Error message and fail for realpath (#8706)

OMCompiler/Compiler/Util/System.mo

@@ -40,6 +40,7 @@ encapsulated package System
 
 protected
 import Autoconf;
+import Error;
 
 public function trim
 "removes chars in charsToRemove from begin and end of inString"
@@ -172,6 +173,8 @@ public function tolower
 end tolower;
 
 public function strtok
+  "Break string into a series of tokens using the delimiter token.
+   See strtok from C standard."
   input String string;
   input String token;
   output list<String> strings;
@@ -1082,9 +1085,22 @@ public function numBits
 end numBits;
 
 public function realpath
+  "Return the canonicalized absolute pathname"
   input String path;
   output String fullpath;
-  external "C" fullpath = System_realpath(path) annotation(Library = {"omcruntime"});
+protected
+  function system_realpath
+    input String path;
+    output String fullpath;
+    external "C" fullpath = System_realpath(path) annotation(Library = {"omcruntime"});
+  end system_realpath;
+algorithm
+  try
+    fullpath := system_realpath(path);
+  else
+    Error.addInternalError(getInstanceName() + " failed", sourceInfo());
+    fail();
+  end try;
 end realpath;
 
 public function getSimulationHelpText

OMCompiler/Compiler/runtime/System_omc.c

@@ -786,6 +786,36 @@ extern const char* System_realpath(const char *path)
 #else
   char buf[PATH_MAX];
   if (realpath(path, buf) == NULL) {
+    fprintf(stderr, "System_realpath failed.\n");
+    switch (errno)
+    {
+    case EACCES:
+      fprintf(stderr, "Read or search permission was denied for a component of the path prefix.\n");
+      break;
+    case EINVAL:
+      fprintf(stderr, "path is NULL.\n");
+      break;
+    case EIO:
+      fprintf(stderr, "An I/O error occurred while reading from the filesystem.\n");
+      break;
+    case ELOOP:
+      fprintf(stderr, "Too many symbolic links were encountered in translating the pathname.\n");
+      break;
+    case ENAMETOOLONG:
+      fprintf(stderr, "A component of a pathname exceeded %u characters, or an entire pathname exceeded %u characters.\n", NAME_MAX, PATH_MAX);
+      break;
+    case ENOENT:
+      fprintf(stderr, "The named file does not exist.\n");
+      break;
+    case ENOMEM:
+      fprintf(stderr, "Out of memory.\n");
+      break;
+    case ENOTDIR:
+      fprintf(stderr, "A component of the path prefix is not a directory.\n");
+      break;
+    default:
+      break;
+    }
     MMC_THROW();
   }
   return omc_alloc_interface.malloc_strdup(buf);