Re: [PATCH] target/arm: Display helpful message when hflags mismatch

[Philippe Mathieu-Daudé]

On 12/12/19 1:36 AM, Richard Henderson wrote:
> On 12/9/19 8:00 AM, Alex Bennée wrote:
> > > -#ifdef CONFIG_DEBUG_TCG
> > > -    assert(flags == rebuild_hflags_internal(env));
> > > -#endif
> > > +    assert_hflags_rebuild_correctly(env);
> >
> > I'm trying to recall why we don't just use:
> >
> >    g_assert_cmphex(flags, =, rebuild_hflags_internal(env))

s/=/==/ ;)

> > I think it came up in one of the reviews.
>
> checkpatch.pl.
>
> Because, I believe, there is an environment variable that causes this to *not*
> abort on mismatch.

Indeed, see commit 6e9389563e5:

commit 6e9389563e56607f72562bdb72db452fcd7e7f74
Author: Dr. David Alan Gilbert <address@hidden>
Date:   Thu Apr 27 17:55:26 2017 +0100

    checkpatch: Disallow glib asserts in main code

    Glib commit a6a875068779 (from 2013) made many of the glib assert
    macros non-fatal if a flag is set.
    This causes two problems:
      a) Compilers moan that your code is unsafe even though you've
         put an assert in before the point of use.
      b) Someone evil could, in a library, call
         g_test_set_nonfatal_assertions() and cause our assertions in
         important places not to fail and potentially allow memory 
overruns.

    Ban most of the glib assertion functions (basically everything except
    g_assert and g_assert_not_reached) except in tests/

    This makes checkpatch gives an error such as:

      ERROR: Use g_assert or g_assert_not_reached
      #77: FILE: vl.c:4725:
      +    g_assert_cmpstr("Chocolate", >, "Cheese");