OpenGL Shader Compile Error - c++

Question

I'm having a bit of a problem with my code for compiling shaders, namely they both register as failed compiles and no log is received.
This is the shader compiling code:
/* Make the shader */
Uint size;
GLchar* file;
loadFileRaw(filePath, file, &size);
const char * pFile = file;
const GLint pSize = size;
newCashe.shader = glCreateShader(shaderType);
glShaderSource(newCashe.shader, 1, &pFile, &pSize);
glCompileShader(newCashe.shader);
GLint shaderCompiled;
glGetShaderiv(newCashe.shader, GL_COMPILE_STATUS, &shaderCompiled);
if(shaderCompiled == GL_FALSE)
{
ReportFiler->makeReport("ShaderCasher.cpp", "loadShader()", "Shader did not compile", "The shader " + filePath + " failed to compile, reporting the error - " + OpenGLServices::getShaderLog(newCashe.shader));
}
And these are the support functions:
bool loadFileRaw(string fileName, char* data, Uint* size)
{
if (fileName != "")
{
FILE *file = fopen(fileName.c_str(), "rt");
if (file != NULL)
{
fseek(file, 0, SEEK_END);
*size = ftell(file);
rewind(file);
if (*size > 0)
{
data = (char*)malloc(sizeof(char) * (*size + 1));
*size = fread(data, sizeof(char), *size, file);
data[*size] = '\0';
}
fclose(file);
}
}
return data;
}
string OpenGLServices::getShaderLog(GLuint obj)
{
int infologLength = 0;
int charsWritten = 0;
char *infoLog;
glGetShaderiv(obj, GL_INFO_LOG_LENGTH,&infologLength);
if (infologLength > 0)
{
infoLog = (char *)malloc(infologLength);
glGetShaderInfoLog(obj, infologLength, &charsWritten, infoLog);
string log = infoLog;
free(infoLog);
return log;
}
return "<Blank Log>";
}
and the shaders I'm loading:
void main(void)
{
gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
}
void main(void)
{
gl_Position = ftransform();
}
In short I get
From: ShaderCasher.cpp, In: loadShader(), Subject: Shader did not compile
Message: The shader Data/Shaders/Standard/standard.vs failed to compile, reporting the error - <Blank Log>
for every shader I compile.
I've tried replacing the file reading with just a hard coded string but I get the same error so there must be something wrong with how I'm compiling them. I have run and compiled example programs with shaders, so I doubt my drivers are the issue, but in any case I'm on a Nvidia 8600m GT.
Can anyone help?

Answer 1

In loadFileRaw, you pass char *data by value. Then you assign to it:
data = (char*)malloc(sizeof(char) * (*size + 1));
so your call
loadFileRaw(filePath, file, &size);
does not change the value of file! To change file, pass it in by pointer:
loadFileRaw(filePath, &file, &size);
and then change your function to
bool loadFileRaw(string fileName, char** data, Uint* size) { ... }
and in it,
*data = (char*)malloc(sizeof(char) * (*size + 1));
etc. (for the remaining references to data).
That said, since you're using C++, look into using std::vector<char> or std::string for your memory management. To get you started,
{
std::vector<char> data;
data.resize(100); // now it has 100 entries, initialized to zero
silly_C_function_that_takes_a_char_pointer_and_a_size(&data[0], 100); // OK
} // presto, memory freed
Also, you can look into using std::ifstream for reading files, instead of using FILE *.

Answer 2

Try with:
glShaderSource(newCashe.shader, 1, &pFile, NULL);
Which is the most commonly used call to load shader sources.