[libcxx] r243030 - Detect and throw on a class of bad regexes that we mistakenly accepted before. Thanks to Trevor Smigiel for the report

[Marshall Clow]

Author: marshall
Date: Thu Jul 23 13:27:51 2015
New Revision: 243030

URL: http://llvm.org/viewvc/llvm-project?rev=243030&view=rev
Log:
Detect and throw on a class of bad regexes that we mistakenly accepted before. Thanks to Trevor Smigiel for the report

Added:
    libcxx/trunk/test/std/re/re.regex/re.regex.construct/bad_repeat.pass.cpp
Modified:
    libcxx/trunk/include/regex
    libcxx/trunk/test/std/re/re.regex/re.regex.construct/bad_escape.pass.cpp

Modified: libcxx/trunk/include/regex
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/regex?rev=243030&r1=243029&r2=243030&view=diff
==============================================================================
--- libcxx/trunk/include/regex (original)
+++ libcxx/trunk/include/regex Thu Jul 23 13:27:51 2015
@@ -4305,6 +4305,14 @@ basic_regex<_CharT, _Traits>::__parse_at
                 }
             }
             break;
+        case '*':
+        case '+':
+        case '?':
+        case '{':
+#ifndef _LIBCPP_NO_EXCEPTIONS
+            throw regex_error(regex_constants::error_badrepeat);
+#endif
+            break;
         default:
             __first = __parse_pattern_character(__first, __last);
             break;

Modified: libcxx/trunk/test/std/re/re.regex/re.regex.construct/bad_escape.pass.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/re/re.regex/re.regex.construct/bad_escape.pass.cpp?rev=243030&r1=243029&r2=243030&view=diff
==============================================================================
--- libcxx/trunk/test/std/re/re.regex/re.regex.construct/bad_escape.pass.cpp (original)
+++ libcxx/trunk/test/std/re/re.regex/re.regex.construct/bad_escape.pass.cpp Thu Jul 23 13:27:51 2015
@@ -22,7 +22,7 @@ static bool error_escape_thrown(const ch
     bool result = false;
     try {
         std::regex re(pat);
-    } catch (std::regex_error &ex) {
+    } catch (const std::regex_error &ex) {
         result = (ex.code() == std::regex_constants::error_escape);
     }
     return result;

Added: libcxx/trunk/test/std/re/re.regex/re.regex.construct/bad_repeat.pass.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/re/re.regex/re.regex.construct/bad_repeat.pass.cpp?rev=243030&view=auto
==============================================================================
--- libcxx/trunk/test/std/re/re.regex/re.regex.construct/bad_repeat.pass.cpp (added)
+++ libcxx/trunk/test/std/re/re.regex/re.regex.construct/bad_repeat.pass.cpp Thu Jul 23 13:27:51 2015
@@ -0,0 +1,42 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <regex>
+
+// template <class charT, class traits = regex_traits<charT>> class basic_regex;
+
+// template <class ST, class SA>
+//    basic_regex(const basic_string<charT, ST, SA>& s);
+
+#include <regex>
+#include <cassert>
+
+static bool error_badrepeat_thrown(const char *pat) 
+{
+    bool result = false;
+    try {
+        std::regex re(pat);
+    } catch (const std::regex_error &ex) {
+        result = (ex.code() == std::regex_constants::error_badrepeat);
+    }
+    return result;
+}
+
+int main() 
+{
+    assert(error_badrepeat_thrown("?a"));
+    assert(error_badrepeat_thrown("*a"));
+    assert(error_badrepeat_thrown("+a"));
+    assert(error_badrepeat_thrown("{a"));
+
+    assert(error_badrepeat_thrown("?(a+)"));
+    assert(error_badrepeat_thrown("*(a+)"));
+    assert(error_badrepeat_thrown("+(a+)"));
+    assert(error_badrepeat_thrown("{(a+)"));
+}