I see that GNU assembler supports -c option:
$ as -c t1.S
However, I cannot find -c option in man as:
$ man as | grep -P '\-c\s+'
gcc -c -g -O -Wa,-alh,-L file.c
A simple question: what is -c option?
Related
So I've been trying to search for a solution that Im having with my make file currently. I get the error:
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/9/../../../x86_64-linux-gnu/Scrt1.o: in function `_start':
(.text+0x24): undefined reference to `main'
So I have 5 files in my src folder: find.c, rebalance.c, remove.c, lib.c, and insert.c. In my src/bin folder I just have main.c and in another folder 'include' outside of src I have bst.h. This is what my makefile looks like:
all: static bin shared
mkdir -p build/bin
mkdir -p build/lib
mkdir -p build/objects
mv *.o build/objects
mv *.a build/lib
mv main build/bin
mv libbst.so build/lib
static:
gcc src/lib.c -c -I include
gcc src/find.c -c -I include
gcc src/insert.c -c -I include
gcc src/rebalance.c -c -I include
gcc src/remove.c -c -I include
ar rcs libbst.a find.o insert.o lib.o rebalance.o remove.o
shared:
gcc -c -o lib.o src/lib.c
gcc -c -o find.o src/find.c
gcc -c -o insert.o src/insert.c
gcc -c -o rebalance.o src/rebalance.c
gcc -c -o remove.o src/remove.c
gcc -shared -o libbst.so find.o insert.o lib.o rebalance.o remove.o
bin:
gcc src/lib.c -c -I include
gcc lib.o -o lib -lbst -L.
gcc src/bin/main.c -c -I include
gcc main.o -o main -lbst -L.
clean:
rm -rf *.so *.a *.o main build
install:
Im assuming that I'm just not using the right commands to link everything together. This always fails in the 'bin' section of the Makefile. I would really appreciate any help or advice on what I can do here, im kind of stumped right now.
So my file structure is basically this -
I have a .zshrc file since I'm on OS X
I have a .my_custom_commands.sh file which contains the shortcuts I want
In my .zshrc I source the commands file
Currently, I'm looking for a solution to compile multiple files with flags using the "gcc" command
For example, if I want to compile a.c and b.c
gcc -Wall -Werror -ansi -pedantic -o output.c a.c b.c
However, I don't want to type this out every time, so I was thinking there would be a way to create a custom command say 'gccf' (gcc flags). The thing is that I don't know zsh programming language so I'm just wondering if there is a way to pass multiple args into the function I created in the commands file.
I have something like this right now
function gccf() {
gcc -Wall -Werror -ansi -pedantic -o output.c $1 $2
}
I understand that the args you pass into the command line are represented by $1, $2..., but is there anyway to check how many args have been passed? Because if $2 isn't passed then this won't work I think.
Set CFLAGS as you want and just use the default rules for make. You don't even need a makefile:
$ rm -f Makefile
$ ls a.c
a.c
$ make a
cc a.c -o a
$ rm -f a.o a
$ export CFLAGS=-pedantic
$ make a
cc -pedantic a.c -o a
If you have multiple source files, you'll need a (trivial) makefile:
$ rm -f a *.o output Makefile
$ unset CFLAGS
$ make a
cc a.c -o a
$ export CFLAGS='-Wall -Werror -ansi -pedantic'
$ rm a; make a
cc -Wall -Werror -ansi -pedantic a.c -o a
$ printf 'output: a.o b.o\n\t$(CC) $(LDFLAGS) $^ -o $# $(LDLIBS)\n' > Makefile
$ make output
cc -Wall -Werror -ansi -pedantic -c -o a.o a.c
cc -Wall -Werror -ansi -pedantic -c -o b.o b.c
cc a.o b.o -o output
$ rm -rf *.o output
$ export CC=gcc LDLIBS=-lm
$ make output
gcc -Wall -Werror -ansi -pedantic -c -o a.o a.c
gcc -Wall -Werror -ansi -pedantic -c -o b.o b.c
gcc a.o b.o -o output -lm
In other words, don't try to reinvent the wheel. Your use case has been encountered by many people, and there are long standing conventions and tools in place to enable the work flow.
Note that you may want to include LOADLIBES along with LDLIBS, but the former name should (probably?) no longer be used.
In Bourne-heritage shells (e.g. sh, zsh, bash, ksh), to specify all arguments passed to a program or function, use "$#" (including the double quotes!), which expands to any number of args passed, including none.
But if you follow the Unix philosophy of using the one tool that does just one thing, you want to look at make as suggested in comments and other answers.
PS: you also want -o output, not -o output.c, since your program is not a C source file, but an executable.
