Adding path and linking libraries - linux

I am trying to complete the installation for some software. According to which I have to add path. I am not getting it how to do that. Please guide me how to do the following steps.
Add the path to Rpa/Tk headers:
-I/usr/include/rpatk
To link to the Rpa/Tk libraries on Linux add the following link options:
-lrpa -lrvm -lrex -lrlib -lm
RVM library uses some math functions from the system math library, that is why you must include '-lm' to include the math library to your project in addition to the Rpa/Tk built libraries:
librpa librex librvm librlib
http://www.rpasearch.com/rpatk/doc/doxygen/rpadoc/html/rpatk_build.html

this will be within your configure script -- you will need to hack this and add the paths to where gcc/cc gets called
give the link to the actual tar.gz
looking at the example code: http://www.rpasearch.com/rpatk/doc/doxygen/rpadoc/html/js-tokenizer_8c-example.html
gcc -I/usr/include/rpatk -o js-tokenizer js-tokenizer.c -lrex -lrlib
so in short :
export LD_LIBRARY_PATH=/usr/include/rpatk:/usr/local/lib:/lib:/usr/lib
then running the configure may fix the issue
where the bit in bold would the path to the includes for this project

Related

Autotools AC_SEARCH_LIBS finds the library, but doesn't add it to $LIBS

I am using autotools to configure and build my project which uses dlopen and its friends.
I've got the following snippet in my root configure.ac:
AC_SEARCH_LIBS([dlopen], [dl dld], [], [
AC_MSG_ERROR([unable to find the dlopen() function])
])
which I got from https://autotools.io/autoconf/finding.html
The library is found by autotools:
checking for library containing dlopen... -ldl
However, the library doesn't appear to get added to $(LIBS) because:
a_out_LDADD=-ldl
works (i.e. project compiles, and runs), and
a_out_LDADD=$(LIBS)
does not (i.e. undefined reference to 'dlopen')
What am I missing?
(Full disclosure, I'm the author of the linked documentation.)
Are you sure the LIBS variable is not getting somehow clobbered? You can check config.log to see what the final output is. I think the most common problem with this is a later line that goes LIBS=${SOMEDEPS_LIBS} without prepending the old LIBS value.
Also you should not need to do _LDADD=$(LIBS) because the latter is added by default to all linking commands.

How to properly create autoconf setup of netcdf 4.x?

I am not sure exactly what my question is as I get seriously turned around by autoconf/automake/libtoolize etc. Several of us are trying to autoconferize mbsystem. I've thrown a repo up of the work to date here:
https://bitbucket.org/schwehr/mbsystem
I'm trying to improve the netcdf setup to use nc-config, but am uncertain how to do this correctly. I am working on configure.in. It seems unable to find a header with AC_CHECK_HEADER("netcdfcpp.h") after INCLUDES="$INCLUDES ``$nc_config --cflags``" (pardon the incorrect back ticks) as taken from the gdl netcdf check. What is the correct way to update the path from nc-config --cflags?
http://gnudatalanguage.cvs.sourceforge.net/viewvc/gnudatalanguage/gdl/configure.in?revision=1.121
I then tried to use AX_PATH_GENERIC and get stuck on this error with m4_include([m4/ax_path_generic.m4])
Running autoconf ...
configure.in:29: error: possibly undefined macro: AC_SUBST
If this token and others are legitimate, please use m4_pattern_allow.
See the Autoconf documentation.
configure:12992: error: possibly undefined macro: AC_MSG_RESULT
Any help in getting better at creating a netcdf check that actually will work with funky non-standard install locations via nc-config and figuring out how to properly put a macro in the m4 directory would be a huge help.
A pointer to a package doing this really cleanly would be a super help. I've been looking at the netcdf, gdal, geos and gdl sources for examples. And things like the octopus netcdf check do not use nc-config... http://www.tddft.org/trac/octopus/browser/trunk/m4/netcdf.m4
The current setup with fink for netcdf 4.x:
nc-config --cflags --libs
-I/sw/opt/netcdf7/include -I/sw/include
-L/sw/opt/netcdf7/lib -lnetcdf
Thanks!
See Makefile.am: How to use curl-config and xml2-config in configure.ac? and substitute xml2/curl by netcdf.
Just use
PKG_CHECK_MODULES([libnetcdf], [netcdf])
in configure.ac, and then, in Makefile.am:
AM_CPPFLAGS = ${libnetcdf_CFLAGS}
bin_PROGRAMS = foo
foo_SOURCES = ...
foo_LDADD = ${libnetcdf_LIBS}
The "correct" way to use a third party m4 macro is to use aclocal (usually via automake) to generate aclocal.m4. If you are using automake, just add
ACLOCAL_AMFLAGS = -I m4
to Makefile.am and put
AC_CONFIG_MACRO_DIR([m4])
in configure.ac (after renaming configure.in).
If you are not using automake, add '-I m4' when you invoke aclocal. If you are not using aclocal, then you'll have to append the definition of the macro to the end of aclocal.m4 (and be careful to never run aclocal, as that will overwrite the file.)
There is no good example of a clean way to use conf scripts to do a build because using such scripts is an inherently flawed approach. A slightly cleaner approach is to stop using custom scripts and use pkg-config via PKG_CHECK_MODULES, but the cleanest way to do this is to educate your users. If the user wants to install the library in funky non-standard locations then they need to be educated enough to set LDFLAGS and CPPFLAGS appropriately.

