I was using flex and bison to build a simple calculator project I cloned from Github.
But after I typed make in terminal, I got the following message:
gcc -o calc calc.tab.c lex.yy.c -lfl
calc.y:48:1: warning: type specifier missing, defaults to 'int' [-Wimplicit-int]
main() {
^~~~
1 warning generated.
ld: library not found for -lfl
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [calc] Error 1
How could I resolve this problem?
let me guess, trying to use flex on OS/X?
Try -ll instead of -lfl
Using Flex on OS/X
So yea, the flex library name on OS/X is just arbitrarily different for some reason. OS/X is not exactly Linux, but it's pretty close. You have some options here.
You can just simply have a separate build system and source files for OS/X. Certainly Apple might like that with their pushing XCode, objective-C and not much interoperability.
You can build vs Linux and then engage with Mac Ports and Homebrew.
You can create your project using autotools. That's not an awesome link, learning this system is rough going, but it's a standard thing for Linux for sure. This will actually work, I find if you have the patience for it, OS/X is close enough that autotools based builds will work on it.
Lately, I've been turned on to Cocoapods, which I believe to be an attempt to join the open source community and XCode. It's kind of half 1 and 3 sorta with an emphasis on modularizing the external source and getting it compiled into a .app (via Xcode).
warning: type specifier missing, defaults to 'int'
mean that you should declare return type for main function. Place int in function difinition.
ld: library not found for -lfl
flag -l mean that compiller must use libfl.a to build programm. As #waTeim said above, for Mac OS you can use libl.a instead, but this lib can be not exist alse. There is another way is to place
%option noyywrap
at the top of flex *.l file. In this case you can compile without additional libs.
Related
The full terminal output is as follows:
>g++ -std=c++98 -static mainP1.o -o mainP1
>
>ld: library not found for -lcrt0.o
>
>clang: error: linker command failed with exit code 1 (use -v to see invocation)
>
>make: *** [mainP1] Error 1
I'm on a 2020 MacBook Pro with an intel CPU using Visual Studio Code. When I write basic OOP programs in C++ it compiles fine without any clang errors. However, when working with big OOP programs with multiple classes inheriting from a base class I would get this error.
I tried searching online for solutions, but no solution or explanation was found. I double-checked my makefile to ensure I was not linking classes incorrectly.
I thought maybe I should just dual-boot with UBUNTU Linux to avoid this weird XCODE issue I was encountering with clang, but that was also a fruitless endeavor.
The problem was my compiler path in Visual Studio Code.
I changed it to clang++, and now all my code compiles and executes without any problems.
How I changed it:
CMD + SHIFT + P
Typed in: C/C++: Edit Configurations (UI)
Made sure that "Mac" was selected under configuration name.
Changed Compiler Path to: /usr/bin/clang++
I have started learning C++ on Ubuntu. I am only a few months into using Linux as well.
I am attempting to port over a 2D Ball Collision Script from Javascript to C++ for learning purposes.
I am using simple2D for the drawing in C++: https://github.com/simple2d/simple2d
I go to run this command:
simple2d build c-code-test.cpp
I receive this response:
cc1plus: warning: command line option ‘-std=c11’ is valid for C/ObjC but not for C++
/usr/bin/ld: /tmp/ccl07DBG.o: undefined reference to symbol '_ZNSt8ios_base4InitD1Ev##GLIBCXX_3.4'
//usr/lib/x86_64-linux-gnu/libstdc++.so.6: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
Due to how fresh I am with Linux and C++ I am unable to make the correct inferences to solve this based on previous questions on stack overflow. I have installed libstdc++6 so I would have though it would be linked correctly.
Can someone walk me through in steps 1, 2, 3 ... Please? Thank you kindly!
The errors you see look to be from trying to compile C++ as C. The command line option is selecting the C11 standard, which is for C, not C++. The missing symbol is because the C++ library isn't being linked in, which also happens when linking a program as C.
I haven't used simple2d, but my guess here is that the compile script they wrote does not support C++ or there is some option you need to use C++. If we look at docs:
The simple2d build command is a helpful shortcut for compiling a
single source file. Of course, you can also use a compiler directly,
for example on Unix-like systems:
cc triangle.c `simple2d --libs` -o triangle
Why don't you try something like their example that invokes the compiler directly. But you would need to use g++ instead of cc. Something like: g++ c-code-test.cpp `simple2d --libs` -o c-code-test
This is a bug with the simple2d script.
They're basically using the wrong build command for C++.
You could work around it by patching in the fix I've linked to, or using the manual build step shown by TrentP.
Or wait for the next version after v1.1.0.
