A.2.13 –E

Runs the preprocessor on source files; does not compile.

Directs the CC driver to run only the preprocessor on C++ source files, and to send the result to stdout (standard output). No compilation is done; no .o files are generated.

This option causes preprocessor-type line number information to be included in the output.

A.2.13.1 Examples

This option is useful for determining the changes made by the preprocessor. For example, the following program, foo.cc, generates the output shown in A.2.13.1 Examples

Example A–1 Preprocessor Example Program foo.cc

#if __cplusplus < 199711L
int power(int, int);
#else
template <> int power(int, int);
#endif

int main () {
  int x;
  x=power(2, 10);
}
.

Example A–2 Preprocessor Output of foo.cc Using -E Option

example% CC -E foo.cc
#4 "foo.cc"
template < > int power (int, int);


int main () {
int x;
x = power (2, 10);
}

Warnings

Output of this option might not be usable as input to a C++ compilation if the code contains templates under the "definitions-separate" model.

See also

–P