What does this option to ld mean?
-lrt
I know to some degree it means that ld is looking for the library with real-time extensions, but after searching extensively, I couldn't find an exact definition (or which library) this is referring to.
With Bionic (android) libc, the android NDK docs detail that this (along with pthreads) has been integrated.
I ask because it seems to be implicit (ie when I invoke the compiler, a custom-compiled gdc, directly, I get a message saying that ld cannot find -lrt)
EDIT
From the Bionic Overview
Bionic's C library comes with its own pthread implementation bundled
in. This is different from other historical C libraries which:
- place it in an external library (-lpthread)
- play linker tricks with weak symbols at dynamic link time
The support for real-time features (a.k.a. -lrt) is also bundled in
the C library.
The problem is that collect2 is passing the option -lrt (and also -lpthreads) to ld.
dan#devbox:~/projects/gdc_test/jni/src$ $DC gdc_test.d -v -mthumb
Using built-in specs.
Target: arm-linux-androideabi
Configured with: /arm/ndk-git/src/build/../gcc/gcc-4.4.3/configure --prefix=/arm/ndk-git/ndk/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86 --target=arm-linux-androideabi --host=x86_64-linux-gnu --build=x86_64-linux-gnu --with-gnu-as --with-gnu-ld --enable-languages=c,c++ --with-gmp=/arm/ndk-git/build_run/temp-install --with-mpfr=/arm/ndk-git/build_run/temp-install --disable-libssp --enable-threads --disable-nls --disable-libmudflap --disable-libgomp --disable-libstdc__-v3 --disable-sjlj-exceptions --disable-shared --disable-tls --enable-languages=c,d,c++ --enable-lto --with-float=soft --with-fpu=vfp --with-arch=armv5te --enable-target-optspace --enable-shared--prefix=/arm/ndk-git/ndk/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86 --enable-initfini-array --disable-nls --prefix=/arm/ndk-git/ndk/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86 --with-sysroot=/arm/ndk-git/ndk/toolchains/arm-linux-androideabi-4.4.3/prebuilt/linux-x86/sysroot --with-binutils-version=2.19 --with-mpfr-version=2.4.1 --with-gmp-version=4.2.4 --with-gcc-version=4.4.3 --with-gdb-version=6.6 --with-arch=armv5te --enable-libstdc__-v3 --disable-werrors --enable-languages=c,d,c++ --enable-shared --enable-multilib --disable-threads --program-transform-name='s,^,arm-linux-androideabi-,'
Thread model: single
gcc version 4.4.3 20100121 (gdc hg, using dmd 1.067) (GCC)
COLLECT_GCC_OPTIONS='-v' '-mthumb' '-shared-libgcc' '-pthread' '-march=armv5te' '-mfloat-abi=soft' '-mfpu=vfp'
/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../libexec/gcc/arm-linux-androideabi/4.4.3/cc1d gdc_test.d -mbionic -fpic -quiet -dumpbase gdc_test.d -mthumb -march=armv5te -mfloat-abi=soft -mfpu=vfp -auxbase gdc_test -version -imultilib thumb -iprefix /home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc/arm-linux-androideabi/4.4.3/ -isysroot /home/dan/projects/arm-linux-androideabi-4.4.3/bin/../sysroot -fmultilib-dir=thumb -o /tmp/cc2yu97y.s
GNU D (GCC) version 4.4.3 20100121 (gdc hg, using dmd 1.067) (arm-linux-androideabi)
compiled by GNU C version 4.5.2, GMP version 4.2.4, MPFR version 2.4.1.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU D (GCC) version 4.4.3 20100121 (gdc hg, using dmd 1.067) (arm-linux-androideabi)
compiled by GNU C version 4.5.2, GMP version 4.2.4, MPFR version 2.4.1.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
COLLECT_GCC_OPTIONS='-v' '-mthumb' '-shared-libgcc' '-pthread' '-march=armv5te' '-mfloat-abi=soft' '-mfpu=vfp'
/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc/arm-linux-androideabi/4.4.3/../../../../arm-linux-androideabi/bin/as -v -march=armv5te -mfloat-abi=soft -mfpu=vfp -meabi=5 -o /tmp/ccuFGEfj.o /tmp/cc2yu97y.s
GNU assembler version 2.19 (arm-linux-androideabi) using BFD version (GNU Binutils) 2.19
COMPILER_PATH=/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../libexec/gcc/arm-linux-androideabi/4.4.3/:/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../libexec/gcc/:/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc/arm-linux-androideabi/4.4.3/../../../../arm-linux-androideabi/bin/
LIBRARY_PATH=/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc/arm-linux-androideabi/4.4.3/thumb/:/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc/arm-linux-androideabi/4.4.3/../../../../arm-linux-androideabi/lib/thumb/:/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc/arm-linux-androideabi/4.4.3/:/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc/:/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc/arm-linux-androideabi/4.4.3/../../../../arm-linux-androideabi/lib/:/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../sysroot/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-mthumb' '-shared-libgcc' '-pthread' '-march=armv5te' '-mfloat-abi=soft' '-mfpu=vfp'
/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../libexec/gcc/arm-linux-androideabi/4.4.3/collect2 --sysroot=/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../sysroot --eh-frame-hdr -dynamic-linker /system/bin/linker -X -m armelf_linux_eabi /home/dan/projects/arm-linux-androideabi-4.4.3/bin/../sysroot/usr/lib/crtbegin_dynamic.o -L/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc/arm-linux-androideabi/4.4.3/thumb -L/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc/arm-linux-androideabi/4.4.3/../../../../arm-linux-androideabi/lib/thumb -L/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc/arm-linux-androideabi/4.4.3 -L/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc -L/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc/arm-linux-androideabi/4.4.3/../../../../arm-linux-androideabi/lib -L/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../sysroot/usr/lib /tmp/ccuFGEfj.o -lgphobos -lm -lrt -lgcc_s -lgcc -lpthread -lc -ldl -lgcc_s -lgcc /home/dan/projects/arm-linux-androideabi-4.4.3/bin/../sysroot/usr/lib/crtend_android.o
/home/dan/projects/arm-linux-androideabi-4.4.3/bin/../lib/gcc/arm-linux-androideabi/4.4.3/../../../../arm-linux-androideabi/bin/ld: cannot find -lrt
collect2: ld returned 1 exit status
Is there a way to override this behavior?