I'm trying to use cuda in ns3, but when I tried to run CXX="nvcc" ./waf configure, it shows the following message on the screen:
Checking for 'g++' (C++ compiler) : not found
Checking for 'clang++' (C++ compiler) : not found
Checking for 'icpc' (C++ compiler) : not found
could not configure a C++ compiler!
(complete log in /home/kelu/workspace/ns-3.24/build/config.log)
I checked the config.log, it says the following:
Checking for 'g++' (C++ compiler)
find program='nvcc' paths=['/usr/local/sbin', '/usr/local/bin', '/usr/sbin', '/usr/bin', '/sbin', '/bin', '/usr/local/cuda/bin'] var='CXX' -> ['nvcc']
from /home/kelu/workspace/ns-3.24: Could not determine the compiler type
not found
----------------------------------------
Checking for 'clang++' (C++ compiler)
find program='nvcc' paths=['/usr/local/sbin', '/usr/local/bin', '/usr/sbin', '/usr/bin', '/sbin', '/bin', '/usr/local/cuda/bin'] var='CXX' -> ['nvcc']
from /home/kelu/workspace/ns-3.24: Not clang/clang++
not found
----------------------------------------
Checking for 'icpc' (C++ compiler)
find program='nvcc' paths=['/usr/local/sbin', '/usr/local/bin', '/usr/sbin', '/usr/bin', '/sbin', '/bin', '/usr/local/cuda/bin'] var='CXX' -> ['nvcc']
from /home/kelu/workspace/ns-3.24: Not icc/icpc
not found
from /home/kelu/workspace/ns-3.24: could not configure a C++ compiler!
nvcc is located in /usr/local/cuda/bin, which is in path. But it seems to me that the building script of ns3 does not resolve nvcc as a compiler.
Could anybody please tell me the right way to make nvcc the CXX compiler in ns3?
Thanks.
Your problem probably was that Waf actually checks the compiler's built-in #defines to check whether a compiler invoked as "gcc" actually is gcc or not. As a concrete example, it will error out if it detects that the compiler is Intel's icc (because it #defined __INTEL_COMPILER) but was invoked with a "gcc" command line!
The code that does the identification is at https://waf.io/apidocs/_modules/waflib/Tools/c_config.html#get_cc_version .
So, if you don't have a compiler which tries hard to look like one of the supported ones, looks like you are supposed to write your own Waf tool.
However, you can try to hack your way through. For example, let's say that your compiler is compatible enough with gcc but still it doesn't get past Waf's absurdly stringent test. A fix is to run "waf configure" using the real gcc, and then edit the file where Waf stores the detection results, so at the build step Waf will actually run your compiler instead of gcc. You can do this by editing build/c4che/_cache.py: change the CC definition to your compiler's full path.
I haven't found a way to use nvcc in ns-3, but I did find a work around for this problem. I'm happy to share my solution here to help others:
Make your cuda code a static library:
ar rcs libcudacode.a a.o b.o c.o (you need to make the *.o files first using g++, nvcc, or anything else you want)
put libcudacode.a in /your/lib/folder/ and put your cuda code in /your/src/folder
Add lib folder and src folder into waf:
CXXFLAGS_EXTRA="-I/your/src/folder -I/your/cuda/dir/include" LINKFLAGS_EXTRA="-L/your/lib/folder -L/your/cuda/dir/lib64 -lcudacode -lcudart" ./waf configure.
./waf
Your code should be compiled now. You can access any public functions in your cuda code by #including "corresponding_header.h"
A little bit explanation:
CXXFLAGS_EXTRA and LINKFLAGS_EXTRA add compilation flags in ns-3's compiling system. You need to add both your cuda code and NVidia's cuda library to use the functions.
If you used any other libraries, also put them in CXXFLAGS_EXTRA and LINKFLAGS_EXTRA
Check the cuda directory name in your system. It's probably not lib64 in your machine.
I use MinGW64+msys on Winodws7 64bit
Now I’m trying to build CMAKE but I can’t.
When I typed ./configure soon an error happened. .
---------------------------------------------
CMake 3.2.3, Copyright 2000-2015 Kitware, Inc.
Found GNU toolchain
C compiler on this system is: gcc
---------------------------------------------
Error when bootstrapping CMake:
Cannot find appropriate C++ compiler on this system.
Please specify one using environment variable CXX.
See cmake_bootstrap.log for compilers attempted.
I also find error messages in Bootstrap.cmk/cmake_bootstrap.log like bellow.
