Re: [PATCH v2 1/3] dt-bindings: add DTS style checker

Rob Herring
2026-05-06T18:33:40Z

On Wed, Apr 29, 2026 at 03:21:24PM +0100, Daniel Golle wrote:
> Add a Python tool that checks DTS coding style on examples in YAML
> binding files and on .dts/.dtsi/.dtso source files. Rules are kept in
> a small declarative registry, each tagged 'relaxed' (default; must be
> zero-violation on the current tree) or 'strict' (opt-in for new
> submissions). Promoting a rule from strict to relaxed is a one-line
> edit once the tree is clean.
>
> Relaxed mode covers trailing whitespace, tab characters in YAML
> examples, mixed tab+space indents, and the per-input-type indent
> character (1 tab for .dts/.dtsi/.dtso). Strict mode adds:
>
> - indent unit and depth consistency (4 spaces for YAML, 1 tab for
> DTS) plus a stricter YAML variant requiring exactly 4 spaces;
> - blank-line policy: no consecutive blanks or blanks at body
> edges; required blank line before each child node and before
> "status";
> - property ordering by canonical bucket (compatible, reg/reg-names,
> ranges, standard, vendor, status) with declarative within-bucket
> pairing rules (<x>-names follows <x>, pinctrl-names follows the
> last pinctrl-N) and natural-sort fallback;
> - sibling node ordering: by unit address when present, by natural-
> sort node name otherwise;
> - line length capped at 80 columns;
> - continuation alignment of multi-line property values under the
> first '<' or '"' after the '=' sign;
> - hex literals lowercase; unit addresses lowercase hex without
> leading zeros; single-spaced values inside <...>; closing brace
> on its own line;
> - unused-label detection (skipped for .dtsi/.dtso since labels
> there are exported to includers/applies-to).
>
> Together these constrain a DT structure to a single canonical
> rendering, modulo the author's choice of when to wrap a property
> across lines for readability, and not covering comments.
>
> The tool reads file paths from @argfile and parallelises across CPUs
> via -j N. With no -j given it picks up $PARALLELISM (set by
> scripts/jobserver-exec from the GNU make jobserver) and falls back to
> os.cpu_count() otherwise. Running as one Python invocation amortises
> the ruamel.yaml import across the whole tree -- ~2s on a 32-CPU host
> vs ~28s sequential.
>
> Signed-off-by: Daniel Golle <daniel@makrotopia.org>
> ---
> Changes since v1:
> - renamed dt-check-example-style -> dt-check-style; tool now also
> accepts .dts/.dtsi/.dtso files directly (tab-indent variant) and
> distinguishes .dts/.dtsi/.dtso so unused-labels skips .dtsi/.dtso
> where labels are exported to includers/applies-to
> - rules declared in a registry tagged relaxed/strict; default
> relaxed mode is zero-violation on the current tree
> - added -j N with $PARALLELISM (jobserver) awareness
> - dropped node-name [a-z0-9-] check (Rob: better as a meta-schema)
> - property-order rebuilt around buckets + declarative pairing rules
> (<x>-names after <x>, pinctrl-names after last pinctrl-N) plus
> natural-sort fallback
> - added child-name-order, required-blank-lines, hex-case,
> unit-address-format, value-whitespace, node-close-alone,
> line-length and continuation-alignment to strict mode
>
> scripts/dtc/dt-check-style | 1063 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 1063 insertions(+)
> create mode 100755 scripts/dtc/dt-check-style
>
> diff --git a/scripts/dtc/dt-check-style b/scripts/dtc/dt-check-style
> new file mode 100755
> index 000000000000..477d3e427fc1
> --- /dev/null
> +++ b/scripts/dtc/dt-check-style
> @@ -0,0 +1,1063 @@
> +#!/usr/bin/env python3
> +# SPDX-License-Identifier: GPL-2.0-only
> +#
> +# Check DTS coding style on YAML binding examples and on
> +# .dts/.dtsi/.dtso source files. Enforces rules from
> +# Documentation/devicetree/bindings/dts-coding-style.rst.
> +#
> +# Two modes:
> +# --mode=relaxed (default)
> +# Only rules that produce zero warnings on the current tree.
> +# Suitable for dt_binding_check.
> +# --mode=strict
> +# All rules. Required for new submissions.
> +#
> +# Two input types (auto-detected by file extension):
> +# *.yaml -- DT binding; check each example block
> +# *.dts/*.dtsi/*.dtso -- DTS source; whole file is one block
> +#
> +# Rules are declared in a registry (see RULES below); each rule is
> +# tagged with the lowest mode that runs it. Promoting a rule from
> +# 'strict' to 'relaxed' is a one-line change.
> +
> +import argparse
> +import re
> +import sys
> +from enum import Enum, auto
> +
> +import ruamel.yaml
> +
> +
> +# ---------------------------------------------------------------------------
> +# Line classification
> +# ---------------------------------------------------------------------------
> +
> +class LineType(Enum):
> + BLANK = auto()
> + COMMENT = auto() # // ... or /* ... */ on one line
> + COMMENT_START = auto() # /* without closing */
> + COMMENT_BODY = auto() # inside a multi-line comment
> + COMMENT_END = auto() # closing */
> + PREPROCESSOR = auto() # #include / #define / #ifdef / ...