When you see a -lsomething, the library name is libsomething. Doing a man librt says the following:
NAME
librt, libposix4 - POSIX.1b Realtime Extensions library
SYNOPSIS
cc [ flag... ] file... -lrt [ library... ]
DESCRIPTION
Functions in this library provide most of the interfaces
specified by the POSIX.1b Realtime Extension. See stan-
dards(5). Specifically, this includes the interfaces defined
under the Asynchronous I/O, Message Passing, Process
Scheduling, Realtime Signals Extension, Semaphores, Shared
Memory Objects, Synchronized I/O, and Timers options. The
interfaces defined under the Memory Mapped Files, Process
Memory Locking, and Range Memory Locking options are pro-
vided in libc(3LIB)
See the man pages for the individual interfaces in section
3RT for information on required headers.
The name libposix4 is maintained for backward compatibility
and should be avoided. librt is the preferred name for this
library.
-l is the flag used to link a library into your final executable. In this case, the library in question is librt.a (or librt.so or librt.dylib, depending on your system). librt is the realtime extensions library.
Answering my own question: it was hardcoded into gdc/d/d-spec.c
Related
I had this problem, and the solution was to explicitly pass libstdc++.a to g++, like the following:
/usr/local/gcc-10.2.0/bin/g++ -I/usr/local/gcc-10.2.0/include -L/usr/local/gcc-10.2.0/lib64 -Wl,-rpath,/usr/local/gcc-10.2.0/lib64 b.cpp /usr/local/gcc-10.2.0/lib64/libstdc++.a
My question: Why do I need to explicitly pass libstdc++.a? How can I make it automatic so that libstdc++.a is used by default? How can I find the answer to the two questions?
The test code:
#include <sstream>
using namespace std;
int
main ()
{
ostringstream oss;
unsigned long k = 5;
oss << k;
}
Compiled with the following parameters:
/usr/local/gcc-10.2.0/bin/g++ -I/usr/local/gcc-10.2.0/include -L/usr/local/gcc-10.2.0/lib64 -Wl,-rpath,/usr/local/gcc-10.2.0/lib64 -lstdc++ b.cpp
Got the following output:
/tmp/cclRSXGV.o: In function main': b.cpp:(.text+0x35): undefined reference to std::ostream::operator<<(unsigned long)'
collect2: error: ld returned 1 exit status
Using GNU gcc 10.2.0, installed with the following:
../gcc-10.2.0/configure --prefix=/usr/local/gcc-10.2.0 --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-languages=c,c++ --disable-dssi --enable-libgcj-multifile --with-ppl --with-cloog --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux && make install-strip
Already had GNU gcc 4.4.7 installed by default at /usr, and GNU gcc 9.2.0 at /usr/local/gcc-9.2.0
Running /usr/local/gcc-10.2.0/bin/g++ -v b.cpp produces the following:
Using built-in specs.
COLLECT_GCC=/usr/local/gcc-10.2.0/bin/g++
COLLECT_LTO_WRAPPER=/usr/local/gcc-10.2.0/libexec/gcc/x86_64-redhat-linux/10.2.0/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../gcc-10.2.0/configure --prefix=/usr/local/gcc-10.2.0 --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-languages=c,c++ --disable-dssi --enable-libgcj-multifile --with-ppl --with-cloog --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 10.2.0 (GCC)
COLLECT_GCC_OPTIONS='-v' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
/usr/local/gcc-10.2.0/libexec/gcc/x86_64-redhat-linux/10.2.0/cc1plus -quiet -v -D_GNU_SOURCE b.cpp -quiet -dumpbase b.cpp -mtune=generic -march=x86-64 -auxbase b -version -o /tmp/ccJiMH6j.s
GNU C++14 (GCC) version 10.2.0 (x86_64-redhat-linux)
compiled by GNU C version 10.2.0, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.18-GMP
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/../../../../x86_64-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/../../../../include/c++/10.2.0
/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/../../../../include/c++/10.2.0/x86_64-redhat-linux
/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/../../../../include/c++/10.2.0/backward
/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/include
/usr/local/include
/usr/local/gcc-10.2.0/include
/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/include-fixed
/usr/include
End of search list.
GNU C++14 (GCC) version 10.2.0 (x86_64-redhat-linux)
compiled by GNU C version 10.2.0, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.18-GMP
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 410dfe626634fcd13dbcedee05209c5e
COLLECT_GCC_OPTIONS='-v' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
as -v --64 -o /tmp/ccUyoUr2.o /tmp/ccJiMH6j.s
GNU assembler version 2.35 (x86_64-pc-linux-gnu) using BFD version (GNU Binutils) 2.35
COMPILER_PATH=/usr/local/gcc-10.2.0/libexec/gcc/x86_64-redhat-linux/10.2.0/:/usr/local/gcc-10.2.0/libexec/gcc/x86_64-redhat-linux/10.2.0/:/usr/local/gcc-10.2.0/libexec/gcc/x86_64-redhat-linux/:/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/:/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/
LIBRARY_PATH=/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/:/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/../../../../lib64/:/lib/../lib64/:/usr/lib/../lib64/:/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
/usr/local/gcc-10.2.0/libexec/gcc/x86_64-redhat-linux/10.2.0/collect2 -plugin /usr/local/gcc-10.2.0/libexec/gcc/x86_64-redhat-linux/10.2.0/liblto_plugin.so -plugin-opt=/usr/local/gcc-10.2.0/libexec/gcc/x86_64-redhat-linux/10.2.0/lto-wrapper -plugin-opt=-fresolution=/tmp/ccfGN6NK.res -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 /usr/lib/../lib64/crt1.o /usr/lib/../lib64/crti.o /usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/crtbegin.o -L/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0 -L/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/../../../../lib64 -L/lib/../lib64 -L/usr/lib/../lib64 -L/usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/../../.. /tmp/ccUyoUr2.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/local/gcc-10.2.0/lib/gcc/x86_64-redhat-linux/10.2.0/crtend.o /usr/lib/../lib64/crtn.o
/usr/local/bin/ld: /tmp/ccUyoUr2.o: in function `main':
b.cpp:(.text+0xc9): undefined reference to `std::cout'
/usr/local/bin/ld: b.cpp:(.text+0x35): undefined reference to std::ostream::operator<<(unsigned long)'
collect2: error: ld returned 1 exit status
By default g++ links against the dynamic libstdc++ library (libstdc++.so). By passing libstdc++.a explicitly you're linking against the static counterpart. You could achieve the same end result with -static-libstdc++.
Both static and dynamic linking against libstdc++ should work. Your issue could be possibly caused by building or installing GCC incorrectly (e.g. applying an incorrect patch, or mixing include files from different GCC builds).
To investigate, produce object file b.o by adding -c to your g++ command line, and preprocessed source b.ii by adding -E -o b.ii. Use nm -u b.o to get mangled names of undefined symbols (add -C to demangle). You'll see that mangled name of the missing symbol is _ZNSolsEm. Try to grep the missing symbol in the list of symbols defined by libstdc++ (nm -D --defined-only /usr/local/gcc-10.2.0/lib64/libstdc++.so). If it is missing from the library, the issue is that the included files expect the library to provide those template instantiations, while the actual library does not.
