OpenGL: Reimplement shader uid debugging.

Source/Core/VideoCommon/Src/ShaderGenCommon.h

@@ -51,6 +51,11 @@ public:
 		return memcmp(this->values, obj.values, sizeof(values)) == 0;
 	}
 
+	bool operator != (const ShaderUid& obj) const
+	{
+		return memcmp(this->values, obj.values, sizeof(values)) != 0;
+	}
+
 	// TODO: Store last frame used and order by that? makes much more sense anyway...
 	bool operator < (const ShaderUid& obj) const
 	{

Source/Plugins/Plugin_VideoOGL/Src/ProgramShaderCache.cpp

@@ -23,6 +23,9 @@
 #include "ImageWrite.h"
 #include "Render.h"
 
+#include <algorithm>
+#include <type_traits>
+
 namespace OGL
 {
 
@@ -353,14 +356,71 @@ GLuint ProgramShaderCache::CompileSingleShader (GLuint type, const char* code )
 	return result;
 }
 
+template<class UidT> UidT GetPartialUid(const SHADERUID& uid);
+template<> PixelShaderUid GetPartialUid(const SHADERUID& uid) { return uid.puid; }
+template<> VertexShaderUid GetPartialUid(const SHADERUID& uid) { return uid.vuid; }
+
+template<class CodeT> const std::string& GetShaderCode(const SHADER& shader);
+template<> const std::string& GetShaderCode<PixelShaderCode>(const SHADER& shader) { return shader.strpprog; }
+template<> const std::string& GetShaderCode<VertexShaderCode>(const SHADER& shader) { return shader.strvprog; }
+
+template<class UidT, class CodeT>
+void CheckForUidMismatch(const ProgramShaderCache::PCache& cache, CodeT& new_code, const UidT& new_uid)
+{
+	static std::map<UidT,std::string> s_shaders;
+	static std::vector<UidT> s_uids;
+
+	bool uid_is_indexed = std::find(s_uids.begin(), s_uids.end(), new_uid) != s_uids.end();
+	if (!uid_is_indexed)
+	{
+		s_uids.push_back(new_uid);
+		s_shaders[new_uid] = new_code.GetBuffer();
+	}
+	else
+	{
+		// uid is already in the index => check if there's a shader with the same uid but different code
+		auto& old_code = s_shaders[new_uid];
+		if (strcmp(old_code.c_str(), new_code.GetBuffer()) != 0)
+		{
+			static int num_failures = 0;
+
+			char szTemp[MAX_PATH];
+			sprintf(szTemp, "%s%ssuid_mismatch_%04i.txt", File::GetUserPath(D_DUMP_IDX).c_str(),
+					std::is_same<UidT,PixelShaderUid>::value ? "p" : std::is_same<UidT,VertexShaderUid>::value ? "v" : "o",
+					++num_failures);
+
+			// TODO: Should also dump uids
+			std::ofstream file;
+			OpenFStream(file, szTemp, std::ios_base::out);
+			file << "Old shader code:\n" << old_code;
+			file << "\n\nNew shader code:\n" << new_code.GetBuffer();
+			file.close();
+
+			// TODO: Make this more idiot-proof
+			ERROR_LOG(VIDEO, "%s shader uid mismatch!",
+					  std::is_same<UidT,PixelShaderUid>::value ? "Pixel" : std::is_same<UidT,VertexShaderUid>::value ? "Vertex" : "Other");
+		}
+	}
+}
 
 
 void ProgramShaderCache::GetShaderId(SHADERUID* uid, DSTALPHA_MODE dstAlphaMode, u32 components)
 {
 	GetPixelShaderUid(uid->puid, dstAlphaMode, API_OPENGL, components);
 	GetVertexShaderUid(uid->vuid, components, API_OPENGL);
-}
 
+	if (g_ActiveConfig.bEnableShaderDebugging)
+	{
+		PixelShaderCode pcode;
+		VertexShaderCode vcode;
+
+		GeneratePixelShaderCode(pcode, dstAlphaMode, API_OPENGL, components);
+		GenerateVertexShaderCode(vcode, components, API_OPENGL);
+
+		CheckForUidMismatch<PixelShaderUid,PixelShaderCode>(pshaders, pcode, uid->puid);
+		CheckForUidMismatch<VertexShaderUid,VertexShaderCode>(pshaders, vcode, uid->vuid);
+	}
+}
 
 
 ProgramShaderCache::PCacheEntry ProgramShaderCache::GetShaderProgram(void)