Adding upstream version 247.3.upstream/247.3upstream

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

1 files changed, 585 insertions, 0 deletions

diff --git a/src/basic/utf8.c b/src/basic/utf8.c
new file mode 100644
index 0000000..59663c0
--- /dev/null
+++ b/src/basic/utf8.c
@@ -0,0 +1,585 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+/* Parts of this file are based on the GLIB utf8 validation functions. The
+ * original license text follows. */
+
+/* gutf8.c - Operations on UTF-8 strings.
+ *
+ * Copyright (C) 1999 Tom Tromey
+ * Copyright (C) 2000 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include "alloc-util.h"
+#include "gunicode.h"
+#include "hexdecoct.h"
+#include "macro.h"
+#include "string-util.h"
+#include "utf8.h"
+
+bool unichar_is_valid(char32_t ch) {
+
+        if (ch >= 0x110000) /* End of unicode space */
+                return false;
+        if ((ch & 0xFFFFF800) == 0xD800) /* Reserved area for UTF-16 */
+                return false;
+        if ((ch >= 0xFDD0) && (ch <= 0xFDEF)) /* Reserved */
+                return false;
+        if ((ch & 0xFFFE) == 0xFFFE) /* BOM (Byte Order Mark) */
+                return false;
+
+        return true;
+}
+
+static bool unichar_is_control(char32_t ch) {
+
+        /*
+          0 to ' '-1 is the C0 range.
+          DEL=0x7F, and DEL+1 to 0x9F is C1 range.
+          '\t' is in C0 range, but more or less harmless and commonly used.
+        */
+
+        return (ch < ' ' && !IN_SET(ch, '\t', '\n')) ||
+                (0x7F <= ch && ch <= 0x9F);
+}
+
+/* count of characters used to encode one unicode char */
+static size_t utf8_encoded_expected_len(uint8_t c) {
+        if (c < 0x80)
+                return 1;
+        if ((c & 0xe0) == 0xc0)
+                return 2;
+        if ((c & 0xf0) == 0xe0)
+                return 3;
+        if ((c & 0xf8) == 0xf0)
+                return 4;
+        if ((c & 0xfc) == 0xf8)
+                return 5;
+        if ((c & 0xfe) == 0xfc)
+                return 6;
+
+        return 0;
+}
+
+/* decode one unicode char */
+int utf8_encoded_to_unichar(const char *str, char32_t *ret_unichar) {
+        char32_t unichar;
+        size_t len, i;
+
+        assert(str);
+
+        len = utf8_encoded_expected_len(str[0]);
+
+        switch (len) {
+        case 1:
+                *ret_unichar = (char32_t)str[0];
+                return 0;
+        case 2:
+                unichar = str[0] & 0x1f;
+                break;
+        case 3:
+                unichar = (char32_t)str[0] & 0x0f;
+                break;
+        case 4:
+                unichar = (char32_t)str[0] & 0x07;
+                break;
+        case 5:
+                unichar = (char32_t)str[0] & 0x03;
+                break;
+        case 6:
+                unichar = (char32_t)str[0] & 0x01;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        for (i = 1; i < len; i++) {
+                if (((char32_t)str[i] & 0xc0) != 0x80)
+                        return -EINVAL;
+
+                unichar <<= 6;
+                unichar |= (char32_t)str[i] & 0x3f;
+        }
+
+        *ret_unichar = unichar;
+
+        return 0;
+}
+
+bool utf8_is_printable_newline(const char* str, size_t length, bool allow_newline) {
+        const char *p;
+
+        assert(str);
+
+        for (p = str; length > 0;) {
+                int encoded_len, r;
+                char32_t val;
+
+                encoded_len = utf8_encoded_valid_unichar(p, length);
+                if (encoded_len < 0)
+                        return false;
+                assert(encoded_len > 0 && (size_t) encoded_len <= length);
+
+                r = utf8_encoded_to_unichar(p, &val);
+                if (r < 0 ||
+                    unichar_is_control(val) ||
+                    (!allow_newline && val == '\n'))
+                        return false;
+
+                length -= encoded_len;
+                p += encoded_len;
+        }
+
+        return true;
+}
+
+char *utf8_is_valid_n(const char *str, size_t len_bytes) {
+        /* Check if the string is composed of valid utf8 characters. If length len_bytes is given, stop after
+         * len_bytes. Otherwise, stop at NUL. */
+
+        assert(str);
+
+        for (const char *p = str; len_bytes != (size_t) -1 ? (size_t) (p - str) < len_bytes : *p != '\0'; ) {
+                int len;
+
+                if (_unlikely_(*p == '\0') && len_bytes != (size_t) -1)
+                        return NULL; /* embedded NUL */
+
+                len = utf8_encoded_valid_unichar(p,
+                                                 len_bytes != (size_t) -1 ? len_bytes - (p - str) : (size_t) -1);