> + NODE_OPEN = auto() # something { (with optional label/name/addr)
> + NODE_CLOSE = auto() # };
> + PROPERTY = auto() # name = value; or name;
> + CONTINUATION = auto() # continuation of a multi-line property
> +
> +
> +re_cpp_directive = re.compile(
> + r'^#\s*(include|define|undef|ifdef|ifndef|if|else|elif|endif|'
> + r'pragma|error|warning)\b')
> +
> +# label: name@addr { -- label and addr optional; name can be "/"
> +re_node_header = re.compile(
> + r'^(?:([a-zA-Z_][a-zA-Z0-9_]*):\s*)?'
> + r'([a-zA-Z][a-zA-Z0-9,._+-]*|/)'
> + r'(?:@([0-9a-fA-F,]+))?'
> + r'\s*\{$')
> +
> +re_ref_node = re.compile(
> + r'^&([a-zA-Z_][a-zA-Z0-9_]*)\s*\{$')
> +
> +
> +def is_preprocessor(stripped):
> + """Tell C preprocessor directives apart from DTS '#'-prefixed props."""
> + return re_cpp_directive.match(stripped) is not None
> +
> +
> +class DtsLine:
> + __slots__ = ('lineno', 'raw', 'linetype', 'indent_str', 'stripped',
> + 'prop_name', 'continuations',
> + 'node_name', 'node_addr', 'label', 'ref_name', 'depth')
> +
> + def __init__(self, lineno, raw, linetype, indent_str, stripped):
> + self.lineno = lineno # 1-based within the block
> + self.raw = raw
> + self.linetype = linetype
> + self.indent_str = indent_str # leading whitespace as-is
> + self.stripped = stripped
> + self.prop_name = None
> + self.continuations = []
> + self.node_name = None
> + self.node_addr = None
> + self.label = None
> + self.ref_name = None
> + self.depth = 0 # filled in by classify_lines
> +
> +
> +def classify_lines(text):
> + """Return a list of DtsLine. Tracks { } depth and groups
> + continuation lines onto their leading PROPERTY line."""
> + out = []
> + in_block_comment = False
> + prev_complete = True
> + depth = 0
> +
> + # Split preserving the indent string verbatim
> + re_lead = re.compile(r'^([ \t]*)(.*)$')
> +
> + for i, raw in enumerate(text.split('\n'), start=1):
> + m = re_lead.match(raw)
> + indent_str = m.group(1)
> + stripped = m.group(2)
> +
> + if not stripped:
> + dl = DtsLine(i, raw, LineType.BLANK, '', '')
> + dl.depth = depth
> + out.append(dl)
> + continue
> +
> + if in_block_comment:
> + ltype = (LineType.COMMENT_END if '*/' in stripped
> + else LineType.COMMENT_BODY)
> + if ltype == LineType.COMMENT_END:
> + in_block_comment = False
> + dl = DtsLine(i, raw, ltype, indent_str, stripped)
> + dl.depth = depth
> + out.append(dl)
> + continue
> +
> + if stripped.startswith('/*'):
> + if '*/' in stripped:
> + ltype = LineType.COMMENT
> + else:
> + in_block_comment = True
> + ltype = LineType.COMMENT_START
> + dl = DtsLine(i, raw, ltype, indent_str, stripped)
> + dl.depth = depth
> + out.append(dl)
> + continue
> +
> + if stripped.startswith('//'):
> + dl = DtsLine(i, raw, LineType.COMMENT, indent_str, stripped)
> + dl.depth = depth
> + out.append(dl)
> + continue
> +
> + if stripped.startswith('#') and is_preprocessor(stripped):
> + dl = DtsLine(i, raw, LineType.PREPROCESSOR,
> + indent_str, stripped)
> + dl.depth = depth
> + out.append(dl)
> + prev_complete = True
> + continue
> +
> + if not prev_complete:
> + dl = DtsLine(i, raw, LineType.CONTINUATION,
> + indent_str, stripped)
> + dl.depth = depth
> + out.append(dl)
> + prev_complete = (stripped.endswith(';') or
> + stripped.endswith('{') or
> + stripped.endswith('};'))
> + continue
> +
> + if stripped == '};' or stripped == '}':
> + depth = max(depth - 1, 0)
> + dl = DtsLine(i, raw, LineType.NODE_CLOSE, indent_str, stripped)
> + dl.depth = depth
> + out.append(dl)
> + prev_complete = True
> + continue
> +
> + if stripped.endswith('{'):
> + dl = DtsLine(i, raw, LineType.NODE_OPEN, indent_str, stripped)
> + parse_node_header(dl)
> + dl.depth = depth
> + out.append(dl)
> + depth += 1
> + prev_complete = True
> + continue
> +
> + # Property (or first line of a multi-line property).
> + dl = DtsLine(i, raw, LineType.PROPERTY, indent_str, stripped)
> + parse_property_name(dl)
> + dl.depth = depth
> + out.append(dl)
> + prev_complete = stripped.endswith(';')
> +
> + # Group continuation lines onto their leading PROPERTY.