If you look in b.ii, you'll find that it declares the corresponding extern template towards the end:
extern template class basic_ostringstream<char>;
If you look into sstream.tcc file from gcc install tree that this line comes from, you'll see it's guarded by #if _GLIBCXX_EXTERN_TEMPLATE. The definition of this macro is in c++config.h, and is set depending on --enable-extern-template option at libstdc++ configuration time. If the library is built with --disable-extern-template, it will not provide those template instantiations.
I'm getting the following error
cannot find -lstdc++
collect2.exe: error: ld returned 1 exit status
it's a simple Hello World program.
g++ version returns
g++ (MinGW.org GCC Build-2) 9.2.0
g++ -v <filename.cpp> returns
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=c:/mingw/bin/../libexec/gcc/mingw32/9.2.0/lto-wrapper.exe
Target: mingw32
Configured with: ../src/gcc-9.2.0/configure --build=x86_64-pc-linux-gnu --host=mingw32 --target=mingw32 --disable-win32-registry --with-arch=i586 --with-tune=generic --enable-static --enable-shared --enable-threads --enable-languages=c,c++,objc,obj-c++,fortran,ada --with-dwarf2 --disable-sjlj-exceptions --enable-version-specific-runtime-libs --enable-libgomp --disable-libvtv --with-libiconv-prefix=/mingw --with-libintl-prefix=/mingw --enable-libstdcxx-debug --disable-build-format-warnings --prefix=/mingw --with-gmp=/mingw --with-mpfr=/mingw --with-mpc=/mingw --with-isl=/mingw --enable-nls --with-pkgversion='MinGW.org GCC Build-2'
Thread model: win32
gcc version 9.2.0 (MinGW.org GCC Build-2)
COLLECT_GCC_OPTIONS='-v' '-shared-libgcc' '-mtune=generic' '-march=i586'
c:/mingw/bin/../libexec/gcc/mingw32/9.2.0/cc1plus.exe -quiet -v -iprefix c:\mingw\bin\../lib/gcc/mingw32/9.2.0/ hw.cpp -quiet -dumpbase hw.cpp -mtune=generic -march=i586 -auxbase hw -version -o C:\Users\move78~1\AppData\Local\Temp\ccQus9Kp.s
GNU C++14 (MinGW.org GCC Build-2) version 9.2.0 (mingw32)
compiled by GNU C version 9.2.0, GMP version 6.1.2, MPFR version 4.0.2, MPC version 1.1.0, isl version isl-0.21-GMP
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "c:\mingw\bin\../lib/gcc/mingw32/9.2.0/../../../../mingw32/include"
ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/9.2.0/include/c++"
ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/9.2.0/include/c++/mingw32"
ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/9.2.0/include/c++/backward"
ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/9.2.0/include"
ignoring duplicate directory "/mingw/lib/gcc/mingw32/9.2.0/../../../../include"
ignoring duplicate directory "c:/mingw/lib/gcc/../../include"
ignoring duplicate directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/9.2.0/include-fixed"
ignoring nonexistent directory "c:/mingw/lib/gcc/../../lib/gcc/mingw32/9.2.0/../../../../mingw32/include"
ignoring duplicate directory "/mingw/include"
#include "..." search starts here:
#include <...> search starts here:
c:\mingw\bin\../lib/gcc/mingw32/9.2.0/include/c++
c:\mingw\bin\../lib/gcc/mingw32/9.2.0/include/c++/mingw32
c:\mingw\bin\../lib/gcc/mingw32/9.2.0/include/c++/backward
c:\mingw\bin\../lib/gcc/mingw32/9.2.0/include
c:\mingw\bin\../lib/gcc/mingw32/9.2.0/../../../../include
c:\mingw\bin\../lib/gcc/mingw32/9.2.0/include-fixed
End of search list.
GNU C++14 (MinGW.org GCC Build-2) version 9.2.0 (mingw32)
compiled by GNU C version 9.2.0, GMP version 6.1.2, MPFR version 4.0.2, MPC version 1.1.0, isl version isl-0.21-GMP
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: cb31672760a9c1b42d1ddb86616116cd
COLLECT_GCC_OPTIONS='-v' '-shared-libgcc' '-mtune=generic' '-march=i586'
c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/as.exe -v -o C:\Users\move78~1\AppData\Local\Temp\cctjBjko.o C:\Users\move78~1\AppData\Local\Temp\ccQus9Kp.s
GNU assembler version 2.32 (mingw32) using BFD version (GNU Binutils) 2.32
COMPILER_PATH=c:/mingw/bin/../libexec/gcc/mingw32/9.2.0/;c:/mingw/bin/../libexec/gcc/;c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/
LIBRARY_PATH=c:/mingw/bin/../lib/gcc/mingw32/9.2.0/;c:/mingw/bin/../lib/gcc/;c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/lib/;c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../
COLLECT_GCC_OPTIONS='-v' '-shared-libgcc' '-mtune=generic' '-march=i586'
c:/mingw/bin/../libexec/gcc/mingw32/9.2.0/collect2.exe -plugin c:/mingw/bin/../libexec/gcc/mingw32/9.2.0/liblto_plugin-0.dll -plugin-opt=c:/mingw/bin/../libexec/gcc/mingw32/9.2.0/lto-wrapper.exe -plugin-opt=-fresolution=C:\Users\move78~1\AppData\Local\Temp\ccxROszG.res -plugin-opt=-pass-through=-lmingw32 -plugin-opt=-pass-through=-lmingwex -plugin-opt=-pass-through=-lmingw32 -plugin-opt=-pass-through=-lmingwex -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lmoldname -plugin-opt=-pass-through=-lmsvcrt -plugin-opt=-pass-through=-ladvapi32 -plugin-opt=-pass-through=-lshell32 -plugin-opt=-pass-through=-luser32 -plugin-opt=-pass-through=-lkernel32 -plugin-opt=-pass-through=-lmingw32 -plugin-opt=-pass-through=-lmingwex -plugin-opt=-pass-through=-lmingw32 -plugin-opt=-pass-through=-lmingwex -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lmoldname -plugin-opt=-pass-through=-lmsvcrt -Bdynamic -u ___register_frame_info -u ___deregister_frame_info c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../crt2.o c:/mingw/bin/../lib/gcc/mingw32/9.2.0/crtbegin.o -Lc:/mingw/bin/../lib/gcc/mingw32/9.2.0 -Lc:/mingw/bin/../lib/gcc -Lc:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/lib -Lc:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../.. C:\Users\move78~1\AppData\Local\Temp\cctjBjko.o -lstdc++ -lmingw32 -lmingwex -lmingw32 -lmingwex -lgcc_s -lgcc -lmoldname -lmsvcrt -ladvapi32 -lshell32 -luser32 -lkernel32 -lmingw32 -lmingwex -lmingw32 -lmingwex -lgcc_s -lgcc -lmoldname -lmsvcrt c:/mingw/bin/../lib/gcc/mingw32/9.2.0/crtend.o
c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe: cannot find -lstdc++
collect2.exe: error: ld returned 1 exit status
You need 3 things to build:
Your tools (like g++.exe) need to be in your PATH (or specified via their full path when calling them, e.g. C:\mingw\mingw32\bin\g++.exe).
