Bug 18393 – REG(v2.078.1=>master) function re-declarations causes conflict, but should not

``` void fun(); void fun(); ``` dmd -o- main.d DMD64 D Compiler v2.078.1 => ok DMD64 D Compiler v2.078.2-beta.1-653-g7e8bea0e8-dirty => Error: function test_all.fun() conflicts with previous declaration at main.d(20)

NOTE: it's in git master(git rev-parse HEAD 7e8bea0e83314f39b8c8b2bddbfbff2b0bdee74d) not in 2.078.2

on a vaguely related note: ``` void fun_bad3(T)(T a); void fun_bad3(T)(T a){} void test(){ fun_bad3(1); } ``` Error: test_all.fun_bad3 called with argument types (int) matches both: main.d(11): test_all.fun_bad3!int.fun_bad3(int a) and: main.d(12): test_all.fun_bad3!int.fun_bad3(int a) is that intended that only functions can be pre-declared, but not function templates?

It's not a bug, it's a feature - https://github.com/dlang/dmd/pull/7577 A lot better than the segfaults or silent errors you got before. DMD never supported this. I just didn't complain loudly to you before. > on a vaguely related note: That's a different issue. Please open a new issue ;-)

I'm confused: https://github.com/dlang/dmd/pull/7577/files says: Issue 14147 - Compiler crash on identical functions in a single module the bugs this fixes are cases of multiply defined functions, not multiply declared functions: in your eg in https://github.com/dlang/dmd/pull/7577/files: the bug i'm reporting below is multiply declared functions: ``` void fun(); void fun(); ``` why would this be OK: ``` void f1(); void f1() {} ``` but not this: ``` void f1(); void f1(); void f1() {} ``` ?

probably related to this PR: https://github.com/dlang/dmd/pull/7577/files#diff-3084a264389e086215b36670ae9f4a3dR392 snippet: /* Allow the hack that is actually used in druntime, + * to ignore function attributes for extern (C) functions. + * TODO: Must be reconsidered in the future. + * BUG: https://issues.dlang.org/show_bug.cgi?id=18206 + * + * extern(C): + * alias sigfn_t = void function(int); + * alias sigfn_t2 = void function(int) nothrow @nogc; + * sigfn_t bsd_signal(int sig, sigfn_t func); + * sigfn_t2 bsd_signal(int sig, sigfn_t2 func) nothrow @nogc; // no error + */ why would extern(C) be allowed to redeclare but not extern(C++)? from looking at druntime it shows: ``` extern(C): sigfn_t bsd_signal(int sig, sigfn_t func); sigfn_t2 bsd_signal(int sig, sigfn_t2 func); ``` indeed, `bsd_signal` is being redeclared... not sure i understand the details of why that’s needed but I don’t understand why extern(C++) would differ from extern(C)

Sorry about eagerly closing this. It seems that the following use shouldn't trigger the error. Multiple declaration of the same type if they both have no body.

I cannot reproduce the original bug example. Is this still valid? If not please close it.

I can't reproduce the problem.