-o changes the output filename (I found that using --help)
But I can't find out what -Wall does?
views:
137answers:
4
+8
A:
It's short for "warn all" -- it turns on (almost) all the warnings that g++ can tell you about. Typically a good idea, especially if you're a beginner, because understanding and fixing those warnings can help you fix lots of different kinds of problems in your code.
MatrixFrog
2010-03-09 09:55:55
More warnings (some of which are pretty useful) can be turned on with `-Wextra` and `-pedantic`.
gnud
2010-03-09 09:58:19
There are actually a lot of warnings it doesn't enable (such as nonvirtual dtor in a class with virtual methods).
Mark B
2010-03-09 15:28:58
+1
A:
It shows all warnings. I'd recommend also use -pedantic to warn about some non-conformant parts of code.
Kirill V. Lyadvinsky
2010-03-09 09:57:34
For gcc doc: "Some users try to use -pedantic to check programs for strict ISO C conformance. They soon find that it does not do quite what they want: it finds some non-ISO practices, but not all—only those for which ISO C requires a diagnostic, and some others for which diagnostics have been added."
AProgrammer
2010-03-09 10:14:59
If you hadn't written *some* instead of *all* in "to warn about *all* non-conformant parts", I wouldn't have commented. But your current formulation just spread the misconception the gcc documentation warn against.
AProgrammer
2010-03-09 12:13:03
Fixed. But in practice it is rather looks like a "most of" and not "some".
Kirill V. Lyadvinsky
2010-03-09 13:05:03
+2
A:
It enables warnings which are deemed useful and easy to avoid at the source by gcc writers. There is also -W (-Wextra in newer releases) which are deemed useful but for which work-arounding false positives can be difficult or result in clumsy code.
gcc has also a bunch of other warnings, generally less useful. See http://gcc.gnu.org/onlinedocs/gcc-4.4.3/gcc/Warning-Options.html#Warning-Options
AProgrammer
2010-03-09 10:09:30