www.digitalmars.com         C & C++   DMDScript  

D.gnu - Can the runtime be disabled in GDC?

reply "Mike" <none none.com> writes:
I finally got a GDC cross-compiler compiled, and I'm currently 
trying to test it.  My simple "hello world" program does not use 
any D runtime features, and I was able to compile it with LDC 
-noruntime -nodefaultlib.

However, when I try to use GDC, I get...

"cannot find source code for runtime library file 'object.d'"

Are there similar options in GDC to disable the D runtime, or 
will I have to write stubs?

And, does GDC have any D-specific options?

Thanks,
Mike
Dec 01 2013
next sibling parent Iain Buclaw <ibuclaw gdcproject.org> writes:
On Dec 1, 2013 8:25 AM, "Mike" <none none.com> wrote:

 I finally got a GDC cross-compiler compiled, and I'm currently trying to


test it.  My simple "hello world" program does not use any D runtime
features, and I was able to compile it with LDC -noruntime -nodefaultlib.

 However, when I try to use GDC, I get...

 "cannot find source code for runtime library file 'object.d'"

 Are there similar options in GDC to disable the D runtime, or will I have


to write stubs?

 And, does GDC have any D-specific options?


You will require at least an object.d file to provide stubs - minilibd
sbould be sufficient IIRC.

There is -nodefaultlibs, or -nostdlib (which bypasses libgcc also).
However, the compiler may generate calls to memcmp, memset, memcpy and
memmove.  So these should be provided for if you are not linking against
some sort of libc.

If you are linking against libc, and just don't want phobos, then there is
-nophoboslib.  This will also omit linking to druntime as currently there
are bundled as one library.

You also have -nostartfiles if you wish to also provide for the
crtstart.o/crtend.o startup files.

Currently there is no way to interface with dmd's -betterC switch. So if
you don't want moduleinfo tidbits to be written, then you'll have to patch
the compiler (d-lang.cc: d_init_options) - I can of course get this in as
soon as possible .  I'm not sure of ldc's -noruntime switch, but I am going
to assume its functionality and say there is no equivalent in gdc.  What
would be nice though is a warning on any operations that cause implicit
allocation/external calls.

Regards
-- 
Iain Buclaw

*(p < e ? p++ : p) = (c & 0x0f) + '0';
Dec 01 2013
prev sibling parent Iain Buclaw <ibuclaw gdcproject.org> writes:
On 1 December 2013 10:17, Iain Buclaw <ibuclaw gdcproject.org> wrote:

 On Dec 1, 2013 8:25 AM, "Mike" <none none.com> wrote:

 I finally got a GDC cross-compiler compiled, and I'm currently trying to
 test it.  My simple "hello world" program does not use any D runtime
 features, and I was able to compile it with LDC -noruntime -nodefaultlib.

 However, when I try to use GDC, I get...

 "cannot find source code for runtime library file 'object.d'"

 Are there similar options in GDC to disable the D runtime, or will I have
 to write stubs?

 And, does GDC have any D-specific options?


 You will require at least an object.d file to provide stubs - minilibd
 sbould be sufficient IIRC.

 There is -nodefaultlibs, or -nostdlib (which bypasses libgcc also). However,
 the compiler may generate calls to memcmp, memset, memcpy and memmove.  So
 these should be provided for if you are not linking against some sort of
 libc.

 If you are linking against libc, and just don't want phobos, then there is
 -nophoboslib.  This will also omit linking to druntime as currently there
 are bundled as one library.

 You also have -nostartfiles if you wish to also provide for the
 crtstart.o/crtend.o startup files.

 Currently there is no way to interface with dmd's -betterC switch. So if you


The interface with dmd's -betterC is -fno-emit-moduleinfo

Regards
Iain.
Dec 05 2013