The compiler needs to be able to find the include files. If needed you can add include paths (pointing to the folder, not the actual file) using -I flags (or you can use C_INCLUDE_PATH (for C) and CPLUS_INCLUDE_PATH (for C++) environment variables).
The linker needs be able to find your libraries (like libstdc++.a). If needed you can add library paths (pointing to the folder, not the actual file) using -L flags (or you can use LIBRARY_PATH environment variable).
If you use MSYS2 shell these things should already have been set up.
The standalone build from http://winlibs.com/ looks for relative locations and should just work wherever you extract it on your disk.
You didn't mention which shell you were running your commands from (Command Prompt, PowerShell, MSYS), but it's important the above is respected correctly in whatever shell you are using.
As far as I know http://winlibs.com/ works in MSYS shell, Command Prompt and PowerShell (though parameters starting with - need to be put in quotes when using PowerShell).
That's the question. Basically my problem is that I am trying to compile an app for ARM with an options -fsanitize=address -static-libasan (cool thing for debugging a wrong pointers and etc.). This compiles fine directly to executable file, but doesn't work for compiling from an object files. Ofc I found that the static lib is libasan.a; anyway when I am trying to link everything from an object file, it says about a bunch of an undefined references in «pthread» and some functions whose lib-owner I didn't even managed to find.
So, I just want to compile a file with -fsanitize=address -static-libasan and see which a libraries were linked statically, so that I could later do it from an object file.
An executable stores no trace of any static libraries it pulled object files from. Mostly these libraries are explicitly specified when linking, though. The compiler only pulls in a few standard static libraries. For gcc you can see various information including the actual command line passed to the linker using the -v option (it seems some implementations want to use --verbose and for the linker -Wl,--verbose). This output should show all implicitly linked libraries like -lgcc and -lstdc++.
Note that you should link using the language specific frontend and the same compiler flags as when compiling. Your problem description sounds as if you use -pthread with g++ when compiling but you tried to link using gcc without the -pthread flags (there are a few different threading related flags; from the description it is impossible to tell which one was used).
Just to deal with the insults, here is an example output when using the -v option on my computer:
ThreadGard:stackoverflow kuehl$ cat hello.cpp
#include <iostream>
int main()
{
std::cout << "hello, world\n";
return 0;
}
ThreadGard:stackoverflow kuehl$ g++ -v -static hello.cpp
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/opt/gcc-4.9.2/libexec/gcc/x86_64-apple-darwin13.4.0/4.9.2/lto-wrapper
Target: x86_64-apple-darwin13.4.0
Configured with: ../gcc-4.9.2/configure --prefix=/opt/gcc-4.9.2 --with-gmp=/opt/gcc-infrastructure --with-mpfr=/opt/gcc-infrastructure --enable-decimal-float=bid --enable-lto --enable-languages=c,c++
Thread model: posix
gcc version 4.9.2 (GCC)
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.9.4' '-v' '-static' '-mtune=core2'
/opt/gcc-4.9.2/libexec/gcc/x86_64-apple-darwin13.4.0/4.9.2/cc1plus -quiet -v -D__STATIC__ hello.cpp -quiet -dumpbase hello.cpp -mmacosx-version-min=10.9.4 -mtune=core2 -auxbase hello -version -o /var/folders/b_/64plfvs936v5ylx36qwc8rg00000gp/T//ccrt7fXS.s
GNU C++ (GCC) version 4.9.2 (x86_64-apple-darwin13.4.0)
compiled by GNU C version 4.9.2, GMP version 5.0.5, MPFR version 3.1.1, MPC version 1.0.1
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/../../../../x86_64-apple-darwin13.4.0/include"
#include "..." search starts here:
#include <...> search starts here:
/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/../../../../include/c++/4.9.2
/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/../../../../include/c++/4.9.2/x86_64-apple-darwin13.4.0
/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/../../../../include/c++/4.9.2/backward
/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/include
/usr/local/include
/opt/gcc-4.9.2/include
/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/include-fixed
/usr/include
/System/Library/Frameworks
/Library/Frameworks
End of search list.
