A directory teeming with demonstration files called ncurses-examples-20200725 is available here:
[ftp://ftp.invisible-island.net/ncurses-examples/current/ncurses-examples.tar.gz][1]
I wanted to study the workings of the form_driver_w example so I built the programs in accordance with the README file.
If I run ./form_driver_w, the result is a command line statement: "This program requires the wide-ncurses and forms library".
That outcome occurs because the following statement is not true:
#if USE_WIDEC_SUPPORT && USE_LIBFORM && (defined(NCURSES_VERSION_PATCH) && NCURSES_VERSION_PATCH >= 20131207)
Trying to trace how and where in the labyrinth of header files and compiler switches USE_WIDEC_SUPPORT is set to true is diabolically difficult. Furthermore, since the source code uses form_driver_w, I would have expected the compiler to link to ncursesw. However the compiler call is like this:
gcc -g -O2 -o form_driver_w ../ncurses-examples-20200725/form_driver_w.o ../ncurses-examples-20200725/popup_msg.o -L/lib64 -I. -I. -I../test -DHAVE_CONFIG_H -DDATA_DIR=\"/usr/local/share\" -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=600 -D_XPG5 -g -O2 -DNCURSES_STATIC -lform -lmenu -lpanel -lncurses -lutil -lm
My Debian Bullseye installation includes a binary called form_driver_w in the /usr/lib/ncurses/examples/ directory. That binary runs correctly. I do not know how it was compiled.
Compiling and running form_driver_w must be a trivial task. Does anybody know how to do it?
You'd have to configure using ncursesw:
configure --with-screen=ncursesw
(and, of course, have the development library available).
The place to find this information is by running
configure --help
which lists a few options:
General Options:
--disable-stripping do not strip (debug info) installed executables
--enable-string-hacks work around bogus compiler/loader warnings
--with-pkg-config{=path} enable/disable use of pkg-config
--disable-echo do not display "compiling" commands
Curses Version-dependent Options:
--with-ncurses-wrap-prefix naming-prefix for ncurses wrapped-variables
--disable-widec disable checks for wide-character functions
--with-curses-dir=DIR directory in which (n)curses is installed
--with-screen=XXX use specified curses-libraries
--with-ncursesw use wide ncurses-libraries
--with-ncurses use ncurses-libraries
--with-pdcurses compile/link with pdcurses X11 library
--with-curses-colr compile/link with HPUX 10.x color-curses
--with-curses-5lib compile/link with SunOS 5lib curses
--with-Xaw3d link with Xaw 3d library
--with-Xaw3dxft link with Xaw 3d xft library
--with-neXtaw link with neXT Athena library
--with-XawPlus link with Athena-Plus library
--with-x use the X Window System
--with-x11-rgb=FILE file containing X11 rgb information (EPREFIX/lib/X11/rgb.txt)
--with-form-libname=XXX override form basename of library
--with-menu-libname=XXX override menu basename of library
--with-panel-libname=XXX override panel basename of library
--disable-panel disable checks for panel functions
--disable-menu disable checks for menu functions
--disable-form disable checks for form functions
Testing/development Options:
--enable-warnings test: turn on gcc compiler warnings
--with-dmalloc test: use Gray Watson's dmalloc library
--with-dbmalloc test: use Conor Cahill's dbmalloc library
--with-valgrind test: use valgrind
--disable-leaks test: free permanent memory, analyze leaks
--disable-rpath-hack don't add rpath options for additional libraries
Related
Hi team,
I have three files which I need to compile for testing, btw im using CentOS linux.
source_code.c
library.h
library.c
how do I put the library.h in the gcc library, so I can use it?
how do I compile the source_code.c to use that library?
Thank you very much.
This is basic knowledge of your tools, but you can do this:
#include "library.h" in the include section of the library.c code (at top of the file).
gcc source_code.c library.c in the linux terminal will link and compile both source_code.c and library.c. This will generate an executable named "a.out" (if there were no compilation problems). You can change its name, by adding the option -o name to the gcc command (gcc source_code.c library.c -o mycode will generate an executable named "mycode").
If you really need a library that will be used by a lot of other programs, you can look for "shared libraries", but I think that you are asking for a basic thing.
You dont need this library.h while building and executable (with gcc) as you should have specified the exact location of the library in the source file. All you need to do is gcc sourcefile1.c sourcefile2.c -o exename
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.
There is a set with - files with extension.с: avl_tree.c, buf_read.c, db_prep.c, file_process.c, global_header.c, traverser.c. Used include files are in folder/usr/gcc/4.4/bin/include except for jni.h, and libraries are in folder/usr/gcc/4.4/bin/lib. How from them to create.so the file (if it is possible specify all options in this command)? It me interests in communication by creation of native of methods by means of JNI.
