Making Dynamic Library from Static ones using gcc --shared -m64 -Wl,--whole-archive ./*.a

Question

I am getting this set of gcc errors, and I can't seem to get an answer from google or the man pages. Any insight on what these mean or where to start looking?

Here is the line in the makefile:

#After building several otehr bits of code into static libraries
...
# Grand finally link all the object files into one
        gcc --shared  \
        -m64 \
        -Wl,--whole-archive ./release64/*.a \
        -o ./release64/libMYLIB.so.1.0
        ln -sf libArcGIS.so.1.0 ./release64/libMYLIB.so
        ln -sf libArcGIS.so.1.0 ./release64/libMYLIB.so.1

I get the following errors (there are many more I took the top n just to give an idea:

/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_muldi3.o): In function `__multi3':
(.text+0x0): multiple definition of `__multi3'
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_muldi3.o):(.text+0x0): first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_negdi2.o): In function `__negti2':
(.text+0x0): multiple definition of `__negti2'
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_negdi2.o):(.text+0x0): first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_lshrdi3.o): In function `__lshrti3':
(.text+0x0): multiple definition of `__lshrti3'
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_lshrdi3.o):(.text+0x0): first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_ashldi3.o): In function `__ashlti3':
(.text+0x0): multiple definition of `__ashlti3'
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_ashldi3.o):(.text+0x0): first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_ashrdi3.o): In function `__ashrti3':
(.text+0x0): multiple definition of `__ashrti3'
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_ashrdi3.o):(.text+0x0): first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_cmpdi2.o): In function `__cmpti2':
(.text+0x0): multiple definition of `__cmpti2'
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_cmpdi2.o):(.text+0x0): first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_ucmpdi2.o): In function `__ucmpti2':
(.text+0x0): multiple definition of `__ucmpti2'
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_ucmpdi2.o):(.text+0x0): first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_clear_cache.o): In function `__clear_cache':
(.text+0x0): multiple definition of `__clear_cache'
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_clear_cache.o):(.text+0x0): first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_enable_execute_stack.o): In function `__enable_execute_stack':
(.text+0x0): multiple definition of `__enable_execute_stack'
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_enable_execute_stack.o):(.text+0x0): first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_absvsi2.o): In function `__absvsi2':
(.text+0x0): multiple definition of `__absvsi2'
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_absvsi2.o):(.text+0x0): first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_absvsi2.o): In function `__absvdi2':
(.text+0x20): multiple definition of `__absvdi2'
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_absvsi2.o):(.text+0x20): first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_absvdi2.o): In function `__absvti2':
(.text+0x0): multiple definition of `__absvti2'
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_absvdi2.o):(.text+0x0): first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_addvsi3.o): In function `__addvsi3':
(.text+0x0): multiple definition of `__addvsi3'
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_addvsi3.o):(.text+0x0): first defined here
/usr/lib/gcc/x86_64-redhat-linux/4.4.5/libgcc.a(_addvsi3.o): In function `__addvdi3':

---

Update

The static libraries I am trying to combine are:

-rw-rw-r-- 1 mehoggan mehoggan  487770 Jan  3 11:17 libfreetype.a
-rw-rw-r-- 1 mehoggan mehoggan  227814 Jan  3 11:17 libjpeg.a
-rw-rw-r-- 1 mehoggan mehoggan  258576 Jan  3 11:17 libpng.a
-rw-rw-r-- 1 mehoggan mehoggan 2392136 Jan  3 11:17 libSkia.a
-rw-rw-r-- 1 mehoggan mehoggan  696756 Jan  3 11:17 libSQlite.a
-rw-rw-r-- 1 mehoggan mehoggan 1517832 Jan  3 11:16 libSymbolXLib.a
-rw-rw-r-- 1 mehoggan mehoggan  928934 Jan  3 11:17 libxml2.a

I performed seperate compilation on each of the files so no linking was performed. I looked through the source and I don't see anything that involves libgcc. This is why the error makes not since to me.

Answer 1

You are missing a closing --no-whole-archive. That is

    gcc --shared  \
    -m64 \
    -Wl,--whole-archive ./release64/*.a -Wl,--no-whole-archive \
    -o ./release64/libMYLIB.so.1.0
    ln -sf libArcGIS.so.1.0 ./release64/libMYLIB.so
    ln -sf libArcGIS.so.1.0 ./release64/libMYLIB.so.1

Without the closing --no-whole-archive, the initial --whole-archive will affect all the libraries passed on to the linker, libgcc in particular which is always passed on implicitly. That's why you are getting duplicate symbols.

Answer 2

It means just what it says. There are two or more .a files that contain .o files that contain definitions of these functions. In particular, it looks as if your directory contains either two variations on libgcc.a or a something containing a copy of it.

Don't do this to libgcc.a at all. To omit libgcc add -nostdlib or even -nodefaultlibs.