I'm trying to link an external library but not linking. Using gcc version:
gcc (MinGW.org GCC Build-2) 9.2.0
Windows 10
Command I'm tried:
gcc -g test.c -Wall -I ../inc/ -L ../lib -l:libFp.a -o test.exe
gcc -g test.c -Wall -I ../inc/ -L ../lib64 -l:libFp.a -o test.exe
gcc -g -Wall -I ../inc/ -L ../lib -l:libFp.a test.c -o test.exe
gcc -g -Wall ../lib/libFp.a test.c -I ../inc/ -o test.exe
Error:
c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe: C:\Users\XXXXXXXX\AppData\Local\Temp\cciWnORn.o: in function `main':
D:\C_Training\utils\XXXXXXXX\testApp/test.c:35: undefined reference to `addition'
collect2.exe: error: ld returned 1 exit status
Folder Hierarchy:
XXXX
==docs
==inc
==lib
--libFp.a
--fP.lib
==lib64
--libFp.a
==src
==testApp [cwd]
--test.c
Tried different solutions from StackOverflow but still same error.
Update: gcc -g -Wall -I ../inc -L ../lib test.c -o test.exe -lFp -Xlinker --verbose command output
Linker Output Verbose
This question already has answers here:
Undefined Reference to `pthread_init' When Using -lpthread Flag:
(1 answer)
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
Why does order in which input libraries are specified matter?
(3 answers)
Closed 5 years ago.
I am trying create a C executable which depends on multiple C static libraries.
I have two libraries :
../libs/libsulibs.a and ../ppm_client/libppm_client.a. libppm_client.a calls some functions of libsulibs.a
Here are my Makefiles
../libs/Makefile
LIBS=-lpthread
CC=gcc
CFLAGS=-Wall -g
INCLUDES=-I .
OBJ=WheelTimer.o threadApi.o LinkedListApi.o
TARGET=libsulibs.a
${TARGET}:$(OBJ)
ar rs ${TARGET} $(OBJ)
%.o:%.c
${CC} ${CFLAGS} -c ${INCLUDES} $<
clean:
rm *.o
rm ${TARGET}
I successfully create libsulibs.a through this makefile
../ppm_client/Makefile
CC=gcc
CFLAGS=-Wall -g
INCLUDES=-I . -I ../libs -I ../ppm
OBJ=ppm_pkt_enums.o ppm_client.o ppm_client_sock.o
TARGET=libppm_client.a
${TARGET}:$(OBJ)
ar rs ${TARGET} ${OBJ}
ppm_pkt_enums.o:ppm_pkt_enums.c
gcc -g -c ${INCLUDES} ppm_pkt_enums.c -o ppm_pkt_enums.o
ppm_client.o:ppm_client.c
gcc -g -c ${INCLUDES} ppm_client.c -o ppm_client.o
ppm_client_sock.o:ppm_client_sock.c
gcc -g -c ${INCLUDES} ppm_client_sock.c -o ppm_client_sock.o
clean:
rm *.o
rm ${TARGET}
This makefile too successfully create the libppm_client.a.
Now, in current dir, I have main Makefile to create executable
CC=gcc
CFLAGS=-g -Wall
STANDARD_LIBS=-lpthread
PPM_OBJ=ppm.o ppm_main.o
LIBS_OBJ=libs/LinkedListApi.o libs/threadApi.o libs/WheelTimer.o
PPM_LIBS=../libs/libsulibs.a
PPM_CLIENT_LIBS=../ppm_client/libppm_client.a
INCLUDES=-I . -I ../libs -I ../ppm_client
TARGET:exe ${PPM_LIBS} ${PPM_CLIENT_LIBS}
ppm.o:ppm.c
gcc -g -c ${INCLUDES} ppm.c -o ppm.o
ppm_main.o:ppm_main.c
gcc -g -c ${INCLUDES} ppm_main.c -o ppm_main.o
${PPM_LIBS}:
(cd ../libs; make)
${PPM_CLIENT_LIBS}:
(cd ../ppm_client; make)
exe:${PPM_LIBS} ${PPM_OBJ} ${STANDARD_LIBS} ${PPM_CLIENT_LIBS}
${CC} ${CFLAGS} ${PPM_OBJ} -o exe -L ../libs -lsulibs -L ../ppm_client -lppm_client ${STANDARD_LIBS}
clean:
rm *.o
(cd ../libs; make clean)
(cd ../ppm_client; make clean)
rm exe
But when I run make, it ends up with the error : undefined reference to pthread_init . pthread_init is a function defined in libsulibs.a and is dependent on standard pthread library.
