Preprocessing Operations
Preprocessing carries out the following
operations on your program source files:
- New-line characters are introduced as
needed to replace system-dependent end-of-line
characters, and other system-dependent character-set
translations are performed as needed. Trigraph sequences
are replaced by equivalent single characters.
- Each \ (backslash) followed by a new-line
character is deleted, and the next source line is
appended to the line that contained the backslash.
- The source text is decomposed into
preprocessing tokens tokens and sequences of white space.
A single white space replaces each comment. A source file
cannot end with a partial token or comment.
- Preprocessing directives are run, and
macros are expanded.
- Escape sequences in character constants
and string literals are replaced by their equivalent
values.
- Adjacent string literals are concatenated.
The rest of the compilation process operates on
the preprocessor output, which is syntactically and semantically
analyzed and translated, and then linked as necessary with other
programs and libraries.

Preprocessor
Directives
Preprocessor Macros
Conditional
Compilation Directives

Source Program Character Set