Quoting Johannes Sixt (2019-10-05 07:09:11)
> Am 04.10.19 um 23:30 schrieb Stephen Boyd:
> > While reviewing some dts diffs recently I noticed that the hunk header
> > logic was failing to find the containing node. This is because the regex
> > doesn't consider properties that may span multiple lines, i.e.
> >
> > property = <something>,
> > <something_else>;
>
> What if the property spans more than two lines?
>
> property = <something>,
> more,
> <something_else>;
>
> Can the second line "more," begin with a word, or are the angle brackets
> mandatory?
Angle brackets aren't mandatory, but it is very odd to have a property
with mixed numbers and strings because parsing becomes difficult.
>
> I understand that the continuation lines can begin with a word when the
> property is an expression that is distributed over a number of lines.
> Such continuation lines could be picked up as hunk headers.
>
> But I don't want to complicate things: The hunk header patterns do not
> have to be perfect; it is sufficient when they are helpful in a good
> majority of cases that occur in practice.
>
> > and it got hung up on comments inside nodes that look like the root node
> > because they start with '/*'. Add tests for these cases and update the
> > regex to find them. Maybe detecting the root node is too complicated but
> > forcing it to be a backslash with any amount of whitespace up to an open
> > bracket seemed OK. I tried to detect that a comment is in-between the
> > two parts but I wasn't happy so I just dropped it.
> >
> > Cc: Rob Herring <robh...@kernel.org>
> > Cc: Frank Rowand <frowand.l...@gmail.com>
> > Signed-off-by: Stephen Boyd <sb...@kernel.org>
> > ---
> > t/t4018/dts-nodes-multiline-prop | 12 ++++++++++++
> > t/t4018/dts-root | 2 +-
> > t/t4018/dts-root-comment | 8 ++++++++
> > userdiff.c | 3 ++-
> > 4 files changed, 23 insertions(+), 2 deletions(-)
> > create mode 100644 t/t4018/dts-nodes-multiline-prop
> > create mode 100644 t/t4018/dts-root-comment
> >
> > diff --git a/t/t4018/dts-nodes-multiline-prop
> > b/t/t4018/dts-nodes-multiline-prop
> > new file mode 100644
> > index 000000000000..f7b655935429
> > --- /dev/null
> > +++ b/t/t4018/dts-nodes-multiline-prop
> > @@ -0,0 +1,12 @@
> > +/ {
> > + label_1: node1@ff00 {
> > + RIGHT@deadf00,4000 {
> > + multilineprop = <3>,
> > + <4>;
>
> You could insert more lines to demonstrate that "<x>," on a line by
> itself is not picked up.
Maybe I should add another test?
>
> > +
> > +
> > +> + ChangeMe = <0xffeedd00>;
>
> Sufficient distance to the incorrect candidates above. Good.
>
> > + };
> > + };
> > +};
> > diff --git a/t/t4018/dts-root b/t/t4018/dts-root
> > index 2ef9e6ffaa2c..4353b8220c91 100644
> > --- a/t/t4018/dts-root
> > +++ b/t/t4018/dts-root
> > @@ -1,4 +1,4 @@
> > -/RIGHT { /* Technically just supposed to be a slash */
> > +/ { RIGHT /* Technically just supposed to be a slash and brace */
>
> Do I understand correctly that the updated form, "/ {", is the common
> way to spell a root node, but "/" or "/word" are not?
Correct. A root node is '/' and the '{' opens the node. There is the
possibility of something like '/delete-node nodename;' or
'/delete-property property;', where the latter exists inside some node.
The regex would need to avoid all of those.
>
> > #size-cells = <1>;
> >
> > ChangeMe = <0xffeedd00>;
> > diff --git a/t/t4018/dts-root-comment b/t/t4018/dts-root-comment
> > new file mode 100644
> > index 000000000000..333a625c7007
> > --- /dev/null
> > +++ b/t/t4018/dts-root-comment
> > @@ -0,0 +1,8 @@
> > +/ { RIGHT /* Technically just supposed to be a slash and brace */
>
> Devil's advocate here: insert ';' or '=' in the comment, and the line
> would not be picked up. Does that hurt in practice?
I don't think it hurts in practice so I'd like to ignore it.
>
> > + #size-cells = <1>;
> > +
> > + /* This comment should be ignored */
> > +
> > + some-property = <40+2>;
> > + ChangeMe = <0xffeedd00>;
> > +};
> > diff --git a/userdiff.c b/userdiff.c
> > index 86e3244e15dd..651b56caec56 100644
> > --- a/userdiff.c
> > +++ b/userdiff.c
> > @@ -25,8 +25,9 @@ IPATTERN("ada",
> > "|=>|\\.\\.|\\*\\*|:=|/=|>=|<=|<<|>>|<>"),
> > PATTERNS("dts",
> > "!;\n"
> > + "!.*=.*\n"
>
> This behaves the same way as just
>
> "!=\n"
>
> no?
>
Not exactly. Properties don't always get assigned. There are boolean
properties that can be tested for by the presence of some string with an
ending semi-colon, like 'this-is-true;'. If we just check for not equal
to a line with a semicolon and newline then we'll see boolean
properties. Should I add that as another test?
