From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- Documentation/sphinx/rstFlatTable.py | 365 +++++++++++++++++++++++++++++++++++ 1 file changed, 365 insertions(+) create mode 100755 Documentation/sphinx/rstFlatTable.py (limited to 'Documentation/sphinx/rstFlatTable.py') diff --git a/Documentation/sphinx/rstFlatTable.py b/Documentation/sphinx/rstFlatTable.py new file mode 100755 index 000000000..3d19569e5 --- /dev/null +++ b/Documentation/sphinx/rstFlatTable.py @@ -0,0 +1,365 @@ +#!/usr/bin/env python3 +# -*- coding: utf-8; mode: python -*- +# SPDX-License-Identifier: GPL-2.0 +# pylint: disable=C0330, R0903, R0912 + +""" + flat-table + ~~~~~~~~~~ + + Implementation of the ``flat-table`` reST-directive. + + :copyright: Copyright (C) 2016 Markus Heiser + :license: GPL Version 2, June 1991 see linux/COPYING for details. + + The ``flat-table`` (:py:class:`FlatTable`) is a double-stage list similar to + the ``list-table`` with some additional features: + + * *column-span*: with the role ``cspan`` a cell can be extended through + additional columns + + * *row-span*: with the role ``rspan`` a cell can be extended through + additional rows + + * *auto span* rightmost cell of a table row over the missing cells on the + right side of that table-row. With Option ``:fill-cells:`` this behavior + can be changed from *auto span* to *auto fill*, which automatically inserts + (empty) cells instead of spanning the last cell. + + Options: + + * header-rows: [int] count of header rows + * stub-columns: [int] count of stub columns + * widths: [[int] [int] ... ] widths of columns + * fill-cells: instead of autospann missing cells, insert missing cells + + roles: + + * cspan: [int] additionale columns (*morecols*) + * rspan: [int] additionale rows (*morerows*) +""" + +# ============================================================================== +# imports +# ============================================================================== + +from docutils import nodes +from docutils.parsers.rst import directives, roles +from docutils.parsers.rst.directives.tables import Table +from docutils.utils import SystemMessagePropagation + +# ============================================================================== +# common globals +# ============================================================================== + +__version__ = '1.0' + +# ============================================================================== +def setup(app): +# ============================================================================== + + app.add_directive("flat-table", FlatTable) + roles.register_local_role('cspan', c_span) + roles.register_local_role('rspan', r_span) + + return dict( + version = __version__, + parallel_read_safe = True, + parallel_write_safe = True + ) + +# ============================================================================== +def c_span(name, rawtext, text, lineno, inliner, options=None, content=None): +# ============================================================================== + # pylint: disable=W0613 + + options = options if options is not None else {} + content = content if content is not None else [] + nodelist = [colSpan(span=int(text))] + msglist = [] + return nodelist, msglist + +# ============================================================================== +def r_span(name, rawtext, text, lineno, inliner, options=None, content=None): +# ============================================================================== + # pylint: disable=W0613 + + options = options if options is not None else {} + content = content if content is not None else [] + nodelist = [rowSpan(span=int(text))] + msglist = [] + return nodelist, msglist + + +# ============================================================================== +class rowSpan(nodes.General, nodes.Element): pass # pylint: disable=C0103,C0321 +class colSpan(nodes.General, nodes.Element): pass # pylint: disable=C0103,C0321 +# ============================================================================== + +# ============================================================================== +class FlatTable(Table): +# ============================================================================== + + """FlatTable (``flat-table``) directive""" + + option_spec = { + 'name': directives.unchanged + , 'class': directives.class_option + , 'header-rows': directives.nonnegative_int + , 'stub-columns': directives.nonnegative_int + , 'widths': directives.positive_int_list + , 'fill-cells' : directives.flag } + + def run(self): + + if not self.content: + error = self.state_machine.reporter.error( + 'The "%s" directive is empty; content required.' % self.name, + nodes.literal_block(self.block_text, self.block_text), + line=self.lineno) + return [error] + + title, messages = self.make_title() + node = nodes.Element() # anonymous container for parsing + self.state.nested_parse(self.content, self.content_offset, node) + + tableBuilder = ListTableBuilder(self) + tableBuilder.parseFlatTableNode(node) + tableNode = tableBuilder.buildTableNode() + # SDK.CONSOLE() # print --> tableNode.asdom().toprettyxml() + if title: + tableNode.insert(0, title) + return [tableNode] + messages + + +# ============================================================================== +class ListTableBuilder(object): +# ============================================================================== + + """Builds a table from a double-stage list""" + + def __init__(self, directive): + self.directive = directive + self.rows = [] + self.max_cols = 0 + + def buildTableNode(self): + + colwidths = self.directive.get_column_widths(self.max_cols) + if isinstance(colwidths, tuple): + # Since docutils 0.13, get_column_widths returns a (widths, + # colwidths) tuple, where widths is a string (i.e. 'auto'). + # See https://sourceforge.net/p/docutils/patches/120/. + colwidths = colwidths[1] + stub_columns = self.directive.options.get('stub-columns', 0) + header_rows = self.directive.options.get('header-rows', 0) + + table = nodes.table() + tgroup = nodes.tgroup(cols=len(colwidths)) + table += tgroup + + + for colwidth in colwidths: + colspec = nodes.colspec(colwidth=colwidth) + # FIXME: It seems, that the stub method only works well in the + # absence of rowspan (observed by the html builder, the docutils-xml + # build seems OK). This is not extraordinary, because there exists + # no table directive (except *this* flat-table) which allows to + # define coexistent of rowspan and stubs (there was no use-case + # before flat-table). This should be reviewed (later). + if stub_columns: + colspec.attributes['stub'] = 1 + stub_columns -= 1 + tgroup += colspec + stub_columns = self.directive.options.get('stub-columns', 0) + + if header_rows: + thead = nodes.thead() + tgroup += thead + for row in self.rows[:header_rows]: + thead += self.buildTableRowNode(row) + + tbody = nodes.tbody() + tgroup += tbody + + for row in self.rows[header_rows:]: + tbody += self.buildTableRowNode(row) + return table + + def buildTableRowNode(self, row_data, classes=None): + classes = [] if classes is None else classes + row = nodes.row() + for cell in row_data: + if cell is None: + continue + cspan, rspan, cellElements = cell + + attributes = {"classes" : classes} + if rspan: + attributes['morerows'] = rspan + if cspan: + attributes['morecols'] = cspan + entry = nodes.entry(**attributes) + entry.extend(cellElements) + row += entry + return row + + def raiseError(self, msg): + error = self.directive.state_machine.reporter.error( + msg + , nodes.literal_block(self.directive.block_text + , self.directive.block_text) + , line = self.directive.lineno ) + raise SystemMessagePropagation(error) + + def parseFlatTableNode(self, node): + """parses the node from a :py:class:`FlatTable` directive's body""" + + if len(node) != 1 or not isinstance(node[0], nodes.bullet_list): + self.raiseError( + 'Error parsing content block for the "%s" directive: ' + 'exactly one bullet list expected.' % self.directive.name ) + + for rowNum, rowItem in enumerate(node[0]): + row = self.parseRowItem(rowItem, rowNum) + self.rows.append(row) + self.roundOffTableDefinition() + + def roundOffTableDefinition(self): + """Round off the table definition. + + This method rounds off the table definition in :py:member:`rows`. + + * This method inserts the needed ``None`` values for the missing cells + arising from spanning cells over rows and/or columns. + + * recount the :py:member:`max_cols` + + * Autospan or fill (option ``fill-cells``) missing cells on the right + side of the table-row + """ + + y = 0 + while y < len(self.rows): + x = 0 + + while x < len(self.rows[y]): + cell = self.rows[y][x] + if cell is None: + x += 1 + continue + cspan, rspan = cell[:2] + # handle colspan in current row + for c in range(cspan): + try: + self.rows[y].insert(x+c+1, None) + except: # pylint: disable=W0702 + # the user sets ambiguous rowspans + pass # SDK.CONSOLE() + # handle colspan in spanned rows + for r in range(rspan): + for c in range(cspan + 1): + try: + self.rows[y+r+1].insert(x+c, None) + except: # pylint: disable=W0702 + # the user sets ambiguous rowspans + pass # SDK.CONSOLE() + x += 1 + y += 1 + + # Insert the missing cells on the right side. For this, first + # re-calculate the max columns. + + for row in self.rows: + if self.max_cols < len(row): + self.max_cols = len(row) + + # fill with empty cells or cellspan? + + fill_cells = False + if 'fill-cells' in self.directive.options: + fill_cells = True + + for row in self.rows: + x = self.max_cols - len(row) + if x and not fill_cells: + if row[-1] is None: + row.append( ( x - 1, 0, []) ) + else: + cspan, rspan, content = row[-1] + row[-1] = (cspan + x, rspan, content) + elif x and fill_cells: + for i in range(x): + row.append( (0, 0, nodes.comment()) ) + + def pprint(self): + # for debugging + retVal = "[ " + for row in self.rows: + retVal += "[ " + for col in row: + if col is None: + retVal += ('%r' % col) + retVal += "\n , " + else: + content = col[2][0].astext() + if len (content) > 30: + content = content[:30] + "..." + retVal += ('(cspan=%s, rspan=%s, %r)' + % (col[0], col[1], content)) + retVal += "]\n , " + retVal = retVal[:-2] + retVal += "]\n , " + retVal = retVal[:-2] + return retVal + "]" + + def parseRowItem(self, rowItem, rowNum): + row = [] + childNo = 0 + error = False + cell = None + target = None + + for child in rowItem: + if (isinstance(child , nodes.comment) + or isinstance(child, nodes.system_message)): + pass + elif isinstance(child , nodes.target): + target = child + elif isinstance(child, nodes.bullet_list): + childNo += 1 + cell = child + else: + error = True + break + + if childNo != 1 or error: + self.raiseError( + 'Error parsing content block for the "%s" directive: ' + 'two-level bullet list expected, but row %s does not ' + 'contain a second-level bullet list.' + % (self.directive.name, rowNum + 1)) + + for cellItem in cell: + cspan, rspan, cellElements = self.parseCellItem(cellItem) + if target is not None: + cellElements.insert(0, target) + row.append( (cspan, rspan, cellElements) ) + return row + + def parseCellItem(self, cellItem): + # search and remove cspan, rspan colspec from the first element in + # this listItem (field). + cspan = rspan = 0 + if not len(cellItem): + return cspan, rspan, [] + for elem in cellItem[0]: + if isinstance(elem, colSpan): + cspan = elem.get("span") + elem.parent.remove(elem) + continue + if isinstance(elem, rowSpan): + rspan = elem.get("span") + elem.parent.remove(elem) + continue + return cspan, rspan, cellItem[:] -- cgit v1.3.1