On Thu, May 15, 2014 at 04:43:15PM +0200, Ivo Sieben wrote:
> When picking up a complete statement block #if/#else/#endif prepocesor
> boundaries are taken into account by pushing current level & type on a stack.
> But on an #else the level was read from stack again (without actually popping
> it
> from stack) causing the statement block to end too early on the next ';'.
> Fixed this.
>
> For example the following code:
>
> if (!test()) {
> #ifdef NEVER
> foo();
> bar();
> #else
> bar();
> foo();
> #endif
> }
>
> Results in statement block:
>
> STATEMENT<+ if (!test()) {
> +#ifdef NEVER
> + foo();
> + bar();
> +#else
> + bar();>
> CONDITION<+ if (!test())>
>
> While you would expect:
>
> STATEMENT<+ if (!test()) {
> +#ifdef NEVER
> + foo();
> + bar();
> +#else
> + bar();
> + foo();
> +#endif
> + }>
> CONDITION<+ if (!test())>
>
> Signed-off-by: Ivo Sieben <meltedpiano...@gmail.com>
> ---
>
> Request for comments:
> I think I fixed a problem here that I encountered while I was working on
> another
> changeset in which I check the statement block after a condition.
> Somehow the statement block did not contain everything I expected.
>
> scripts/checkpatch.pl | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 34eb216..e7bca89 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -878,7 +878,7 @@ sub ctx_statement_block {
> if ($remainder =~ /^#\s*(?:ifndef|ifdef|if)\s/) {
> push(@stack, [ $type, $level ]);
> } elsif ($remainder =~ /^#\s*(?:else|elif)\b/) {
> - ($type, $level) = @{$stack[$#stack - 1]};
> + # no changes to stack: type & level remain the same
> } elsif ($remainder =~ /^#\s*endif\b/) {
> ($type, $level) = @{pop(@stack)};
> }
> @@ -1050,7 +1050,7 @@ sub ctx_block_get {
> if ($lines[$line] =~ /^.\s*#\s*(?:ifndef|ifdef|if)\s/) {
> push(@stack, $level);
> } elsif ($lines[$line] =~ /^.\s*#\s*(?:else|elif)\b/) {
> - $level = $stack[$#stack - 1];
> + # no changes to stack: type & level remain the same
> } elsif ($lines[$line] =~ /^.\s*#\s*endif\b/) {
> $level = pop(@stack);
> }
> --
> 1.7.9.5
It doesn't seem right to remove the restore of the state. If you
consider the effect of an #if/#else/#endif combination the state of the
statement parser should be reset to the state at #if at the #else as the
code there is an alternative for the code in the other branch(s) of the
preprocessor, either is a continuation of the statement in progress when
reached. This contrived example should make it clear we need to
restore:
c = (d +
#if A
a)
#else
b)
#endif
That said it appears to be doing something wrong in your example.
/me will have a poke and get back to you.
-apw
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