match.is_external_reference(decl)
+
+
+def is_public_impl(decl):
+    if not _KIND.is_decl(decl.kind):
+        return False
+    # See filter_forward() about "is_public".
+    return getattr(decl, 'is_public', False)
+
+
+def is_module_global_decl(decl):
+    if is_public_impl(decl):
+        return False
+    if _match.is_forward_decl(decl):
+        return False
+    return not _match.is_local_var(decl)
+
+
+##################################
+# filtering with matchers
+
+def filter_forward(items, *, markpublic=False):
+    if markpublic:
+        public = set()
+        actual = []
+        for item in items:
+            if is_public_api(item):
+                public.add(item.id)
+            elif not _match.is_forward_decl(item):
+                actual.append(item)
+            else:
+                # non-public duplicate!
+                # XXX
+                raise Exception(item)
+        for item in actual:
+            _info.set_flag(item, 'is_public', item.id in public)
+            yield item
+    else:
+        for item in items:
+            if _match.is_forward_decl(item):
+                continue
+            yield item
+
+
+##################################
+# grouping with matchers
+
+def group_by_storage(decls, **kwargs):
+    def is_module_global(decl):
+        if not is_module_global_decl(decl):
+            return False
+        if decl.kind == _KIND.VARIABLE:
+            if _info.get_effective_storage(decl) == 'static':
+                # This is covered by is_static_module_global().
+                return False
+        return True
+    def is_static_module_global(decl):
+        if not _match.is_global_var(decl):
+            return False
+        return _info.get_effective_storage(decl) == 'static'
+    def is_static_local(decl):
+        if not _match.is_local_var(decl):
+            return False
+        return _info.get_effective_storage(decl) == 'static'
+    #def is_local(decl):
+    #    if not _match.is_local_var(decl):
+    #        return False
+    #    return _info.get_effective_storage(decl) != 'static'
+    categories = {
+        #'extern': is_extern,
+        'published': is_public_impl,
+        'module-global': is_module_global,
+        'static-module-global': is_static_module_global,
+        'static-local': is_static_local,
+    }
+    return _match.group_by_category(decls, categories, **kwargs)