GNU C++ (GCC) version 4.9.2 (x86_64-apple-darwin13.4.0)
compiled by GNU C version 4.9.2, GMP version 5.0.5, MPFR version 3.1.1, MPC version 1.0.1
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: fea0def5b69cf8ae349b2f1faf4b1d23
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.9.4' '-v' '-static' '-mtune=core2'
as -arch x86_64 -force_cpusubtype_ALL -static -o /var/folders/b_/64plfvs936v5ylx36qwc8rg00000gp/T//ccPF77oR.o /var/folders/b_/64plfvs936v5ylx36qwc8rg00000gp/T//ccrt7fXS.s
COMPILER_PATH=/opt/gcc-4.9.2/libexec/gcc/x86_64-apple-darwin13.4.0/4.9.2/:/opt/gcc-4.9.2/libexec/gcc/x86_64-apple-darwin13.4.0/4.9.2/:/opt/gcc-4.9.2/libexec/gcc/x86_64-apple-darwin13.4.0/:/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/:/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/
LIBRARY_PATH=/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/:/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/../../../:/usr/lib/
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.9.4' '-v' '-static' '-mtune=core2'
/opt/gcc-4.9.2/libexec/gcc/x86_64-apple-darwin13.4.0/4.9.2/collect2 -static -arch x86_64 -macosx_version_min 10.9.4 -weak_reference_mismatches non-weak -o a.out -lcrt0.o -L/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2 -L/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/../../.. /var/folders/b_/64plfvs936v5ylx36qwc8rg00000gp/T//ccPF77oR.o /opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/../../../libstdc++.a -no_compact_unwind -no_pie -lgcc_eh -lgcc -v
collect2 version 4.9.2
/usr/bin/ld -static -arch x86_64 -macosx_version_min 10.9.4 -weak_reference_mismatches non-weak -o a.out -lcrt0.o -L/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2 -L/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/../../.. /var/folders/b_/64plfvs936v5ylx36qwc8rg00000gp/T//ccPF77oR.o /opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/../../../libstdc++.a -no_compact_unwind -no_pie -lgcc_eh -lgcc -v
#(#)PROGRAM:ld PROJECT:ld64-241.9
configured to support archs: armv6 armv7 armv7s arm64 i386 x86_64 x86_64h armv6m armv7m armv7em
Library search paths:
/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2
/opt/gcc-4.9.2/lib
/usr/lib
/usr/local/lib
Framework search paths:
/Library/Frameworks/
/System/Library/Frameworks/
ld: library not found for -lcrt0.o
collect2: error: ld returned 1 exit status
There are not all static libraries installed to make it actually link. However, that's besides the point as the output clearly lists the linker invocation:
/usr/bin/ld -static -arch x86_64 -macosx_version_min 10.9.4 -weak_reference_mismatches non-weak -o a.out -lcrt0.o -L/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2 -L/opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/../../.. /var/folders/b_/64plfvs936v5ylx36qwc8rg00000gp/T//ccPF77oR.o /opt/gcc-4.9.2/lib/gcc/x86_64-apple-darwin13.4.0/4.9.2/../../../libstdc++.a -no_compact_unwind -no_pie -lgcc_eh -lgcc -v
(with some emphasis added to make it easier for readers - it seems to be necessary)
I've been trying to figure out why g++ cannot link a program with the armadillo library. The problem is simple:
macbook-pro:arma-xc jmlopez$ g++-4.9 inputs-arma.cpp -larmadillo
ld: library not found for -larmadillo
collect2: error: ld returned 1 exit status
Perhaps I did specify where the library should be
macbook-pro:arma-xc jmlopez$ ls -l /usr/lib/libarma*
-rwxr-xr-x 1 root wheel 37928 Aug 18 14:30 /usr/lib/libarmadillo.4.32.2.dylib
lrwxr-xr-x 1 root wheel 25 Aug 18 14:30 /usr/lib/libarmadillo.4.dylib -> libarmadillo.4.32.2.dylib
lrwxr-xr-x 1 root wheel 20 Aug 18 14:30 /usr/lib/libarmadillo.dylib -> libarmadillo.4.dylib
Let us try again
macbook-pro:arma-xc jmlopez$ g++-4.9 -L/usr/lib inputs-arma.cpp -larmadillo
ld: library not found for -larmadillo
collect2: error: ld returned 1 exit status
Ok, that did not fix it. Let us see what is going on, for this we will use the -v option which will generate some long output.
macbook-pro:arma-xc jmlopez$ g++-4.9 -L/usr/lib inputs-arma.cpp -larmadillo -v
Using built-in specs.
COLLECT_GCC=g++-4.9
COLLECT_LTO_WRAPPER=/usr/local/Cellar/gcc/4.9.1/libexec/gcc/x86_64-apple-darwin13.3.0/4.9.1/lto-wrapper
Target: x86_64-apple-darwin13.3.0
Configured with: ../configure --build=x86_64-apple-darwin13.3.0 --prefix=/usr/local/Cellar/gcc/4.9.1 --enable-languages=c,c++,objc,obj-c++,fortran --program-suffix=-4.9 --with-gmp=/usr/local/opt/gmp --with-mpfr=/usr/local/opt/mpfr --with-mpc=/usr/local/opt/libmpc --with-cloog=/usr/local/opt/cloog --with-isl=/usr/local/opt/isl --with-system-zlib --enable-version-specific-runtime-libs --enable-libstdcxx-time=yes --enable-stage1-checking --enable-checking=release --enable-lto --disable-werror --with-pkgversion='Homebrew gcc 4.9.1' --with-bugurl=https://github.com/Homebrew/homebrew/issues --enable-plugin --disable-nls --enable-multilib --with-native-system-header-dir=/usr/include --with-sysroot=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk
Thread model: posix
gcc version 4.9.1 (Homebrew gcc 4.9.1)
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.9.3' '-L/usr/lib' '-v' '-shared-libgcc' '-mtune=core2'
/usr/local/Cellar/gcc/4.9.1/libexec/gcc/x86_64-apple-darwin13.3.0/4.9.1/cc1plus -quiet -v -D__DYNAMIC__ inputs-arma.cpp -fPIC -quiet -dumpbase inputs-arma.cpp -mmacosx-version-min=10.9.3 -mtune=core2 -auxbase inputs-arma -version -o /var/folders/6x/ss29s2r51z5cv0_g1ffx0c0c0000gn/T//ccApA95Q.s
GNU C++ (Homebrew gcc 4.9.1) version 4.9.1 (x86_64-apple-darwin13.3.0)
compiled by GNU C version 4.9.1, GMP version 6.0.0, MPFR version 3.1.2-p8, MPC version 1.0.2
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/local/include"
ignoring nonexistent directory "/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1/../../../../x86_64-apple-darwin13.3.0/include"
ignoring nonexistent directory "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/Library/Frameworks"
#include "..." search starts here:
#include <...> search starts here:
/Users/jmlopez/github/excentury/excentury/extern/include
/usr/include
/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1/include/c++
/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1/include/c++/x86_64-apple-darwin13.3.0
/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1/include/c++/backward
/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1/include
/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1/include-fixed
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/System/Library/Frameworks
End of search list.
