Messages in this thread | | | Date | Mon, 22 Oct 2018 09:05:47 +0200 | From | Willy Tarreau <> | Subject | Re: [PATCH 1/2] Compiler Attributes: add support for __fallthrough (gcc >= 7.1) |
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On Mon, Oct 22, 2018 at 02:58:00AM -0400, Theodore Y. Ts'o wrote: > On Sun, Oct 21, 2018 at 05:42:18PM -0700, Matthew Wilcox wrote: > > On Sun, Oct 21, 2018 at 07:14:13PM +0200, Miguel Ojeda wrote: > > > +#if __has_attribute(__fallthrough__) > > > +# define __fallthrough __attribute__((__fallthrough__)) > > > +#else > > > +# define __fallthrough > > > +#endif > > > > Why is the #else not: > > > > # define __fallthrough /* fallthrough */ > > > > Would this solve the Coverity problem, or does Coverity look at the raw > > source code before preprocessing? > > Wouldn't the "/* ... */" be eaten by the preprocessor before defining > the __fallthrough cpp macro? (e.g., try running the attached script)
You're right, even on older versions (4.7 here) :
$ echo -e '#define foobar quux /* foobar */\nfoobar\n' | gcc -E - # 1 "<stdin>" # 1 "<command-line>" # 1 "<stdin>"
quux
Willy
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