Modify core.stdc.stdlib.d is missing some type definitions for wasm32-unknown-unknown-wasm target #4673

[Sticky-fingerz]

When import core.stdc.stdlib.d (for example,to use malloc) in wasm project and build next command

ldc2 -c -betterC -mtriple=wasm32-unknown-unknown-wasm src/wasmproject.d  

these errors ocuured.

C:\ldc2\bin\..\import\core\stdc\stdlib.d(73): Error: undefined identifier `c_long`
C:\ldc2\bin\..\import\core\stdc\stdlib.d(74): Error: undefined identifier `c_long`
C:\ldc2\bin\..\import\core\stdc\stdlib.d(112): Error: undefined identifier `c_long`
C:\ldc2\bin\..\import\core\stdc\stdlib.d(121): Error: undefined identifier `c_long`
C:\ldc2\bin\..\import\core\stdc\stdlib.d(125): Error: undefined identifier `c_ulong`
C:\ldc2\bin\..\import\core\stdc\stdlib.d(202): Error: undefined identifier `c_long`
C:\ldc2\bin\..\import\core\stdc\stdlib.d(209): Error: undefined identifier `c_long`
C:\ldc2\bin\..\import\core\stdc\stdlib.d(209): Error: undefined identifier `c_long`
C:\ldc2\bin\..\import\core\stdc\stdlib.d(217): Error: undefined identifier `wchar_t`, did you mean `dchar`? 
C:\ldc2\bin\..\import\core\stdc\stdlib.d(221): Error: undefined identifier `wchar_t`, did you mean `dchar`? 
C:\ldc2\bin\..\import\core\stdc\stdlib.d(223): Error: undefined identifier `wchar_t`, did you mean `dchar`? 

These problems solved by adding type definitions to the three files (config.d,stddef.d,stdlib.d) in the binary directory(ldc\import\core\stdc).

config.d

Add to line 135 
else version (WebAssembly)
{
    static if ( (void*).sizeof > int.sizeof )
    {
        enum __c_longlong  : long;
        enum __c_ulonglong : ulong;

        alias long  c_long;
        alias ulong c_ulong;

        alias long   cpp_long;
        alias ulong  cpp_ulong;

        alias __c_longlong  cpp_longlong;
        alias __c_ulonglong cpp_ulonglong;
    }
    else
    {
        enum __c_long  : int;
        enum __c_ulong : uint;

        alias int   c_long;
        alias uint  c_ulong;

        alias __c_long   cpp_long;
        alias __c_ulong  cpp_ulong;

        alias long  cpp_longlong;
        alias ulong cpp_ulonglong;
    }
}

stddef.d

Add to line 32
else version (WebAssembly)
{
    ///
    alias dchar wchar_t;
}

stdlib.d

Add to line 105
else version (WebAssembly) enum RAND_MAX = 0x7fffffff;

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[dkorpel]

WebAssembly doesn't define these C types or malloc, are you using WASI? In that case, compiling with -mtriple=wasm32-unknown-unknown-wasi should work, as there are version(WASI) blocks. If not, then where did you get these type definitons from?

[Sticky-fingerz]

In fact, I don't really understand,but I wanted to develop wasm game with raylib and dlang.
At first, to use ldc2, my game source compile to wasm object(index.o) ,
and to link index.o and libraylib.a by emscripten created index.wasm.
This approach worked for zig,odin and rust.
this is my command.

ldc2 -c -betterC -mtriple=wasm32-unknown-unknown-wasm src/hello.d  --od=dist
emcc -o dist/index.html dist/index.o libs/libraylib.a -s USE_GLFW=3 -s ASYNCIFY --preload-file resources

This approach seems to be working in my game.
Is emscripten's malloc being called?

[Sticky-fingerz]

By the way,I didn't realize it until you mentioned it.
I tried "-mtriple=wasm32-unknown-unknown-wasi" and it worked.　
Maybe it's better to remove this PR?

[dkorpel]

Is emscripten's malloc being called?

Yes, emscripten provides a C runtime with the right JavaScript hooks IIRC

Maybe it's better to remove this PR?

While I do wish D supported WebAssembly better out of the box, I don't think this PR is correct, so I'll close it.

[JohanEngelen]

@Sticky-fingerz Note -mtriple=wasm32-unknown-unknown-emscripten does not set version(WASI) but does set version(Emscripten), so I think still this work needed (with adjustment).

[Sticky-fingerz]

I tried the above commit with changeing version(WebAssembly) → version(Emscripten) and build with
"-mtriple=wasm32-unknown-unknown-emscripten",
but it didn't work with same errors.
It's a mystery,when I build
"-mtriple=wasm32-unknown-unknown-emscripten"
with the above commit(version(WebAssembly)), it worked.
If I develop game with wasi and a problem occurs, i might commit version(Emscripten), but I don't know if I can solve it.

[JohanEngelen]

@kassane Can you give a hand here? :) thanks!

@Sticky-fingerz -mtriple=wasm32-unknown-unknown-emscripten requires LDC master, it's not released yet.

[kassane]

@kassane Can you give a hand here?

Hi @Sticky-fingerz,

WiP ldc2-1.39/2.109.0: wasm32-unknown-emscripten simplifies linking with emcc-libc, preferably with LTO enabled.

You could also try using wasm32-unknown-unknown-wasm with tinyd-rt (based on arsd-webassembly).

References

• WebAssembly: doesn't support emscripten data layout ldc-developers/ldc#4670
• https://github.com/KitsunebiGames/tinyd-rt

[Sticky-fingerz]

@JohanEngelen　I understood.thanks.
@kassane 　Thank you for the information.