I wrote a very simple ncurses program to be run in BusyBox environment. However, it seems like that I cannot get my program to compile with everything. I used:
g++ menu.cpp -ohello -lncurses --> Works fine
g++ -static menu.cpp -ohello -lncurses --> Undefined reference to SP (many times)
I found this question but it ignores linking to ncurses. I need a very single executable. My targeted environment is fixed, so I do not concern portability.
You should paste the exact compiler calls and the exact error messages that you are getting.
Do you have a static version of the ncurses library?
More importantly, do you have a static version of the ncurses library compiled for your target environment? For example your target environment may be using ulibc instead of glibc or it could even be a whole different platform (hint: tell us what your target platform is).
Are you certain that you are compiling with the right flags? The compiler flags that you are showing seem more suited to compiling an application for use in the build host environment...
Related
In Windows, the dynamic loader always looks for modules in the path of the loaded executable first, making it possible to have private libraries without affecting system libraries.
The dynamic loader on Linux only looks for libraries in a fixed path, in the sense that it is independent on the chosen binary. I needed GCC 5 for its overflow checked arithmetic functions, but since the C++ ABI changed between 4.9 and 5, some applications became unstable and recompiling them solved the issue. While waiting for my distro [kubuntu] to upgrade the default compiler, is it possible to have newly compiled application linking to the new runtime, while packaged application still links to the old library, either by static linkage, or something that mimics the Windows behavior?
One way of emulating it would be to create a wrapper script
#!/bin/bash
LD_LIBRARY_PATH=$(dirname $(which your_file)) your_file
And after the linking step copy the affected library but it is sort of a hack.
You can use rpath.
Let's say your "new ABI" shared libraries are in /usr/local/newapi-libs.
gcc -L/usr/local/newapi-libs
-Wl,-rpath,/usr/local/newapi-libs
program.cpp -o program -lsomething`
The -rpath option of the linker is the runtime counterpart to -L. When a program compiled this way is run, the linker will first look in /usr/local/newapi-libs before searching the system library paths.
More information here and here.
You can emulate the Windows behavior of looking in the executable's directory by specifying -Wl,-rpath,.
[edit] added missing -L parameter and dashes before rpath.
I am trying to cabal install a component of wxHaskell (Haskell platform 2013.2 against wxWidgets 3.0).
I was able to compile the git version with 32 bit mingw from mingw.org. But in the end, the installed wx cannot function correct, and running a minimal example gives runtime exceptions in wxc.dll. So I try to compile the same thing under TDM-GCC 4.8.1 64bit, since the wxWidgets people provide their binary in the form of TDM-GCC compiled binaries.
But I immediately run into compilation errors with TDM-GCC, telling me
error: 'strnlen' was not declared in this scope
What surprises me is that even though both mingw32 and TDM-gcc uses the same external gcc from Haskell Platform c:\HaskellPlatform\2013.2.0.0\mingw\bin\gcc.exe, one would give an error while the other compiles fine.
The first file causing problem is src\cpp\eljaccelerator.cpp. It compiles OK under mingw32:
...
c:\HaskellPlatform\2013.2.0.0\mingw\bin\gcc.exe -Wl,--hash-size=31 -Wl,--reduce-
memory-overheads -Isrc/include -IC:/MinGW/msys/1.0/local/include/wx-3.0 -IC:/Min
GW/msys/1.0/local/lib/wx/include/msw-unicode-3.0 -D__WXMSW__ -DWXUSINGDLL -D_LAR
GEFILE_SOURCE=unknown -DwxcREFUSE_MEDIACTRL -DBUILD_DLL -c src\cpp\eljaccelerato
r.cpp -o dist\build\src/cpp/eljaccelerator.o
but gives an error under TDM-gcc:
Building wxc
c:\HaskellPlatform\2013.2.0.0\mingw\bin\gcc.exe -Wl,--hash-size=31 -Wl,--reduce-
memory-overheads -Isrc/include -IC:/mingw/msys/1.0/local/include/wx-3.0 -IC:/min
gw/msys/1.0/local/lib/wx/include/msw-unicode-3.0 -D__WXMSW__ -DWXUSINGDLL -D_FIL
E_OFFSET_BITS=64 -DwxcREFUSE_MEDIACTRL -DBUILD_DLL -c src\cpp\eljaccelerator.cpp
-o dist\build\src/cpp/eljaccelerator.o
In file included from C:/mingw/msys/1.0/local/include/wx-3.0/wx/crt.h:19:0,
from C:/mingw/msys/1.0/local/include/wx-3.0/wx/string.h:4305,
from C:/mingw/msys/1.0/local/include/wx-3.0/wx/memory.h:15,
from C:/mingw/msys/1.0/local/include/wx-3.0/wx/object.h:19,
from C:/mingw/msys/1.0/local/include/wx-3.0/wx/wx.h:15,
from src/include/wrapper.h:20,
from src\cpp\eljaccelerator.cpp:1:
C:/mingw/msys/1.0/local/include/wx-3.0/wx/wxcrt.h: In function 'size_t wxStrnlen
(const char*, size_t)':
C:/mingw/msys/1.0/local/include/wx-3.0/wx/wxcrt.h:173:92: error: 'strnlen' was n
ot declared in this scope
C:/mingw/msys/1.0/local/include/wx-3.0/wx/wxcrt.h: In function 'size_t wxStrnlen
(const wchar_t*, size_t)':
C:/mingw/msys/1.0/local/include/wx-3.0/wx/wxcrt.h:187:95: error: 'wcsnlen' was n
ot declared in this scope
Failed to install wxc-0.90.1.1
I was wondering if anyone has any similar experience. Any idea what went wrong and how to fix compilation for TDM-GCC? I tried adding #include <cstring> to wxcrt.h but it doesn't change anything.
