Bug#891489: gcc-8: attribute no_sanitize does not accept multiple options as documented

[Ron <ron@debian.org>]

Package: gcc-8
Version: 8-20180218-1
Severity: normal

Hi,

In https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-no_005fsanitize-function-attribute
gcc 8.0.1 claims to add a no_sanitize attribute which works the same as
the clang one does.

In practice however it doesn't, and it currently will only accept a
single option.  The example given above is:

  $ cat nosan.c
  void __attribute__ ((no_sanitize ("alignment", "object-size")))
  f () { /* Do something. */; }

  int main(void) { return 0; }


Which results in:

  $ gcc-8 nosan.c 
  nosan.c:3:1: error: wrong number of arguments specified for ‘no_sanitize’ attribute
   f () { /* Do something. */; }
   ^


It would be really nice if that did work as documented, to avoid having
to special case this in user code even more than we already do.

  Cheers,
  Ron