> + last_prop = None
> + grouped = []
> + for dl in out:
> + if dl.linetype == LineType.CONTINUATION and last_prop is not None:
> + last_prop.continuations.append(dl)
> + continue
> + if dl.linetype == LineType.PROPERTY:
> + last_prop = dl
> + elif dl.linetype != LineType.BLANK and \
> + dl.linetype not in (LineType.COMMENT, LineType.COMMENT_BODY,
> + LineType.COMMENT_END,
> + LineType.COMMENT_START):
> + last_prop = None
> + grouped.append(dl)
> + return grouped
> +
> +
> +def parse_node_header(dl):
> + m = re_node_header.match(dl.stripped)
> + if m:
> + dl.label = m.group(1)
> + dl.node_name = m.group(2)
> + dl.node_addr = m.group(3)
> + return
> + m = re_ref_node.match(dl.stripped)
> + if m:
> + dl.ref_name = m.group(1)
> +
> +
> +def parse_property_name(dl):
> + m = re.match(r'^([a-zA-Z#][a-zA-Z0-9,._+#-]*)\s*[=;]', dl.stripped)
> + if m:
> + dl.prop_name = m.group(1)
> +
> +
> +def collect_labels_and_refs(text):
> + """Return (defined_labels, referenced_labels) found anywhere outside
> + /* */ comments. Labels named fake_intc* (injected by
> + dt-extract-example) are skipped."""
> + # Strip block comments first so labels inside them don't count
> + stripped = re.sub(r'/\*.*?\*/', '', text, flags=re.DOTALL)
> + # Strip line comments
> + stripped = re.sub(r'//[^\n]*', '', stripped)
> + defined = set()
> + referenced = set()
> + for m in re.finditer(r'(?:^|[\s{])([a-zA-Z_][a-zA-Z0-9_]*):\s*[a-zA-Z/&]',
> + stripped):
> + name = m.group(1)
> + if not name.startswith('fake_intc'):
> + defined.add(name)
> + for m in re.finditer(r'&([a-zA-Z_][a-zA-Z0-9_]*)', stripped):
> + referenced.add(m.group(1))
> + return defined, referenced
> +
> +
> +# ---------------------------------------------------------------------------
> +# Rule registry
> +# ---------------------------------------------------------------------------
> +
> +class Ctx:
> + """Context passed to each rule check. Carries the parsed lines,
> + raw text, mode, and indent kind."""
> +
> + def __init__(self, lines, text, mode, indent_kind):
> + self.lines = lines
> + self.text = text
> + self.mode = mode # 'relaxed' or 'strict'
> + self.indent_kind = indent_kind # 'spaces' or 'tab'
> +
> +
> +class Rule:
> + __slots__ = ('name', 'mode', 'description', 'check', 'applies_to')
> +
> + def __init__(self, name, mode, description, check,
> + applies_to=('yaml', 'dts', 'dtsi', 'dtso')):
> + self.name = name
> + self.mode = mode # 'relaxed' or 'strict'
> + self.description = description
> + self.check = check
> + self.applies_to = applies_to # input types this rule covers
> +
> +
> +# --- individual rule check functions --------------------------------------
> +
> +def check_trailing_whitespace(ctx):
> + for dl in ctx.lines:
> + if dl.raw != dl.raw.rstrip():
> + yield (dl.lineno, 'trailing whitespace')
> +
> +
> +def check_tab_in_dts(ctx):
> + """Reject literal tabs in DTS lines when input is YAML.
> +
> + For YAML examples, indent and content must use spaces. Tabs inside
> + a #define value are tolerated (those are CPP macros, not DTS).
> + For .dts files, this rule does not apply -- tabs are required.
> + """
> + if ctx.indent_kind != 'spaces':
> + return
> + for dl in ctx.lines:
> + if dl.linetype == LineType.PREPROCESSOR:
> + continue
> + if dl.linetype == LineType.BLANK:
> + continue
> + if '\t' in dl.raw:
> + yield (dl.lineno, 'tab character not allowed in DTS example')
> +
> +
> +def check_mixed_indent_chars(ctx):
> + """Indent must be all-spaces or all-tabs, never mixed on one line."""
> + for dl in ctx.lines:
> + if not dl.indent_str:
> + continue
> + if dl.linetype == LineType.PREPROCESSOR:
> + continue
> + if ' ' in dl.indent_str and '\t' in dl.indent_str:
> + yield (dl.lineno, 'mixed tabs and spaces in indent')
> +
> +
> +def detect_indent_unit(ctx):
> + """Find the indent unit used at depth 1 in this block.
> +
> + Returns one of: ' ' (2 spaces), ' ' (4 spaces), '\\t' (tab),
> + or None if depth-1 is empty or ambiguous."""
> + for dl in ctx.lines:
> + if dl.depth != 1:
> + continue
> + if dl.linetype in (LineType.BLANK, LineType.PREPROCESSOR):
> + continue
> + if dl.linetype in (LineType.COMMENT_BODY, LineType.COMMENT_END):
> + continue
> + if not dl.indent_str:
> + continue
> + if dl.indent_str == '\t':
> + return '\t'
> + if dl.indent_str == ' ':
> + return ' '
> + if dl.indent_str == ' ':
> + return ' '
> + # Anything else at depth 1 is non-canonical; flag elsewhere.
> + return dl.indent_str
> + return None
> +
> +
> +def check_indent_unit_relaxed(ctx):
> + """YAML examples: 2 or 4 spaces. Never tabs or other widths."""
> + unit = detect_indent_unit(ctx)
> + if unit is None:
> + return
> + if unit not in (' ', ' '):
> + yield (1, 'indent unit must be 2 or 4 spaces, got %r' % unit)
> +
> +
> +def check_indent_unit_dts(ctx):
> + """DTS files: 1 tab per level. Always required."""
> + unit = detect_indent_unit(ctx)
> + if unit is None:
> + return
> + if unit != '\t':
> + yield (1, 'indent unit must be 1 tab in DTS, got %r' % unit)
> +
> +
> +def check_indent_unit_strict(ctx):
> + """YAML: must be exactly 4 spaces. DTS: 1 tab (same as relaxed)."""
