Best GCC warning flags for compiling C++
Share on Mastodon
A recent discussion on ACCU-general gave people an opportunity to share the warning flags they like to use with g++.
I thought I’d write down the consensus as I understood it, mainly for my own reference:
-Wredundant-decls -Wcast-align -Wmissing-declarations -Wmissing-include-dirs -Wswitch-enum -Wswitch-default -Wextra -Wall -Werror -Winvalid-pch -Wredundant-decls -Wmissing-prototypes -Wformat=2 -Wmissing-format-attribute -Wformat-nonliteral
We were advised by Jonathan Wakely that -Weffc++ is not very useful since it is mostly based on the first edition of the book Effective C++, many of whose recommendations were improved in the second edition, and also apparently GCC doesn’t do a great job of warning about them.
Update: thanks to an article[1] by Roger Orr in CVu these flags are highly recommended in GCC 5.2+:
-flto -Wodr
[1] Orr, Roger “One Definition Rule“, in CVu Volume 27, Issue 5 p16 (editor: Steve Love)
Thanks Andy,
Would be nice to have each one linked to the right spot in the documentation [1], but that seems unsupported.
What advised the ordering of this list?
cheers,
Martin
[1] e.g. http://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html, -Wcast-align
Hi Martin, I don’t think the order matters does it? I just copied in from people’s emails in the order I found them…
Hi Andy,
The compiler probably cares less :)
-Wall
-Wcast-align
-Werror
-Wextra
-Wformat-nonliteral
-Wformat=2
-Winvalid-pch
-Wmissing-declarations
-Wmissing-format-attribute
-Wmissing-include-dirs
-Wmissing-prototypes
-Wredundant-decls
-Wredundant-decls
-Wswitch-default
-Wswitch-enum
-Wredundant-decls is duplicated