ECE 209 C Preprocessor

The C preprocessor, generally called cpp, transforms your code before passes it to the C compiler.

The C preprocessor
Removes most comments, but adds a few giving the name of files and line numbers within files. The C compiler uses these when generating error messages. Before After
Allows the splitting of long lines. Before After
Substitutes for trigraphs if you ask. Before After
Allows the definition of manifest constants. Before After
Allows the use of macros. Before After
Allows the use of useful macros, if you add in enough parentheses. Before After
Stringizes. Before After
Glues. Before After
Reads your include files. Before After
Reads the standard include files. Before After
"Branches" according to what is defined are by values of constants. Before After
Has a common technique, wrapper #ifndef or #include guard, or macro guard , for avoiding multiple inclusion of include files. Before After
Allows complicated tests on integers for branches. Before After
Has some preloaded macros specified by ANSI C standard. Before After
Can stop compilation when something is wrong. For example
Can define complex statements, if you work at in Before After
Makes C++ happy to use your C For example
Allows a variable number of arguments in C99 Before After
Knows about the #pragma, as in Open MP For example
Allows instructors to figure out the answers Before After