> + unit = detect_indent_unit(ctx)
> + if unit is None:
> + return
> + if ctx.indent_kind == 'spaces':
> + if unit != ' ':
> + yield (1, 'indent unit must be 4 spaces in strict mode, '
> + 'got %r' % unit)
> +
> +
> +def check_indent_consistent(ctx):
> + """All indented lines must be a multiple of the detected unit."""
> + unit = detect_indent_unit(ctx)
> + if unit is None:
> + return
> + if ctx.indent_kind == 'spaces':
> + if unit not in (' ', ' '):
> + return # let check_indent_unit_* report this
> + else:
> + if unit != '\t':
> + return
> +
> + for dl in ctx.lines:
> + if dl.linetype in (LineType.BLANK, LineType.PREPROCESSOR):
> + continue
> + if dl.linetype == LineType.CONTINUATION:
> + continue # continuations align to <, not to indent unit
> + if dl.linetype in (LineType.COMMENT_BODY, LineType.COMMENT_END):
> + continue
> + if not dl.indent_str:
> + continue
> + # The indent must be 'unit' repeated dl.depth times, exactly.
> + # NODE_CLOSE lines have depth equal to the post-decrement value,
> + # which matches the indent expected.
> + expected = unit * dl.depth
> + if dl.indent_str != expected:
> + yield (dl.lineno,
> + 'indent mismatch (expected depth %d * %r)' %
> + (dl.depth, unit))
> +
> +
> +def check_blank_lines(ctx):
> + """No two consecutive blank lines, no leading/trailing blank lines
> + in any node body."""
> + lines = ctx.lines
> + # Consecutive blanks
> + for i in range(1, len(lines)):
> + if lines[i].linetype == LineType.BLANK and \
> + lines[i - 1].linetype == LineType.BLANK:
> + yield (lines[i].lineno, 'consecutive blank lines')
> + # Blank right after { or right before }
> + for i, dl in enumerate(lines):
> + if dl.linetype != LineType.BLANK:
> + continue
> + prev = lines[i - 1] if i > 0 else None
> + nxt = lines[i + 1] if i + 1 < len(lines) else None
> + if prev is not None and prev.linetype == LineType.NODE_OPEN:
> + yield (dl.lineno, 'blank line at start of node body')
> + if nxt is not None and nxt.linetype == LineType.NODE_CLOSE:
> + yield (dl.lineno, 'blank line at end of node body')
> +
> +
> +def _walk_bodies(lines):
> + """Yield lists of immediate-child NODE_OPEN lines for each node body
> + in the input. Skips ref-nodes (&label) since those don't have an
> + intrinsic ordering."""
> + body_stack = [[]]
> + for dl in lines:
> + if dl.linetype == LineType.NODE_OPEN:
> + body_stack[-1].append(dl)
> + body_stack.append([])
> + continue
> + if dl.linetype == LineType.NODE_CLOSE:
> + if len(body_stack) <= 1:
> + # Unbalanced; ignore to avoid crashing on malformed input
> + continue
> + yield body_stack.pop()
> + continue
> + while body_stack:
> + yield body_stack.pop()
> +
> +
> +def _natural_sort_key(s):
> + """Split a string into a tuple of (kind, value) pairs that compares
> + numeric runs as ints, so 'foo10' sorts after 'foo2'."""
> + parts = []
> + for part in re.split(r'(\d+)', s):
> + if part.isdigit():
> + parts.append((0, int(part)))
> + else:
> + parts.append((1, part))
> + return tuple(parts)
> +
> +
> +def check_child_address_order(ctx):
> + """Addressed siblings (foo@N) must appear in ascending address
> + order within their parent node body."""
> + for children in _walk_bodies(ctx.lines):
> + addressed = []
> + for c in children:
> + if c.node_addr is None:
> + continue
> + try:
> + parts = tuple(int(p, 16) for p in c.node_addr.split(','))
> + except ValueError:
> + continue
> + addressed.append((parts, c))
> + for i in range(1, len(addressed)):
> + if addressed[i][0] < addressed[i - 1][0]:
> + dl = addressed[i][1]
> + yield (dl.lineno,
> + 'child node @%s out of address order' %
> + dl.node_addr)
> +
> +
> +def check_child_name_order(ctx):
> + """Unaddressed siblings must appear in natural-sort order by node
> + name within their parent node body. Addressed children are scoped
> + by check_child_address_order; reference nodes (&label { ... }) and
> + the root node are skipped."""
> + for children in _walk_bodies(ctx.lines):
> + unaddressed = []
> + for c in children:
> + if c.node_addr is not None:
> + continue
> + if c.node_name in (None, '/'):
> + continue
> + if c.ref_name is not None:
> + continue
> + unaddressed.append((_natural_sort_key(c.node_name), c))
> + for i in range(1, len(unaddressed)):
> + if unaddressed[i][0] < unaddressed[i - 1][0]:
> + dl = unaddressed[i][1]
> + yield (dl.lineno,
> + 'child node %r out of name order' % dl.node_name)
> +
> +
> +def _property_bucket(name):
> + """Return the canonical bucket index for a property:
> + 0 compatible
> + 1 reg / reg-names
> + 2 ranges
> + 3 standard properties (no vendor comma in #-stripped name)
> + 4 vendor-specific properties
> + 5 status
> + Plus a sub-key inside the bucket for fixed slots (compatible, reg,
> + reg-names, ranges, status). 'standard' and 'vendor' return None for
> + the sub-key, signalling that the within-bucket key is computed by
> + the pairing rules."""