+                if (_unlikely_(len < 0))
+                        return NULL; /* invalid character */
+
+                p += len;
+        }
+
+        return (char*) str;
+}
+
+char *utf8_escape_invalid(const char *str) {
+        char *p, *s;
+
+        assert(str);
+
+        p = s = malloc(strlen(str) * 4 + 1);
+        if (!p)
+                return NULL;
+
+        while (*str) {
+                int len;
+
+                len = utf8_encoded_valid_unichar(str, (size_t) -1);
+                if (len > 0) {
+                        s = mempcpy(s, str, len);
+                        str += len;
+                } else {
+                        s = stpcpy(s, UTF8_REPLACEMENT_CHARACTER);
+                        str += 1;
+                }
+        }
+
+        *s = '\0';
+        (void) str_realloc(&p);
+        return p;
+}
+
+static int utf8_char_console_width(const char *str) {
+        char32_t c;
+        int r;
+
+        r = utf8_encoded_to_unichar(str, &c);
+        if (r < 0)
+                return r;
+
+        /* TODO: we should detect combining characters */
+
+        return unichar_iswide(c) ? 2 : 1;
+}
+
+char *utf8_escape_non_printable_full(const char *str, size_t console_width) {
+        char *p, *s, *prev_s;
+        size_t n = 0; /* estimated print width */
+
+        assert(str);
+
+        if (console_width == 0)
+                return strdup("");
+
+        p = s = prev_s = malloc(strlen(str) * 4 + 1);
+        if (!p)
+                return NULL;
+
+        for (;;) {
+                int len;
+                char *saved_s = s;
+
+                if (!*str) /* done! */
+                        goto finish;
+
+                len = utf8_encoded_valid_unichar(str, (size_t) -1);
+                if (len > 0) {
+                        if (utf8_is_printable(str, len)) {
+                                int w;
+
+                                w = utf8_char_console_width(str);
+                                assert(w >= 0);
+                                if (n + w > console_width)
+                                        goto truncation;
+
+                                s = mempcpy(s, str, len);
+                                str += len;
+                                n += w;
+
+                        } else {
+                                for (; len > 0; len--) {
+                                        if (n + 4 > console_width)
+                                                goto truncation;
+
+                                        *(s++) = '\\';
+                                        *(s++) = 'x';
+                                        *(s++) = hexchar((int) *str >> 4);
+                                        *(s++) = hexchar((int) *str);
+
+                                        str += 1;
+                                        n += 4;
+                                }
+                        }
+                } else {
+                        if (n + 1 > console_width)
+                                goto truncation;
+
+                        s = mempcpy(s, UTF8_REPLACEMENT_CHARACTER, strlen(UTF8_REPLACEMENT_CHARACTER));
+                        str += 1;
+                        n += 1;
+                }
+
+                prev_s = saved_s;
+        }
+
+ truncation:
+        /* Try to go back one if we don't have enough space for the ellipsis */
+        if (n + 1 >= console_width)
+                s = prev_s;
+
+        s = mempcpy(s, "…", strlen("…"));
+
+ finish:
+        *s = '\0';
+        (void) str_realloc(&p);
+        return p;
+}
+
+char *ascii_is_valid(const char *str) {
+        const char *p;
+
+        /* Check whether the string consists of valid ASCII bytes,
+         * i.e values between 0 and 127, inclusive. */
+
+        assert(str);
+
+        for (p = str; *p; p++)
+                if ((unsigned char) *p >= 128)
+                        return NULL;
+
+        return (char*) str;
+}
+
+char *ascii_is_valid_n(const char *str, size_t len) {
+        size_t i;
+
+        /* Very similar to ascii_is_valid(), but checks exactly len
+         * bytes and rejects any NULs in that range. */
+
+        assert(str);
+
+        for (i = 0; i < len; i++)
+                if ((unsigned char) str[i] >= 128 || str[i] == 0)
+                        return NULL;
+
+        return (char*) str;
+}
+
+/**
+ * utf8_encode_unichar() - Encode single UCS-4 character as UTF-8
+ * @out_utf8: output buffer of at least 4 bytes or NULL
+ * @g: UCS-4 character to encode
+ *
+ * This encodes a single UCS-4 character as UTF-8 and writes it into @out_utf8.