[First Message in the log file]
In file included from c:/mingw64/x86_64-w64-mingw32/include/c++/iosfwd:40:0,^M
from c:/mingw64/x86_64-w64-mingw32/include/c++/ios:38,^M
from c:/mingw64/x86_64-w64-mingw32/include/c++/ostream:38,^M
from c:/mingw64/x86_64-w64-mingw32/include/c++/iostream:39,^M
from cmake_bootstrap_4468_test.cxx:3:^M
c:/mingw64/x86_64-w64-mingw32/include/c++/bits/postypes.h:40:35: fatal error: cw
char: No such file or directory^M
compilation terminated.^M
[Second Message in the log file]
cmake_bootstrap_4468_test.cxx:5:23: fatal error: iostream.h: No such file or dir
ectory^M
compilation terminated.^M
Test failed to compile
They said cwchar and iostream.h doesn't exist, although I have them and set their path to environmental variable.
The first massage said my C++ compiler isn’t appropriate. I installed it by mingw-get.exe.
Does anyone know, how can I get appropriate C++ compiler?
You mixed two compilers. I recommend: delete your old one and install msys2+mingw64.
I am trying to port a fairly large C++ project to using g++ 4.0 on Mac OS X. My project compiles without errors, but I can't get GDB to work properly. When I look at the stack by typing "bt" on the GDB command line, all file names and line numbers displayed are wrong.
For example, according to the GDB stack trace, my main() function is supposed to be in stdexcept from the Mac OS X SDK, which does not make any sense.
What could cause GDB to malfunction so badly? I've already checked for #line and #file statements in my code and made sure that the code only has unix line endings. I've also cleaned and rebuilt the project. I've also tried debugging a Hello World project and that one did not have the same problem.
Could the problem have to do with one of the third party libraries I am linking and the way those are compiled? Or is it something completely different?
Here are two exemplary calls to gcc and ld as executed by Xcode. AFAIK all cpp-files in my project are compiled and linked with the same parameters.
/Developer/usr/bin/gcc-4.0 -x c++
-arch i386 -fmessage-length=0 -pipe -Wno-trigraphs -fpascal-strings -fasm-blocks -O0 -fpermissive -Wreturn-type -Wunused-variable -DNO_BASS_SOUND -D_DEBUG -DXCODE -D__WXMAC__ -isysroot /Developer/SDKs/MacOSX10.5.sdk
-mfix-and-continue -fvisibility-inlines-hidden -mmacosx-version-min=10.4 -gdwarf-2 -D_FILE_OFFSET_BITS=64 -D_LARGE_FILES -D__WXDEBUG__ -D__WXMAC__ -c "/Users/adriangrigore/Documents/Gemsweeper
Mac/TSDLGameBase.cpp" -o
"/Users/adriangrigore/Documents/Gemsweeper
Mac/build/Gemsweeper
Mac.build/Debug/Gemsweeper
Mac.build/Objects-normal/i386/TSDLGameBase.o"
/Developer/usr/bin/g++-4.0 -arch i386
-isysroot /Developer/SDKs/MacOSX10.5.sdk
"-L/Users/adriangrigore/Documents/Gemsweeper
Mac/build/Debug"
-L/Developer/SDKs/MacOSX10.5.sdk/usr/local/lib
-L/opt/local/lib "-F/Users/adriangrigore/Documents/Gemsweeper
Mac/build/Debug"
-F/Users/adriangrigore/Library/Frameworks
-F/Developer/SDKs/MacOSX10.5.sdk/Library/Frameworks
-filelist "/Users/adriangrigore/Documents/Gemsweeper
Mac/build/Gemsweeper
Mac.build/Debug/Gemsweeper
Mac.build/Objects-normal/i386/Gemsweeper
Mac.LinkFileList"
-mmacosx-version-min=10.4 /opt/local/lib/libboost_program_options-mt.a
/opt/local/lib/libboost_filesystem-mt.a
/opt/local/lib/libboost_serialization-mt.a
/opt/local/lib/libboost_system-mt.a
/opt/local/lib/libboost_thread-mt.a
"/Users/adriangrigore/Documents/Gemsweeper
Mac/3rd
party/FreeImage/Dist/libfreeimage.a"
"/Users/adriangrigore/Documents/Gemsweeper
Mac/3rd
party/cpuinfo-1.0/libcpuinfo.a"
-L/usr/local/lib -framework IOKit -framework Carbon -framework Cocoa -framework System -framework QuickTime -framework OpenGL -framework AGL -lwx_macd_richtext-2.8 -lwx_macd_aui-2.8 -lwx_macd_xrc-2.8 -lwx_macd_qa-2.8 -lwx_macd_html-2.8 -lwx_macd_adv-2.8 -lwx_macd_core-2.8 -lwx_base_carbond_xml-2.8 -lwx_base_carbond_net-2.8 -lwx_base_carbond-2.8 -framework SDL -framework Cocoa -o "/Users/adriangrigore/Documents/Gemsweeper
Mac/build/Debug/Gemsweeper
Mac.app/Contents/MacOS/Gemsweeper Mac"
Please note that I have already asked a similar question regarding the Xcode debugger here, but I am reposting since I just learned that this is in fact not Xcode's fault, but a problem with GCC / ld / GDB.
