compile: link dynamic OR static library in Windows

[Ferhat Kurtulmuş]

On Saturday, 4 February 2023 at 15:52:33 UTC, Alexander Zhirov 
wrote:

> PS C:\sources\pxe-restore\source> dmd -i app.d 
> -LC:\msys64\home\user\postgresql-15.1\installed\mingw64\lib\libpq.dll
> lld-link: error: 
> C:\msys64\home\user\postgresql-15.1\installed\mingw64\lib\libpq.dll: bad file type. Did you specify a DLL instead of an import library?
> lld-link: error: could not open 'pq.lib': no such file or 
> directory
> Error: linker exited with status 1

> through a simple `dmd`?

On Windows, dub's default behavior is to search for "foo.lib", 
usually compiled with Visual Studio C/C++ compilers. However, you 
have mingw-compiled "libfoo.a". I would not use MinGW-compiled 
libs with d compilers. I don't know how d compilers improved to 
support it, but in the past, I experienced ABI compatibility 
issues with d and MinGW.

I took a quick look at https://www.postgresql.org/download/. When 
I tried to download, I saw that the archive contained *.lib 
files. So, why don't you use them?

you will also need definitions of the functions in your d code 
like `extern(C) void fooDB();`. I am not sure how 
[importC](https://dlang.org/spec/importc.html) is usable with 
PostgreSQL. In addition, there are some bindings in the dub 
registry https://code.dlang.org/search?q=PostgreSQL.