GNU C++ (Homebrew gcc 4.9.1) version 4.9.1 (x86_64-apple-darwin13.3.0)
compiled by GNU C version 4.9.1, GMP version 6.0.0, MPFR version 3.1.2-p8, MPC version 1.0.2
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 5a051bcf2be886a5c6eb8ba33f338693
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.9.3' '-L/usr/lib' '-v' '-shared-libgcc' '-mtune=core2'
as -arch x86_64 -force_cpusubtype_ALL -o /var/folders/6x/ss29s2r51z5cv0_g1ffx0c0c0000gn/T//cchm9rVF.o /var/folders/6x/ss29s2r51z5cv0_g1ffx0c0c0000gn/T//ccApA95Q.s
COMPILER_PATH=/usr/local/Cellar/gcc/4.9.1/libexec/gcc/x86_64-apple-darwin13.3.0/4.9.1/:/usr/local/Cellar/gcc/4.9.1/libexec/gcc/x86_64-apple-darwin13.3.0/4.9.1/:/usr/local/Cellar/gcc/4.9.1/libexec/gcc/x86_64-apple-darwin13.3.0/:/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1/:/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/
LIBRARY_PATH=/usr/lib/:/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1/:/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1/../../../:/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib/
COLLECT_GCC_OPTIONS='-mmacosx-version-min=10.9.3' '-L/usr/lib' '-v' '-shared-libgcc' '-mtune=core2'
/usr/local/Cellar/gcc/4.9.1/libexec/gcc/x86_64-apple-darwin13.3.0/4.9.1/collect2 -dynamic -arch x86_64 -macosx_version_min 10.9.3 -syslibroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk -weak_reference_mismatches non-weak -o a.out -L/usr/lib -L/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1 -L/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1/../../.. -L/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib /var/folders/6x/ss29s2r51z5cv0_g1ffx0c0c0000gn/T//cchm9rVF.o -larmadillo -lstdc++ -no_compact_unwind -lSystem -lgcc_ext.10.5 -lgcc -lSystem -v
collect2 version 4.9.1
/usr/bin/ld -dynamic -arch x86_64 -macosx_version_min 10.9.3 -syslibroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk -weak_reference_mismatches non-weak -o a.out -L/usr/lib -L/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1 -L/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1/../../.. -L/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib /var/folders/6x/ss29s2r51z5cv0_g1ffx0c0c0000gn/T//cchm9rVF.o -larmadillo -lstdc++ -no_compact_unwind -lSystem -lgcc_ext.10.5 -lgcc -lSystem -v
#(#)PROGRAM:ld PROJECT:ld64-236.4
configured to support archs: armv6 armv7 armv7s arm64 i386 x86_64 armv6m armv7m armv7em
Library search paths:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib
/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1
/usr/local/Cellar/gcc/4.9.1/lib
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib
Framework search paths:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/System/Library/Frameworks/
ld: library not found for -larmadillo
collect2: error: ld returned 1 exit status
The important information is here:
Library search paths:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib
/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1
/usr/local/Cellar/gcc/4.9.1/lib
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib
Somehow it is not looking in /usr/lib. I have tried specifying this directory by first
exporting the variable LD_LIBRARY_PATH
macbook-pro:arma-xc jmlopez$ export LD_LIBRARY_PATH=/usr/lib
macbook-pro:arma-xc jmlopez$ g++-4.9 -L/usr/lib inputs-arma.cpp -larmadillo
ld: library not found for -larmadillo
collect2: error: ld returned 1 exit status
No luck. Finally, thinking that ld might be broken I did this:
macbook-pro:arma-xc jmlopez$ ln -s /usr/lib/libarmadillo.dylib /usr/local/Cellar/gcc/4.9.1/lib/libarmadillo.dylib
macbook-pro:arma-xc jmlopez$ g++-4.9 inputs-arma.cpp -larmadillo
Now it works. I'm not sure if there is something wrong with my system but it seems that I have no way of specifying other paths for ld to look for my libraries. Instead I have to use any of the following:
Library search paths:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib
/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1
/usr/local/Cellar/gcc/4.9.1/lib
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib
Is there a way to fix this? Notice that I'm using the g++ from homebrew since I thought that the one that came with xcode was broken. In any case, no luck, at least the homebrew g++ told me the paths where the library was being searched.
Update:
I decided to see if I could add another path:
g++-4.9 -L/Users/jmlopez/ -L/Users/jmlopez/Desktop -L/usr/lib inputs-arma.cpp -larmadillo -v
Now the list of paths where it searches for the libraries is:
Library search paths:
/Users/jmlopez/
/Users/jmlopez/Desktop
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib
/usr/local/Cellar/gcc/4.9.1/lib/gcc/x86_64-apple-darwin13.3.0/4.9.1
/usr/local/Cellar/gcc/4.9.1/lib
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/lib
Where is /usr/lib? What is so special about this directory that ld refuses to look in this directory. It searches in my home directory and in my Desktop. I tried adding /usr/local and it adds it to the list of directories. I'm now starting to wonder about the permissions on the directories... Any ideas?
It is likely that your homebrew g++ was compiled with a custom prefix. The prefix for gcc is usually /usr, meaning that it will look for binaries in /usr/bin, headers in /usr/include and libraries in /usr/lib. If you've compiled with a custom prefix (/usr/local/Cellar/gcc/4.9.1/ in this case, it seems) the it won't look in /usr/lib.
LD_LIBRARY_PATH is how you tell the runtime linker where to look for libraries. So if you had linked to /usr/my/bizarre/lib/path/libmylib.so, then you run it like this:
> LD_LIBRARY_PATH=/usr/my/bizarre/lib/path myprog
To tell g++ where to find libraries, you use the -L command-line option. So your command-line should look like this:
g++-4.9 inputs-arma.cpp -L/usr/lib -larmadillo
I ran into this thread trying to answer a similar question myself. Hopefully this will help out.
You need ld_library_path for the homebrew compiler to work and dyld_library_path for os x to appropriately use the library.
put the following exports somewhere where they can get sourced.
export LD_LIBRARY_PATH=/usr/lib:$LD_LIBRARY_PATH
export DYLD_LIBRARY_PATH=$LD_LIBRARY_PATH:$DYLD_LIBRARY_PATH
This worked for me when compiling with homebrew gcc on OS X 10.9 and 10.10.
The reason for this is that Xcode sets the SDK (in your case the macOS SDK) as the virtual root. So all search paths of the compiler and the linker are being interpreted as relative to the SDK folder.
Specifically, the Linker will not look in /usr/lib, it will look in [macOS SDK]/usr/lib.
If you need to use /usr/lib (e.g. when linking against OpenSSL's libssl which only exist in /usr/lib but not in [macOS SDK]/usr/lib, you can set "-isysroot /" as the first two "Other Linker Flags" of your project's or target's build settings. This ensures that the Linker will use / as the root (and hence will find libraries in /usr/lib), while the compiler will continue to use the virtual root set by Xcode (i.e. the macOS SDK).
I have installed and built the BOTAN cryptographic library.
Everything seems correctly installed, since I have the following entries in /usr/local/lib directory:
-rw-r--r-- 1 root root 7676350 2012-06-03 11:01 libbotan-1.10.a
lrwxrwxrwx 1 root root 20 2012-06-03 11:01 libbotan-1.10.so -> libbotan-1.10.so.0.1
lrwxrwxrwx 1 root root 20 2012-06-03 11:01 libbotan-1.10.so.0 -> libbotan-1.10.so.0.1
-rwxr-xr-x 1 root root 3396354 2012-06-03 11:01 libbotan-1.10.so.0.1
and in the /usr/local/include one too:
drwxr-xr-x 3 root root 4096 2012-06-03 11:01 botan-1.10
And eventually I managed to include the libraries in the main of my program, and write code without error.
