OpenGL Shader Compilation Errors: unexpected $undefined at token "<undefined>"
c++, compilation, error-handling, glsl, opengl
Solution
That error message means that the shader compiler is seeing a garbage character (something other than a printable ASCII character, a space, a tab, or a newline) on the first line of the shader. Which most likely means that the string you're passing to `glShaderSource` is garbage -- probably a dangling pointer that once pointed at your shader code but no longer does due to something getting destructed.
edit
I see from your link you have code that looks like:
s.Source = shader.toStdString().c_str();
That will set `s.Source` pointing at the internal buffer of a temporary `std::string` object that will be destroyed shortly after this line, leaving `s.Source` a dangling pointer...
Problem
I saw this question and it really shedded some light. Despite this, I can't seem to figure out how I'm "improperly" loading my shader, because this has executed before without any recent changes to the shader loading code, so I assume these errors must be coming from my draw calls. Despite this, I'll still post the shader files for the sake of brevity, the draw function used to draw the circle I'm trying to render, and the code which loads in the shader file as a string. Basically what I need to know is why I'm getting these errors and what in the hell is wrong with them? (From debug output) ``` ERROR { OpenGL Says: Vertex info ----------- 0(1) : error C0000: syntax error, unexpected $undefined at token "<undefined>" Fragment info ------------- 0(1) : error C0000: syntax error, unexpected $undefined at token "<undefined>" }; ``` Draw Code ``` void Circle::draw( GLuint program ) { const size_t centerMag = mCenter.length(); glUseProgram( program ); for( float t = 0; t < mCircumference; t += 0.1 ) { float x = centerMag + glm::cos( 2 * M_PI * t ); float y = centerMag + glm::sin( 2 * M_PI * t ); mVertices->push_back( glm::vec4( x, y, 0, 1 ) ); } QListIterator< glm::vec4 > iVertices( *mVertices ); const size_t size = mVertices->size(); float** verts = new float*[ size ]; size_t i = 0; glEnableClientState( GL_VERTEX_ARRAY ); while( iVertices.hasNext() ) { verts[ i ] = new float[ size ]; verts[ i ] = const_cast< float* >( glm::value_ptr( iVertices.next() ) ); glVertexPointer( 4, GL_FLOAT, 0, verts[ i ] ); glDrawArrays( GL_LINES, 0, 4 ); ++i; } glDisableClientState( GL_VERTEX_ARRAY ); for( unsigned iMem = 0; iMem < size; ++iMem ) { delete[] verts[ iMem ]; verts[ iMem ] = NULL; } delete[] verts; verts = NULL; } ``` FileUtility ``` QString FileUtility::readShader( QString filepath ) { std::ifstream in( filepath.toStdString().c_str() ); std::stringstream shaderDat; shaderDat << in.rdbuf(); QString shaderFile; shaderFile += shaderDat.str().c_str(); in.close(); return shaderFile; } ``` GenericColor.frag ``` #version 330 out vec4 outputColor; void main() { outputColor = vec4(1.0f, 0, 0, 1.0f); } ``` Position.vert ``` #version 330 layout(location = 0) in vec4 position; void main() { gl_Position = position; } ``` Update Since my shader binding/compilation code was requested, I figured I may as well just post my entire shader handler, as well as the engine class. -Engine -ShaderHandler. Update Here are the shader strings parsed (`Info` is a debug output): ``` Info { Shader Source #version 330 in uniform mvp; layout(location = 0) in vec4 position; void main() { gl_ModelViewProjectionMatrix = mvp; gl_Position = position; } }; Info { Shader Source #version 330 out vec4 outputColor; void main() { outputColor = vec4(1.0f, 0, 0, 1.0f); } }; ```