Re: protected alloca class for malloc fallback

[Aldy Hernandez <aldyh at redhat dot com>]

On 08/05/2016 04:07 PM, Richard Biener wrote:
> On August 5, 2016 8:15:54 PM GMT+02:00, Oleg Endo <oleg.endo@t-online.de> wrote:
> > On Fri, 2016-08-05 at 19:55 +0200, Richard Biener wrote:
> >
> > > Please don't use std::string.  For string building you can use
> > > obstacks.
> >
> > Just out of curiosity ... why?  I remember there was some discussion
> > about it, what was the conclusion?  Is that now a general rule or does
> > it depend on the context where strings are used?
>
> Because you make a messy mix of string handling variants.  Std::string is not powerful enough to capture all uses, it is vastly more expensive to embed into structs and it pulls in too much headers.
> (Oh, and I hate I/o streams even more)

Oh, and there is prior use in ipa-chkp.c, although I suppose it could've 
crept in:

  std::string s;

  /* called_as_built_in checks DECL_NAME to identify calls to
     builtins.  We want instrumented calls to builtins to be
     recognized by called_as_built_in.  Therefore use original
     DECL_NAME for cloning with no prefixes.  */
  s = IDENTIFIER_POINTER (DECL_NAME (fndecl));
  s += ".chkp";
  DECL_NAME (new_decl) = get_identifier (s.c_str ());

You can't tell me obstacks are easier on the eyes for this ;-).

Aldy