> + stripped = name.lstrip('#')
> + if name == 'compatible':
> + return (0, 0)
> + if name == 'reg':
> + return (1, 0)
> + if name == 'reg-names':
> + return (1, 1)
> + if name == 'ranges':
> + return (2, 0)
> + if name == 'status':
> + return (5, 0)
> + return (4 if ',' in stripped else 3, None)
> +
> +
> +# Declarative pairing rules: each is a callable
> +# (name, all_names) -> anchor_name_or_None
> +# If a rule returns an anchor, the property sorts immediately after the
> +# anchor. Rules are tried in order; the first match wins. If none
> +# matches, the within-bucket key falls back to natural sort by the
> +# #-stripped name.
> +
> +def _pair_pinctrl_names(name, all_names):
> + """pinctrl-names follows the highest pinctrl-N in the same node."""
> + if name != 'pinctrl-names':
> + return None
> + cands = [n for n in all_names if re.match(r'^pinctrl-\d+$', n)]
> + if not cands:
> + return None
> + return max(cands, key=_natural_sort_key)
> +
> +
> +def _pair_x_names(name, all_names):
> + """Generic <x>-names follows its owning property. The owner is
> + usually plural (clocks/clock-names, dmas/dma-names,
> + resets/reset-names) but occasionally singular (reg/reg-names is
> + handled by the fixed slot above; this rule catches anything else)."""
> + if not name.endswith('-names'):
> + return None
> + base = name[:-len('-names')]
> + # Try plural and singular forms.
> + if (base + 's') in all_names:
> + return base + 's'
> + if base in all_names:
> + return base
> + return None
> +
> +
> +PAIRING_RULES = (_pair_pinctrl_names, _pair_x_names)
> +
> +
> +def _property_sort_key(name, all_names):
> + """Sort key for a property among its node-body siblings.
> +
> + Format: (bucket, within_key, tiebreak). 'within_key' for
> + standard/vendor buckets follows pairing rules: a property paired
> + with anchor X sorts as if it were X with a higher tiebreak."""
> + bucket, fixed_sub = _property_bucket(name)
> + if fixed_sub is not None:
> + return (bucket, (), fixed_sub)
> +
> + for rule in PAIRING_RULES:
> + anchor = rule(name, all_names)
> + if anchor is not None:
> + return (bucket, _natural_sort_key(anchor.lstrip('#')), 1)
> +
> + return (bucket, _natural_sort_key(name.lstrip('#')), 0)
> +
> +
> +def check_property_order(ctx):
> + """Properties within a node body must appear in canonical order:
> + compatible, reg(/reg-names), ranges, then the standard group, then
> + the vendor-specific group, then status. Inside the standard and
> + vendor groups, pairing rules apply (e.g. <x>-names follows <x>);
> + everything else falls back to natural sort by the #-stripped name."""
> + lines = ctx.lines
> + for i, dl in enumerate(lines):
> + if dl.linetype != LineType.NODE_OPEN:
> + continue
> + body_depth = dl.depth + 1
> + props = []
> + for j in range(i + 1, len(lines)):
> + d = lines[j]
> + if d.linetype == LineType.NODE_CLOSE and \
> + d.depth == body_depth - 1:
> + break
> + if d.linetype == LineType.PROPERTY and d.depth == body_depth \
> + and d.prop_name is not None:
> + props.append(d)
> + if len(props) < 2:
> + continue
> + all_names = [p.prop_name for p in props]
> + keyed = [(p, _property_sort_key(p.prop_name, all_names))
> + for p in props]
> + for k in range(1, len(keyed)):
> + if keyed[k][1] < keyed[k - 1][1]:
> + p = keyed[k][0]
> + prev = keyed[k - 1][0]
> + yield (p.lineno,
> + 'property %r out of canonical order '
> + '(should sort before %r)' %
> + (p.prop_name, prev.prop_name))
> +
> +
> +def _strip_strings_and_comments(text):
> + """Remove string literals and /* */ + // comments from a single
> + line, replacing them with empty strings. Used so syntactic checks
> + (whitespace, hex case, etc.) don't false-positive on contents of
> + quoted strings or comments."""
> + text = re.sub(r'"(?:[^"\\]|\\.)*"', '""', text)
> + text = re.sub(r'/\*.*?\*/', '', text)
> + text = re.sub(r'//.*$', '', text)
> + return text
> +
> +
> +def check_required_blank_lines(ctx):
> + """A blank line must precede each child node and the 'status'
> + property within a node body, except when these are the first
> + substantive item in the body."""
> + lines = ctx.lines
> + for i, open_dl in enumerate(lines):
> + if open_dl.linetype != LineType.NODE_OPEN:
> + continue
> + body_depth = open_dl.depth + 1
> + prev_substantive = None
> + between_blanks = 0
> + depth_inside = 0
> + for j in range(i + 1, len(lines)):
> + d = lines[j]
> + if d.linetype == LineType.NODE_CLOSE and \
> + d.depth == body_depth - 1 and depth_inside == 0:
> + break
> + # Track depth inside nested children so we only look at
> + # immediate-body items.
