• Sebastian Trent (11/11) Jan 11 2018 Hello,
• Adam D. Ruppe (10/18) Jan 11 2018 Same way you would in C itself: instruct the linker to use your

Sebastian Trent <null null.com> writes:

Hello,

I'm writing an operating system in D for some exotic hardware. I 
understand the D runtime environment depends on a C stdlib being 
available (at compile time or run time?)

As a consequence of the hardware, I need to use our own C std lib 
for the operating system. How can I set about directing the 
compiler (or run-time) to non-default implementation?

Alternatively, I infer there's nothing breaking about replacing 
all of core.stdc with an implementation written in -betterC?

Thanks,


ST.

Adam D. Ruppe <destructionator gmail.com> writes:

On Friday, 12 January 2018 at 03:21:15 UTC, Sebastian Trent wrote:
 I'm writing an operating system in D for some exotic hardware. 
 I understand the D runtime environment depends on a C stdlib 
 being available (at compile time or run time?)

both

 As a consequence of the hardware, I need to use our own C std 
 lib for the operating system. How can I set about directing the 
 compiler (or run-time) to non-default implementation?

Same way you would in C itself: instruct the linker to use your 
runtime instead. On Linux, something like `-L-nostdlib 
-L-lmy_c_library` should do it. The -L option to dmd passes the 
rest of the option down to the linker (gcc, which then passes it 
to ld), so that `-nostdlib` flag is actually one of gcc's.

 Alternatively, I infer there's nothing breaking about replacing 
 all of core.stdc with an implementation written in -betterC?

core.stdc has no code per se, it is just function prototypes to 
access the C library. The C library itself is provided externally 
by the linker.