CL.EXE Input Files

A command-line token that does not begin with a hyphen, forward slash or @ sign (and, exceptionally, is not an argument for some earlier option) names an input file. CL recognises several types of input file. The type is ordinarily inferred from the (case-insensitive) extension in the name as given.

However, this inference of the type from the file extension is abandoned under the influence of the /TC, /TO and /TP options, which each set one type (C source file, object file and C++ source file, respectively) for all input files that are named in their own command-line tokens, whatever the file extensions.

An input file can also be named through the /Tc, /To or /Tp options, with the file type then being implied by the option (C source file, object file or C++ source file, respectively).

An input file whose type is not decided by the above rules is ordinarily treated as an object file, after a warning (D4024). However, if the compiler is limited to pre-processing because of a /E or /EP option (though not the otherwise closely related /P), unrecognised input files are instead treated as C source files, with no warning.

Compiler Modules

Each of the different types of input file has a different selection of compiler modules (including the linker) that can be involved with the file.

Under the action of various compiler options (/B1_5, /BK, /c, /E, /EP, /P, /Zg, /Zs and /ZX), one or more modules can be disabled. If it turns out that the modules wanted for working with some input file are all disabled, the file is ignored after a warning (D4027).