Re: [PATCH 3/4] libbacktrace: work with aslr on windows

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 21 Jan 2023 17:18:14 +0800
> Cc: gcc@hazardy.de, gcc-patches@gcc.gnu.org, gcc@gcc.gnu.org
> From: LIU Hao <lh_mouse@126.com>
> 
> 在 2023-01-21 12:05, Eli Zaretskii via Gcc 写道:
> > I'm not sure I follow the logic.  A program that calls
> > GetModuleHandleW will refuse to start on Windows that doesn't have
> > that API.  So any version before XP is automatically excluded the
> > moment you use code which calls that API directly (i.e. not through a
> > function pointer or somesuch).
> 
> Are _you_ still willing to maintain backward compatibility with Windows 9x? Even mingw-w64 has been 
> defaulting to Windows Server 2003 since 2007. Why would anyone build a modern compiler for such old 
> operating systems?

I'm only saying that we should not deliberately break those old
platforms unless we have a good reason.  And I see no such good reason
in this case: GetModuleHandleA will do the job exactly like
GetModuleHandleW will.

> With any Windows that is modern enough, wide APIs should always be preferred to ANSI ones, 
> especially when the argument is constant. Almost all ANSI APIs (the only exception I know of is 
> `OutputDebugStringA` which does the inverse) translate their ANSI string arguments to wide strings 
> and delegate to wide ones, so by calling wide APIs explicitly, such overhead can be avoided.

The overhead is only relevant in code that is run in performance
critical places.  I don't think this is such a place.