However when building my project (on Eclipse Indigo) I get the following output on console, with the red stderr fashion:
error while loading shared libraries: libbotan-1.10.so.0: cannot open shared object file: No such file or directory
The code I'm trying to execute is the following:
try
{
cout << "In try" << endl;
Botan::LibraryInitializer init;
}catch(std::exception& e)
{
cout << "In catch" << endl;
cerr << e.what() << endl;
}
I have the following doubts:
Is it a problem of the Linker? (And if yes, why isn't the linker throwing the error, but the stderr?)
If not, how can I figure out to let my program find the libbotan-1.10.so.0 file which is actually there? (in /usr/local/lib).
Note that my environment variable $LD_LIBRARY_PATH is currently set, and has the following value:
$> echo $LD_LIBRARY_PATH
$> /usr/local/lib/
Compiler Command Line:
Invoking: GCC C++ Compiler
g++ -I/usr/include/c++/4.5.2 -I/usr/local/include/botan-1.10 -O3 -g3 -Wall -c -fmessage-length=0 -std=c++0x -v -MMD -MP -MF"mainOobClient.d" -MT"mainOobClient.d" -o "mainOobClient.o" "../mainOobClient.cpp"
g++ -I/usr/include/c++/4.5.2 -I/usr/local/include/botan-1.10 -O3 -g3 -Wall -c -fmessage-length=0 -std=c++0x -v -MMD -MP -MF"oobClientClass.d" -MT"oobClientClass.d" -o "oobClientClass.o" "../oobClientClass.cpp"
Invoking: GCC C++ Linker
g++ -L/usr/local/lib -o "MTVS_oobClient" ./mainOobClient.o ./oobClientClass.o -lbotan-1.10
Complete Build Output:
Build of configuration Debug for project MTVS_oobClient
make all
Building file: ../mainOobClient.cpp
Invoking: GCC C++ Compiler
g++ -I/usr/include/c++/4.5.2 -I/usr/local/include/botan-1.10 -O3 -g3 -Wall -c -fmessage-length=0 -std=c++0x -v -MMD -MP -MF"mainOobClient.d" -MT"mainOobClient.d" -o "mainOobClient.o" "../mainOobClient.cpp"
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/lto-wrapper
Target: i686-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.5.2-8ubuntu4' --with-bugurl=file:///usr/share/doc/gcc-4.5/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.5 --enable-shared --enable-multiarch --with-multiarch-defaults=i386-linux-gnu --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib/i386-linux-gnu --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.5 --libdir=/usr/lib/i386-linux-gnu --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-plugin --enable-gold --enable-ld=default --with-plugin-ld=ld.gold --enable-objc-gc --enable-targets=all --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=i686-linux-gnu --host=i686-linux-gnu --target=i686-linux-gnu
Thread model: posix
gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu4)
Finished building: ../mainOobClient.cpp
Building file: ../oobClientClass.cpp
Invoking: GCC C++ Compiler
g++ -I/usr/include/c++/4.5.2 -I/usr/local/include/botan-1.10 -O3 -g3 -Wall -c -fmessage-length=0 -std=c++0x -v -MMD -MP -MF"oobClientClass.d" -MT"oobClientClass.d" -o "oobClientClass.o" "../oobClientClass.cpp"
COLLECT_GCC_OPTIONS='-I/usr/include/c++/4.5.2' '-I/usr/local/include/botan-1.10' '-O3' '-g3' '-Wall' '-c' '-fmessage-length=0' '-std=c++0x' '-v' '-MMD' '-MP' '-MFmainOobClient.d' '-MTmainOobClient.d' '-o' 'mainOobClient.o' '-shared-libgcc' '-mtune=generic' '-march=i686'
/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/cc1plus -quiet -v -I/usr/include/c++/4.5.2 -I/usr/local/include/botan-1.10 -MMD mainOobClient.d -MFmainOobClient.d -MP -MTmainOobClient.d -MQ mainOobClient.o -dD -D_GNU_SOURCE ../mainOobClient.cpp -D_FORTIFY_SOURCE=2 -quiet -dumpbase mainOobClient.cpp -mtune=generic -march=i686 -auxbase-strip mainOobClient.o -g3 -O3 -Wall -std=c++0x -version -fmessage-length=0 -fstack-protector -o /tmp/ccLIYQkV.s
Finished building: ../oobClientClass.cpp
GNU C++ (Ubuntu/Linaro 4.5.2-8ubuntu4) version 4.5.2 (i686-linux-gnu)
Building target: MTVS_oobClient
Invoking: GCC C++ Linker
g++ ./mainOobClient.o ./oobClientClass.o -lbotan-1.10 -L/usr/local/lib -o "MTVS_oobClient"
compiled by GNU C version 4.5.2, GMP version 4.3.2, MPFR version 3.0.0-p8, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "/usr/local/include/i386-linux-gnu"
ignoring nonexistent directory "/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/../../../../../i686-linux-gnu/include"
ignoring duplicate directory "/usr/include/c++/4.5.2"
as it is a non-system directory that duplicates a system directory
Finished building target: MTVS_oobClient
#include "..." search starts here:
#include <...> search starts here:
/usr/local/include/botan-1.10
/usr/include/c++/4.5
/usr/include/c++/4.5/i686-linux-gnu
/usr/include/c++/4.5/backward
/usr/local/include
/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/include
/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/include-fixed
/usr/include/i386-linux-gnu
/usr/include
End of search list.
