CPP: The preprocessor

CPP produces a Often, when the compiler reports an error inside a
list (in a file) macro or an include file, you can get more information
of a C source about what the error is if you can see the include
program in which files or the results of the macro expansions. In many
include files and multi-pass compilers, a separate pass performs this
#define macros work, and the results of the pass can be examined.
have been Since Turbo C++ uses an integrated single-pass compil-
expanded. It is er, we provided CPP to supply the first-pass
not needed for functionality found in other compilers.
normal compil-
ations of C You use CPP just as you would use TCC, the standalone
programs. compiler. CPP reads the same TURBOC.CFG file for
default options, and accepts the same command-line
options as TCC.
The TCC options that don't pertain to CPP are simply
ignored by CPP. To see the list of arguments handled by
CPP, type cpp at the DOS prompt. To see how those
arguments work, see Chapter 5 in the Programmer's
Guide.
With one exception, the file names listed on the CPP
command line are treated like they are in TCC, with
wildcards allowed. The exception to this is that all
files are treated as C source files. There is no
special treatment for .OBJ, .LIB, or .ASM files.
For each file processed by CPP, the output is written
to a file in the current directory (or the output
directory named by the -n option) with the same name as
the source name but with an extension of .I.