I am running Ubuntu 64bit version, and downloaded the latest 64bit Eclipse.
Installed g++ along with build-essential. Tested g++ to make sure it works from terminal, and it works fine.
alex#ubuntu:~/Desktop$ g++ test.cpp -o test
alex#ubuntu:~/Desktop$ ./test
Hello World!alex#ubuntu:~/Desktop$
However, trying to build simple C++ Hello Word project(one of the default projects that comes with Eclipse), I am getting error.
Description Resource Path Location Type
Program "g++" not found in PATH Preferences, C++/Build/Settings/Discovery, [CDT GCC Builtin Compiler Settings] options C/C++ Scanner Discovery Problem
I have added Environment variable named g++ with value /usr/bin/g++ and the above error went away, however, now I am getting unresolved errors, though project compiles and in the Console shows !!!Hello World!!!
Description Resource Path Location Type
Symbol 'endl' could not be resolved test_hello.cpp /test_hello/src line 13 Semantic Error
Symbol 'cout' could not be resolved test_hello.cpp /test_hello/src line 13 Semantic Error
Symbol 'std' could not be resolved test_hello.cpp /test_hello/src line 10 Semantic Error
Have I correctly entered Environmental variable ?? How can I get fix the "unresolved" error ?? Thanks !
When compiling there are two important things to consider:
1.) Is my path up-to-date with executables?
2.) Is my library path correct?
It appears you satisfy 1.) but not 2.)
The unresolved symbol error means that Eclipse cannot find your library via LD_LIBRARY_PATH or some other medium. It's attempting to locate the standard compiled C++ library.
How did you install g++?
Kindly do this and post the results:
Project > Properties > C/C++ Build > Environment
If everything there appears nominal, you can try
/sbin/ldconfig
which should hopefully re-parse your system library paths and might update your environment.
Related
Most of my team uses a .bat file to set paths and then run a build. The .bat file allows selection of multiple different compiler/target platforms, but all use some version of GCC/G++ or similar compiler.
I created an Eclipse project that simply uses the .bat file rather than re-inventing the wheel and tracking down all the paths needed for each build (which I'd need to update if anyone ever updated the .bat file anyway).
This works great for building, and I can even see compiler errors/warnings, but there are some extra errors always present:
Program "gcc" not found in PATH
Program "g++" not found in PATH
I've seen many questions about these and similar errors, but in those case the user couldn't build, and the solution was to install the tools and/or update their PATH or Eclipse environment settings. I don't want to do that; all the tools I need are installed, and the .bat file works just fine to set the PATH for building. Is there a way to suppress these errors, or have Eclipse not try to find the compiler executable, since the build succeeds anyway?
Edit: As suggested in the answer I've received so far, here is output on the console after putting a full path to a compiler in the global discovery settings, which isn't exactly my favorite solution even if it worked, but I'll probably deal with it. Regardless the errors don't go away:
15:27:24 **** Running scanner discovery: CDT GCC Built-in Compiler Settings MinGW ****
"C:\\redacted\\localapps\\MinGW5\\bin\\g++.exe" -E -P -v -dD C:/Project_Files/redacted/code_workspaces/redacted/.metadata/.plugins/org.eclipse.cdt.managedbuilder.core/spec.C
Reading specs from C:/redacted/localapps/MinGW5/bin/../lib/gcc/mingw32/3.4.2/specs
Configured with: ../gcc/configure --with-gcc --with-gnu-ld --with-gnu-as --host=mingw32 --target=mingw32 --prefix=/mingw --enable-threads --disable-nls --enable-languages=c,c++,f77,ada,objc,java --disable-win32-registry --disable-shared --enable-sjlj-exceptions --enable-libgcj --disable-java-awt --without-x --enable-java-gc=boehm --disable-libgcj-debug --enable-interpreter --enable-hash-synchronization --enable-libstdcxx-debug
Thread model: win32
gcc version 3.4.2 (mingw-special)
C:/redacted/localapps/MinGW5/bin/../libexec/gcc/mingw32/3.4.2/cc1plus.exe -E -quiet -v -P -iprefix C:\redacted\localapps\MinGW5\bin\../lib/gcc/mingw32/3.4.2/ C:/Project_Files/redacted/code_workspaces/redacted/.metadata/.plugins/org.eclipse.cdt.managedbuilder.core/spec.C -dD
ignoring nonexistent directory "C:/redacted/localapps/MinGW5/bin/../lib/gcc/mingw32/3.4.2/../../../../mingw32/include"
#define __cplusplus 1
ignoring nonexistent directory "/mingw/lib/gcc/mingw32/../../../include/c++/3.4.2"
#define __STDC_HOSTED__ 1
ignoring nonexistent directory "/mingw/lib/gcc/mingw32/../../../include/c++/3.4.2/mingw32"
#define __GNUC__ 3
ignoring nonexistent directory "/mingw/lib/gcc/mingw32/../../../include/c++/3.4.2/backward"
...
