In a Visual Studio project with assembler source code files, Yasm settings are entered in the “Yasm Assembler” item in the projects Property Dialogue. The items available correspond with those available on Yasm’s command line and are mostly self explanatory but one item--“Object Filename”--does need further explanation.

If the “Object Filename” item refers to a directory (the default), MSBUILD will collect all the assembler files in the project together as a batch and invoke VSYASM in multiple file mode. In order to assemble files one at a time it is necessary to change this to the name of an output file such as, for example, “$(IntDir)%(Filename).obj”.