Hi,
I am a newbie in C++ programming. When compiling I never use any option.
This is my day to day command:
g++ MyCode.cc -o MyCode
For safety practice what's the best option to use?
+11
A:
“-Werror”: treats all warnings as errors so you have to fix them. Incredibly valuable.
Bombe
2009-02-20 08:09:49
Along with -Wall to turn on all the useful warnings, of course.
Greg Hewgill
2009-02-20 08:15:46
+15
A:
g++ -W -Wall -Werror
Will display all errors and warnings possible and treat them as errors.
LiraNuna
2009-02-20 08:15:11
To the OP - Do what this poster suggests! You will save yourself many headaches if you just listen to the compiler warnings. Do not ignore them!
eduffy
2009-02-20 14:44:04
Actually, it doesn't enable all possible warnings. -Wwrite-strings and -Wconversion are good too.
Steve Jessop
2009-07-13 22:27:09
+4
A:
g++ -Wall -Weffc++ -Werror -pedantic
When I'm using Boost, though, I drop it down to:
g++ -Wall -Werror
I'm anxiously awaiting GCC 4.4 and 4.5, though. There are some features coming that I really badly need.
greyfade
2009-02-20 08:28:13
Lambdas (which I'm hoping show up in 4.5), auto variables (4.4), strongly-typed enums (4.4), and, most importantly, atomic<>, which I'm desperately hoping gets done in 4.5.
greyfade
2009-02-20 18:04:23
I know. That's why I don't use it with Boost - just including a Boost header creates another 30-40 warnings.
greyfade
2009-03-17 16:52:25
+3
A:
-pipe, it speeds up compilation a little bit. Also -O2, which speeds up execution.
Marc
2009-02-20 10:43:44
Optimization will generally interfere with debugging. For a newbie, using the -g and without -Ox would be preferable.
Calyth
2009-02-20 22:25:57
What speed improvements have you seen with -pipe? I find it doesn't make a significant difference, as the bulk of the time is spent linking (which can't be parallelized across multiple cores, like compilation).
Tom
2009-03-17 13:02:51
+2
A:
I like -march=athlon -O2 -pipe for building most programs (I run Gentoo at home), and I use -ansi -pedantic -Wall for code I write myself.
Kristo
2009-02-20 14:38:21
+1
A:
-ansi -pedantic
-D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS -D__STDC_LIMIT_MACROS -D_GNU_SOURCE -D_REENTRANT
-Wall -Wextra -Wwrite-strings -Winit-self -Wcast-align -Wcast-qual -Wold-style-cast -Wpointer-arith -Wstrict-aliasing -Wformat=2 -Wuninitialized -Wmissing-declarations -Woverloaded-virtual -Wnon-virtual-dtor -Wctor-dtor-privacy -Wno-long-long
-O3 -ftree-vectorize -ftree-vectorizer-verbose=2 -ffast-math -fstrict-aliasing -march=native/pentium4/nocona/core2 -msse2 -mfpmath=sse
Tom
2009-03-17 13:07:55