gcc：错误：Makfile中无法识别的命令行选项“ -Wl”

Question

I run the command " make test " in this source code:

https://github.com/sanandrea/CSecretKey

but it give me this error :

gcc: error: unrecognized command line option '-Wl'
Makefile:18: recipe for target 'lib_plain' failed
make: *** [lib_plain] Error 1

This is the line 18 in the makefile gcc -shared -Wl -o libhmacenc.so hmac_256_plain.o sha2.o -lc

This is the list of the files:

• Android.mk
• hmac_sha256.c
• hmac_sha256.h
• reverse_test.py
• sha2.c
• sha2.h
• test.c

This is the complete "makefile":

all: lib test
test: clean lib_plain
    gcc -o test test.c -lhmacenc -L.

production: clean lib
    gcc -o test test.c -lhmacenc -L.

hmac_256.o: hmac_sha256.c hmac_sha256.h
    $(CC) -Wall -c hmac_sha256.c -o hmac_256.o

hmac_256_plain.o: hmac_sha256.c hmac_sha256.h
    $(CC) -Wall -DSHOW_PASS -c hmac_sha256.c -o hmac_256_plain.o

lib: hmac_256.o sha2.o
    gcc -shared -Wl -o libhmacenc.so hmac_256.o sha2.o -lc

lib_plain: hmac_256_plain.o sha2.o
    gcc -shared -Wl -o libhmacenc.so hmac_256_plain.o sha2.o -lc

sha2.o: sha2.c sha2.h
    $(CC) -c sha2.c -o sha2.o

clean:
    - rm -rf *.o hmac *.so

Someone would knows how I can fix this error?

Thanks!

Answer 1

As suggested by @missimer, there is option field not specified in your makefile for linker option '-Wl'.

Generally, for creating shared library, the following syntax is used with '-Wl':

gcc -shared -Wl,-export-dynamic 

Hope this helps you.

Answer 2

There is another branch of the code that deals with Cygwin and has a different Makefile.

https://github.com/sanandrea/CSecretKey/tree/cygwin

Always try to use a GNU-Linux environment to compile programs in pure C. Avoid Cygwin because their behavior is different in the Makefile.