[review] Use strerror_r in safe_strerror if available

["Simon Marchi (Code Review)" <gerrit at gnutoolchain-gerrit dot osci dot io>]

Simon Marchi has posted comments on this change.

Change URL: https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/474
......................................................................


Patch Set 1:

(2 comments)

https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/474/1/gdb/gdbsupport/posix-strerror.c 
File gdb/gdbsupport/posix-strerror.c:

https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/474/1/gdb/gdbsupport/posix-strerror.c@24 
PS1, Line 24: 
19 | 
20 | #include "common-defs.h"
21 | 
22 | /* Implementation of safe_strerror as defined in common-utils.h.  */
23 | 
24 > char *
25 | safe_strerror (int errnum)
26 | {
27 |   static thread_local char buf[1024];
28 | 
29 |   char *msg = nullptr;

Just wondering, maybe we could make safe_strerror return a `const char *`?  I suppose we never want the caller to modify what we return, since it could point to some immutable string.


https://gnutoolchain-gerrit.osci.io/r/c/binutils-gdb/+/474/1/gdb/gdbsupport/posix-strerror.c@31 
PS1, Line 31: 
26 | {
27 |   static thread_local char buf[1024];
28 | 
29 |   char *msg = nullptr;
30 | #ifdef HAVE_STRERROR_R
31 > #if !__GLIBC__ || ((_POSIX_C_SOURCE >= 200112L) && !  _GNU_SOURCE)
32 |   /* Glibc has two different, incompatible versions of strerror_r.  */
33 |   if (strerror_r (errnum, buf, sizeof (buf)) == 0)
34 |     msg = buf;
35 | #else
36 |   msg = strerror_r (errnum, buf, sizeof (buf));

Just a nit, can you "indent" the preprocessor declarations, like

 #ifdef HAVE_STRERROR_R
 # if ...

?  I think it makes it easier to read.



-- 
Gerrit-Project: binutils-gdb
Gerrit-Branch: master
Gerrit-Change-Id: I81048fbaf148035c221c528727f7efe58ba528eb
Gerrit-Change-Number: 474
Gerrit-PatchSet: 1
Gerrit-Owner: Christian Biesinger <cbiesinger@google.com>
Gerrit-CC: Simon Marchi <simon.marchi@polymtl.ca>
Gerrit-Comment-Date: Thu, 31 Oct 2019 19:53:25 +0000
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