I'm trying to use float or double values in my ring0 c application, but im getting the Linker ERRORs:
Fehler LNK1120 1 nicht aufgelöste Externe
Fehler LNK2001 Nicht aufgelöstes externes Symbol "_fltused".
float test = 1.2;
How can i solve this error?
Your compiler inserts a dependency on _fltused to force you to link with a float support library. Do you have such a library capable of running in ring0?
Related
I am writing a program using C, which, given two points, and a value x in between them, a function "Interp" will interpolate a corresponding value for y. I am receiving a message that says "undefined symbols for architecture", and I'm not sure how to fix it. Any help would be appreciated.
#include <stdio.h>
#include <math.h>
double Interp(double x_1, double y_1, double x_2, double y_2, double x) {
double k,y,b;
k = (y_2-y_1)/(x_2-x_1);
b = y_2-(k*x_2)
y = k*x+b;
return(y);
}
The result is a message saying "Undefined symbols for architecture x86_64:
"_main", referenced from:
implicit entry/start for main executable
ld: symbol(s) not found for architecture x86_64
clang: error linker command failed with exit code 1"
I don't know what this means so any guidance would be very helpful!
I have started using gsl recenltly in a huge old C project. I have managed to add the libraries by adding the location in my system in Properties>C/C++>General>Additional Include Directories.
In my code, I am also including the following:
#include "gsl/gsl_matrix.h"
#include "gsl/gsl_matrix_complex_double.h"
#include "gsl/gsl_matrix_complex_float.h"
#include "gsl/gsl_matrix_complex_long_double.h"
#include "gsl/gsl_math.h"
#include "gsl/gsl_spmatrix.h"
#include "gsl/gsl_complex.h"
#include "gsl/gsl_complex_math.h"
#include "gsl/gsl_inline.h"
#include "gsl/gsl_complex.h"
I can now use most functions of gsl. but in the fowllowing function:
void vector_complex_mul_elements(gsl_vector_complex *v1, gsl_vector_complex *v2)
{
gsl_complex cpx1, cpx2, cpx3;
GSL_SET_COMPLEX(&cpx1, 0, 0);
GSL_SET_COMPLEX(&cpx2, 0, 0);
GSL_SET_COMPLEX(&cpx3, 0, 0);
if(v1->size != v2->size)
{
printf("Error: Lenght of arrays do not match.\n");
return;
}
for(i=0; i < v1->size; i++)
{
cpx1 = gsl_vector_complex_get(v1, i);
cpx2 = gsl_vector_complex_get(v2, i);
//cpx3 = gsl_complex_mul(cpx1 , cpx2);
gsl_vector_complex_set(v1, i, cpx3);
}
}
When I uncomment the line:
cpx3 = gsl_complex_mul(cpx1 , cpx2);
I get the following errors:
Error LNK2001: Unresolved external symbol "_log1p".
Error LNK2001: Unresolved external symbol "_log1p".
Error LNK2001: Unresolved external symbol "_hypot".
Error LNK1120: 2 unresolved external references.
I have already tried writing it like:
gsl_vector_complex_set(v1, i, gsl_complex_mul(cpx1 , cpx2));
Then I get these errors:
Error LNK2019: Reference to unresolved external symbol "_log1p" in function "_gsl_complex_logabs".
Error LNK2019: Reference to unresolved external symbol "_hypot" in function "_gsl_complex_div".
Error LNK2001: Unresolved external symbol "_log1p".
Error LNK1120: 2 unresolved external references.
Is this a only a linking problem or the way I am using it is wrong?
These (lop1p and hypot) functions are in the standard maths library. Are you including math.h and linking to it (-lm)? As per the GSL documentation.
It seems to me that you are wrong linked GSL library.
Try to rebuild GSL as a dll and relink it, as I showed you in your other post.
This question already has answers here:
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
Closed 5 years ago.
#include <stdio.h>
#include <math.h>
int main () {
float a, b, c, s, ar;
s=((a+b+c)/2);
printf("Ingrese los lado del triangulo");
scanf("%f%f%f",&a,&b,&c);
ar=(sqrt(s*(s-a)*(s-b)*(s-c)));
printf("el perimetro es %f",ar);
return 0;
}
I do not understand why when compiling me throw this error
tmp/ccs6PFsP.o: En la función main':ejercicio 34.c:(.text+0x87): referencia asqrt' sin definir
collect2: error: ld returned 1 exit status
To use the math library in C, pass the lm flag to the compiler:
gcc main.c -lm
Then your program will compile and link against the math library.