Edit: My project makes use of the following third-party libraries: SDL, Boost, wxWidgets. I am not sure if this matters for this problem, but I just wanted to mention it just in case it does.
I've tried compiling an Xcode SDL project template and did not experience the same problem, so it must be due to something special in my project.
Second Edit: As I just found out, I made a mistake while searching files with the string "This is an automatically generated". I just found several dozen files with the same string, all belonging to FreeImage, one of the third party libraries I am using. So, the problem seems to be related to FreeImage, but I am not still not sure how to proceed.
I got those symptoms, when my gdb version didn't match my g++ version.
Try to get the newest gdb.
Your cpp files certainly have debug symbols in them (the -gdwarf-2 option).
Do you use a separate dSYM file for the debug symbols? Or are they inside the object files. I would first try to use DWARF in dSYM files and see if that helps (or vice versa)
The third party libraries appear to be release builds though (unless you renamed them yourself of course) e.g. I know for sure boost uses the -d monniker in the library names to denote debug libraries (e.g. libboost_filesystem-mt-d.a).
Now, this shouldn't really pose a problem, it should just mean you can't step into the calls made to third party libraries. (at least not make any sense of it when you do ;) But since you have problems, it might be worth a try to link with debug versions of those libraries...
Are you compiling with optimization on? I've found that O2 or higher messes with the symbols quite a bit, making gdb and core files pretty much useless.
Also, be sure you are compiling with the -g option.
Can it be that you are using SDL? SDL redefines main so your main will be named SDL_main and that the SDL parts might be heavy optimized so down there you'll have problem getting good gdb output.
...just a thought
Read this
For a test, you could check if addr2line gives you expected values. If so, this would indicate that there's nothing wrong with the ELF generated by your compile/link parameters and casts all suspicion on GDB. If not, then suspicion is still on both the tools and the ELF file.
I've tried compiling an XCode SDL
project template and did not
experience the same problem, so it
must be due to something special in my
project.
Correct. Your project settings are the thing that is different.
You will need to disable the debug optimizations in the Xcode project settings for the debug build. Xcode unfortunately makes GDB jump to weird lines (out of order) when you would expect it to move sequentially.
Go to your project settings. Set the following
1) Instruction Scheduling = None
2) Optimization Level = None [-O0]
3) ZERO_LINK = None
Your problems should go after after doing this.
Here is the project settings screen that you need to change the settings on:
From your flags the debug information should be in the object files.
Does your project settings build the executable in one location then move the final executable to another location when completed? If this is the case then gdb may not be finding the objectects files and thus not correctly retrieving the debug information from the object files.
Just a guess.
I encountered this several years ago when transitioning from the Codewarrior compilers to Xcode. I believe the way to get around this is to put the flag "-fno-inline-functions" in Other C Flags (for Dev only).
This problem was more pronounced on the PowerPC architecture for us.
What about if you remove the "-fvisibility-inlines-hidden" and "-mfix-and-continue" flags?
I've never had the "fix and continue" feature work properly for me.
WxWidgets do also define their own main if you use their IMPLEMENT_APP() macro
From here
As in all programs there must be a "main" function. Under wxWidgets main is implemented using this macro, which creates an application instance and starts the program.
IMPLEMENT_APP(MyApp)
See my answer here
I have now downloaded and compiled the FreeImage sources and yes, the file b44ExpLogTable.cpp is compiled into libfreeimage.a. The problem looks like the script gensrclist.sh just collects all .cpp files without skipping the one with a main in. That script generates a file named Makefile.srcs but one is already supplied. (running it on my Leopard failed, some problem with sh - it worked if I changed sh to bash)
Before you have changed anything this gives an a.out
c++ libfreeimage.a
The file Makefile.srcs has already been created so you should be able to remove the file b44ExpLogTable.cpp from it. Then do
make -f Makefile.osx clean
make -f Makefile.osx
When this is done the above c++ libfreeimage.a should give the following error
Undefined symbols:
"_main", referenced from:
start in crt1.10.5.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
I have a new thing you can try.
Just before your own main you can write
#ifdef main
# error main is defined
#endif
int main(int argc, char *argv[]) {
this should give an error if you have some header that redefines main.
If you define an own you might get an warning where a previous definition was made
#define main foo
int main(int argc, char *argv[]) {
You can also try to undef just before your main
#undef main
int main(int argc, char *argv[]) {