dtc: dt-check-style: Re-work classifying property continuations

Script has an enumeration of DTS Line types (LineType) and one type is a
continuation of multi-line property.  This has limitations, because it
basically hides true type of a continued line which makes certain checks
difficult.  For example detecting consecutive blank lines
(LineType.BLANK) will fail if the type is continuation.

    clock-names = "foo",

                  /* Comment */
                  "bar";

Above code not only fails check_blank_lines() rule, but also messes up
how DtsLine array is constructed - the two middle continued lines are
not put under the DtsLine.continuations array.

The concepts of type of line (blank, preprocessor, property etc) and
actual continuation are orthogonal to most of the checks - the checks
need to know what sort of continued line it is.  Fixing this solves
false positives of continued properties with blank lines and comments:

  arch/arm64/boot/dts/exynos/exynos5433-tm2-common.dtsi:135: [blank-lines] consecutive blank lines
  arch/arm64/boot/dts/exynos/exynos5433-tm2-common.dtsi:135: [blank-lines] blank line at end of node body

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260911-dts-style-checker-blank-lines-v1-1-85e779600d98@oss.qualcomm.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

1 files changed, 16 insertions, 20 deletions

diff --git a/scripts/dtc/dt-check-style b/scripts/dtc/dt-check-style
index b8c40873905c..46aa4dda6d33 100755
--- a/scripts/dtc/dt-check-style
+++ b/scripts/dtc/dt-check-style
@@ -44,7 +44,6 @@ class LineType(Enum):
     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(
@@ -80,11 +79,12 @@ def is_preprocessor(stripped):
 
 class DtsLine:
     __slots__ = ('lineno', 'raw', 'code', 'linetype', 'indent_str', 'stripped', 'is_root',
-                 'prop_name', 'continuations',
+                 'prop_name', 'continuation', 'continuations',
                  'node_name', 'node_addr', 'label', 'ref_name', 'parent', 'depth',
                  'closures')
 
-    def __init__(self, lineno, raw, linetype, depth, indent_str, stripped, is_root = False):
+    def __init__(self, lineno, raw, linetype, depth, indent_str, stripped,
+                 continuation = False, is_root = False):
         self.lineno = lineno      # 1-based within the block
         self.raw = raw            # Entire raw line
         self.linetype = linetype
@@ -95,6 +95,7 @@ class DtsLine:
         self.code = _strip_strings_and_comments(stripped).rstrip()
         self.is_root = is_root
         self.prop_name = None
+        self.continuation = continuation    # Continuation of a multi-line property
         self.continuations = []
         self.node_name = None
         self.node_addr = None
@@ -175,7 +176,7 @@ def classify_lines(text):
             continue
 
         if not stripped:
-            dl = DtsLine(i, raw, LineType.BLANK, depth, '', '')
+            dl = DtsLine(i, raw, LineType.BLANK, depth, '', '', continuation=not prev_complete)
             out.append(dl)
             continue
 
@@ -184,7 +185,7 @@ def classify_lines(text):
                      else LineType.COMMENT_BODY)
             if ltype == LineType.COMMENT_END:
                 in_block_comment = False
-            dl = DtsLine(i, raw, ltype, depth, indent_str, stripped)
+            dl = DtsLine(i, raw, ltype, depth, indent_str, stripped, continuation=not prev_complete)
             out.append(dl)
             continue
 
@@ -202,20 +203,12 @@ def classify_lines(text):
         if opens_block:
             in_block_comment = True
 
-        if not prev_complete:
-            dl = DtsLine(i, raw, LineType.CONTINUATION, depth, indent_str, code)
-            out.append(dl)
-            prev_complete = (code.endswith(';') or
-                             code.endswith('{') or
-                             code.endswith('};'))
-            continue
-
         # Pure-comment line: nothing left after stripping. Classify as
         # COMMENT_START (carries to next line) or COMMENT, and skip the
         # structural classification entirely.
         if not code:
             ltype = LineType.COMMENT_START if opens_block else LineType.COMMENT
-            dl = DtsLine(i, raw, ltype, depth, indent_str, stripped)
+            dl = DtsLine(i, raw, ltype, depth, indent_str, stripped, continuation=not prev_complete)
             out.append(dl)
             continue
 
@@ -245,7 +238,8 @@ def classify_lines(text):
             continue
 
         # Property (or first line of a multi-line property).
-        dl = DtsLine(i, raw, LineType.PROPERTY, depth, indent_str, code)
+        dl = DtsLine(i, raw, LineType.PROPERTY, depth, indent_str, code,
+                     continuation=not prev_complete)
         parse_property_name(dl)
         out.append(dl)
         prev_complete = code.endswith(';')
@@ -254,7 +248,7 @@ def classify_lines(text):
     last_prop = None
     grouped = []
     for dl in out:
-        if dl.linetype == LineType.CONTINUATION and last_prop is not None:
+        if dl.continuation and last_prop is not None:
             last_prop.continuations.append(dl)
             continue
         if dl.linetype == LineType.PROPERTY:
@@ -535,6 +529,8 @@ def check_continuation_alignment(ctx):
         dl_value_complete = rest.endswith('",') or rest.endswith('>,')
         target_col = _display_col(_strip_strings_and_comments(dl.raw[:eq + 1 + m.start(1)]))
         for cont in dl.continuations:
+            if cont.linetype == LineType.BLANK:
+                continue
             target_offset = 0
             err_msg_explanation = 'to < or "'
             if not dl_value_complete:
@@ -582,10 +578,10 @@ def check_indent_consistent(ctx):
             return
 
     for dl in ctx.lines:
+        if dl.continuation:
+            continue   # continuations align to <, not to indent unit
         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:
@@ -890,6 +886,8 @@ def check_required_blank_lines(ctx):
             if d.linetype == LineType.NODE_CLOSE and \
                     d.depth == body_depth - 1 and depth_inside == 0:
                 break
+            if d.continuation:
+                continue
             # Track depth inside nested children so we only look at
             # immediate-body items.
             if d.linetype == LineType.NODE_OPEN and \
@@ -909,8 +907,6 @@ def check_required_blank_lines(ctx):
                               LineType.COMMENT_BODY, LineType.COMMENT_END,
                               LineType.PREPROCESSOR):
                 continue
-            if d.linetype == LineType.CONTINUATION:
-                continue
 
             needs_blank = False
             if d.linetype == LineType.NODE_OPEN: