The following complete program succeed when run with no arguments. What it should do is fail on the second assert. extern(C) void main(string[] args) { import core.stdc.stdio: printf; assert(args.length == 1); assert(args[0].ptr == null); } When 'extern(C)' is removed, this code fails as args[0] contains the path used to invoke the program, as provided by the OS. I noticed this when trying to write an extremely simple C program in D, with -betterC, where I spent more than 20 minutes being perplexed by 'impossible' NULL dereferences. The behavior comes with the extern(C) however, and doesn't require a -betterC flag. This behavior is observed with LDC 1.15.0 and DMD64 D Compiler v2.086.1, and with the nightly DMD build of v2.089.0-rc.1-master-2bbd37b extern(C) void main(int argc, char **argv) works fine, but I argue if string[] args isn't supported, compilation should fail with an error instead of providing the current behavior.
I don't think straight up erroring is a good idea. extern(C) void main(string[]) is perfectly *valid*; I don't think the language says anything special about the type of extern(C) main. However I do agree that, with the current behaviour, errors such as yours are likely to occur. Proposal: make it a warning with a 'did you mean (int argc, char **argv)?' which also notes that if you really do want that behaviour you can silence the warning with pragma(mangle, "main") void cmain(string[])
(In reply to elronnd from comment #1) > I don't think straight up erroring is a good idea. extern(C) void > main(string[]) is perfectly *valid*; I don't think the language says > anything special about the type of extern(C) main. The spec says nothing about extern(C) main at all. https://dlang.org/spec/function.html#main As far as its concerned it should be invalid. https://issues.dlang.org/show_bug.cgi?id=20378
this has been fixed by https://github.com/dlang/dmd/pull/13749
*** This issue has been marked as a duplicate of issue 22831 ***