bpo-36876: Fix the C analyzer tool. (GH-22841)

The original tool wasn't working right and it was simpler to create a new one, partially re-using some of the old code. At this point the tool runs properly on the master. (Try: ./python Tools/c-analyzer/c-analyzer.py analyze.)  It take ~40 seconds on my machine to analyze the full CPython code base.

Note that we'll need to iron out some OS-specific stuff (e.g. preprocessor). We're okay though since this tool isn't used yet in our workflow. We will also need to verify the analysis results in detail before activating the check in CI, though I'm pretty sure it's close.

https://bugs.python.org/issue36876

Tools/c-analyzer/c_parser/datafiles.py

@@ -0,0 +1,150 @@
+import os.path
+
+import c_common.tables as _tables
+import c_parser.info as _info
+
+
+BASE_COLUMNS = [
+    'filename',
+    'funcname',
+    'name',
+    'kind',
+]
+END_COLUMNS = {
+    'parsed': 'data',
+    'decls': 'declaration',
+}
+
+
+def _get_columns(group, extra=None):
+    return BASE_COLUMNS + list(extra or ()) + [END_COLUMNS[group]]
+    #return [
+    #    *BASE_COLUMNS,
+    #    *extra or (),
+    #    END_COLUMNS[group],
+    #]
+
+
+#############################
+# high-level
+
+def read_parsed(infile):
+    # XXX Support other formats than TSV?
+    columns = _get_columns('parsed')
+    for row in _tables.read_table(infile, columns, sep='\t', fix='-'):
+        yield _info.ParsedItem.from_row(row, columns)
+
+
+def write_parsed(items, outfile):
+    # XXX Support other formats than TSV?
+    columns = _get_columns('parsed')
+    rows = (item.as_row(columns) for item in items)
+    _tables.write_table(outfile, columns, rows, sep='\t', fix='-')
+
+
+def read_decls(infile, fmt=None):
+    if fmt is None:
+        fmt = _get_format(infile)
+    read_all, _ = _get_format_handlers('decls', fmt)
+    for decl, _ in read_all(infile):
+        yield decl
+
+
+def write_decls(decls, outfile, fmt=None, *, backup=False):
+    if fmt is None:
+        fmt = _get_format(infile)
+    _, write_all = _get_format_handlers('decls', fmt)
+    write_all(decls, outfile, backup=backup)
+
+
+#############################
+# formats
+
+def _get_format(file, default='tsv'):
+    if isinstance(file, str):
+        filename = file
+    else:
+        filename = getattr(file, 'name', '')
+    _, ext = os.path.splitext(filename)
+    return ext[1:] if ext else default
+
+
+def _get_format_handlers(group, fmt):
+    # XXX Use a registry.
+    if group != 'decls':
+        raise NotImplementedError(group)
+    if fmt == 'tsv':
+        return (_iter_decls_tsv, _write_decls_tsv)
+    else:
+        raise NotImplementedError(fmt)
+
+
+# tsv
+
+def iter_decls_tsv(infile, extracolumns=None, relroot=None):
+    for info, extra in _iter_decls_tsv(infile, extracolumns, relroot):
+        decl = _info.Declaration.from_row(info)
+        yield decl, extra
+
+
+def write_decls_tsv(decls, outfile, extracolumns=None, *,
+                    relroot=None,
+                    **kwargs
+                    ):
+    # XXX Move the row rendering here.
+    _write_decls_tsv(rows, outfile, extracolumns, relroot, kwargs)
+
+
+def _iter_decls_tsv(infile, extracolumns=None, relroot=None):
+    columns = _get_columns('decls', extracolumns)
+    for row in _tables.read_table(infile, columns, sep='\t'):
+        if extracolumns:
+            declinfo = row[:4] + row[-1:]
+            extra = row[4:-1]
+        else:
+            declinfo = row
+            extra = None
+        if relroot:
+            # XXX Use something like tables.fix_row() here.
+            declinfo = [None if v == '-' else v
+                        for v in declinfo]
+            declinfo[0] = os.path.join(relroot, declinfo[0])
+        yield declinfo, extra
+
+
+def _write_decls_tsv(decls, outfile, extracolumns, relroot,kwargs):
+    columns = _get_columns('decls', extracolumns)
+    if extracolumns:
+        def render_decl(decl):
+            if type(row) is tuple:
+                decl, *extra = decl
+            else:
+                extra = ()
+            extra += ('???',) * (len(extraColumns) - len(extra))
+            *row, declaration = _render_known_row(decl, relroot)
+            row += extra + (declaration,)
+            return row
+    else:
+        render_decl = _render_known_decl
+    _tables.write_table(
+        outfile,
+        header='\t'.join(columns),
+        rows=(render_decl(d, relroot) for d in decls),
+        sep='\t',
+        **kwargs
+    )
+
+
+def _render_known_decl(decl, relroot, *,
+                       # These match BASE_COLUMNS + END_COLUMNS[group].
+                       _columns = 'filename parent name kind data'.split(),
+                       ):
+    if not isinstance(decl, _info.Declaration):
+        # e.g. Analyzed
+        decl = decl.decl
+    rowdata = decl.render_rowdata(_columns)
+    if relroot:
+        rowdata['filename'] = os.path.relpath(rowdata['filename'], relroot)
+    return [rowdata[c] or '-' for c in _columns]
+    # XXX
+    #return _tables.fix_row(rowdata[c] for c in columns)