> + if d.linetype == LineType.NODE_OPEN and \
> + d.depth >= body_depth and depth_inside > 0:
> + depth_inside += 1
> + continue
> + if d.linetype == LineType.NODE_CLOSE and depth_inside > 0:
> + depth_inside -= 1
> + continue
> + if depth_inside > 0:
> + continue
> + if d.linetype == LineType.BLANK:
> + if prev_substantive is not None:
> + between_blanks += 1
> + continue
> + if d.linetype in (LineType.COMMENT, LineType.COMMENT_START,
> + LineType.COMMENT_BODY, LineType.COMMENT_END,
> + LineType.PREPROCESSOR):
> + continue
> + if d.linetype == LineType.CONTINUATION:
> + continue
> +
> + needs_blank = False
> + if d.linetype == LineType.NODE_OPEN:
> + needs_blank = True
> + depth_inside = 1 # entered the child body
> + elif d.linetype == LineType.PROPERTY and d.prop_name == 'status':
> + needs_blank = True
> +
> + if needs_blank and prev_substantive is not None and \
> + between_blanks == 0:
> + if d.linetype == LineType.NODE_OPEN:
> + yield (d.lineno,
> + 'child node must be preceded by a blank line')
> + else:
> + yield (d.lineno,
> + '"status" must be preceded by a blank line')
> +
> + prev_substantive = d
> + between_blanks = 0
> +
> +
> +def check_hex_case(ctx):
> + """Hex literals (0xN) must use lowercase digits and prefix."""
> + for dl in ctx.lines:
> + if dl.linetype in (LineType.BLANK, LineType.COMMENT,
> + LineType.COMMENT_START, LineType.COMMENT_BODY,
> + LineType.COMMENT_END, LineType.PREPROCESSOR):
> + continue
> + text = _strip_strings_and_comments(dl.raw)
> + for m in re.finditer(r'\b0[xX][0-9a-fA-F]+\b', text):
> + lit = m.group(0)
> + if any(c.isupper() for c in lit[2:]) or lit[1] == 'X':
> + yield (dl.lineno,
> + 'hex literal %r must be lowercase' % lit)
> +
> +
> +def check_unit_address_format(ctx):
> + """Unit addresses must be lowercase hex without leading zeros.
> + For multi-cell addresses (comma-separated), each part is checked
> + independently. A single '0' is permitted (canonical zero)."""
> + for dl in ctx.lines:
> + if dl.linetype != LineType.NODE_OPEN:
> + continue
> + if dl.node_addr is None:
> + continue
> + addr = dl.node_addr
> + for part in addr.split(','):
> + if any(c in 'ABCDEF' for c in part):
> + yield (dl.lineno,
> + 'unit address %r must be lowercase hex' % addr)
> + break
> + if len(part) > 1 and part.startswith('0'):
> + yield (dl.lineno,
> + 'unit address %r has leading zeros' % addr)
> + break
> +
> +
> +def check_value_whitespace(ctx):
> + """Inside a <...> cell list use single spaces between values; no
> + leading or trailing whitespace inside the brackets. Outside
> + strings and comments only."""
> + for dl in ctx.lines:
> + if dl.linetype not in (LineType.PROPERTY, LineType.CONTINUATION):
> + continue
> + text = _strip_strings_and_comments(dl.raw)
> + for m in re.finditer(r'<([^<>]*)>', text):
> + content = m.group(1)
> + if content != content.strip():
> + yield (dl.lineno,
> + 'extra whitespace inside <...>')
> + break
> + if re.search(r'[ \t]{2,}', content):
> + yield (dl.lineno,
> + 'multiple spaces inside <...>')
> + break
> +
> +
> +def check_node_close_alone(ctx):
> + """The closing '};' of a node must be on its own line. The
> + classifier already accepts only `};` or `}` as NODE_CLOSE; any
> + other line that still contains `};` (in code, not in strings or
> + comments) is mixing a node close with something else."""
> + for dl in ctx.lines:
> + if dl.linetype in (LineType.BLANK, LineType.COMMENT,
> + LineType.COMMENT_START, LineType.COMMENT_BODY,
> + LineType.COMMENT_END, LineType.PREPROCESSOR,
> + LineType.NODE_CLOSE):
> + continue
> + text = _strip_strings_and_comments(dl.raw)
> + if '};' in text:
> + yield (dl.lineno,
> + 'closing brace must be on its own line')
> +
> +
> +def check_line_length(ctx):
> + """Lines must not exceed 80 characters. Trailing newlines do not
> + count. Tabs in DTS files are counted as 8 columns to match how
> + `printf` and most editors render them, matching the kernel-wide
> + line length convention."""
> + for dl in ctx.lines:
> + if dl.linetype == LineType.BLANK:
> + continue
> + # Compute display width: tabs count as 8 columns, advancing to
> + # the next multiple of 8.
> + cols = 0
> + for ch in dl.raw:
> + if ch == '\t':
> + cols = (cols // 8 + 1) * 8
> + else:
> + cols += 1
> + if cols > 80:
> + yield (dl.lineno,
> + 'line exceeds 80 columns (%d)' % cols)
> +
> +
> +def check_continuation_alignment(ctx):
> + """A multi-line property's continuation lines must align their
> + first non-whitespace character to the column of the first '<' or
> + '"' after the '=' in the leading line."""
> + for dl in ctx.lines:
> + if dl.linetype != LineType.PROPERTY:
> + continue
> + if not dl.continuations:
> + continue
> + eq = dl.raw.find('=')
> + if eq < 0:
> + continue
> + # First '<' or '"' after '='
> + rest = dl.raw[eq + 1:]
> + m = re.search(r'[<"]', rest)
> + if not m:
> + continue
> + target_col = eq + 1 + m.start()
> + for cont in dl.continuations:
> + if len(cont.indent_str) != target_col:
> + yield (cont.lineno,
> + 'continuation should align to column %d '
> + '(under "<" or \\")' % (target_col + 1))
> +
> +
> +def check_unused_labels(ctx):
> + """Labels defined but never referenced are clutter."""