CMake finds the correct library, but VC++ attempts to link with something else

I have a CMake module to locate FreeGLUT:
FIND_PATH(FREEGLUT_INCLUDE_DIR NAMES GL/freeglut.h)
FIND_LIBRARY(FREEGLUT_LIBRARY NAMES freeglut freeglut_static)
SET(FREEGLUT_LIBRARIES ${FREEGLUT_LIBRARY})
SET(FREEGLUT_INCLUDE_DIRS ${FREEGLUT_INCLUDE_DIR})
INCLUDE(FindPackageHandleStandardArgs)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(FreeGLUT DEFAULT_MSG FREEGLUT_LIBRARY FREEGLUT_INCLUDE_DIR)
MARK_AS_ADVANCED(FREEGLUT_INCLUDE_DIR FREEGLUT_LIBRARY)
It works fine and locates freeglut_static.lib when I generate NMake Makefiles on Windows. I'm attempting to statically link FreeGLUT into my DLL:
FIND_PACKAGE(FreeGLUT REQUIRED)
ADD_LIBRARY(vti SHARED ${VTI_SOURCES})
ADD_DEFINITIONS("-DBUILD_VTI=1 -DFREEGLUT_STATIC=1")
INCLUDE_DIRECTORIES(${CMAKE_SOURCE_DIR}/include ${FREEGLUT_INCLUDE_DIRS})
TARGET_LINK_LIBRARIES(vti ${FREEGLUT_LIBRARIES})
My source code builds correctly, but when it gets to the linking stage, VC++ fails with:
LINK : fatal error LNK1104: cannot open file 'freeglut.lib'
Which is strange since freeglut.lib isn't mentioned anywhere that I can see in the generated NMake makefiles. It should be trying to link with freeglut_static.lib, which CMake locates and sets in FREEGLUT_LIBRARIES.
What might be causing this?
This is caused with pragma directives in FreeGLUT code (see freeglut_std.h). Using FREEGLUT_STATIC should really fix that for you, but I think you should pass it to CMake without quotes: ADD_DEFINITIONS(-DBUILD_VTI -DFREEGLUT_STATIC)

