charset.c (_cpp_valid_ucn): In identifiers, reject a partial UCN rather than printing an error.

2005-03-15  Geoffrey Keating  <geoffk@apple.com>

	* charset.c (_cpp_valid_ucn): In identifiers, reject a partial
	UCN rather than printing an error.

Index: gcc/testsuite/ChangeLog
2005-03-15  Geoffrey Keating  <geoffk@apple.com>

	* gcc.dg/cpp/ucnid-7.c: New.

From-SVN: r96546
diff --git a/libcpp/charset.c b/libcpp/charset.c
index f028b37..ba53f63 100644
--- a/libcpp/charset.c
+++ b/libcpp/charset.c
@@ -923,9 +923,8 @@
    program is ill-formed.
 
    *PSTR must be preceded by "\u" or "\U"; it is assumed that the
-   buffer end is delimited by a non-hex digit.  Returns zero if UCNs
-   are not part of the relevant standard, or if the string beginning
-   at *PSTR doesn't syntactically match the form 'NNNN' or 'NNNNNNNN'.
+   buffer end is delimited by a non-hex digit.  Returns zero if the
+   UCN has not been consumed.
 
    Otherwise the nonzero value of the UCN, whether valid or invalid,
    is returned.  Diagnostics are emitted for invalid values.  PSTR
@@ -974,10 +973,15 @@
     }
   while (--length && str < limit);
 
+  /* Partial UCNs are not valid in strings, but decompose into
+     multiple tokens in identifiers, so we can't give a helpful
+     error message in that case.  */
+  if (length && identifier_pos)
+    return 0;
+  
   *pstr = str;
   if (length)
     {
-      /* We'll error when we try it out as the start of an identifier.  */
       cpp_error (pfile, CPP_DL_ERROR,
 		 "incomplete universal character name %.*s",
 		 (int) (str - base), base);