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