As pointed out, to use -lm flag while compiling, although it seems the logic is not correct.
In order to make your program work, you should insert this statement
s=((a+b+c)/2);
after the scanf statement.
In your code, you are calculating the sum of a, b and c before even reading the values from terminal.
I'm trying to write a C script able to open .mat files. The .mat files were written in Matlab 2015b 64-bit version. I'm using Visual Studio 2010 to compile the code. Here it is:
#include <stdio.h> /*Std library*/
#include "..\matlablib\mat.h" /*provided by MathWorks*/
int main(){
MATFile * pMF;
printf("Abrindo arquivo .mat...\n"); /*check (1)*/
pMF = matOpen("teste.mat","r");
printf("Arquivo .mat aberto.\n"); /*check (2)*/
getch();
}
As I compile this, I get the following message error:
matread.obj : error LNK2019: unresolved external symbol _matOpen
referenced in function _main
matread.exe : fatal error LNK1120: 1 unresolved externals
Have anyone had a similar problem before?
Thanks in advance,
Porto
It is a known Topic, but i cant find the solution.
What i did:
createt and console Application.
Add a c source File
Add The path to my Header File to "additional include directorys"
write my code( or ctrl+c + crtl+v)
compile = error
Firste the Code:
#include <stdio.h>
#include <stdlib.h>
#include <sndfile.h>
int main()
{
SNDFILE *sf;
SF_INFO info;
int num_channels;
int num, num_items;
int *buf;
int f,sr,c;
int i,j;
FILE *out;
/* Open the WAV file. */
info.format = 0;
sf = sf_open("file.wav",SFM_READ,&info);
if (sf == NULL)
{
printf("Failed to open the file.\n");
exit(-1);
}
/* Print some of the info, and figure out how much data to read. */
f = info.frames;
sr = info.samplerate;
c = info.channels;
printf("frames=%d\n",f);
printf("samplerate=%d\n",sr);
printf("channels=%d\n",c);
num_items = f*c;
printf("num_items=%d\n",num_items);
/* Allocate space for the data to be read, then read it. */
buf = (int *) malloc(num_items*sizeof(int));
num = sf_read_int(sf,buf,num_items);
sf_close(sf);
printf("Read %d items\n",num);
/* Write the data to filedata.out. */
out = fopen("filedata.out","w");
for (i = 0; i < num; i += c)
{
for (j = 0; j < c; ++j)
fprintf(out,"%d ",buf[i+j]);
fprintf(out,"\n");
}
fclose(out);
return 0;
}
The Error Message:
1>SoundIO.obj : error LNK2019: Verweis auf nicht aufgelöstes externes Symbol "_sf_open" in Funktion "_main".
1>SoundIO.obj : error LNK2019: Verweis auf nicht aufgelöstes externes Symbol "_sf_read_int" in Funktion "_main".
1>SoundIO.obj : error LNK2019: Verweis auf nicht aufgelöstes externes Symbol "_sf_close" in Funktion "_main".
1>C:\Users\Stephan\Desktop\BA\Audio_Coding\SoundIO\Debug\SoundIO.exe : fatal error LNK1120: 3 nicht aufgelöste Externe
The Settings: http://img5.picload.org/image/lccigod/settings.png
What i wanted to do? Simply this: http://ubuntuforums.org/showthread.php?t=968690
What i need? A way to fix this (And how to do it) or an easy guide to get this running.
The linker is telling you that you are missing definitions for the functions from libsndfile. You need to either:
Compile libsndfile from its sources, and link the resulting objects to your program.
Link an import library for libsndfile so that you can dynamically link to libsndfile.
Which solution you opt for depends on how you want to link to libsndfile.
From: http://www.cprogramming.com/tutorial/compiler_linker_errors.html
You may have issues with how you set up your compiler. For instance,
even if you include the correct header files for all of your functions,
you still need to provide your linker with the correct path to the library
that has the actual implementation. Otherwise, you will get "undefined function"
error messages...
While it looks like you've correctly included the necessary headers in your code and you've got everything compiling, you need to either statically or dynamically link to libsndfile in order to resolve your linker errors.
If you are including header files then you must ensure that they are in the include directory of your C++ directory. If it is an external file then you must add their path to your project from project properties.