Re: [PATCH] x86: Avoid undefined behavior in macro expansion

2016-03-21 Thread Vinicius Tinti
On Fri, Mar 18, 2016 at 11:15 PM, Al Viro wrote: > On Wed, Mar 16, 2016 at 11:48:49PM -0300, Vinicius Tinti wrote: >> C11 standard (at 6.10.3.3) says that ## operator (paste) has undefined >> behavior when one of the result operands is not a valid preprocessing >> token. >> >> Therefore the macro

[PATCH] x86: Avoid undefined behavior in macro expansion

2016-03-19 Thread Vinicius Tinti
C11 standard (at 6.10.3.3) says that ## operator (paste) has undefined behavior when one of the result operands is not a valid preprocessing token. Therefore the macro expansion may depend on compiler implementation which may or no preserve the leading white space. Moreover other places in kernel

Re: [PATCH] x86: Avoid undefined behavior in macro expansion

2016-03-18 Thread Al Viro
On Wed, Mar 16, 2016 at 11:48:49PM -0300, Vinicius Tinti wrote: > C11 standard (at 6.10.3.3) says that ## operator (paste) has undefined > behavior when one of the result operands is not a valid preprocessing > token. > > Therefore the macro expansion may depend on compiler implementation > which