I have never programmed in Windows, so I don't quite understand how to link the library correctly. I have a compiled Postgres library from under mingw. There is both a static library *.a and a dynamic library *.dll. I don't understand how to compile my project correctly at all. I tried to do everything through dub first.json, then I realized that the idea was too rash and decided to compile a simple project through the CLI. In the end , here 's what happened:

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

After Googling a bit, I came across this page. Do I really need to rewrite the header of the Postgres library to use it in my project?

Do I need to list all the functions called from the library? Or is there a way to somehow attach it in a more civilized way through a simple dmd?

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

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 is usable with PostgreSQL. In addition, there are some bindings in the dub registry https://code.dlang.org/search?q=PostgreSQL.

On Saturday, 4 February 2023 at 17:02:11 UTC, Ferhat Kurtulmuş wrote:

I can't link to the library *.a and I don't understand why?

PS C:\sources\pxe-restore\source> dmd -i app.d C:\msys64\home\user\postgresql-15.1\installed\mingw64\lib\libpq.a
Error: unrecognized file extension a

Is there any way to convert the library dll to lib? Without using Visual Studio?

On Saturday, 4 February 2023 at 17:02:11 UTC, Ferhat Kurtulmuş wrote:

At this stage, everything is fine. I'm using a project that I build on Linux without any problems. All connections are set up there.

On Saturday, 4 February 2023 at 15:56:41 UTC, Richard (Rikki) Andrew Cattermole wrote:

I don't understand why the compiler doesn't see the library.

User@WIN-D3SHRBHN7F6 MINGW64 /home/user/pxe-restore/source
# ls -la "C:\Program Files\PostgreSQL\15\lib\libpq.lib"
-rw-r--r-- 1 User Отсутствует 37002 Nov  9 06:45 'C:\Program Files\PostgreSQL\15\lib\libpq.lib'

User@WIN-D3SHRBHN7F6 MINGW64 /home/user/pxe-restore/source
# dmd -i app.d -L'C:\Program Files\PostgreSQL\15\lib\libpq.lib'
lld-link: error: could not open 'pq.lib': no such file or directory
Error: linker exited with status 1

On Sunday, 5 February 2023 at 11:52:01 UTC, Alexander Zhirov wrote:

User@WIN-D3SHRBHN7F6 MINGW64 /home/user/pxe-restore/source
# ls -la "C:\Program Files\PostgreSQL\15\lib\libpq.lib"
-rw-r--r-- 1 User Отсутствует 37002 Nov  9 06:45 'C:\Program Files\PostgreSQL\15\lib\libpq.lib'

User@WIN-D3SHRBHN7F6 MINGW64 /home/user/pxe-restore/source
# dmd -i app.d -L'C:\Program Files\PostgreSQL\15\lib\libpq.lib'
lld-link: error: could not open 'pq.lib': no such file or directory
Error: linker exited with status 1

try

dmd -i app.d -L'-LC:\Program Files\PostgreSQL\15\lib' -Llpq

the first linker command gives a search path, the second a libname.

On Sunday, 5 February 2023 at 13:37:16 UTC, user1234 wrote:

dmd -i app.d -L'-LC:\Program Files\PostgreSQL\15\lib' -Llpq

It doesn't work

C:\sources\pxe-restore\source>dmd -i app.d -L'-LC:\Program Files\PostgreSQL\15\lib' -Llpq
Error: cannot find input file `Files\PostgreSQL\15\lib'.d`
import path[0] = C:\D\dmd2\windows\bin64\..\..\src\phobos
import path[1] = C:\D\dmd2\windows\bin64\..\..\src\druntime\import

C:\sources\pxe-restore\source>dmd -i app.d -L'-L"C:\Program Files\PostgreSQL\15\lib"'
LINK : fatal error LNK1104: не удается открыть файл "'-LC:\Program Files\PostgreSQL\15\lib'.obj"
Error: linker exited with status 1104

C:\sources\pxe-restore\source>dmd -i app.d -L-L'C:\Program Files\PostgreSQL\15\lib'
Error: cannot find input file `Files\PostgreSQL\15\lib'.d`
import path[0] = C:\D\dmd2\windows\bin64\..\..\src\phobos
import path[1] = C:\D\dmd2\windows\bin64\..\..\src\druntime\import

On Monday, 6 February 2023 at 05:20:33 UTC, Richard (Rikki) Andrew Cattermole wrote:

For some reason, the obj file is link instead of the library.

C:\sources\pxe-restore\source>dmd -L'-LC:\Program\ Files\PostgreSQL\15\lib' -Llpq -i app.d
Error: cannot find input file `Files\PostgreSQL\15\lib'.d`
import path[0] = C:\D\dmd2\windows\bin64\..\..\src\phobos
import path[1] = C:\D\dmd2\windows\bin64\..\..\src\druntime\import

C:\sources\pxe-restore\source>dmd -L'-L"C:\Program\ Files\PostgreSQL\15\lib"' -Llpq -i app.d
LINK : fatal error LNK1104: не удается открыть файл "'-LC:\Program\ Files\PostgreSQL\15\lib'.obj"
Error: linker exited with status 1104