Issue on linux/arm64

[TurkeyMan]

Does anyone have any idea why I see this only on arm64 linux?

/opt/hostedtoolcache/ldc2/1.42.0/arm64/ldc2-1.42.0-linux-aarch64/bin/../import/core/stdc/stdio.d(1363): Error: undefined identifier `__va_list`, did you mean alias `va_list`?
        int vfprintf(FILE* stream, scope const char* format, va_list arg);
            ^
/opt/hostedtoolcache/ldc2/1.42.0/arm64/ldc2-1.42.0-linux-aarch64/bin/../import/core/stdc/stdio.d(1363): Error: `pragma(printf)` function `vfprintf` must have signature `int vfprintf([parameters...], const(char)*, va_list)`
        int vfprintf(FILE* stream, scope const char* format, va_list arg);
            ^
/opt/hostedtoolcache/ldc2/1.42.0/arm64/ldc2-1.42.0-linux-aarch64/bin/../import/core/stdc/stdio.d(1366): Error: `pragma(scanf)` function `__isoc99_vfscanf` must have signature `int __isoc99_vfscanf([parameters...], const(char)*, va_list)`
        int __isoc99_vfscanf(FILE* stream, scope const char* format, va_list arg);
            ^
/opt/hostedtoolcache/ldc2/1.42.0/arm64/ldc2-1.42.0-linux-aarch64/bin/../import/core/stdc/stdio.d(1371): Error: `pragma(printf)` function `vsprintf` must have signature `int vsprintf([parameters...], const(char)*, va_list)`
        int vsprintf(scope char* s, scope const char* format, va_list arg);
            ^
/opt/hostedtoolcache/ldc2/1.42.0/arm64/ldc2-1.42.0-linux-aarch64/bin/../import/core/stdc/stdio.d(1374): Error: `pragma(scanf)` function `__isoc99_vsscanf` must have signature `int __isoc99_vsscanf([parameters...], const(char)*, va_list)`
        int __isoc99_vsscanf(scope const char* s, scope const char* format, va_list arg);
            ^
/opt/hostedtoolcache/ldc2/1.42.0/arm64/ldc2-1.42.0-linux-aarch64/bin/../import/core/stdc/stdio.d(1379): Error: `pragma(printf)` function `vprintf` must have signature `int vprintf([parameters...], const(char)*, va_list)`
        int vprintf(scope const char* format, va_list arg);
            ^
/opt/hostedtoolcache/ldc2/1.42.0/arm64/ldc2-1.42.0-linux-aarch64/bin/../import/core/stdc/stdio.d(1382): Error: `pragma(scanf)` function `__isoc99_vscanf` must have signature `int __isoc99_vscanf([parameters...], const(char)*, va_list)`
        int __isoc99_vscanf(scope const char* format, va_list arg);
            ^
/opt/hostedtoolcache/ldc2/1.42.0/arm64/ldc2-1.42.0-linux-aarch64/bin/../import/core/stdc/stdio.d(1607): Error: `pragma(printf)` function `vsnprintf` must have signature `int vsnprintf([parameters...], const(char)*, va_list)`
        int  vsnprintf(scope char* s, size_t n, scope const char* format, va_list arg);
             ^

[thewilsonator]

The first one is presumably the cause of the other issues. I see no uses of __va_list in that file. va_list should be https://github.com/ldc-developers/ldc/blob/master/runtime/druntime/src/core/stdc/stdarg.d#L133 that alias

[TurkeyMan]

Not clear why the error even appears though; it doesn't reference any line of my own code, and I never import those druntime modules as far as I can tell (unless there's something implicit somewhere).

Maybe it's this:

extern(C) int snprintf(const char*, const size_t, const char*, ...) pure nothrow @nogc;

I do call that in one place; just prototype the C function, how does the implementation handle the ... in that C declaration?

[kinke]

This probably stems from the frontend check:

ldc/dmd/funcsem.d

Lines 3796 to 3799 in c8305d0

	bool isVa_list(Parameter p)
	{
	return p.type.equals(target.va_listType(funcdecl.loc, sc));
	}

for Linux AArch64 calling

ldc/gen/abi/aarch64.cpp

Lines 158 to 162 in c8305d0

	// We need to pass the actual va_list type for correct mangling. Simply
	// using TypeIdentifier here is a bit wonky but works, as long as the name
	// is actually available in the scope (this is what DMD does, so if a
	// better solution is found there, this should be adapted).
	return TypeIdentifier::create(Loc(), Identifier::idPool("__va_list"));

which depends on

ldc/runtime/druntime/src/object.d

Lines 104 to 105 in c8305d0

	else version (AArch64)
	public import core.internal.vararg.aarch64 : __va_list;

A testcase would obviously be helpful.