GNU C++ (Ubuntu/Linaro 4.5.2-8ubuntu4) version 4.5.2 (i686-linux-gnu)
compiled by GNU C version 4.5.2, GMP version 4.3.2, MPFR version 3.0.0-p8, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 0c5cb630517b5952f4898dfa56d7e8e5
COLLECT_GCC_OPTIONS='-I/usr/include/c++/4.5.2' '-I/usr/local/include/botan-1.10' '-O3' '-g3' '-Wall' '-c' '-fmessage-length=0' '-std=c++0x' '-v' '-MMD' '-MP' '-MFmainOobClient.d' '-MTmainOobClient.d' '-o' 'mainOobClient.o' '-shared-libgcc' '-mtune=generic' '-march=i686'
as -V -Qy --32 -o mainOobClient.o /tmp/ccLIYQkV.s
GNU assembler version 2.21.0 (i686-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.21.0.20110327
COMPILER_PATH=/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/:/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/:/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/:/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/:/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/
LIBRARY_PATH=/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/:/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/../../../:/lib/:/usr/lib/:/usr/lib/i386-linux-gnu/
COLLECT_GCC_OPTIONS='-I/usr/include/c++/4.5.2' '-I/usr/local/include/botan-1.10' '-O3' '-g3' '-Wall' '-c' '-fmessage-length=0' '-std=c++0x' '-v' '-MMD' '-MP' '-MFmainOobClient.d' '-MTmainOobClient.d' '-o' 'mainOobClient.o' '-shared-libgcc' '-mtune=generic' '-march=i686'
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/lto-wrapper
Target: i686-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.5.2-8ubuntu4' --with-bugurl=file:///usr/share/doc/gcc-4.5/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.5 --enable-shared --enable-multiarch --with-multiarch-defaults=i386-linux-gnu --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib/i386-linux-gnu --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.5 --libdir=/usr/lib/i386-linux-gnu --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-plugin --enable-gold --enable-ld=default --with-plugin-ld=ld.gold --enable-objc-gc --enable-targets=all --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=i686-linux-gnu --host=i686-linux-gnu --target=i686-linux-gnu
Thread model: posix
gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu4)
COLLECT_GCC_OPTIONS='-I/usr/include/c++/4.5.2' '-I/usr/local/include/botan-1.10' '-O3' '-g3' '-Wall' '-c' '-fmessage-length=0' '-std=c++0x' '-v' '-MMD' '-MP' '-MFoobClientClass.d' '-MToobClientClass.d' '-o' 'oobClientClass.o' '-shared-libgcc' '-mtune=generic' '-march=i686'
/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/cc1plus -quiet -v -I/usr/include/c++/4.5.2 -I/usr/local/include/botan-1.10 -MMD oobClientClass.d -MFoobClientClass.d -MP -MToobClientClass.d -MQ oobClientClass.o -dD -D_GNU_SOURCE ../oobClientClass.cpp -D_FORTIFY_SOURCE=2 -quiet -dumpbase oobClientClass.cpp -mtune=generic -march=i686 -auxbase-strip oobClientClass.o -g3 -O3 -Wall -std=c++0x -version -fmessage-length=0 -fstack-protector -o /tmp/ccTuqeWw.s
GNU C++ (Ubuntu/Linaro 4.5.2-8ubuntu4) version 4.5.2 (i686-linux-gnu)
compiled by GNU C version 4.5.2, GMP version 4.3.2, MPFR version 3.0.0-p8, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "/usr/local/include/i386-linux-gnu"
ignoring nonexistent directory "/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/../../../../../i686-linux-gnu/include"
ignoring duplicate directory "/usr/include/c++/4.5.2"
as it is a non-system directory that duplicates a system directory
#include "..." search starts here:
#include <...> search starts here:
/usr/local/include/botan-1.10
/usr/include/c++/4.5
/usr/include/c++/4.5/i686-linux-gnu
/usr/include/c++/4.5/backward
/usr/local/include
/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/include
/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/include-fixed
/usr/include/i386-linux-gnu
/usr/include
End of search list.
GNU C++ (Ubuntu/Linaro 4.5.2-8ubuntu4) version 4.5.2 (i686-linux-gnu)
compiled by GNU C version 4.5.2, GMP version 4.3.2, MPFR version 3.0.0-p8, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 0c5cb630517b5952f4898dfa56d7e8e5
../oobClientClass.cpp: In member function ‘void oobClientClass::authenticateTransaction()’:
../oobClientClass.cpp:126:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result
../oobClientClass.cpp:164:63: warning: ignoring return value of ‘ssize_t write(int, const void*, size_t)’, declared with attribute warn_unused_result
../oobClientClass.cpp:59:6: warning: ‘confirmationChoice’ may be used uninitialized in this function
COLLECT_GCC_OPTIONS='-I/usr/include/c++/4.5.2' '-I/usr/local/include/botan-1.10' '-O3' '-g3' '-Wall' '-c' '-fmessage-length=0' '-std=c++0x' '-v' '-MMD' '-MP' '-MFoobClientClass.d' '-MToobClientClass.d' '-o' 'oobClientClass.o' '-shared-libgcc' '-mtune=generic' '-march=i686'
as -V -Qy --32 -o oobClientClass.o /tmp/ccTuqeWw.s
GNU assembler version 2.21.0 (i686-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.21.0.20110327
COMPILER_PATH=/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/:/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/:/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/:/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/:/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/
LIBRARY_PATH=/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/:/usr/lib/i386-linux-gnu/gcc/i686-linux-gnu/4.5.2/../../../:/lib/:/usr/lib/:/usr/lib/i386-linux-gnu/
COLLECT_GCC_OPTIONS='-I/usr/include/c++/4.5.2' '-I/usr/local/include/botan-1.10' '-O3' '-g3' '-Wall' '-c' '-fmessage-length=0' '-std=c++0x' '-v' '-MMD' '-MP' '-MFoobClientClass.d' '-MToobClientClass.d' '-o' 'oobClientClass.o' '-shared-libgcc' '-mtune=generic' '-march=i686'
**** Build Finished ****
The error is coming at run-time. You need to specify the rpath for the binary at build time - Where you have the:
-L/usr/local/lib
You also need:
-Wl,-rpath=/usr/local/lib
This instructs ld to use this path when trying to find the library at run-time. Your LD_LIBRARY_PATH is probably being overridden by the launcher of eclipse, which is why the variable is not being used.
Alternatives:
Make sure that /usr/local/lib is in the /etc/ld.so.conf, and that ldconfig has been run after installing the library.
Link to the .a, using the command line:
g++ -o "MTVS_oobClient" ./mainOobClient.o ./oobClientClass.o -L/usr/local/lib -Wl,-Bstatic -lbotan-1.10 -Wl,-Bdynamic
or using:
g++ -o "MTVS_oobClient" ./mainOobClient.o ./oobClientClass.o /usr/local/lib/libbotan-1.10.a
... both should have the same effect
Since the program build ends correctly, it is clear that it's a run-time problem due to the fact that the program can't find the Shared Library.
I looked for other people with same run-time issue and found out the solution (that I'll briefly sum up) thanks to another SO question.
What I did was to build the dynamically-linked executable, that wishes to be linked against libbotan-1.10.so.0 at execution time. The linking during the build phase was done with command line option -L/usr/local/lib.
There are a few options to make botan (or any other library) available at run-time:
Create a symlink to botan in a directory listed in /etc/ld.so.conf (or /lib or /usr/lib)
Copy botan to a directory listed in /etc/ld.so.conf (or /lib or /usr/lib) (defaults)
Add the directory containing botan to /etc/ld.so.conf
Set LD_LIBRARY_PATH=/usr/local/lib before running your executable.
Recompile the program statically. (It will work, but don't bother.)
After any of the first 3, rerun ldconfig so the linker cache is updated. (You can then run ldconfig -v to verify it's resolvable.)
Note those aren't steps, they're options. You only need to do 1 of them.
Updating the linker cache with ldconfig made it work for me.