On 16 July 2014 21:03, Johannes Pfau via D.gnu <d.gnu@puremagic.com> wrote: > Am Wed, 16 Jul 2014 15:35:09 +0100 > schrieb "Iain Buclaw via D.gnu" <d.gnu@puremagic.com>: > >> On 16 July 2014 15:12, Mike via D.gnu <d.gnu@puremagic.com> wrote: >> > On Wednesday, 16 July 2014 at 13:52:57 UTC, Mike wrote: >> >> >> >> I received a question from Dicebot in at the end of my >> >> presentation. He asked about the --gc-sections linker flag >> >> breaking code from GDC. >> >> >> >> I recently discovered how one can see why this is occurring, and I >> >> hope this will help identify the problem and lead to a solution. >> >> >> >> Compile any simple hello world program with the following gcc >> >> command: gcc --verbose -Wl,--verbose test.c. >> >> >> >> Part of the output is GCC's internal linker script as shown >> >> below. I believe this is the source of the problem. Here's my >> >> theory. >> >> >> >> D is not C, and is likely generating code that the GCC internal >> >> linker script doesn't know about. This code may be incorrectly >> >> identified as dead code because there is no 'link' to it and, >> >> therefore, appears unused. If D or GDC is generating any code >> >> like this, it needs to be marked as KEEP in the linker script. >> >> You can see examples of this in GCC's internal linker script below. >> >> >> >> If my theory is correct, GDC may have to make an internal linker >> >> script specifically for D's code generation that marks such code >> >> as KEEP. >> >> >> >> I hope I'm not just blowing smoke. >> >> >> >> Mike >> > >> > >> > And I just checked with GDC... >> > gdc --verbose -Wl,--verbose test.d >> > >> > ... and the internal linker script is exactly the same as the C >> > version. That doesn't seem right to me. I would expect them to be >> > at least a little different. >> > >> > Mike >> >> Using a D-specific linker script in is outside the scope of GDC >> itself. I'd have to make a patch to Binutils. >> >> And yes, a bespoke linker script would solve many problems that are >> currently managed by the compiler. >> >> Regards >> Iain > > Please don't start working on a D specific linker script, cause I'm > already working on that ;-) I've only done moduleinfo so far, but TLS > is next, then shared library support.
I wish I could clone you.
