Re: Re: Fix modification of string literal by swprintf

[Renlin Li <renlin dot li at arm dot com>]

Hi there,

It seems this patch cause few regressions on arm/aarch64 baremetal targets.

libstdc++-v3:
FAIL: 21_strings/basic_string/numeric_conversions/wchar_t/dr1261.cc execution test
FAIL: 21_strings/basic_string/numeric_conversions/wchar_t/stof.cc execution test
FAIL: 21_strings/basic_string/numeric_conversions/wchar_t/to_wstring.cc execution test
FAIL: 27_io/basic_ostream/inserters_arithmetic/wchar_t/4402.cc execution test

newlib:
FAIL: newlib.stdio/swprintf.c execution

Regards,
Renlin

On 09/06/17 14:32, Corinna Vinschen wrote:
> On Jun  8 13:15, Thomas Preudhomme wrote:
> > Please find his updated patch attached.
> >
> > Best regards,
> >
> > Thomas
>
> > >From ee96a273969b0bccd308b81bcdf37a6fdefa06f6 Mon Sep 17 00:00:00 2001
> > From: Silviu Baranga <silviu.baranga@arm.cm>
> > Date: Mon, 5 Jun 2017 09:54:42 +0100
> > Subject: [PATCH] Don't overread or write memory returned by _DTOA_R
> >
> > Don't over-read memory returned by _DTOA_R, and never write to it
> > since the result might be a string literal.
> >
> > For example, when doing:
> >    swprintf(tt, 20, L"%.*f", 6, 0.0);
> >
> > we will get back "0".
> >
> > Instead, write the result returned by _DTOA_R to the output buffer.
> > After this, write the 0 chars directly to the the output buffer
> > (if there are any). This also has the (marginal) advantage that
> > we read/write less memory overall.
>
> Pushed.
>
>
> Thanks,
> Corinna