https://issues.dlang.org/show_bug.cgi?id=24276

          Issue ID: 24276
           Summary: ImportC: typedef aliases not emitted correctly in .di
                    files
           Product: D
           Version: D2
          Hardware: x86
                OS: Mac OS X
            Status: NEW
          Severity: normal
          Priority: P1
         Component: dmd
          Assignee: nobody@puremagic.com
          Reporter: mail@tomaskral.sk

Consider the following C file with a typedef alias:

// hmm.c
typedef union hmm_vec2
{
     struct { float X, Y; };
     float Elements[2];
} hmm_vec2;
typedef hmm_vec2 hmm_v2;

used in a D program:

// main.d
import hmm;
void main() {
  hmm_v2 v2 = { X: 1, Y: 2 };
}

Compiling both files in a single pass, without emitting the .di file, i.e.:

$ dmd main.d hmm.c

works fine.

But doing it by generating hmm.o and hmm.di first, and then linking the program, fails:

$ dmd -c hmm.c -Hf=hmm.di
$ dmd main.d hmm.o
hmm.di(13): Error: union `hmm.hmm_vec2` conflicts with union `hmm.hmm_vec2` at
hmm.di(4)

The emitted .di file looks like this:

extern (C)
{
        union hmm_vec2
        {
                struct
                {
                        float X = void;
                        float Y = void;
                }
                float[2] Elements = void;
        }
        union hmm_vec2;
...

The second union is incorrect; it should have been the typedef alias

alias hmm_v2 = hmm_vec2;

instead.

--