[7/7,D] libiberty: Refactor and add tests for decoding hexdigits.

commit de5523a4ff9d755940fc7dc5beadb65f0aafd0df
Author: Iain Buclaw <ibuclaw@gdcproject.org>
Date:   Sat Apr 15 13:10:43 2017 +0200

    libiberty/ChangeLog:
    
    2017-04-15  Iain Buclaw  <ibuclaw@gdcproject.org>
    
    	* d-demangle.c (dlang_hexdigit): New function.
    	(ascii2hex): Remove function.
    	(dlang_parse_string): Update to call dlang_hexdigit.
    	* testsuite/d-demangle-expected: Add tests.

diff --git a/libiberty/d-demangle.c b/libiberty/d-demangle.c
index 84a7186..ed97d2d 100644
--- a/libiberty/d-demangle.c
+++ b/libiberty/d-demangle.c
@@ -223,6 +223,34 @@  dlang_number (const char *mangled, long *ret)
   return mangled;
 }
 
+/* Extract the hex-digit from MANGLED, and assign the result to RET.
+   Return the remaining string on success or NULL on failure.  */
+static const char *
+dlang_hexdigit (const char *mangled, char *ret)
+{
+  char c;
+
+  /* Return NULL if trying to extract something that isn't a hexdigit.  */
+  if (mangled == NULL || !ISXDIGIT (mangled[0]) || !ISXDIGIT (mangled[1]))
+    return NULL;
+
+  c = mangled[0];
+  if (!ISDIGIT (c))
+    *ret = (c - (ISUPPER (c) ? 'A' : 'a') + 10);
+  else
+    *ret = (c - '0');
+
+  c = mangled[1];
+  if (!ISDIGIT (c))
+    *ret = (*ret << 4) | (c - (ISUPPER (c) ? 'A' : 'a') + 10);
+  else
+    *ret = (*ret << 4) | (c - '0');
+
+  mangled += 2;
+
+  return mangled;
+}
+
 /* Demangle the calling convention from MANGLED and append it to DECL.
    Return the remaining string on success or NULL on failure.  */
 static const char *
@@ -1070,22 +1098,6 @@  dlang_parse_real (string *decl, const char *mangled)
   return mangled;
 }
 
-/* Convert VAL from an ascii hexdigit to value.  */
-static char
-ascii2hex (char val)
-{
-  if (val >= 'a' && val <= 'f')
-    return (val - 'a' + 10);
-
-  if (val >= 'A' && val <= 'F')
-    return (val - 'A' + 10);
-
-  if (val >= '0' && val <= '9')
-    return (val - '0');
-
-  return 0;
-}
-
 /* Extract the string value from MANGLED and append it to DECL.
    Return the remaining string on success or NULL on failure.  */
 static const char *
@@ -1103,48 +1115,45 @@  dlang_parse_string (string *decl, const char *mangled)
   string_append (decl, "\"");
   while (len--)
     {
-      if (ISXDIGIT (mangled[0]) && ISXDIGIT (mangled[1]))
+      char val;
+      const char *endptr = dlang_hexdigit (mangled, &val);
+
+      if (endptr == NULL)
+	return NULL;
+
+      /* Sanitize white and non-printable characters.  */
+      switch (val)
 	{
-	  char a = ascii2hex (mangled[0]);
-	  char b = ascii2hex (mangled[1]);
-	  char val = (a << 4) | b;
+	case ' ':
+	  string_append (decl, " ");
+	  break;
+	case '\t':
+	  string_append (decl, "\\t");
+	  break;
+	case '\n':
+	  string_append (decl, "\\n");
+	  break;
+	case '\r':
+	  string_append (decl, "\\r");
+	  break;
+	case '\f':
+	  string_append (decl, "\\f");
+	  break;
+	case '\v':
+	  string_append (decl, "\\v");
+	  break;
 
-	  /* Sanitize white and non-printable characters.  */
-	  switch (val)
+	default:
+	  if (ISPRINT (val))
+	    string_appendn (decl, &val, 1);
+	  else
 	    {
-	    case ' ':
-	      string_append (decl, " ");
-	      break;
-	    case '\t':
-	      string_append (decl, "\\t");
-	      break;
-	    case '\n':
-	      string_append (decl, "\\n");
-	      break;
-	    case '\r':
-	      string_append (decl, "\\r");
-	      break;
-	    case '\f':
-	      string_append (decl, "\\f");
-	      break;
-	    case '\v':
-	      string_append (decl, "\\v");
-	      break;
-
-	    default:
-	      if (ISPRINT (val))
-		string_appendn (decl, &val, 1);
-	      else
-		{
-		  string_append (decl, "\\x");
-		  string_appendn (decl, mangled, 2);
-		}
+	      string_append (decl, "\\x");
+	      string_appendn (decl, mangled, 2);
 	    }
 	}
-      else
-	return NULL;
 
-      mangled += 2;
+      mangled = endptr;
     }
   string_append (decl, "\"");
 
diff --git a/libiberty/testsuite/d-demangle-expected b/libiberty/testsuite/d-demangle-expected
index 9fc1551..8c349fd 100644
--- a/libiberty/testsuite/d-demangle-expected
+++ b/libiberty/testsuite/d-demangle-expected
@@ -850,6 +850,14 @@  _D8demangle22__T4testVG3uw3_616263Zv
 demangle.test!("abc"w)
 #
 --format=dlang
+_D8demangle16__T4testVAyaa0_Zv
+demangle.test!("")
+#
+--format=dlang
+_D8demangle32__T4testVAyaa8_20090a0d0c0b00ffZv
+demangle.test!(" \t\n\r\f\v\x00\xff")
+#
+--format=dlang
 _D8demangle22__T4testVAiA4i1i2i3i4Zv
 demangle.test!([1, 2, 3, 4])
 #
@@ -1068,10 +1076,18 @@  _D15__T4testVfe0p1Zv
 _D15__T4testVfe0p1Zv
 #
 --format=dlang
+_D15__T4testVAyaa1_
+_D15__T4testVAyaa1_
+#
+--format=dlang
 _D16__T4testVAyaa0aZv
 _D16__T4testVAyaa0aZv
 #
 --format=dlang
+_D18__T4testVAyaa1_0GZv
+_D18__T4testVAyaa1_0GZv
+#
+--format=dlang
 _D18__T4testVAyaa1_YYZv
 _D18__T4testVAyaa1_YYZv
 #
@@ -1228,6 +1244,14 @@  _D8demangle34__T2fnVai97Vai9Vai0Vui257Vwi65537Z2fnFZv
 demangle.fn!('a', '\x09', '\x00', '\u0101', '\U00010001').fn()
 #
 --format=dlang
+_D8demangle39__T2fnVAyaa12_d0bfd180d0b8d0bcd0b5d180Z2fnFZv
+demangle.fn!("\xd0\xbf\xd1\x80\xd0\xb8\xd0\xbc\xd0\xb5\xd1\x80").fn()
+#
+--format=dlang
+_D8demangle26__T2fnVAyaa6_e4b896e7958cZ2fnFZv
+demangle.fn!("\xe4\xb8\x96\xe7\x95\x8c").fn()
+#
+--format=dlang
 _D2gc11gctemplates56__T8mkBitmapTS3std5range13__T4iotaTiTiZ4iotaFiiZ6ResultZ8mkBitmapFNbNiNfPmmZv
 gc.gctemplates.mkBitmap!(std.range.iota!(int, int).iota(int, int).Result).mkBitmap(ulong*, ulong)
 #