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?

score 10 · Accepted Answer · edited Sep 26 '18 at 18:04

10

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"

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

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

See these other questions for more information:

edited Sep 26 '18 at 18:04

zzxyz

answered Sep 17 '10 at 04:28

Matt Joiner

Neither of these are equivalent to the options he's asking about. – Matthew Flaschen Sep 17 '10 at 12:51
@MatthewFlaschen These settings affect all functions defined later in a source file, so to some extent they can be equivalent: put them on the top and they kind of become global. – Mingye Wang Sep 26 '18 at 17:58
No debug unfortunately it seems: https://stackoverflow.com/questions/2006821/is-there-a-gcc-pragma-to-override-generation-of-debug-info-g-for-some-section – Ciro Santilli Путлер Капут 六四事 Feb 04 '19 at 14:05
Is there a pragma for setting an -f/-fno flag (e.g., ` -fno-ipa-icf`)? – PSkocik Dec 29 '20 at 00:11

score 1 · Answer 2 · answered Sep 17 '10 at 00:28

1

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

CFLAGS += -g -Wall

answered Sep 17 '10 at 00:28

Matthew Flaschen

`-Wall` has an in source equivalent. – Matt Joiner Sep 17 '10 at 12:28
@Matt, what is it? Your answer doesn't give one, and `#pragma GCC diagnostic warning "-Wall"` definitely doesn't work in GCC 4.4. – Matthew Flaschen Sep 17 '10 at 12:49

2 Answers2