Reusing custom makefile for static library with cmake

I guess this would be a generic question on including libraries with existing makefiles within cmake; but here's my context -
I'm trying to include scintilla in another CMake project, and I have the following problem:
On Linux, scintilla has a makefile in (say) the ${CMAKE_CURRENT_SOURCE_DIR}/scintilla/gtk directory; if you run make in that directory (as usual), you get a ${CMAKE_CURRENT_SOURCE_DIR}/scintilla/bin/scintilla.a file - which (I guess) is the static library.
Now, if I'd try to use cmake's ADD_LIBRARY, I'd have to manually specify the sources of scintilla within cmake - and I'd rather not mess with that, given I already have a makefile. So, I'd rather call the usual scintilla make - and then instruct CMAKE to somehow refer to the resulting scintilla.a. (I guess that this then would not ensure cross-platform compatibility - but note that currently cross-platform is not an issue for me; I'd just like to build scintilla as part of this project that already uses cmake, only within Linux)
So, I've tried a bit with this:
ADD_CUSTOM_COMMAND(
OUTPUT scintilla.a
COMMAND ${CMAKE_MAKE_PROGRAM}
WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/scintilla/gtk
COMMENT "Original scintilla makefile target" )
... but then, add_custom_command adds a "target with no output"; so I'm trying several approach to build upon that, all of which fail (errors given as comment):
ADD_CUSTOM_TARGET(scintilla STATIC DEPENDS scintilla.a) # Target "scintilla" of type UTILITY may not be linked into another target.
ADD_LIBRARY(scintilla STATIC DEPENDS scintilla.a) # Cannot find source file "DEPENDS".
ADD_LIBRARY(scintilla STATIC) # You have called ADD_LIBRARY for library scintilla without any source files.
ADD_DEPENDENCIES(scintilla scintilla.a)
I'm obviously quote a noob with cmake - so, is it possible at all to have cmake run a pre-existing makefile, and "capture" its output library file, such that other components of the cmake project can link against it?
Many thanks for any answers,
Cheers!
EDIT: possible duplicate: CMake: how do i depend on output from a custom target? - Stack Overflow - however, here the breakage seems to be due to the need to specifically have a library that the rest of the cmake project would recognize...
Another related: cmake - adding a custom command with the file name as a target - Stack Overflow; however, it specifically builds an executable from source files (which I wanted to avoid)..
You could also use imported targets and a custom target like this:
# set the output destination
set(SCINTILLA_LIBRARY ${CMAKE_CURRENT_SOURCE_DIR}/scintilla/gtk/scintilla.a)
# create a custom target called build_scintilla that is part of ALL
# and will run each time you type make
add_custom_target(build_scintilla ALL
COMMAND ${CMAKE_MAKE_PROGRAM}
WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/scintilla/gtk
COMMENT "Original scintilla makefile target")
# now create an imported static target
add_library(scintilla STATIC IMPORTED)
# Import target "scintilla" for configuration ""
set_property(TARGET scintilla APPEND PROPERTY IMPORTED_CONFIGURATIONS NOCONFIG)
set_target_properties(scintilla PROPERTIES
IMPORTED_LOCATION_NOCONFIG "${SCINTILLA_LIBRARY}")
# now you can use scintilla as if it were a regular cmake built target in your project
add_dependencies(scintilla build_scintilla)
add_executable(foo foo.c)
target_link_libraries(foo scintilla)
# note, this will only work on linux/unix platforms, also it does building
# in the source tree which is also sort of bad style and keeps out of source
# builds from working.
OK, I think I have it somewhat; basically, in the CMakeLists.txt that build scintilla, I used this only:
ADD_CUSTOM_TARGET(
scintilla.a ALL
COMMAND ${CMAKE_MAKE_PROGRAM}
WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/scintilla/gtk
COMMENT "Original scintilla makefile target" )
... and then, the slightly more complicated part, was to find the correct cmake file elsewhere in the project, where the ${PROJECT_NAME} was defined - so as to add a dependency:
ADD_DEPENDENCIES(${PROJECT_NAME} scintilla.a)
... and finally, the library needs to be linked.
Note that in the commands heretofore, the scintilla.a is merely a name/label/identifier/string (so it could be anything else, like scintilla--a or something); but for linking - the full path to the actual `scintilla.a file is needed (which in this project ends up in a variable ${SCINTILLA_LIBRARY}). In this project, the linking basically occurs through a form of a
list(APPEND PROJ_LIBRARIES ${SCINTILLA_LIBRARY} )
... and I don't really know how cmake handles the actual linking afterwards (but it seems to work)
For consistency, I tried to use ${SCINTILLA_LIBRARY} instead of scintilla.a as identifier in the ADD_CUSTOM_TARGET, but got error: "Target names may not contain a slash. Use ADD_CUSTOM_COMMAND to generate files". So probably this could be solved smarter/more correct with ADD_CUSTOM_COMMAND - however, I read that it "defines a new command that can be executed during the build process. The outputs named should be listed as source files in the target for which they are to be generated."... And by now I'm totally confused so as to what is a file, what is a label, and what is a target - so I think I'll leave at this (and not fix it if it ain't broken :) )
Well, it'd still be nice to know a more correct way to do this eventually,
Cheers!