You really should read the documentation of GCC. Notably invoking GCC. The program library howto is also relevant.
Very often, some builder is used to drive the build. GNU make is often used and has a good tutorial documentation. If your Makefile-s are complex, you may also want to use GNU remake to debug them (remake is a debugging variant for make).
You usually want to compile each individual C source file into position independent code because shared objects have PIC code. You can use
gcc -Wall -fPIC -o foo.pic.o foo.c
to compile a C source foo.c into a position independent object file foo.pic.o and you may need some other compiler options (e.g. -I to add include directories, or -D to define some preprocessor symbols, -g for debugging, and -O for optimizing).
I strongly suggest to enable almost all warnings with -Wall (and to improve your code till no warnings are given; this will improve a little bit your code's quality).
Then you have to link all these *.pic.o files together into a shared object with
gcc -shared *.pic.o -o foo.so
You can link some shared libraries into a shared object.
You may want to read Levine's book on linkers and loaders
Of course if you use GNU make you'll have rules in your Makefile for all this.
You could use GNU libtool also.
Maybe dlopen(3) could interest you.
The question should probably give more information.
Most sets of sources have a Makefile, configure script or some other item to set up to make the output (the .so library you want).
gcc -dynamic -o file.so file.c
will create an so file from one of the source files, but you probably want a single so from all of them.
I have a shared library which is supposed to export only one function which is marked with __attribute__ ((visibility ("default"))). It also links with another static library (fftw), and
#include<fftw3.h>
is preceded with:
#pragma GCC visibility push(hidden)
The linker command used:
g++.exe -fvisibility=hidden -shared -o mylib.dll -Wl,--out-implib,mylib.dll.a -Wl,--no-whole-archive libfftw3.a libfftw3_omp.a -lgomp
Now the resulting library is huge and if I check the exported functions it includes ALL fftw functions, and ALL function from my files. It looks like mingw ignores visibility options. I read that previously it gave warning about -fvisibility, but now it compiles with no warnings whatsoever.
Does mingw and gcc 4.6.1 support visibility flags? If yes, how do I get rid of all unnecessary stuff in my shared library?
Mingw is a Windows port of GCC toolchain but Windows dll are not Linux so. Especially the link part is different. To specify the visibility with MingGW you have to go the Windows way and annotate your classes and functions with :
__declspec(dllexport) while compiling the library
__declspec(dllimport) while linking
If you want multiplatform support for the GCC toolchain you can add a header in your project doing that for you. For a step by step example and lots of details have a look at GCC's visibility guide.
Windows PE object files do not have visibility attributes. The closest is dllexport/dllimport, but that's only for shared libraries (DLL's). So either you don't mark all FFTW functions with __declspec(dllexport), and hope linking the static library does The Right Thing (tm), or you take care not to link to FFTW if linking with your library.
It should warn about bad visibility attributes, perhaps you need to turn up the warning level -Wall -Wextra -pedantic).
My gcc compiler is at a custom location /my/path/hpgcc
I've downloaded the boost sources. Executed bootstrap.sh, but it fails because it runs with the default gcc.
Looking into it, I see that it fails at the first thing it does: building the Boost.Build engine:
gcc -o bootstrap/jam0 command.c compile.c debug.c expand.c glob.c hash.c hdrmacro.c headers.c jam.c jambase.c jamgram.c lists.c make.c make1.c newstr.c option.c output.c parse.c pathunix.c pathvms.c regexp.c rules.c scan.c search.c subst.c timestamp.c variable.c modules.c strings.c filesys.c builtins.c pwd.c class.c native.c md5.c w32_getreg.c modules/set.c modules/path.c modules/regex.c modules/property-set.c modules/sequence.c modules/order.c execunix.c fileunix.c
(fails because executed with the default gcc, and not my gcc version).
I've tried to change the gcc path in the user-config.jam file, but it doesn't help. Probably because the Boost.Build's build script boost_1_47_0/tools/build/v2/engine/build.sh doesn't use user-config.jam, and just uses the default locations.
Any solution?
Add the line:
using gcc : : /my/path/hpgcc ;
to user-config.jam. user-config.jam will usually be in /path/to/boost/tools/build/v2/, but you can put a custom user-config.jam or site-config.jam in any of the places listed here.
/my/path/hpgcc should be the full path to the g++ executable.
EDIT (Igor Oks) : What eventually solved the problem is that I edited boost_1_47_0/tools/build/v2/engine/build.sh to make it use my custom gcc.
We do this in our build environment by simply defining the PATH and LD_LIBRARY_PATH environment variables to pickup our desired GCC first.