vm#vm:~/Documents/PeriodicPacketManager/ppm$ make
(cd ../libs; make)
make[1]: Entering directory `/home/vm/Documents/PeriodicPacketManager/libs'
gcc -Wall -g -c -I . WheelTimer.c
gcc -Wall -g -c -I . threadApi.c
gcc -Wall -g -c -I . LinkedListApi.c
ar rs libsulibs.a WheelTimer.o threadApi.o LinkedListApi.o
ar: creating libsulibs.a
make[1]: Leaving directory `/home/vm/Documents/PeriodicPacketManager/libs'
gcc -g -c -I . -I ../libs -I ../ppm_client ppm.c -o ppm.o
gcc -g -c -I . -I ../libs -I ../ppm_client ppm_main.c -o ppm_main.o
(cd ../ppm_client; make)
make[1]: Entering directory `/home/vm/Documents/PeriodicPacketManager/ppm_client'
gcc -g -c -I . -I ../libs -I ../ppm ppm_pkt_enums.c -o ppm_pkt_enums.o
gcc -g -c -I . -I ../libs -I ../ppm ppm_client.c -o ppm_client.o
gcc -g -c -I . -I ../libs -I ../ppm ppm_client_sock.c -o ppm_client_sock.o
ar rs libppm_client.a ppm_pkt_enums.o ppm_client.o ppm_client_sock.o
ar: creating libppm_client.a
make[1]: Leaving directory `/home/vm/Documents/PeriodicPacketManager/ppm_client'
gcc -g -Wall ppm.o ppm_main.o -o exe -L ../libs -lsulibs -L ../ppm_client -lppm_client -lpthread
../ppm_client/libppm_client.a(ppm_client_sock.o): In function `ppm_client_init_socket':
/home/vm/Documents/PeriodicPacketManager/ppm_client/ppm_client_sock.c:138: undefined reference to `pthread_init'
collect2: error: ld returned 1 exit status
make: *** [exe] Error 1
Kindly help what am I missing here.
Woa !!
#Antti Haapalam
Changing the order of libraries worked.
In Main Makefile, i changed the order from :
${CC} ${CFLAGS} ${PPM_OBJ} -o exe -L ../libs -lsulibs -L ../ppm_client -lppm_client ${STANDARD_LIBS}
To:
${CC} ${CFLAGS} ${PPM_OBJ} -o exe -L ../ppm_client -lppm_client -L ../libs -lsulibs ${STANDARD_LIBS}
Can anyone comment the reasoning ?
Is it possible to make two files in a single makefile? Essentially a program and a programtest. I have seen other answers, but their syntax went completely over my head. Right now my Makefile only makes one of the programs, and I cant figure out how to have it make both
Would it be possible for someone to provide a template for how a Makefile would be structured to compile two programs?
all: main test
test: objects/Math.o objects/Stack.o objects/Queue.o objects/myUnitTesting.o objects/test.o
gcc objects/test.o objects/Math.o objects/Stack.o objects/Queue.o objects/myUnitTesting -o test
main: objects/Stack.o objects/Queue.o objects/Math.o objects/Point.o objects/main.o
gcc objects/main.o objects/Stack.o objects/Queue.o objects/Point.o objects/Math.o -o main
objects/test.o: test.c
gcc -g -Wall -O -c -o objects/test.o test.c
objects/main.o: main.c
gcc -g -Wall -O -c -o objects/main.o main.c
objects/myUnitTesting.o: cs/myUnitTesting.c
gcc -g -Wall -O -c -o objects/myUnitTesting cs/myUnitTesting.c
objects/Math.o: cs/Math.c
gcc -g -Wall -O -c -o objects/Math.o cs/Math.c
objects/Stack.o: cs/Stack.c
gcc -g -Wall -O -c -o objects/Stack.o cs/Stack.c
objects/Queue.o: cs/Queue.c
gcc -g -Wall -O -c -o objects/Queue.o cs/Queue.c
objects/Point.o: cs/Point.c
gcc -g -Wall -O -c -o objects/Point.o cs/Point.c
clean:
rm -f objects/*o main
Then you only need to type:
make all
and it is going to compile your main.c and test.c files
You can multiple exes in one makefile, here is sample for building 2,
you need to do make all to build
prog1: prog1.o
gcc prog1.o -o prog1 2>>compile.log 1>&2
prog2: prog2.o
gcc prog2.o -o prog2 2>>compile.log 1>&2
all: prog1 prog2
.c.o:
gcc -o $# -c $*.c 2>>compile.log 1>&2
Here is a scenario where 2 targets are main1 and main2.
TARGET1 = main1
TARGET2 = main2
$(TARGET1): main1.o
gcc main1.o -o $#
$(TARGET2): main2.o
gcc main2.o -o $#
%.o: %.c
gcc -c $< -o $#
run1: $(TARGET1)
./$(TARGET1)
run2: $(TARGET2)
./$(TARGET2)
all: $(TARGET1) $(TARGET2)
./$(TARGET1)
./$(TARGET2)
Remember that the indentation is a <tab> character, not space characters.
The following command will compile and run main1 executable.
make run1
The following command will compile and run main2 executable.
make run2
The following command will compile and run main1 executable followed by main2 executable.
make all
It is possible.
Here is a simpler version of the Makefile:
all: program programtest
program:
gcc -o program program.c
programtest:
gcc -o programtest programtest.c
Then you just have to type make:
$ make
gcc -o program program.c
gcc -o programtest programtest.c