[GH #911] Provide strerror for unknown filehandle errors

Unify printed type: filehandle => FileHandle, to sync with generic Parrot_io_open
"Cannot open %s, no path", vtable->name errmsg.

src/io/filehandle.c

@@ -1,5 +1,5 @@
 /*
-Copyright (C) 2001-2012, Parrot Foundation.
+Copyright (C) 2001-2013, Parrot Foundation.
 
 =head1 NAME
 
@@ -469,9 +469,14 @@ io_filehandle_open(PARROT_INTERP, ARGMOD(PMC *handle), ARGIN(STRING *path), INTV
 
     os_handle = Parrot_io_internal_open(interp, path, flags);
 
-    if (os_handle == PIO_INVALID_HANDLE)
-        Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_PIO_ERROR,
-            "Unable to open filehandle from path '%Ss'", path);
+    if (os_handle == PIO_INVALID_HANDLE) {
+        if (errno)
+            Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_PIO_ERROR,
+                "Unable to open filehandle from path '%Ss': %s(%d)", path, strerror(errno), errno);
+        else
+            Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_PIO_ERROR,
+                "Unable to open filehandle from path '%Ss'", path);
+    }
 
     /* Set generic flag here if is a terminal then
      * FileHandle can know how to setup buffering.

src/pmc/filehandle.pmc

@@ -1,5 +1,5 @@
 /*
-Copyright (C) 2008-2011, Parrot Foundation.
+Copyright (C) 2008-2013, Parrot Foundation.
 
 =head1 NAME
 
@@ -249,6 +249,30 @@ invocant is modified and becomes an open filehandle. A copy of the invocant is
 also returned by the method (some subclasses may create this as the primary
 filehandle, rather than modifying the invocant).
 
+Exceptions:
+
+EXCEPTION_PIO_ERROR with the following messages:
+
+Empty filename
+
+    "Cannot open FileHandle, no path"
+
+Already open filehandle
+
+    "Cannot reopen already open FileHandle"
+
+Invalid handle, no errno as with ISDIR:
+
+    "Unable to open filehandle from path '$path'"
+
+Invalid handle (fd < 0), or other error:
+
+    "Unable to open filehandle from path '$path': $strerror($errno)"
+
+EXCEPTION_INVALID_OPERATION with:
+
+    "Invalid mode for file open"
+
 =cut
 
 */
@@ -259,7 +283,7 @@ filehandle, rather than modifying the invocant).
 
         if (!Parrot_io_is_closed(INTERP, SELF))
             Parrot_ex_throw_from_c_args(INTERP, NULL, EXCEPTION_PIO_ERROR,
-                                "Cannot reopen already open filehandle");
+                                "Cannot reopen already open FileHandle");
 
         if (!got_mode || STRING_IS_NULL(mode))
             GET_ATTR_mode(INTERP, SELF, mode);

t/pmc/filehandle.t

@@ -1,5 +1,5 @@
 #!perl
-# Copyright (C) 2006-2011, Parrot Foundation.
+# Copyright (C) 2006-2013, Parrot Foundation.
 
 use strict;
 use warnings;
@@ -137,11 +137,34 @@ pir_output_is( <<'CODE', <<'OUT', 'wrong open' );
     finalize eh
   reportreopen:
     say i
+
+    i = 0
+    set_label eh, catchother
+    fh.'open'('noREADME.pod')
+    goto reportother
+  catchother:
+    i = 1
+    finalize eh
+  reportother:
+    say i
+
+    i = 0
+    set_label eh, catchdir
+    fh.'open'('t')
+    goto reportdir
+  catchdir:
+    i = 1
+    finalize eh
+  reportdir:
+    say i
+
     pop_eh
 .end
 CODE
 1
 1
+1
+1
 OUT
 
 pir_output_is( <<'CODE', <<'OUT', 'isatty' );