This question already has answers here:
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
Closed 7 years ago.
The compiler throws errors like:
" [Linker error] main.o:main.cpp:(.text+0x972): undefined reference to `_imp__glutReshapeFunc#4' "
Do you know how to use GLUT in Dev C++?
DevC++ is seriously outdated. I recommend using Codeblocks instead.
The error line you quoted simply indicated, that the linker is missing the functions of the GLUT library. Including the headers is not enough (they just provide the compiler with sort of an index). But the linker still needs to be told which libraries to actually link against.
Related
This question already has answers here:
Undefined reference to sqrt (or other mathematical functions)
(5 answers)
Undefined reference to pow( ) in C, despite including math.h [duplicate]
(1 answer)
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
Why do you have to link the math library in C?
(14 answers)
Closed last year.
I just installed ubuntu via dual boot on my laptop and further installed vscode along with build-essenttial command.
Everything is working fine in my current knowledge but in any code where #include<math.h> is used and inside main function pow() is used. Vs code is giving this error. I have tried every possible thing but can't resolve it.
image :
This question already has answers here:
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
How does the compilation/linking process work?
(5 answers)
Closed 2 years ago.
I'm new to C++ and I'm trying to implement all functions in a separate Functions.cpp file and calling them in the main.cpp file defining all the function declarations on the top. Both Main and the Functions file are in the same folder (sources).
But I keep getting the error undefined reference to my functions. I'm using CodeBlocks 20.30.
somebody, please help.
Main.cpp file
Functions.cpp file
Error
This question already has answers here:
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
Closed 11 months ago.
#include<graphics.h>
#include<stdio.h>
main()
{
int gd=DETECT,gm;
int i,x,y;
initgraph(&gd,&gm,"");
line(0,0,640,0);
line(0,0,0,480);
line(639,0,639,480);
line(639,479,0,479);
for(i=0;i<=1000;i++)
{
x=rand()%639;
y=rand()%480;
putpixel(x,y,15);
}
getch();
closegraph();
}
The Following is a Basic Graphic Program,It Shows the Errors as
undefined reference to 'initgraph'
undefined reference to 'closegraph'
undefined reference to 'line'[4 times]
undefined reference to 'putpixel'
Compiler : CodeBlocks; Language:c++;
I Have Copied the graphics.h and winbgim.h in include folder and the libbgi.a in the lib folder also i have linked all the libraries required to be linked. Please Help.
Change
initgraph(&gd,&gm,"");
to
initgraph(&gd,&gm,NULL);
for compiling:
g++ -o filename filename.cpp -lgraph
to execute:
./filename
The functions in graphics.h are only supported by old ancient Turbo C and Turbo C++ compilers. Those functions can not be used by any modern 32-bit compiler. You can either get a copy of that old MS-DOS compiler or use win32 api GDI functions or get one of several graphics libraries such as OpenGL and QT.
This question already has answers here:
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
Closed 8 years ago.
I am using C library antlr3c. I installed the library using: sudo apt-get install libantlr3c-dev
#include "antlr3defs.h"
..
string DBparser::sparqlParser(const string& _sparql, SPARQLquery& _sparql_query)
{
pANTLR3_INPUT_STREAM input;
pSparqlLexer lex;
pANTLR3_COMMON_TOKEN_STREAM tokens;
pSparqlParser parser;
input = antlr3StringStreamNew((ANTLR3_UINT8 *)(_sparql.c_str()),ANTLR3_ENC_UTF8,_sparql.length(),(ANTLR3_UINT8 *)"QueryString");
}
When I run the program containing the above fragment I get the error:
NetBeansProjects/gstore/Parser/DBparser.cpp:25: undefined reference to `antlr3StringStreamNew'
I am not getting how to resolve this error as antlr3StringStreamNew is indeed declared in antlr3defs.h. Although I am unable to find its definition.
If this related to incompatibility with version 3.4 of antlr3c (as I have installed version 3.2). If this is indeed the case then, is there any alternate function in antlr3c version 3.4 by which I may achieve the same functionality.
Keith is right - the linker you are using is expecting different symbols due to C++ name mangling. Thus, though your code will compile, at the link stage it fails with that error.
If you surround your header include like so, the linker should find the symbols:
extern "C" {
#include "antlr3defs.h"
}
The result is that your code compiles with references to C-style function names, allowing the linker to match them up with corresponding symbols in the object files of the antlr3 library.
This question already has answers here:
undefined reference to `WinMain#16'
(7 answers)
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
Closed 8 years ago.
I always get this error 'Undefined reference to WinMain#16' after creating a class in Code::Blocks. I have to restart it to make the program works.
Why ?
Thank you!
If you have only one file - your class - and you trying to compile it, you will get this error because file don't have int main() function. It's required by linker to create executable (start point of program).
If you have project with classes, you must have one main function, for example in main.cpp file :)
Also, check that you selected a Console application - GUI (Windows application) neeed WinMain function instead of classical main.
Of course, this is about normal program - library have other requirements.