Adding upstream version 0.11.2.upstream/0.11.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 297 insertions, 0 deletions

diff --git a/src/third-party/scnlib/include/scn/unicode/utf8.h b/src/third-party/scnlib/include/scn/unicode/utf8.h
new file mode 100644
index 0000000..d2ee54d
--- /dev/null
+++ b/src/third-party/scnlib/include/scn/unicode/utf8.h
@@ -0,0 +1,297 @@
+// 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
+//
+// The contents of this file are based on utfcpp:
+//     https://github.com/nemtrif/utfcpp
+//     Copyright (c) 2006 Nemanja Trifunovic
+//     Distributed under the Boost Software License, version 1.0
+
+#ifndef SCN_UNICODE_UTF8_H
+#define SCN_UNICODE_UTF8_H
+
+#include "../detail/error.h"
+#include "../util/expected.h"
+#include "common.h"
+
+namespace scn {
+    SCN_BEGIN_NAMESPACE
+
+    namespace detail {
+        namespace utf8 {
+            template <typename Octet>
+            constexpr bool is_trail(Octet o)
+            {
+                return (mask8(o) >> 6) == 2;
+            }
+
+            template <typename Octet>
+            SCN_CONSTEXPR14 int get_sequence_length(Octet ch)
+            {
+                uint8_t lead = detail::mask8(ch);
+                if (lead < 0x80) {
+                    return 1;
+                }
+                else if ((lead >> 5) == 6) {
+                    return 2;
+                }
+                else if ((lead >> 4) == 0xe) {
+                    return 3;
+                }
+                else if ((lead >> 3) == 0x1e) {
+                    return 4;
+                }
+                return 0;
+            }
+
+            SCN_CONSTEXPR14 bool is_overlong_sequence(code_point cp,
+                                                      std::ptrdiff_t len)
+            {
+                if (cp < 0x80) {
+                    if (len != 1) {
+                        return true;
+                    }
+                }
+                else if (cp < 0x800) {
+                    if (len != 2) {
+                        return true;
+                    }
+                }
+                else if (cp < 0x10000) {
+                    if (len != 3) {
+                        return true;
+                    }
+                }
+
+                return false;
+            }
+
+            template <typename I, typename S>
+            SCN_CONSTEXPR14 error increase_safely(I& it, S end)
+            {
+                if (++it == end) {
+                    return {error::invalid_encoding,
+                            "Unexpected end of range when decoding utf8 "
+                            "(partial codepoint)"};
+                }
+                if (!is_trail(*it)) {
+                    return {error::invalid_encoding,
+                            "Invalid utf8 codepoint parsed"};
+                }
+                return {};
+            }
+
+            template <typename I, typename S>
+            SCN_CONSTEXPR14 error get_sequence_1(I& it, S end, code_point& cp)
+            {
+                SCN_EXPECT(it != end);
+                cp = make_code_point(mask8(*it));
+                return {};
+            }
+            template <typename I, typename S>
+            SCN_CONSTEXPR14 error get_sequence_2(I& it, S end, code_point& cp)
+            {
+                SCN_EXPECT(it != end);
+                uint32_t c = mask8(*it);
+
+                auto e = increase_safely(it, end);
+                if (!e) {
+                    return e;
+                }
+
+                c = static_cast<uint32_t>((c << 6u) & 0x7ffu) +
+                    (static_cast<uint32_t>(*it) & 0x3fu);
+                cp = make_code_point(c);
+
+                return {};
+            }
+            template <typename I, typename S>
+            SCN_CONSTEXPR14 error get_sequence_3(I& it, S end, code_point& cp)
+            {
+                SCN_EXPECT(it != end);
+                uint32_t c = mask8(*it);
+
+                auto e = increase_safely(it, end);
+                if (!e) {
+                    return e;
+                }
+
+                c = static_cast<uint32_t>((c << 12u) & 0xffffu) +
+                    (static_cast<uint32_t>(mask8(*it) << 6u) & 0xfffu);
+
+                e = increase_safely(it, end);
+                if (!e) {
+                    return e;
+                }
+
+                c += static_cast<uint32_t>(*it) & 0x3fu;
+                cp = make_code_point(c);
+
+                return {};
+            }
+            template <typename I, typename S>
+            SCN_CONSTEXPR14 error get_sequence_4(I& it, S end, code_point& cp)
+            {
+                SCN_EXPECT(it != end);
+                uint32_t c = mask8(*it);
+
+                auto e = increase_safely(it, end);
+                if (!e) {
+                    return e;
+                }
+
+                c = ((c << 18u) & 0x1fffffu) +
+                    (static_cast<uint32_t>(mask8(*it) << 12u) & 0x3ffffu);
+
+                e = increase_safely(it, end);
