So my question is simple.
I want to compile a C project file in gcc compiler 4.4.8.
In windows cmd window I can type :
gcc -std=c99 -O2 -DCONTEST -s -static -lm name.c -o name.exe
In Code::Blocks how can I change the compiler default arguments with the above?
I wanted to build a c file and I geting errors like
error: 'for' loop initial declarations are only allowed in C99 mode|
Ok to put your preferred arguments to gnu compiler go to :
Settings -> Debugger -> Compiler settings -> Other Options
and paste there your arguments!
Example:
-std=c99 -O2 -DCONTEST -s -static -lm
Related
I want to compile a C file that only has a function to assembly.
To compile, I'm running the following command
clang -c -m32 -O1 -S exemple.c
Everything works fine but I was wondering if there is any convention regarding the order of which compilation flags should appear.
I wrote a code in C in Ubuntu which checks for balanced brackets in the input given.I compiled it using gcc compiler and I am getting the correct output.This is actually a part of an online course and they are asking me to use the compiler flag
gcc -pipe -O2 -std=c11 filename -lm
I don't think I understand what I am supposed to do so I tried compiling using this flag and my code is not compiling. My question is if my code compiles when I do
gcc filename.c
why isn't it compiling when I do
gcc -pipe -O2 -std=c11 filename -lm
The error message I am getting is :
cc1plus: warning: command line option ‘-std=c11’ is valid for C/ObjC but not for C++
The reason is the file ending. A capital C is interpreted as a C++ file. The solution is to just rename the file like this:
mv filename.C filename.c
My question is if my code compiles when I do gcc filename.C why isn't it compiling when I do gcc -pipe -O2 -std=c11 <filename> -lm
See above. But there are some situations where it would not solve everything. While C11 gives some extensions to previous versions, it's not 100% backwards compatible.
-std=c11 is a correct option
however you need at least gcc 4.7 or higher to have this option
By "<filename>" they mean to substitute in the name of the file you want to compile. Including the literal string "<filename>" will not work.
My C program uses string.h.. Initially I was not able to compile it. But then I used
$ gcc filename.c -E
Then it complied but I am not able to run it with both
./a.out
./filename
The -E option to gcc invokes only the preprocessor. If you want to compile you need to do this:
gcc -g -Wall -Wextra -o filename filename.c
The -o option specifies the name of the executable to create, the -W options enable the common compiler warnings, and -g includes debugging symbols so you can use tools such as gdb to step through the code line by line.
I have to turn off optimizations while compiling c code I wrote while using the gcc compiler on a linux. I have found that I can compile the code but I can only get the code to compile without the executable name specified (default to a.out).
So this works:
gcc -O0 Problem04b.c
But my problem is that I have to submit this assignment and I can't submit an executable called a.out because my instructor needs to know which problem it is. I realize I can probably just run
cp a.out Problem04b
then
rm a.out
but I want to know if there is a way I can just compile the code directly into the executable Problem04b. I've tried to run the command like this:
gcc -O0 Problem04b Problem04b.c
but I'm having no luck.
Thanks for your help.
It's the -o flag:
gcc -O0 -o Problem04b Problem04b.c
To specify the output file, you need to use the -o <filename> option with gcc.
Note : Please mind the lower case here
In your case, it should be
gcc -O0 -o Problem04b Problem04b.c
For reference: From gcc manual
-o file
Place output in file file. This applies to whatever sort of output is being produced, whether it be an executable file, an object file, an assembler file or preprocessed C code.
Actually, you also want to get warnings (that won't change the produced executable, but it is very helpful to you), so compile with
gcc -O0 -Wall -Wextra Problem04b.c -o Problem04b
The -Wall option asks for nearly all warnings, the -Wextra option asks for even more of them.
To run your thing (the ./ is useful because of possible PATH issues):
./Problem04b
Notice that -O0 is optional (since it is the default), you could remove it.
gcc -Wall -Wextra Problem04b.c -o Problem04b
If you want real optimization, e.g. for benchmarking, use e.g. -O1 or -O2 or -O3
You probably want to compile with debug information, then
gcc -g -Wall -Wextra Problem04b.c -o Problem04b
and of course you need to learn how to use the GDB debugger. So read some tutorial about that, then type
gdb ./Problem04b
You'll get a (gdb) prompt. Try help at that time.
You probably want to read the chapter about invoking GCC of the GCC documentation.
I am using alchemy to compile the C code.
This is the way I am compiling
gcc oggvorbis.c -O3 -Wall -swc
oggvorbis.swc -lvorbis
I am getting an error
llvm-gcc: oggvorbis.swc: No such file
or directory.
But the command works fine when i don't use any shared library.
Your command line invocation should probably read (untested)
gcc oggvorbis.c -O3 -Wall -swc -o oggvorbis.swc -lvorbis