When I compiled an Objective-C code on Windows, I got this error.
$ gcc -o abc main.m
In file included from MyClass.m:2,
from main.m:2:
myclass.h:1:32: Foundation/NSObject.h: No such file or directory
In file included from MyClass.m:2,
from main.m:2:
myclass.h:4: error: syntax error before '(' token
myclass.h:6: error: cannot find interface declaration for `NSObject', superclass of `myclass'
Why is that? How can I fix this?
Thanks to initiate my help dear frnds
i hv just got the answer after posting this question. so the command to compile in window environment is this..
gcc `gnustep-config --objc-flags` -o myf main.m -L /GNUstep/System/Library/Libraries -lobjc -lgnustep-base
thanks for all.
You say you're on Windows. Do you in fact have an environment (such as GNUstep or Cocotron) that would give you the Foundation framework installed and set up correctly? Because I would guess not, and not having Foundation would indeed lead to errors about not having Foundation.
Related
I am a newbie to Objective C programs. I'm learning to code from tutorialspoint.com
As mentioned therein I downloaded GNUstep (Windows).
First, installed the MSYS/MinGW System package and then core package.
After that followed the steps mentioned there. I created a simple program with name hello.m and Stored that in C drive (Snapshot 1)
I don't know the meaning of this command below but entered it:
$ gcc gnustep-config --objc-flags -L /GNUstep/System/Library/Libraries hello.m -o hello -lgnustep-base -lobjc
The error it shows is - sh: gcc: command not found
Please help with the same, to compile and run my first Objective C program
gcc is the compiler, the other parameters are for compiling objective-c code.
Apparently you have misconfiguration in MSYS/MinGW setup.
Check out following post which has alternative and easier solution for running gcc under Windows.
I'm learning Objective-C language. Since I don't have a Mac, I'm compiling and running my code within Ubuntu 11.04 platform.
Until now, I was using gcc to compile. I've installed GNUStep and all was working. But then I started to try some Objective-C 2.0 features, like #property and #synthesize, that gcc does not allow.
So I tried to compile the code with Clang, but it seems that it is not correctly linking my code with the GNUStep libraries, not even with a simple Hello world program.
For example, if I compile the following code:
#import <Foundation/Foundation.h>
int main(void) {
NSLog(#"Hello world!");
return 0;
}
The output of the compiler is:
/tmp/cc-dHZIp1.o: In function `main':
test.m:(.text+0x1f): undefined reference to `NSLog'
/tmp/cc-dHZIp1.o: In function `.objc_load_function':
test.m:(.text+0x3c): undefined reference to `__objc_exec_class'
collect2: ld returned 1 exit status
clang: error: linker (via gcc) command failed with exit code 1 (use -v to see invocation)
The command I'm using to compile is
clang -I /usr/include/GNUstep/ test.m -o test
with the -I directive to include the GNUStep libraries (otherwise, Clang is not able to find Foundation.h).
I've googled my problem, and visited both GNUStep and Clang web pages, but I haven't found a solution to it. So any help will be appreciated.
Thanks!
The problem was that the library gnustep-base was not being used by the linker. So the solution to this was using the option -Xlinker, that sends arguments to the linker used by clang:
clang -I /usr/include/GNUstep/ -Xlinker -lgnustep-base test.m -o test
The statement "-X linker -lgnustep-base" made the magic. However, I had problems with this command related to the class that represents a string in Objective-C:
./test: Uncaught exception NSInvalidArgumentException, reason: GSFFIInvocation:
Class 'NXConstantString'(instance) does not respond to forwardInvocation: for
'hasSuffix:'
I could solve it adding the argument "-fconstant-string-class=NSConstantString":
clang -I /usr/include/GNUstep/ -fconstant-string-class=NSConstantString \
-Xlinker -lgnustep-base test.m -o test
In addition, I've tried with some Objective-C 2.0 pieces of code and it seems to work.
Thank you for the help!
You can try gcc compiler:
First of all install GNU Objective-C Runtime: sudo apt-get install gobjc
then compile: gcc -o hello hello.m -Wall -lobjc
You are not able to use ObjC 2.0 features because you're missing a ObjC-runtime supporting those. GCC's runtime is old and outdated, it doesn't support ObjC 2.0. Clang/LLVM doesn't have a acompanied runtime, you need to install the ObjC2-runtime from GNUstep (which can be found here: https://github.com/gnustep/libobjc2 ) and reinstall GNUstep using this runtime.
