Is there a way to compile all .c files in a given folder by using the command line with GCC compiler ?
I've seen this page for Linux : http://www.commandlinefu.com/commands/view/3230/compile-all-c-files-in-a-directory but couldn't find any equivalent for CMD.
I guess gcc itself doesn't have such a parameter.
But you can try the regular wildcard argument of gcc *.c -o Output where the * (wildcard) is to read as "any".
You can compile your files with following command:
gcc -c -Wall file1.c file2.c file3.c
Here. -Wall will give you all the warnings and errors.
Do not forget to browse to the same directory where these files reside.
Related
How to create a makefile for Linux for the next command?
gcc -shared -home/ time.c /libperi.a -o time.so
First, pick a name. This command appears to build time.so, so that's a good name.
The makefile is just a text file. Write it like this:
time.so:
gcc -shared -home/ time.c /libperi.a -o time.so
That whitespace before the gcc is a TAB, not spaces.
Once you have that working, you can read the manual and learn more about Make, which will allow you to write more powerful rules.
Here's my makefile:
assemblera: main.o parsingA.o parsingC.o symbolTable.o
gcc -o assemblera main.o parsingA.o parsingC.o symbolTable.o
main.o: main.c parsingA.h parsingC.h symbolTable.h
gcc -c main.c
parsingA.o: parsingA.c parsingA.h
gcc -c parsingA.c
parsingC.o: parsingC.c parsingC.h
gcc -c parsingC.c
symbolTable.o: symbolTable.c symbolTable.h
gcc -c symbolTable.c
clean:
rm *.o assemblera
Now for the problem: with Windows command prompt I can easily generate all the .o files and .exe file, and if I run the latter it works as intended. Now, if I use the cygwin terminal, I can give the instructions to generate the object files / the exe, but those do not appear nowhere in the folder and no error is returned. Also, if I use the make command, it returns this error:
gcc -c main.c
make: *** [Makefile:5: main.o] Error 1
(I did put tabs in front of every "gcc" and "rm"). I know next to nothing about makefiles and cygwin.
gcc has -M-class options (-MMD, -MF, etc.) that allows to generate dependency file during compiling source file. The dependency file contains Makefile rules describing on which source files and headers the generated object file depends on. The dependency file may be included into Makefile and then make will automatically recompile source file when headers are changed.
I need a similar option but for generating dependency file during linking an executable. The dependency file should contain list of libraries used for linking an executable, so if any of libraries is updated, make will re-execute linking of the executable automatically.
I tried to use the same flags (-MMD, -MF), but they doesn't work for linking. It seems they are only for generating dependency files during compiling.
Is there any other flags or means for generating dependency file for executable?
So far I have not found dedicated gcc options for generating dependency file for executable, but found the --trace option (-Wl,--trace when used with gcc). This option generates list of libraries used during linking. Its output has the next format:
gcc -Wl,--trace myprog.c -o myprog -L. -lmylib
-lmylib (./libmylib.a)
-lgcc_s (/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/libgcc_s.so)
...
The list of libraries then may be converted to Makefile rules using sed:
echo "myprog: " > myprog.dep
gcc -Wl,--trace myprog.c -o myprog -L. -lmylib \
| sed -n 's/.*(\(.*\)).*/\1 \\/p' >> myprog.dep
So myprog.dep will have the following content:
myprog: \
./libmylib.a \
/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.5.2/libgcc_s.so \
...
This dependency file may be included to Makefile and make will relink myprog if any of libraries are updated.
The dependency file doesn't contain list of object files, but the object files are usually known inside Makefile-script without help of compiler:
myprog: $(OBJS)
gcc -Wl,--trace $^ -o myprog -L. -lmylib | sed -n 's/.*(\(.*\)).*/\1 \\/p' >> myprog.dep
I installed OCaml via OPAM, and by default it uses gcc as the command to compile .c files. For instance, if I run ocamlopt -verbose file.c, I obtain:
+ gcc -Wall -D_FILE_OFFSET_BITS=64 -D_REENTRANT -g
-fno-omit-frame-pointer -c -I'/home/user/.opam/4.02.1+fp/lib/ocaml' 'test.c'
I'd like to change the GCC binary that is used by OCaml, for instance to replace it with gcc-5.1 or /opt/my-gcc/bin/gcc.
Is it possible to do so without reconfiguring and recompiling OCaml? I suppose I could add a gcc alias to a directory in the PATH, but I'd prefer a cleaner solution if there is one.
To check if gcc was not chosen based on a textual configuration file (that I could easily change), I searched for occurrences of gcc in my /home/user/.opam/4.02.1+fp directory, but the only occurrence in a non-binary file that I found was in lib/ocaml/Makefile.config, and changing it does nothing for the already-compiled binary.
ocamlopt uses gcc for three things. First, for compiling .c files that appear on the command line of ocamlopt. Second, for assembling the .s files that it generates internally when compiling an OCaml source file. Third, for linking the object files together at the end.
For the first and third, you can supply a different compiler with the -cc flag.
For the second, you need to rebuild the OCaml compiler.
Update
Here's what I see on OS X when compiling a C and an OCaml module with the -verbose flag:
$ ocamlopt -verbose -cc gcc -o m m.ml c.c 2>&1 | grep -v warning
+ clang -arch x86_64 -c -o 'm.o' \
'/var/folders/w4/1tgxn_s936b148fdgb8l9xv80000gn/T/camlasm461f1b.s' \
+ gcc -c -I'/usr/local/lib/ocaml' 'c.c'
+ clang -arch x86_64 -c -o \
'/var/folders/w4/1tgxn_s936b148fdgb8l9xv80000gn/T/camlstartup695941.o' \
'/var/folders/w4/1tgxn_s936b148fdgb8l9xv80000gn/T/camlstartupb6b001.s'
+ gcc -o 'm' '-L/usr/local/lib/ocaml' \
'/var/folders/w4/1tgxn_s936b148fdgb8l9xv80000gn/T/camlstartup695941.o' \
'/usr/local/lib/ocaml/std_exit.o' 'm.o' \
'/usr/local/lib/ocaml/stdlib.a' 'c.o' \
'/usr/local/lib/ocaml/libasmrun.a'
So, the compiler given by the -cc option is used to do the compilation of the .c file and the final linking. To change the handling of the .s files you need to rebuild the compiler. I'm going to update my answer above.
How to create a shared library (.so) file in Mac os X using terminal
Thanks in Advance.
This might be very late, but incase someone stumbles upon this I know how to make an so files for c++/c code. Assuming that you are in the directory with your .cpp/.c and .h files, in the terminal you must type:
g++ -c file1.cpp file2.cpp (add as many cpp/c files you want in the so file)
g++ *.o -dynamiclib -o lib_name.so
Then if you are using a cpp file that will run it:
g++ -c test.cpp -o test.o (compiling the program to see if the shared library works)
g++ -o test test.o -L. -l_name (create an executable to run)
./test (run the test)
For C code so files, it's the same but replace g++ with gcc.