Re: [Qemu-devel] [PATCH V7 03/11] qapi-script: remember line number in schema parsing

[Markus Armbruster]

Wenchao Xia <address@hidden> writes:

> Before this patch, 'QAPISchemaError' scans whole input until 'pos'
> to get error line number. After this patch, the scan is avoided since
> line number is remembered in schema parsing. This patch also benefits
> other error report functions, which would be introduced later.

Not sure avoiding the scan is worthwhile, but since you coded it
already...  no objections.

>
> Signed-off-by: Wenchao Xia <address@hidden>
> ---
>  scripts/qapi.py |   14 ++++++++------
>  1 files changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/scripts/qapi.py b/scripts/qapi.py
> index 3732fe1..c504eb4 100644
> --- a/scripts/qapi.py
> +++ b/scripts/qapi.py
> @@ -39,12 +39,10 @@ class QAPISchemaError(Exception):
>      def __init__(self, schema, msg):
>          self.fp = schema.fp
>          self.msg = msg
> -        self.line = self.col = 1
> -        for ch in schema.src[0:schema.pos]:
> -            if ch == '\n':
> -                self.line += 1
> -                self.col = 1
> -            elif ch == '\t':
> +        self.col = 1
> +        self.line = schema.line
> +        for ch in schema.src[schema.line_pos:schema.pos]:
> +            if ch == '\t':
>                  self.col = (self.col + 7) % 8 + 1

Column computation is wrong.  Should be something like

                   self.col = ((self.col + 7) & ~7) + 1

Not your fault, of course, and you don't have to fix it to get my R-by.
If you want to fix it, separate patch, and please include suitable
tests.

>              else:
>                  self.col += 1
> @@ -60,6 +58,8 @@ class QAPISchema:
>          if self.src == '' or self.src[-1] != '\n':
>              self.src += '\n'
>          self.cursor = 0
> +        self.line = 1
> +        self.line_pos = 0
>          self.exprs = []
>          self.accept()
>  
> @@ -100,6 +100,8 @@ class QAPISchema:
>                  if self.cursor == len(self.src):
>                      self.tok = None
>                      return
> +                self.line += 1
> +                self.line_pos = self.cursor
>              elif not self.tok.isspace():
>                  raise QAPISchemaError(self, 'Stray "%s"' % self.tok)