And then a bunch of #defines
The command string I used in the discovery options for this output was C:\redacted\localapps\MinGW5\bin\${COMMAND}.exe ${FLAGS} -E -P -v -dD "${INPUTS}".
Based on the information provided, these errors are coming from the scanner discovery part of CDT.
On my machine the full error looks like this:
Description Location Type
Program "g++" not found in PATH Preferences, C++/Build/Settings/Discovery, [CDT GCC Built-in Compiler Settings MinGW] options C/C++ Scanner Discovery Problem
Program "gcc" not found in PATH Preferences, C++/Build/Settings/Discovery, [CDT GCC Built-in Compiler Settings MinGW] options C/C++ Scanner Discovery Problem
Or as a screenshot
What is going on here is Eclipse CDT is (attempting to) launch GCC and G++ to find out what the global settings are for things like include paths, etc.
To fix the problem, go to the Location specified in the error message and adjust the scanner settings. Here is the matching setting to go with the specific error I received.
Your error might be in the project or in the global settings.
To update the MinGW setting, you can provide the path to a batch file that looks like GCC/G++ but sets up your environment correctly first, or you can point directly at the GCC that Eclipse CDT did not find on its own.
For example you can have:
D:\path\to\my\compilers\${COMMAND}.exe ${FLAGS} -E -P -v -dD "${INPUTS}"
As the setting instead of the default.
To aid the debugging, check the Allocate console in the Console View to see exactly what is being run and what output is being generated.
And here is what you might see when it does not work. Hopefully the error messages in the console are sufficient to resolve the problem on your machine.
21:12:54 **** Running scanner discovery: CDT GCC Built-in Compiler Settings MinGW ****
"D:\\path\\to\\my\\compilers\\g++.exe" -E -P -v -dD C:/Temp/workspace/.metadata/.plugins/org.eclipse.cdt.managedbuilder.core/spec.C
Cannot run program "D:\path\to\my\compilers\g++.exe": Launching failed
Error: Program "D:\path\to\my\compilers\g++.exe" not found in PATH
PATH=[\bin;\bin; -- snip --]
21:12:54 Build Finished (took 37ms)
Here is a screenshot to match:
If it does work, you should see lots of #defines and the like showing the global state of your compiler.
Using Windows 7 64 bit. I've followed these instructions for installing Eclipse for Parallel Application Developers and Cygwin, the latter because I want gfortran to compile Fortran code. At 18:20 in the linked tutorial he compiles in Eclipse with no errors, but I get the following 2 errors (Project is called "example"):
Description Resource Path Location Type
make: *** [example] Error 1 example C/C++ Problem
recipe for target 'example' failed makefile /example/Debug line 29 C/C++ Problem
My code (main.f90, under project "example") is simply
program main
print*, "hello world"
end program main
I've also tried compiling through the terminal, but get the following:
>>gfortran main.f90
gfortran: fatal error: -fuse-linker-plugin, but cyglto_plugin.dll not found
compilation terminated
Any help is appreciated!
The tutorial, you linked, is 2 years old...
As far as I see from the content of the packages available from http://www.cygwin.com/packages/, you have to install gcc-fortran instead of gcc4-fortran, because the latter one is labeled as obsolete.
The library cyglto_plugin.dll, which is used for Link-Time-Optimization, can be found in the package gcc-core and should be installed as a dependency. You could try to disable this library by using -fno-use-linker-plugin, but this will disable some optimization.
I am having problems getting NSight Eclipse to link in my libraries:
Building target: SA_V1
Invoking: NVCC Linker
nvcc -L/home/streaming/VidApp_V1.0/src/AudioPreconditioning6Ch/dist/Release/GNU-Linux-x86 -L/home/streaming/cuda-workspace/libConfig/Debug -L/usr/lib32 -link -o "SA_V1" ./V1.1/DeckLinkAPIDispatch.o ./V1.1/DeckLinkAPIDispatch_v7_6.o ./V1.1/audio.o ./V1.1/capture.o ./V1.1/cudaEngine.o ./V1.1/decklink.o ./V1.1/engine.o ./V1.1/filter.o ./V1.1/filterKernel.o ./V1.1/initialize.o ./V1.1/main.o ./V1.1/playback.o ./V1.1/utils.o ./V1.1/videoFuncThread.o ./V1.1/vif.o ./V1.1/vof.o -llibAudioPreconditioning6Ch.so -lliblibConfig.so -llibtiff.so.4.3.2
/usr/bin/ld: cannot find -llibAudioPreconditioning6Ch.so
==> searching for the library I get:
/home/streaming/VidApp_V1.0/src/AudioPreconditioning6Ch/dist/Debug/GNU-Linux-x86/libAudioPreconditioning6Ch.so
/home/streaming/VidApp_V1.0/src/AudioPreconditioning6Ch/dist/Release/GNU-Linux-x86/libAudioPreconditioning6Ch.so
/home/streaming/dist/lib64/libAudioPreconditioning6Ch.so
What am I doing wrong?