> + defined, referenced = collect_labels_and_refs(ctx.text)
> + for label in sorted(defined - referenced):
> + # Find the line where this label is defined for line-number
> + # reporting.
> + m = re.search(r'(?m)^.*\b' + re.escape(label) + r'\s*:', ctx.text)
> + lineno = ctx.text[:m.start()].count('\n') + 1 if m else 1
> + yield (lineno, 'label %r defined but never &-referenced' % label)
> +
> +
> +# --- registry --------------------------------------------------------------
> +
> +RULES = [
> + # 'relaxed' is the default; rules in this group must produce zero
> + # output on a clean kernel tree (post the small prep-cleanup
> + # commit at the head of this series).
> + Rule('trailing-whitespace', 'relaxed',
> + 'no trailing whitespace on any line',
> + check_trailing_whitespace),
> + Rule('tab-in-dts', 'relaxed',
> + 'YAML examples may not contain tab characters',
> + check_tab_in_dts, applies_to=('yaml',)),
> + Rule('mixed-indent-chars', 'relaxed',
> + 'indent must not mix tabs and spaces',
> + check_mixed_indent_chars),
> +
> + # DTS files always use tabs; this is not negotiable per kernel
> + # coding style (.dts files are real source). Relaxed mode.
> + Rule('indent-unit-dts', 'relaxed',
> + 'DTS files: 1 tab per nesting level',
> + check_indent_unit_dts,
> + applies_to=('dts', 'dtsi', 'dtso')),
> +
> + # 'strict' rules are opt-in (e.g. for new submissions via
> + # checkpatch.pl in a follow-up series). They flag many existing
> + # files and can be promoted to relaxed once those are cleaned up.
> + Rule('indent-unit', 'strict',
> + 'YAML: 2 or 4 spaces per level',
> + check_indent_unit_relaxed, applies_to=('yaml',)),
> + Rule('indent-unit-strict', 'strict',
> + 'YAML: must be 4 spaces per level',
> + check_indent_unit_strict, applies_to=('yaml',)),
> + Rule('indent-consistent', 'strict',
> + 'every line indented at depth * unit',
> + check_indent_consistent),
> + Rule('blank-lines', 'strict',
> + 'no consecutive blanks; no blanks at node body edges',
> + check_blank_lines),
> + Rule('child-address-order', 'strict',
> + 'addressed siblings must be in ascending address order',
> + check_child_address_order),
> + Rule('child-name-order', 'strict',
> + 'unaddressed siblings must be in natural-sort name order',
> + check_child_name_order),
> + Rule('property-order', 'strict',
> + 'canonical bucket + pairing + natural-sort order of properties',
> + check_property_order),
> + Rule('required-blank-lines', 'strict',
> + 'blank line before child nodes and before "status"',
> + check_required_blank_lines),
> + Rule('hex-case', 'strict',
> + 'hex literals must be lowercase',
> + check_hex_case),
> + Rule('unit-address-format', 'strict',
> + 'unit addresses must be lowercase hex without leading zeros',
> + check_unit_address_format),
> + Rule('value-whitespace', 'strict',
> + 'single-spaced values inside <...>',
> + check_value_whitespace),
> + Rule('node-close-alone', 'strict',
> + 'closing brace must be on its own line',
> + check_node_close_alone),
> + Rule('line-length', 'strict',
> + 'lines must not exceed 80 columns',
> + check_line_length),
> + Rule('continuation-alignment', 'strict',
> + 'multi-line property continuations align under "<" or "\\""',
> + check_continuation_alignment),
> + Rule('unused-labels', 'strict',
> + 'every label must be &-referenced in the same example/file '
> + '(skipped for .dtsi/.dtso since labels there are exported)',
> + check_unused_labels, applies_to=('yaml', 'dts')),
> +]
> +
> +
> +def select_rules(mode, input_kind):
> + """Return rules that apply to the given mode and input type."""
> + rank = {'relaxed': 0, 'strict': 1}
> + out = []
> + for r in RULES:
> + if rank[r.mode] > rank[mode]:
> + continue
> + if input_kind not in r.applies_to:
> + continue
> + out.append(r)
> + return out
> +
> +
> +# ---------------------------------------------------------------------------
> +# Block runner
> +# ---------------------------------------------------------------------------
> +
> +def check_block(text, mode, indent_kind, input_type):
> + """Run all selected rules on a single block of DTS text. Returns a
> + list of (lineno, rule_name, message) tuples."""
> + lines = classify_lines(text)
> + ctx = Ctx(lines, text, mode, indent_kind)
> + rules = select_rules(mode, input_type)
> + findings = []
> + for r in rules:
> + for lineno, msg in r.check(ctx):
> + findings.append((lineno, r.name, msg))
> + findings.sort(key=lambda t: (t[0], t[1]))
> + return findings
> +
> +
> +# ---------------------------------------------------------------------------
> +# Input drivers (YAML examples vs raw DTS)
> +# ---------------------------------------------------------------------------
> +
> +def _yaml_loader():
> + return ruamel.yaml.YAML()
> +
> +
> +def iter_yaml_examples(filepath):
> + """Yield (example_text, base_lineno_in_file, example_index) tuples."""
