Add more informative help text in case of faulty or no OpenCL installation

docs/changes.txt

@@ -11,7 +11,7 @@ It combines all features of all hashcat projects in one project.
 
 - Support for Apple OpenCL runtime
 - Support for NVidia OpenCL runtime (replaces CUDA)
-- Support for Mesa/Clover OpenCL runtime
+- Support for Mesa (Gallium) OpenCL runtime
 - Support for pocl OpenCL runtime
 - Support for Khronos' OSS OpenCL reference implementation for building
 - Support to utilize OpenCL devices-types other than GPU, ex: CPU and FPGA

docs/readme.txt

@@ -221,7 +221,7 @@ NVidia users require NVidia drivers 346.59 or later (recommended 361.x or later)
 - AMD Catalyst
 - Apple
 - Intel
-- Mesa/Clover
+- Mesa (Gallium)
 - NVidia ForceWare
 - pocl
 

src/ext_OpenCL.c

@@ -79,7 +79,20 @@ int ocl_init (OCL_PTR *ocl)
 
   if (ocl->lib == NULL)
   {
-    log_error ("ERROR: cannot load opencl library");
+    log_info ("");
+    log_info ("ATTENTION! Can't find OpenCL ICD loader library");
+    log_info ("");
+    #if defined (LINUX)
+    log_info ("You're probably missing the \"ocl-icd-libopencl1\" package (Debian/Ubuntu)");
+    log_info ("  sudo apt-get install ocl-icd-libopencl1");
+    log_info ("");
+    #elif defined (WIN)
+    log_info ("You're probably missing the OpenCL runtime installation");
+    log_info ("  AMD users require AMD drivers 14.9 or later (recommended 15.12 or later)");
+    log_info ("  Intel users require Intel OpenCL Runtime 14.2 or later (recommended 15.1 or later)");
+    log_info ("  NVidia users require NVidia drivers 346.59 or later (recommended 361.x or later)");
+    log_info ("");
+    #endif
 
     exit (-1);
   }

src/hashcat.c

@@ -12548,7 +12548,14 @@ int main (int argc, char **argv)
 
       if (platforms_cnt == 0)
       {
-        log_error ("ERROR: No OpenCL compatible platform found");
+        log_info ("");
+        log_info ("ATTENTION! No OpenCL compatible platform found");
+        log_info ("");
+        log_info ("You're probably missing the OpenCL runtime installation");
+        log_info ("  AMD users require AMD drivers 14.9 or later (recommended 15.12 or later)");
+        log_info ("  Intel users require Intel OpenCL Runtime 14.2 or later (recommended 15.1 or later)");
+        log_info ("  NVidia users require NVidia drivers 346.59 or later (recommended 361.x or later)");
+        log_info ("");
 
         return (-1);
       }