The Short Version
Linking my executable against several libraries, including libgio-2.0.so.0.4800.1 (libgio-2.0.so) and libz.so.1.2.8 (libz.so), I get two unresolved symbols - deflateSetHeader@ZLIB_1.2.2 and inflateGetHeader@ZLIB_1.2.2. Neither symbol is defined in libz.so, but inflateGetHeader@@ZLIB_1.2.2 and deflateSetHeader@@ZLIB_1.2.2 are:
readelf -s libz.so|grep Header
63: 00007991 28 FUNC GLOBAL DEFAULT 12 inflateGetHeader@@ZLIB_1.2.2
98: 00003319 24 FUNC GLOBAL DEFAULT 12 deflateSetHeader@@ZLIB_1.2.2
367: 00003319 24 FUNC GLOBAL DEFAULT 12 deflateSetHeader
386: 00007991 28 FUNC GLOBAL DEFAULT 12 inflateGetHeader
Other symbols referenced in libgio are successfully resolved by libz, but not these two.
The Long Version
I'm cross-compiling from a Windows host (Xilinx SDK 2016.1 (Eclipse), toolchain "arm-linux-gnueabihf") for a Zynq 7010-based target (krtkl.com) running 32-bit Ubuntu 14.04 with a Linaro 4.4 kernel.
Both the host and target platforms are given, in case you feel the need to ask why I'm doing it that way.
The procedure for using an external shared library is this: download, configure and build library on the target (unless the library already exists on the target), then copy include and library (libabc.so.x.y.z) files to a bespoke project directory on the host, rename libabc.so.x.y.z to abc.so, and set the library path to project directory and library name to abc (i.e. gcc ... -L<project dir> -labc).
I'm using this procedure to include GLib (among others) in my project. GLib (libglib.so) requires GIO (libgio.so), which in turn requires (among others) ZLIB (libz.so).
These libraries are built from source: glib-2.48.1 (including gio, gobject, and gmodule), libffi-3.2.1, zlib-1.2.8. Others are from the Ubuntu distro.
When I run the cross-compiler on Windows ("Project|Build All" in Eclipse), all goes according to plan - libgio-2.0.so, libglib-2.0.so, gobject-2.0.so, libffi.so, libgmodule-2.0.so, libdl.so, libpcre.so, libresolv-2.19.so and libz.so satisfy all external references except deflateSetHeader@ZLIB_1.2.2 and inflateGetHeader@ZLIB_1.2.2.
readelf output (see above) shows similar, but not identical, symbols available in libz.so. I've seen a few mentions of similar problems while searching on-line, but the resolution always has to do with finding an outdated version of ZLIB - not a possibility given my development environment.
Both libgio and libz are well-established libraries in wide use - this can't be a bug, right?
I'm out of ideas - has anyone encountered this or anything similar?
[UPDATE]
gcc version 4.9.2 20140904 (prerelease) (crosstool-NG linaro-1.13.1-4.9-2014.09 - Linaro GCC 4.9-2014.09)
By request, here are example compiler and linker commands emitted by Eclipse:
19:53:13 **** Auto Build of configuration Debug for project Project_2 ****
make -j8 all
'Building file: ../src/Project.c'
'Invoking: ARM v7 Linux gcc compiler'
arm-linux-gnueabihf-gcc -DCONFIGURATION_DEBUG -Wall -O0 -mcpu=cortex-a9 -mfpu=vfpv3 -mfloat-abi=hard -g3 -I"C:\Users\Nick\XSDK\Workspace\snickerdoodle_bsp\ps7_cortexa9_0\include" -I"C:\Users\Nick\XSDK\Workspace\Project_2\src" -I"C:\Users\Nick\XSDK\Workspace\Project_2\src\Dir1" -I"C:\Users\Nick\XSDK\Workspace\Project_2\src\Dir2" -I"C:\Users\Nick\XSDK\Workspace\Project_2\src\Dir3" -I"C:\Users\Nick\XSDK\Workspace\Project_2\src\Dir4" -I"C:\Users\Nick\XSDK\Workspace\Project_2\src\Dir5" -I"C:\Users\Nick\XSDK\Workspace\Project_2\src\Dir6" -I"C:\Users\Nick\XSDK\Workspace\Project_2\src\Dir7" -I"C:\Users\Nick\XSDK\Workspace\Project_2\src\Dir8" -I"C:\Users\Nick\XSDK\Workspace\LibXml2\include" -I"C:\Users\Nick\XSDK\Workspace\LibXml2\include\libxml" -I"C:\Users\Nick\XSDK\Workspace\GLibC\include" -c -fmessage-length=0 -MT"src/Project.o" -MMD -MP -MF"src/Project.d" -MT"src/Project.o" -o "src/Project.o" "../src/Project.c"
'Finished building: ../src/Project.c'
'Invoking: ARM v7 Linux gcc linker'
arm-linux-gnueabihf-gcc -L"C:\Users\Nick\XSDK\Workspace\LibXml2\lib" -L"C:\Users\Nick\XSDK\Workspace\GLibC\lib" -o "Project_2.elf" <all the .o files> -lpthread -lm -lxml2 -llzma -lgio-2.0 -lglib-2.0 -lgobject-2.0 -lffi -lgmodule-2.0 -ldl -lpcre -lresolv-2.19 -lz
c:/xilinx/sdk/2016.1/gnu/aarch32/nt/gcc-arm-linux-gnueabi/bin/../lib/gcc/arm-linux-gnueabihf/4.9.2/../../../../arm-linux-gnueabihf/bin/ld.exe: warning: libz.so.1, needed by C:\Users\Nick\XSDK\Workspace\GLibC\lib/libgio-2.0.so, not found (try using -rpath or -rpath-link)
C:\Users\Nick\XSDK\Workspace\GLibC\lib/libgio-2.0.so: undefined reference to `deflateSetHeader@ZLIB_1.2.2'
C:\Users\Nick\XSDK\Workspace\GLibC\lib/libgio-2.0.so: undefined reference to `inflateGetHeader@ZLIB_1.2.2'
-lzbefore-lgio-2.0. - alvits