Thanks for clarifying this. If the toolchain is not based on GCC, you can simply create a custom Makefile for building your code and import it into VisualGDB as an externally built project. This way VisualGDB will simply invoke make with the specified arguments to build the project and won’t care that the underlying tools are not based on GCC. If the tools report error messages in a non-typical way, you can tweak VisualGDB to recognize them by editing %VISUALGDB_DIR%\Rules\RegularExpressions.xml.
On the debugging side, if the vendor provides a gdb executable for their platform, you can use VisualGDB to debug the code by overriding the gdb path via VisualGDB Project Properties. If they use a completely proprietary debugging protocol, we can still add support for it as a custom paid feature, but it would be a rather complex one.