FYI, I have compiled wxWidgets 3.0.0 from source in mingw and tdm-gcc versions respectively, using
./configure --enable-stl && make && make install
I can provide more details if needed.
First of all, wxWidgets certainly does work with MinGW, the fact that only TDM binaries are provided simply means that someone volunteered to provide the latter but not the former. But all three popular versions of MinGW (the two already mentioned and MinGW-w64) do work, so there must be something wrong with the build...
However while they all work, they are certainly different compilers, so what do you mean that they both use the same gcc binary? It must be either a MinGW one or a TDM one, but it can't be both at once.
It's also very suspicious that the configure detects different flags to use for the large file support. Look at config.log, something must have gone wrong and there must be some errors in the initial stage in it.
Context: I'm using a linux toolchain (includes g++, other build tools, libs, headers, etc) to build my code with statically linked libraries. I want to ensure that I'm using ONLY libraries/headers from my toolchain, not the default ones on the build machine. I can use strace to see what g++ is doing (which libraries it is using) while it is compiling which would be helpful in a normal scenario - but my build system has many wrappers around g++ that hide all of the output.
Question: is there a way to obtain from a statically-linked binary any useful information regarding the library and header files which were used to create the binary? I've taken a look at the objdump tool but I'm not sure if it will help much.
Just pass -v to g++ or gcc at link time. It will show all the linked libraries. Perhaps try make CC='gcc -v' CXX='g++ -v'
More generally, -v passed g++ or gcc shows you the underlying command with its arguments because gcc or g++ is just a driver program (starting cc1, ld or collect2, as, ...)
By passing the -H flag to GCC (i.e. g++ or gcc) you can see every included header. So you can check that only the heanders you expect are included.
You cannot see what static library has been linked, because linking a static library just means linking the relevant object file members in it, so a static library can (and usually is) linked in only partly.
You could use the nm command to find names from such libraries.
If you can simply recompile, then there are ways (using some of the techniques that Basile explained) to get the headers and libraries (static or dynamic) but, unfortunately, there is no way to know which libraries were used after the compilation is complete.
I'm trying to use the 64-bit MinGW from http://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win64/Automated%20Builds/ but when I compile a program with it, the resulting executable fails when a DLL isn't available.
How do I get this compiler to do static linking with the standard library?
Or is there another distribution of 64-bit MinGW that I should be using instead?
The g++ switch is supposed to be
-static
See
http://gcc.gnu.org/onlinedocs/gcc/Link-Options.html.
-static
On systems that support dynamic linking, this prevents linking with
the shared libraries. On other systems, this option has no effect.
You should post the command line, that you use in order to compile/link, in order to get more help if this does not work for you.
I need to compile glibc from source with debug symbols .
Where do i specify the '-g' option for this
How do i later make a sample code link to this particular glibc rather than the one installed on my system?
I need to compile glibc from source with debug symbols
You will have hard time compiling glibc without debug symbols. A default ./configure && make will have -g on compile line.
How do i later make a sample code link to this particular glibc rather than the one installed on my system?
This is somewhat tricky, and answered here.
It is probably a matter of configure tricks. First, try configure --help and then, either configure --enable-debug or perhaps configure CC='gcc -g' or even configure CFLAGS='-g'
For your sample code, perhaps consider playing LD_LIBRARY_PATH or LD_PRELOAD tricks (assuming linking to dynamic library).
But be very careful, since the Glibc is the cornerstone of Gnu/Linux like systems.