> + yaml = _yaml_loader()
> + try:
> + with open(filepath, encoding='utf-8') as f:
> + data = yaml.load(f)
> + except Exception as e:
> + print('%s: error loading YAML: %s' % (filepath, e),
> + file=sys.stderr)
> + return
> + if not isinstance(data, dict) or 'examples' not in data:
> + return
> + examples = data['examples']
> + if not hasattr(examples, '__iter__'):
> + return
> + for i, ex in enumerate(examples):
> + if not isinstance(ex, str):
> + continue
> + try:
> + base = examples.lc.item(i)[0] + 2
> + except Exception:
> + base = 1
> + yield (str(ex), base, i)
> +
> +
> +def iter_dts_file(filepath):
> + """Treat the whole file as a single block."""
> + try:
> + with open(filepath, encoding='utf-8') as f:
> + text = f.read()
> + except Exception as e:
> + print('%s: error reading: %s' % (filepath, e), file=sys.stderr)
> + return
> + yield (text, 1, None)
> +
> +
> +# ---------------------------------------------------------------------------
> +# Top-level processing
> +# ---------------------------------------------------------------------------
> +
> +def input_kind(filepath):
> + p = filepath.lower()
> + if p.endswith('.yaml') or p.endswith('.yml'):
> + return 'yaml'
> + if p.endswith('.dts'):
> + return 'dts'
> + if p.endswith('.dtsi'):
> + return 'dtsi'
> + if p.endswith('.dtso'):
> + return 'dtso'
> + return None
> +
> +
> +# All input types that use tab indentation and follow DTS coding style.
> +DTS_FAMILY = ('dts', 'dtsi', 'dtso')
> +
> +
> +def collect_findings(filepath, mode):
> + """Return a (lines, count) pair for filepath. lines is a list of
> + formatted output strings; count is the number of findings."""
> + kind = input_kind(filepath)
> + if kind == 'yaml':
> + indent_kind = 'spaces'
> + iterator = iter_yaml_examples(filepath)
> + elif kind in DTS_FAMILY:
> + indent_kind = 'tab'
> + iterator = iter_dts_file(filepath)
> + else:
> + return (['%s: unknown file type, skipping' % filepath], 0)
> +
> + out = []
> + for text, base, idx in iterator:
> + for lineno, rule, msg in check_block(text, mode, indent_kind, kind):
> + abs_line = base + lineno - 1
> + ex_tag = '' if idx is None else ' example %d' % idx
> + out.append('%s:%d:%s [%s] %s' %
> + (filepath, abs_line, ex_tag, rule, msg))
> + return (out, len(out))
> +
> +
> +# Worker entry point for ProcessPoolExecutor.map(). Top-level so it is
> +# picklable on every platform.
> +def _worker(args):
> + filepath, mode = args
> + return collect_findings(filepath, mode)
> +
> +
> +def main():
> + import os
> + ap = argparse.ArgumentParser(
> + description='Check DTS coding style on YAML examples and '
> + '.dts/.dtsi/.dtso files.',
> + fromfile_prefix_chars='@')
> + ap.add_argument('--mode', choices=('relaxed', 'strict'),
> + default='relaxed',
> + help='which rule set to apply (default: relaxed)')
> + ap.add_argument('-j', '--jobs', type=int, default=0,
> + metavar='N',
> + help='run N workers in parallel (default: respect '
> + 'the make jobserver via $PARALLELISM, otherwise '
> + 'os.cpu_count(); use 1 to disable multiprocessing)')
> + ap.add_argument('--list-rules', action='store_true',
> + help='print all rules with their mode and exit')
> + ap.add_argument('files', nargs='*', metavar='file',
> + help='YAML binding files or .dts/.dtsi/.dtso files; '
> + 'use @argfile to read paths from a file')
> + args = ap.parse_args()
> +
> + if args.list_rules:
> + for r in RULES:
> + applies = ','.join(r.applies_to)
> + print('%-22s %-7s [%s] %s' %
> + (r.name, r.mode, applies, r.description))
> + return 0
> +
> + if not args.files:
> + ap.error('no input files')
> +
> + if args.jobs > 0:
> + jobs = args.jobs
> + else:
> + # When invoked under scripts/jobserver-exec, $PARALLELISM
> + # holds the slot count make has reserved for us; this lets
> + # `make -j N dt_binding_check` constrain our worker pool to N.
> + try:
> + jobs = int(os.environ['PARALLELISM'])
> + except (KeyError, ValueError):
> + jobs = os.cpu_count() or 1
> + # Single-process path: keep import surface small for tests and
> + # easy debugging.
> + if jobs == 1 or len(args.files) == 1:
> + total = 0
> + for f in args.files:
> + lines, n = collect_findings(f, args.mode)
> + for line in lines:
> + print(line)
> + total += n
> + return 1 if total else 0
> +
> + # Multi-process path. ex.map preserves input order so output is
> + # deterministic across runs.
> + from concurrent.futures import ProcessPoolExecutor
> + total = 0
> + work = [(f, args.mode) for f in args.files]
> + chunk = max(1, len(work) // (jobs * 8)) if work else 1
> + with ProcessPoolExecutor(max_workers=jobs) as ex:
> + for lines, n in ex.map(_worker, work, chunksize=chunk):
> + for line in lines:
> + print(line)

This needs to go to stderr. A quiet build has no output.

> + total += n
> + return 1 if total else 0
> +
> +
> +if __name__ == '__main__':
> + sys.exit(main())
> --
> 2.54.0