Library names in Linux are not the same as in Windows. in VS, i was linking libConfig.lib, so when eclipse asked for the name of the library i typed in: liblibConfig.so which is the name of the file. Uh uh. In Linux the prefix lib is understood as a prefix and the suffix .so is also not part of the name. so entering: libConfig as the library to load (which gets inserted into make as: -llibConfig) solves the problem
Update
Thank you Vladimir for the usefull insights in libraries. I took another approach, developping first in ubuntu (which was a lot easier then messing around with Eclipse/Cygwin/... and now I'm trying to port to windows, which goes rather ok, however I have some questions about that too, posted here: Problems with porting a fortran program from ubuntu to windows
Question
I currently have the following setup and can't get the lapack library configured so that my fortran code can compile:
Windows 7
Cygwin installation (for GNU fortran), added to the windows PATH
lapack and liblapack-devel installed with cygwin
resulting in liblapack.a and libblas.a in the folder C:/cygwin/lib
In my program I call the lapack library using the following code
program myProgram
!use lapack (stays commented now)
...
In Eclipse I used the following setup (with the Photran package):
Fortran Project: executable GNU fortran on Windows (GCC toolchain)
GNU fortran compiler: gfortran ${COMMAND} ${FLAGS} ${OUTPUT_FLAG} ${OUTPUT_PREFIX}${OUTPUT} ${INPUTS}
GNU fortran linker: gfortran ${COMMAND} ${FLAGS} ${OUTPUT_FLAG} ${OUTPUT_PREFIX}${OUTPUT} ${INPUTS}
I compiled the libraries libblas.a and liblapack.a, to use as a static library, for windows and they are located in the C:/cygwin/lib folder. In the GNU fortran linker properties, the libraries were called lapackand blasin the folder C:/cygwin/lib. This results in a part -L"C:/cygwin/lib" -llapack -lblas in the {$COMMAND} section of the compiler and linker. (thanx to #vladimir-f for the help)
In the output there are no error messages left anymore. Only I got now the following error in Eclipse and no final .exe or bins:
Errors occured during the build.
Errors running builder 'CDT Builder' on project 'Hamfem'
Internal error building project Hamfem configuration
Release
java.lang.NullPointerException
Internal error building project Hamfem configuration
Release
java.lang.NullPointerException
However, the result of the build is still an executable, in this case called Hamfem.exe. Running this file results in the error message (instead of the routine): The program can't start because cyglapack-0.dll is missing from your computer. Try reinstalling the program to fix this problem.
That file is currently located in C:/cygwin/lib/lapack/ but I want that this file isn't needed to run the program, so I can run it on different computers. Can someone collaborate on this?
Second, when copy-pasting the .dll file in the folder where the .exe is located, it runs for a brief second, generating a stackdump file. I can't use the debugger in Eclipse-Photran due to the 'Building Workspace' error. Eclipse gives the message Binary not found when I want to run it in Eclipse as a local Fortran program. Any ideas how to resolve this problem?
The problem is here
L/lib/lapack –llapack
try to change it for
-L/lib/lapack –llapack
probably it is in you Makefile.
i.e.
gfortran -funderscoring -O3 -Wall -c -fmessage-length=0 -L/lib/lapack -llapack -o
And make sure lapack.mod is really in /lib/lapack which is probably C:\cygwin\lib\lapack on Cygwin.
On ubuntu 11.10 I installed eclipse from repositories, installed adt and cdt plugins. I am able to compile the hello-jni example using command line, but i would like to use eclipse for the task.
I followed the guide here: http://mhandroid.wordpress.com/2011/01/23/using-eclipse-for-android-cc-development/ and defined a PATH variable in eclipse preferences (window->preferences->c/c++->environment), pointing to the ndk-r7b folder. But the project won't buid. I get this error:
(Cannot run program "ndk-build"
(in directory "/home/athos/android/ndk-r7b/samples/hello-jni"):
java.io.IOException:
error=2, File o directory non esistente)
(last line should be "no such file or directory" in english)
If I specify "${PATH}/ndk-build" or "/home/athos/android/ndk-r7b/ndk-build" as the build command. i get this:
/home/lavoro/android/ndk-r7b/ndk-build
ERROR: Cannot find 'make' program. Please install Cygwin make package
/home/lavoro/android/ndk-r7b/ndk-build: 40: dirname: not found
or define the GNUMAKE variable to point to it.
If I define the GNUMAKE variable in window->preferences->c/c++->environment i get this:
ERROR: Your GNUMAKE variable is defined to an invalid name: /usr/bin/make
Please fix it to point to a valid make executable (e.g. /usr/bin/make)
Which is funny, since It suggests the exact same directory I indicated. Make is installed and present at the indicated location.
What am I missing?
It's a bit ugly, but you can always put
/fully/qualified/path/to/ndk-build
In your build command.