Add GCC options to top of C source file

Question

Is is possible to put something at the top of the C source file, like

// GCC_OPTIONS=-g,-Wall

that will add those options automatically to gcc every time you compile this file?

Answer 1

Yes it is, at least for some flags. You can push and pop diagnostic settings like this:

#pragma GCC diagnostic error "-pedantic"
#pragma GCC diagnostic warning "-Wall"

This is also possible for optimization levels on a per-function level:

#pragma GCC optimize ("string"...)

These #pragma definitions affect all code after them in a source file.

See these other questions for more information:

• Switching off optimization for a specific function in gcc 4.2.2
• Selectively disable GCC warnings for only part of a translation unit?

Answer 2

No. Some compiler options have #define equivalents, but not those. This belongs in your make file (or equivalent). With GNU Make:

CFLAGS += -g -Wall