Cross Compiler

[Jeroen Bollen]

On Tuesday, 4 March 2014 at 01:22:15 UTC, Adam D. Ruppe wrote:
> On Monday, 3 March 2014 at 19:03:20 UTC, Jeroen Bollen wrote:
>> Just realized that's probably the missing runtime. Why does it 
>> need a runtime though? It's just returning.
>
> There's some hidden references to the runtime outputted, 
> especially when you write a D main, which adds references to 
> d_run_main and other such stuff.
>
> If you make it an extern(C) main instead of a regular D main, 
> it gets rid of some of that, but it will still complain about 
> the d_dso_registry thing (at least on Linux).
>
> You can add a dummy "extern(C) void _d_dso_registry() {}" to it 
> to hack past that too, but you probably shouldn't - going 
> without the runtime is a fair amount of work for little 
> practical benefit, though it can be pretty educational.
>
> The definition of this function in druntime is 
> src/rt/sections_linux.d
>
> From that file:
>
> /* For each shared library and executable, the compiler 
> generates code that
>  * sets up CompilerDSOData and calls _d_dso_registry().
>  * A pointer to that code is inserted into both the .ctors and 
> .dtors
>  * segment so it gets called by the loader on startup and 
> shutdown.
>  */
> extern(C) void _d_dso_registry(CompilerDSOData* data)

What does the runtime actually do?