Thoughts about D

[Michael V. Franklin]

On Monday, 4 December 2017 at 00:25:53 UTC, Michael V. Franklin 
wrote:

> A better solution would be to do what Iain said:
>
>> Try compiling a simple "hello world" with an empty object.d 
>> file.  Then inspect what the compiler does.  Does it error and 
>> exit, or does it ICE?  What can be done to prevent that from 
>> happening?
>
>> When you reach the point that there's no way but to declare a 
>> symbol or function, add that to object.d and then move onto 
>> the next error or ICE.  Repeat until you can compile and link 
>> your program.
>
>> Next, try something a little more complex, such as define a 
>> struct and use it.  Then again address all problems that you 
>> encounter with that.

Here's an illustration:

object.d
----------------------------
module object;

alias immutable(char)[] string;

struct ModuleInfo { }

main.d
-----------------------------
module main;

long sys_write(long arg1, in void* arg2, long arg3)
{
     long result;

     asm
     {
         mov RAX, 1;
         mov RDI, arg1;
         mov RSI, arg2;
         mov RDX, arg3;
         syscall;
     }

     return result;
}

void write(in string text)
{
     sys_write(2, text.ptr, text.length);
}

extern(C) void main()
{
     write("Hello\n");
}

.$> dmd -defaultlib= -debuglib= -conf= main.d -of=main
/usr/bin/ld: main.o: relocation R_X86_64_32 against 
`.rodata.str1.1' can not be used when making a shared object; 
recompile with -fPIC
/usr/bin/ld: final link failed: Nonrepresentable section on output

I didn't compile with -shared.  What's going on here?

.$> dmd -defaultlib= -debuglib= -conf= main.d -of=main -fPIC

main.o:(.text.d_dso_init[.data.d_dso_rec]+0x22): undefined 
reference to `_d_dso_registry'

Again, not sure why the compiler's generated code for that?

Would it help for me to file bugzilla issues for things like 
this?  The reason I haven't thus far, is that this is just a 
symptom of a larger issue.  It needs a development strategy to be 
solved holistically.

Mike