Datetime scanning

include/scn/scan.h

@@ -3218,19 +3218,15 @@ class view_interface {
               typename = std::enable_if_t<contiguous_iterator<iterator_t<R>>>>
     constexpr auto data()
     {
-        return ranges::empty(derived())
-                   ? nullptr
-                   : std::addressof(*ranges::begin(derived()));
+        return detail::to_address(ranges::begin(derived()));
     }
 
     template <typename R = D,
               typename = std::enable_if_t<
                   range<const R> && contiguous_iterator<iterator_t<const R>>>>
     constexpr auto data() const
     {
-        return ranges::empty(derived())
-                   ? nullptr
-                   : std::addressof(*ranges::begin(derived()));
+        return detail::to_address(ranges::begin(derived()));
     }
 
     template <typename R = D,
@@ -4042,6 +4038,18 @@ inline constexpr char32_t decode_code_point_exhaustive_valid(
     }
 }
 
+inline constexpr bool is_cp_space(char32_t cp) noexcept
+{
+    // Pattern_White_Space property
+    return (cp >= 0x09 && cp <= 0x0d) ||
+           cp == 0x20 ||    // ASCII space characters
+           cp == 0x85 ||    // NEXT LINE (NEL)
+           cp == 0x200e ||  // LEFT-TO-RIGHT MARK
+           cp == 0x200f ||  // RIGHT-TO-LEFT MARK
+           cp == 0x2028 ||  // LINE SEPARATOR
+           cp == 0x2029;    // PARAGRAPH SEPARATOR
+}
+
 }  // namespace detail
 
 /////////////////////////////////////////////////////////////////
@@ -4192,6 +4200,7 @@ class basic_scan_buffer<CharT>::forward_iterator {
 
     bool stores_parent() const
     {
+        assert(m_begin);
         return m_end == nullptr;
     }
 
@@ -4937,8 +4946,9 @@ class arg_value {
         auto& pctx_ref = *static_cast<parse_context_type*>(pctx);
         auto& ctx_ref = *static_cast<context_type*>(ctx);
 
-        SCN_TRY_ERR(_, s.parse(pctx_ref));
-        SCN_UNUSED(_);
+        SCN_TRY_ERR(fmt_it, s.parse(pctx_ref));
+        pctx_ref.advance_to(fmt_it);
+
         SCN_TRY_ERR(it, s.scan(arg_ref, ctx_ref));
         ctx_ref.advance_to(SCN_MOVE(it));
 
@@ -7867,7 +7877,7 @@ class format_string_checker {
 };
 
 template <typename Source, typename... Args, typename Str>
-auto check_format_string(const Str&)
+constexpr auto check_format_string(const Str&)
     -> std::enable_if_t<!is_compile_string_v<Str>>
 {
     // TODO: SCN_ENFORE_COMPILE_STRING?
@@ -7879,7 +7889,7 @@ auto check_format_string(const Str&)
 }
 
 template <typename Source, typename... Args, typename Str>
-auto check_format_string(Str format_str)
+constexpr auto check_format_string(Str format_str)
     -> std::enable_if_t<is_compile_string_v<Str>>
 {
     using char_type = typename Str::char_type;

src/scn/impl.cpp

@@ -193,15 +193,15 @@ std::string_view::iterator find_classic_space_narrow_fast(
 {
     return find_classic_impl(
         source, [](char ch) { return is_ascii_space(ch); },
-        [](char32_t cp) { return is_cp_space(cp); });
+        [](char32_t cp) { return detail::is_cp_space(cp); });
 }
 
 std::string_view::iterator find_classic_nonspace_narrow_fast(
     std::string_view source)
 {
     return find_classic_impl(
         source, [](char ch) { return !is_ascii_space(ch); },
-        [](char32_t cp) { return !is_cp_space(cp); });
+        [](char32_t cp) { return !detail::is_cp_space(cp); });
 }
 
 std::string_view::iterator find_nondecimal_digit_narrow_fast(

src/scn/impl.h

@@ -1195,18 +1195,6 @@ constexpr auto get_next_code_point_valid(std::basic_string_view<CharT> input)
             detail::decode_code_point_exhaustive_valid(input.substr(0, len))};
 }
 
-constexpr bool is_cp_space(char32_t cp) noexcept
-{
-    // Pattern_White_Space property
-    return (cp >= 0x09 && cp <= 0x0d) ||
-           cp == 0x20 ||    // ASCII space characters
-           cp == 0x85 ||    // NEXT LINE (NEL)
-           cp == 0x200e ||  // LEFT-TO-RIGHT MARK
-           cp == 0x200f ||  // RIGHT-TO-LEFT MARK
-           cp == 0x2028 ||  // LINE SEPARATOR
-           cp == 0x2029;    // PARAGRAPH SEPARATOR
-}
-
 template <typename CharT>
 struct is_first_char_space_result {
     ranges::iterator_t<std::basic_string_view<CharT>> iterator;
@@ -1221,7 +1209,7 @@ inline constexpr auto is_first_char_space(std::basic_string_view<CharT> str)
     // TODO: optimize
     SCN_EXPECT(!str.empty());
     auto res = get_next_code_point(str);
-    return {res.iterator, res.value, is_cp_space(res.value)};
+    return {res.iterator, res.value, detail::is_cp_space(res.value)};
 }
 
 inline constexpr scan_expected<wchar_t> encode_code_point_as_wide_character(
@@ -2107,7 +2095,7 @@ auto read_until_classic_space(Range range) -> ranges::const_iterator_t<Range>
 
         return read_until_code_point(
             ranges::subrange{it, range.end()},
-            [](char32_t cp) noexcept { return is_cp_space(cp); });
+            [](char32_t cp) noexcept { return detail::is_cp_space(cp); });
     }
 }
 