+                if (!e) {
+                    return e;
+                }
+
+                c += static_cast<uint32_t>(mask8(*it) << 6u) & 0xfffu;
+
+                e = increase_safely(it, end);
+                if (!e) {
+                    return e;
+                }
+
+                c += static_cast<uint32_t>(*it) & 0x3fu;
+                cp = make_code_point(c);
+
+                return {};
+            }
+
+            template <typename I, typename S>
+            SCN_CONSTEXPR14 error validate_next(I& it, S end, code_point& cp)
+            {
+                SCN_EXPECT(it != end);
+
+                int len = get_sequence_length(*it);
+                error e{};
+                switch (len) {
+                    case 1:
+                        e = get_sequence_1(it, end, cp);
+                        break;
+                    case 2:
+                        e = get_sequence_2(it, end, cp);
+                        break;
+                    case 3:
+                        e = get_sequence_3(it, end, cp);
+                        break;
+                    case 4:
+                        e = get_sequence_4(it, end, cp);
+                        break;
+                    default:
+                        return {error::invalid_encoding,
+                                "Invalid lead byte for utf8"};
+                }
+
+                if (!e) {
+                    return e;
+                }
+                if (!is_valid_code_point(cp) || is_overlong_sequence(cp, len)) {
+                    return {error::invalid_encoding, "Invalid utf8 code point"};
+                }
+                ++it;
+                return {};
+            }
+
+            template <typename I, typename S>
+            SCN_CONSTEXPR14 expected<I> parse_code_point(I begin,
+                                                         S end,
+                                                         code_point& cp)
+            {
+                code_point c{};
+                auto e = validate_next(begin, end, c);
+                if (e) {
+                    cp = c;
+                    return {begin};
+                }
+                return e;
+            }
+
+            template <typename I>
+            I append(code_point cp, I it)
+            {
+                SCN_EXPECT(is_code_point_valid(cp));
+
+                if (cp < 0x80) {
+                    *(it++) = static_cast<uint8_t>(cp);
+                }
+                else if (cp < 0x800) {
+                    *(it++) = static_cast<uint8_t>(
+                        (static_cast<uint32_t>(cp) >> 6u) | 0xc0u);
+                    *(it++) = static_cast<uint8_t>(
+                        (static_cast<uint32_t>(cp) & 0x3fu) | 0x80u);
+                }
+                else if (cp < 0x10000) {
+                    *(it++) = static_cast<uint8_t>(
+                        (static_cast<uint32_t>(cp) >> 12u) | 0xe0u);
+                    *(it++) = static_cast<uint8_t>(
+                        ((static_cast<uint32_t>(cp) >> 6u) & 0x3fu) | 0x80u);
+                    *(it++) = static_cast<uint8_t>(
+                        (static_cast<uint32_t>(cp) & 0x3fu) | 0x80u);
+                }
+                else {
+                    *(it++) = static_cast<uint8_t>(
+                        (static_cast<uint32_t>(cp) >> 18u) | 0xf0u);
+                    *(it++) = static_cast<uint8_t>(
+                        ((static_cast<uint32_t>(cp) >> 12u) & 0x3fu) | 0x80u);
+                    *(it++) = static_cast<uint8_t>(
+                        ((static_cast<uint32_t>(cp) >> 6u) & 0x3fu) | 0x80u);
+                    *(it++) = static_cast<uint8_t>(
+                        (static_cast<uint32_t>(cp) & 0x3fu) | 0x80u);
+                }
+                return it;
+            }
+
+            template <typename I, typename S>
+            SCN_CONSTEXPR14 expected<I> encode_code_point(I begin,
+                                                          S end,
+                                                          code_point cp)
+            {
+                SCN_EXPECT(begin + 4 <= end);
+
+                if (!is_code_point_valid(cp)) {
+                    return error(error::invalid_encoding,
+                                 "Invalid code point, cannot encode in UTF-8");
+                }
+                return {append(cp, begin)};
+            }
+
+            template <typename I, typename S>
+            SCN_CONSTEXPR14 expected<std::ptrdiff_t> code_point_distance(
+                I begin,
+                S end)
+            {
+                std::ptrdiff_t dist{};
+                code_point cp{};
+                for (; begin < end; ++dist) {
+                    auto e = validate_next(begin, end, cp);
+                    if (!e) {
+                        return e;
+                    }
+                }
+                return {dist};
+            }
+
+        }  // namespace utf8
+    }      // namespace detail
+
+    SCN_END_NAMESPACE
+}  // namespace scn
+
+#endif