Installing and Linking PhysX Libraries in Debian Linux

I am trying to get PhysX working using Ubuntu.
First, I downloaded the SDK here:
http://developer.download.nvidia.com/PhysX/2.8.1/PhysX_2.8.1_SDK_CoreLinux_deb.tar.gz
Next, I extracted the files and installed each package with:
dpkg -i filename.deb
This gives me the following files located in /usr/lib/PhysX/v2.8.1:
libNxCharacter.so
libNxCooking.so
libPhysXCore.so
libNxCharacter.so.1
libNxCooking.so.1
libPhysXCore.so.1
Next, I created symbolic links to /usr/lib:
sudo ln -s /usr/lib/PhysX/v2.8.1/libNxCharacter.so.1 /usr/lib/libNxCharacter.so.1
sudo ln -s /usr/lib/PhysX/v2.8.1/libNxCooking.so.1 /usr/lib/libNxCooking.so.1
sudo ln -s /usr/lib/PhysX/v2.8.1/libPhysXCore.so.1 /usr/lib/libPhysXCore.so.1
Now, using Eclipse, I have specified the following libraries (-l):
libNxCharacter.so.1
libNxCooking.so.1
libPhysXCore.so.1
And the following search paths just in case (-L):
/usr/lib/PhysX/v2.8.1
/usr/lib
Also, as Gerald Kaszuba suggested, I added the following include paths (-I):
/usr/lib/PhysX/v2.8.1
/usr/lib
Then, I attempted to compile the following code:
#include "NxPhysics.h"
NxPhysicsSDK* gPhysicsSDK = NULL;
NxScene* gScene = NULL;
NxVec3 gDefaultGravity(0,-9.8,0);
void InitNx()
{
gPhysicsSDK = NxCreatePhysicsSDK(NX_PHYSICS_SDK_VERSION);
if (!gPhysicsSDK)
{
std::cout<<"Error"<<std::endl;
return;
}
NxSceneDesc sceneDesc;
sceneDesc.gravity = gDefaultGravity;
gScene = gPhysicsSDK->createScene(sceneDesc);
}
int main(int arc, char** argv)
{
InitNx();
return 0;
}
The first error I get is:
NxPhysics.h: No such file or directory
Which tells me that the project is obviously not linking properly. Can anyone tell me what I have done wrong, or what else I need to do to get my project to compile? I am using the GCC C++ Compiler. Thanks in advance!
It looks like you're confusing header files with library files. NxPhysics.h is a source code header file. Header files are needed when compiling source code (not when linking). It's probably located in a place like /usr/include or /usr/include/PhysX/v2.8.1, or similar. Find the real location of this file and make sure you use the -I option to tell the compiler where it is, as Gerald Kaszuba suggests.
The libraries are needed when linking the compiled object files (and not when compiling). You'll need to deal with this later with the -L and -l options.
Note: depending on how you invoke gcc, you can have it do compiling and then linking with a single invocation, but behind the scenes it still does a compile step then a link step.
EDIT: Extra explanation added...
When building a binary using a C/C++ compiler, the compiler reads the source code (.c or .cpp files). While reading it, there are frequently #include statements that are used to read .h files. The #include statements give the names of files that must be loaded. Those exact files must exist in the include path. In your case, a file with the exact name "NxPhysics.h" must be found somewhere in the include path. Typically, /usr/include is in the path by default, and so is the current directory. If the headers are somewhere else such as a subdirectory of /usr/include, then you always need to explicitly tell the compiler where to look using the -I command-line switches (or sometimes with environment variables or other system configuration methods).