@@ -2134,8 +2122,9 @@ auto read_while_classic_space(Range range) -> ranges::const_iterator_t<Range>
             ranges::advance(it, seg.size());
         }
 
-        return read_while_code_point(
-            range, [](char32_t cp) noexcept { return is_cp_space(cp); });
+        return read_while_code_point(range, [](char32_t cp) noexcept {
+            return detail::is_cp_space(cp);
+        });
     }
 }
 

tests/fuzz/CMakeLists.txt

@@ -21,6 +21,7 @@ add_fuzzer(int)
 add_fuzzer(float)
 add_fuzzer(string)
 add_fuzzer(format)
+add_fuzzer(chrono)
 add_fuzzer(string_impl)
 
 add_custom_target(scn_fuzz_prepare ALL

tests/fuzz/chrono_fuzz.cpp

@@ -0,0 +1,61 @@
+// Copyright 2017 Elias Kosunen
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// This file is a part of scnlib:
+//     https://github.com/eliaskosunen/scnlib
+
+#include "fuzz.h"
+
+#include <scn/chrono.h>
+
+namespace scn::fuzz {
+template <typename CharT, typename Source>
+void do_basic_run_for_source(Source& source,
+                             const format_strings_type<CharT>& format_strings)
+{
+    do_basic_run_for_type<CharT, std::tm>(source, format_strings);
+    do_basic_run_for_type<CharT, tm_with_tz>(source, format_strings);
+    do_basic_run_for_type<CharT, datetime_components>(source, format_strings);
+}
+
+namespace {
+void run(const uint8_t* data, size_t size)
+{
+    if (size > max_input_bytes || size == 0) {
+        return;
+    }
+
+    auto [sv, wsv_reinterpret, wsv_transcode] = make_input_views(data, size);
+
+    const auto& f =
+        get_format_strings<char>("{:%T}", "{:%R}", "{:%D}", "{:%F}",
+                                 "{:%Y-%m-%dT%H:%M:%S%z}", "{:%a}", "{:%b}");
+    do_basic_run(sv, f);
+
+    const auto& wf = get_format_strings<wchar_t>(
+        L"{:%T}", L"{:%R}", L"{:%D}", L"{:%F}", L"{:%Y-%m-%dT%H:%M:%S%z}",
+        L"{:%a}", L"{:%b}");
+    do_basic_run(wsv_reinterpret, wf);
+    if (!wsv_transcode.empty()) {
+        do_basic_run(wsv_transcode, wf);
+    }
+}
+}  // namespace
+}  // namespace scn::fuzz
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
+{
+    scn::fuzz::run(data, size);
+    return 0;
+}

tests/fuzz/dictionaries/chrono.txt

@@ -0,0 +1,46 @@
+"1970"
+"2024"
+"1"
+"12"
+"29"
+"31"
+"12"
+"24"
+"00"
+"0"
+"99"
+":"
+"."
+"-"
+"+"
+"T"
+"Z"
+"Europe/Helsinki"
+"America/New_York"
+"GMT"
+"UTC"
+"EST"
+"Monday"
+"Tuesday"
+"Wednesday"
+"Thursday"
+"Friday"
+"Saturday"
+"Sunday"
+"January"
+"February"
+"March"
+"April"
+"May"
+"June"
+"July"
+"August"
+"September"
+"October"
+"November"
+"December"
+"am"
+"a.m."
+"PM"
+"P.M."
+"%"

tests/fuzz/seed-corpora/chrono/1

@@ -0,0 +1 @@
+2024-08-29T23:41:10+02:00

tests/fuzz/seed-corpora/chrono/2

@@ -0,0 +1 @@
+Thursday, Aug 29 2024, 23:41:00, Europe/Helsinki

tests/fuzz/seed-corpora/chrono/3

@@ -0,0 +1 @@
+2024-08-29

tests/fuzz/seed-corpora/chrono/4

@@ -0,0 +1 @@
+23:41

tests/fuzz/seed-corpora/chrono/5

@@ -0,0 +1 @@
+11:41 PM

tests/fuzz/seed-corpora/chrono/6

@@ -0,0 +1 @@
+08/29/24

tests/unittests/CMakeLists.txt

@@ -24,6 +24,7 @@ add_executable(scn_tests
         args_test.cpp
         buffer_test.cpp
         char_test.cpp
+        chrono_test.cpp
         context_test.cpp
         custom_type_test.cpp
         error_test.cpp