From: Ben Boeckel <ben.boeckel@kitware.com>
Date: Tue, 6 Jun 2023 20:50:22 +0000 (-0400)
Subject: libcpp: reject codepoints above 0x10FFFF
X-Git-Tag: basepoints/gcc-15~8185
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c1dbaa6656acc62c586dad1018f06113cde2d8a4;p=thirdparty%2Fgcc.git

libcpp: reject codepoints above 0x10FFFF

Unicode does not support such values because they are unrepresentable in
UTF-16.

libcpp/

	* charset.cc: Reject encodings of codepoints above 0x10FFFF.
	UTF-16 does not support such codepoints and therefore all
	Unicode rejects such values.

Signed-off-by: Ben Boeckel <ben.boeckel@kitware.com>
---

diff --git a/libcpp/charset.cc b/libcpp/charset.cc
index d7f323b2cd52..d4f573e365f0 100644
--- a/libcpp/charset.cc
+++ b/libcpp/charset.cc
@@ -1886,6 +1886,13 @@ cpp_valid_utf8_p (const char *buffer, size_t num_bytes)
       int err = one_utf8_to_cppchar (&iter, &bytesleft, &cp);
       if (err)
 	return false;
+
+      /* Additionally, Unicode declares that all codepoints above 0010FFFF are
+	 invalid because they cannot be represented in UTF-16.
+
+	 Reject such values.*/
+      if (cp >= UCS_LIMIT)
+	return false;
     }
   /* No problems encountered.  */
   return true;