A .h header file typically includes data structure declarations, inline function definitions, function and class declarations, and #define macros. When the compilation is done, a .o object file is created. The compiler does not know about .so or .a libraries and cannot use them in any way, other than to embed a little bit of helper information for the linker. Note that the compiler also embeds some "header" information in the object files. I put "header" in quotes because the information only roughly corresponds to what may or may not be found in the .h files. It includes a binary representation of all exported declarations. No macros are found there. I believe that inline functions are omitted as well (though I could be wrong there).
Once all of the .o files exist, it is time for another program to take over: the linker. The linker knows nothing of source code files or .h header files. It only cares about binary libraries and object files. You give it a collection of libraries and object files. In their "headers" they list what things (data types, functions, etc.) they define and what things they need someone else to define. The linker then matches up requests for definitions from one module with actual definitions for other modules. It checks to make sure there aren't multiple conflicting definitions, and if building an executable, it makes sure that all requests for definitions are fulfilled.
There are some notable caveats to the above description. First, it is possible to call gcc once and get it to do both compiling and linking, e.g.
gcc hello.c -o hello
will first compile hello.c to memory or to a temporary file, then it will link against the standard libraries and write out the hello executable. Even though it's only one call to gcc, both steps are still being performed sequentially, as a convenience to you. I'll skip describing some of the details of dynamic libraries for now.
If you're a Java programmer, then some of the above might be a little confusing. I believe that .net works like Java, so the following discussion should apply to C# and the other .net languages. Java is syntactically a much simpler language than C and C++. It lacks macros and it lacks true templates (generics are a very weak form of templates). Because of this, Java skips the need for separate declaration (.h) and definition (.c) files. It is also able to embed all the relevant information in the object file (.class for Java). This makes it so that both the compiler and the linker can use the .class files directly.
The problem was indeed with my include paths. Here is the relevant command:
g++ -I/usr/include/PhysX/v2.8.1/SDKs/PhysXLoader/include -I/usr/include -I/usr/include/PhysX/v2.8.1/LowLevel/API/include -I/usr/include/PhysX/v2.8.1/LowLevel/hlcommon/include -I/usr/include/PhysX/v2.8.1/SDKs/Foundation/include -I/usr/include/PhysX/v2.8.1/SDKs/Cooking/include -I/usr/include/PhysX/v2.8.1/SDKs/NxCharacter/include -I/usr/include/PhysX/v2.8.1/SDKs/Physics/include -O0 -g3 -DNX_DISABLE_FLUIDS -DLINUX -Wall -c -fmessage-length=0 -MMD -MP -MF"main.d" -MT"main.d" -o"main.o" "../main.cpp"
Also, for the linker, only "PhysXLoader" was needed (same as Windows). Thus, I have:
g++ -o"PhysXSetupTest" ./main.o -lglut -lPhysXLoader
While installing I got the following error
*
dpkg: dependency problems prevent configuration of libphysx-dev-2.8.1:
libphysx-dev-2.8.1 depends on libphysx-2.8.1 (= 2.8.1-4); however:
Package libphysx-2.8.1 is not configured yet.
dpkg: error processing libphysx-dev-2.8.1 (--install):
dependency problems - leaving unconfigured
Errors were encountered while processing:
*
So I reinstalled *libphysx-2.8.1_4_i386.deb*
sudo dpkg -i libphysx-2.8.1_4_i386.deb

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