https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86157
Bug ID: 86157
Summary: Wmisleading-indentation disabled after a #line
directive
Product: gcc
Version: 6.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: chantry.xavier at gmail dot com
Target Milestone: ---
Created attachment 44279
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44279&action=edit
test case with a block macro
Today at work an instance of the "goto fail" bug was discovered and fixed (4
years after being introduced).
We have a coding rule to enforce brackets even for single instructions, exactly
to avoid that kind of bug. It's quite well respected, but we have no tool to
check it.
I learned about the Wmisleading-indentation feature, that is awesome ! But we
already have gcc 6 and -Wall, and the bug was not found. That's because of that
exception : "The warning is not issued after a #line directive, since this
typically indicates autogenerated code, and no assumptions can be made about
the layout of the file that the directive references.".
That's a shame. We have a few #line directives in most of our files (compiled
by gcc) because we use an apple extension called blocks (a kind of closure).
More details at
https://techtalk.intersec.com/2014/11/blocks-rewriting-with-clang/
So it would be great to have the Wmisleading-indentation feature even for files
with #line directives, perhaps with another flag ?
Any idea or suggestion or workaround is welcome.
Well an easy workaround is to disable the #line directives just for running
that check from time to time. So I just did that but still no warning, there is
another problem, I just realized this case is more complex than it looked. See
attachment for a simplified test case. Since the first line hides a block
macro, the problem is not detected anyway.
