Question

The following app crashes with nullpointer. I am wondering whats wrong…

#include "stdio.h"
#include "string.h"

char* getFileData(char* fileName);
bool createShader( int shaderType, const char* shader, const char* shaderFile ) ;
void glShaderSource(int shader, int count, const char** string, const int* length);

int main(int argc, char* argv[])
{
    char* shader = getFileData("filea.csd");
    bool success = createShader(1, shader, "filea.csd");
    return 0;
}

char* getFileData(char* fileName) {
    if(!strcmp(fileName, "filea.csd"))
        return "this is the content of the file a\0";
    else if(!strcmp(fileName, "fileb.csd"))
        return "this is the content of the file b\0";
    else if(!strcmp(fileName, "filec.csd"))
        return "this is the content of the file c\0";
    else 
        return "";
}

bool createShader( int shaderType, const char* shader, const char* shaderFile ) 
{
    int shaderHandle = 122;

    glShaderSource( shaderHandle, 1, &shader, NULL ); ////This line is where it crashes.
    return true;
}

void glShaderSource(int shader, int count, const char** string, const int* length) {
}

Answer 1

Since the Pointer is NULL, try passing the double pointer. Something of the form

bool createShader( GLenum shaderType, const char** shader, const char* shaderFile )//<-- change 
{
    GLuint shaderHandle = glCreateShader( shaderType );

    glShaderSource( shaderHandle, 1, shader, NULL ); //<--change
    glCompileShader( shaderHandle );

    int status = 0;

    glGetShaderiv( shaderHandle, GL_COMPILE_STATUS, &status );
}

void main () {
      char* shader = strdup(getFileData("filea.csd"));
      bool success = createShader(shaderType, &shader, "filea.csd"); //<--change
      delete shader;
      return success;
}