Here are some bash scripts for different Ubuntu versions, that do everything for you:
http://wiki.gnustep.org/index.php/GNUstep_under_Ubuntu_Linux
And please don't try to reinvent GNUstep make, instead, use it:
http://www.gnustep.org/resources/documentation/Developer/Make/Manual/gnustep-make_1.html
If you really don't think so, here is some excerpt from there:
1.2 Structure of a Makefile
Here is an example makefile (named GNUmakefile to emphasis the fact that it relies on special features of the GNU make program).
#
# An example GNUmakefile
#
# Include the common variables defined by the Makefile Package
include $(GNUSTEP_MAKEFILES)/common.make
# Build a simple Objective-C program
TOOL_NAME = simple
# The Objective-C files to compile
simple_OBJC_FILES = simple.m
-include GNUmakefile.preamble
# Include in the rules for making GNUstep command-line programs
include $(GNUSTEP_MAKEFILES)/tool.make
-include GNUmakefile.postamble
This is all that is necessary to define the project.
In your case replace all occurrences of simple with test and you're done
1.3 Running Make
Normally to compile a package which uses the Makefile Package it is purely a matter of typing make from the top-level directory of the package, and the package is compiled without any additional interaction.
Assuming you have your .h and .m ready on a Linux server, which command would you issue to GCC to have it compiled?
The relevant parts:
gcc -c -Wno-import List.m
gcc -o prog -Wno-import List.o main.o -lobjc
. . . make sure that the Objective-C library and header files (objc/Object.h) were installed when gcc was built.
Note that when linking Objective-C with gcc, you need to specify the Objective-C library by using the -lobjc switch.
See this link for more information.
Additional link with possible solution to the missing compiler issue:
Try installing either gobjc++ or gobjc
sudo apt-get install gobjc++
gcc -x objective-c file.m -o out
Google is your friend
I was just starting to study obj-c on Ubuntu Linux today, the tutorial that I followed is http://www.otierney.net/objective-c.html, when I typed in the code that requires for Foundation/NSObject.h, the error appeared:
Fraction.h:1: fatal error: Foundation/NSObject.h: No such file or directory
and i searched for the solutions, and found a proper one
gcc -o Fraction -I/usr/GNUstep/System/Library/Headers
-L/usr/GNUstep/System/Library/Libraries
Fraction.m
-ldl
-lobjc
I tried this, but I found that I cannot find Headers under the Library directory. (My folder of GNUstep is /usr/share/GNUstep).
Does anyone know how to achieve the Headers?
I installed all the dev packages related to GNUstep but still no luck.
Hope I state my question clear enough. Sorry for my English.
Try with gnustep-config
gcc `gnustep-config --objc-flags` \
`gnustep-config --objc-libs` Fraction.m -o Fraction
GNUStep uses a fairly involved set of gmake macros - I wouldn't expect a simple command-line invocation of gcc to work very well, although to be honest I haven't tried that way myself. I found Nicolo Pera's tutorial and the project's own reference page to be quite useful when learning how to write make files for use with GNUStep.
In my case, compiling SOPE on CentOS 7, installed
yum install gnustep-base-devel
This solved the problem.
In my case, I installed gnustep-base to fix this error:
yum install gnustep-base
Using: windows xp, g++ 3.4.4 with cygwin and g++ 3.4.5 with mingw.
I'm compiling a simple unit test class with cppunit.
When I link using g++ 3.4.5 I get a lot of linking errors. When I link with g++ 3.4.4 I don't get any errors and the exe links fine and runs.
I can't seem to trace down the errors, so any thoughts?
Thanks.
EDIT: linking errors: Unreferenced function errors. Like:
SimpleTest.cpp:(.text+0x313): undefined reference to `CppUnit::Message::Message(std::string const&, std::string const&)'
EDIT: cmd line:
g++ -I g:\projects\thirdparty\cppunit-1.12.1\include -L g:\projects\thirdparty\cppunit-1.12.1\lib -l cppunitd -o main.exe main.cpp SimpleTest.cpp
Update: Same code in Visual Studio: No error, unit test runs as expected.
Your problem is likely incorrect link line. The order of sources/object files and libraries on the link line matters. Correct link line:
g++ -I g:\projects\thirdparty\cppunit-1.12.1\include \
-L g:\projects\thirdparty\cppunit-1.12.1\lib \
-o main.exe main.cpp SimpleTest.cpp -lcppunitd
As g++ matures, I'm on 4.2.3, it's type checking has gotten more pedantic and for that matter better. With the little information I'd say it's likely that you should look closely at your calls to these methods. I suspect that the types are not quite right. 3.4.4 doesn't catch it, 3.4.5 does.
....JW
One thing you could perhaps try is to compile with g++ 3.4.5 and/or 3.4.4 on Linux. If the result then is the same, then it is clearly a property of gcc. Otherwise it more sounds like a mingw issue.