[C++/preprocessor Patch] PR c++/53690
Paolo Carlini
paolo.carlini@oracle.com
Wed Jul 1 20:30:00 GMT 2015
Hi,
this issue isn't a regression but it's getting a lot of attention and
duplicates. Essentially, due to the lines at the very end of _cpp_valid_ucn:
if (result == 0)
result = 1;
return result;
}
we can't possibly get the encoding of \U00000000 right in C++, that is
zero, even after Jason's r152614 which added the following special case
for C++ earlier in the function:
else if ((result < 0xa0
&& !CPP_OPTION (pfile, cplusplus)
&& (result != 0x24 && result != 0x40 && result != 0x60))
|| (result & 0x80000000)
|| (result >= 0xD800 && result <= 0xDFFF))
{
cpp_error (pfile, CPP_DL_ERROR,
"%.*s is not a valid universal character",
(int) (str - base), base);
result = 1;
}
thus letting result == 0 thru until the very end of the function. Now,
fixing the problem seems easy: just change the return type of the
function to int, thus return zero for success; add a cppchar_t*
parameter cp where *cp is computed exactly like the current return value
*without* the final reset to one. Note that this is supposed to have
*no* effects whatsoever outside C++ because currently, for all those
languages, the final reset never triggers: in the second conditional
above, a result == 0 triggers a cpp_error and result becomes == 1, thus
the final conditional never sees result == 0.
Thus I'm finishing testing the below...
Thanks!
Paolo.
////////////////////////
-------------- next part --------------
/libcpp
2015-07-01 Paolo Carlini <paolo.carlini@oracle.com>
PR c++/53690
* charset.c (_cpp_valid_ucn): Add cppchar_t * parameter and change
return type to int. Fix encoding of \u0000 and \U00000000 in C++.
(convert_ucn): Adjust call.
* lex.c (forms_identifier_p): Likewise.
* internal.h (_cpp_valid_ucn): Adjust declaration.
/gcc/testsuite
2015-07-01 Paolo Carlini <paolo.carlini@oracle.com>
PR c++/53690
* g++.dg/cpp/pr53690.C: New.
-------------- next part --------------
Index: gcc/testsuite/g++.dg/cpp/pr53690.C
===================================================================
--- gcc/testsuite/g++.dg/cpp/pr53690.C (revision 0)
+++ gcc/testsuite/g++.dg/cpp/pr53690.C (working copy)
@@ -0,0 +1,7 @@
+// PR c++/53690
+// { dg-do compile { target c++11 } }
+
+int array1[U'\U00000000' == 0 ? 1 : -1];
+int array2[U'\u0000' == 0 ? 1 : -1];
+int array3[u'\U00000000' == 0 ? 1 : -1];
+int array4[u'\u0000' == 0 ? 1 : -1];
Index: libcpp/charset.c
===================================================================
--- libcpp/charset.c (revision 225265)
+++ libcpp/charset.c (working copy)
@@ -972,21 +972,20 @@ ucn_valid_in_identifier (cpp_reader *pfile, cppcha
or 0060 (`), nor one in the range D800 through DFFF inclusive.
*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 the
- UCN has not been consumed.
+ buffer end is delimited by a non-hex digit. Returns one if the
+ UCN has not been consumed, zero otherwise.
- Otherwise the nonzero value of the UCN, whether valid or invalid,
- is returned. Diagnostics are emitted for invalid values. PSTR
- is updated to point one beyond the UCN, or to the syntactically
- invalid character.
+ The value of the UCN, whether valid or invalid, is returned in *CP.
+ Diagnostics are emitted for invalid values. PSTR is updated to point
+ one beyond the UCN, or to the syntactically invalid character.
IDENTIFIER_POS is 0 when not in an identifier, 1 for the start of
an identifier, or 2 otherwise. */
-cppchar_t
+int
_cpp_valid_ucn (cpp_reader *pfile, const uchar **pstr,
const uchar *limit, int identifier_pos,
- struct normalize_state *nst)
+ struct normalize_state *nst, cppchar_t *cp)
{
cppchar_t result, c;
unsigned int length;
@@ -1030,8 +1029,11 @@ _cpp_valid_ucn (cpp_reader *pfile, const uchar **p
multiple tokens in identifiers, so we can't give a helpful
error message in that case. */
if (length && identifier_pos)
- return 0;
-
+ {
+ *cp = 0;
+ return 1;
+ }
+
*pstr = str;
if (length)
{
@@ -1079,10 +1081,8 @@ _cpp_valid_ucn (cpp_reader *pfile, const uchar **p
(int) (str - base), base);
}
- if (result == 0)
- result = 1;
-
- return result;
+ *cp = result;
+ return 0;
}
/* Convert an UCN, pointed to by FROM, to UTF-8 encoding, then translate
@@ -1100,7 +1100,7 @@ convert_ucn (cpp_reader *pfile, const uchar *from,
struct normalize_state nst = INITIAL_NORMALIZE_STATE;
from++; /* Skip u/U. */
- ucn = _cpp_valid_ucn (pfile, &from, limit, 0, &nst);
+ _cpp_valid_ucn (pfile, &from, limit, 0, &nst, &ucn);
rval = one_cppchar_to_utf8 (ucn, &bufp, &bytesleft);
if (rval)
Index: libcpp/internal.h
===================================================================
--- libcpp/internal.h (revision 225265)
+++ libcpp/internal.h (working copy)
@@ -744,9 +744,10 @@ struct normalize_state
#define NORMALIZE_STATE_UPDATE_IDNUM(st, c) \
((st)->previous = (c), (st)->prev_class = 0)
-extern cppchar_t _cpp_valid_ucn (cpp_reader *, const unsigned char **,
- const unsigned char *, int,
- struct normalize_state *state);
+extern int _cpp_valid_ucn (cpp_reader *, const unsigned char **,
+ const unsigned char *, int,
+ struct normalize_state *state,
+ cppchar_t *);
extern void _cpp_destroy_iconv (cpp_reader *);
extern unsigned char *_cpp_convert_input (cpp_reader *, const char *,
unsigned char *, size_t, size_t,
Index: libcpp/lex.c
===================================================================
--- libcpp/lex.c (revision 225265)
+++ libcpp/lex.c (working copy)
@@ -1244,9 +1244,10 @@ forms_identifier_p (cpp_reader *pfile, int first,
&& *buffer->cur == '\\'
&& (buffer->cur[1] == 'u' || buffer->cur[1] == 'U'))
{
+ cppchar_t s;
buffer->cur += 2;
- if (_cpp_valid_ucn (pfile, &buffer->cur, buffer->rlimit, 1 + !first,
- state))
+ if (!_cpp_valid_ucn (pfile, &buffer->cur, buffer->rlimit, 1 + !first,
+ state, &s))
return true;
buffer->cur -= 2;
}
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