+ * The length of the character is returned. It is not zero-terminated! If the
+ * output buffer is NULL, only the length is returned.
+ *
+ * Returns: The length in bytes that the UTF-8 representation does or would
+ *          occupy.
+ */
+size_t utf8_encode_unichar(char *out_utf8, char32_t g) {
+
+        if (g < (1 << 7)) {
+                if (out_utf8)
+                        out_utf8[0] = g & 0x7f;
+                return 1;
+        } else if (g < (1 << 11)) {
+                if (out_utf8) {
+                        out_utf8[0] = 0xc0 | ((g >> 6) & 0x1f);
+                        out_utf8[1] = 0x80 | (g & 0x3f);
+                }
+                return 2;
+        } else if (g < (1 << 16)) {
+                if (out_utf8) {
+                        out_utf8[0] = 0xe0 | ((g >> 12) & 0x0f);
+                        out_utf8[1] = 0x80 | ((g >> 6) & 0x3f);
+                        out_utf8[2] = 0x80 | (g & 0x3f);
+                }
+                return 3;
+        } else if (g < (1 << 21)) {
+                if (out_utf8) {
+                        out_utf8[0] = 0xf0 | ((g >> 18) & 0x07);
+                        out_utf8[1] = 0x80 | ((g >> 12) & 0x3f);
+                        out_utf8[2] = 0x80 | ((g >> 6) & 0x3f);
+                        out_utf8[3] = 0x80 | (g & 0x3f);
+                }
+                return 4;
+        }
+
+        return 0;
+}
+
+char *utf16_to_utf8(const char16_t *s, size_t length /* bytes! */) {
+        const uint8_t *f;
+        char *r, *t;
+
+        assert(s);
+
+        /* Input length is in bytes, i.e. the shortest possible character takes 2 bytes. Each unicode character may
+         * take up to 4 bytes in UTF-8. Let's also account for a trailing NUL byte. */
+        if (length * 2 < length)
+                return NULL; /* overflow */
+
+        r = new(char, length * 2 + 1);
+        if (!r)
+                return NULL;
+
+        f = (const uint8_t*) s;
+        t = r;
+
+        while (f + 1 < (const uint8_t*) s + length) {
+                char16_t w1, w2;
+
+                /* see RFC 2781 section 2.2 */
+
+                w1 = f[1] << 8 | f[0];
+                f += 2;
+
+                if (!utf16_is_surrogate(w1)) {
+                        t += utf8_encode_unichar(t, w1);
+                        continue;
+                }
+
+                if (utf16_is_trailing_surrogate(w1))
+                        continue; /* spurious trailing surrogate, ignore */
+
+                if (f + 1 >= (const uint8_t*) s + length)
+                        break;
+
+                w2 = f[1] << 8 | f[0];
+                f += 2;
+
+                if (!utf16_is_trailing_surrogate(w2)) {
+                        f -= 2;
+                        continue; /* surrogate missing its trailing surrogate, ignore */
+                }
+
+                t += utf8_encode_unichar(t, utf16_surrogate_pair_to_unichar(w1, w2));
+        }
+
+        *t = 0;
+        return r;
+}
+
+size_t utf16_encode_unichar(char16_t *out, char32_t c) {
+
+        /* Note that this encodes as little-endian. */
+
+        switch (c) {
+
+        case 0 ... 0xd7ffU:
+        case 0xe000U ... 0xffffU:
+                out[0] = htole16(c);
+                return 1;
+
+        case 0x10000U ... 0x10ffffU:
+                c -= 0x10000U;
+                out[0] = htole16((c >> 10) + 0xd800U);
+                out[1] = htole16((c & 0x3ffU) + 0xdc00U);
+                return 2;
+
+        default: /* A surrogate (invalid) */
+                return 0;
+        }
+}
+
+char16_t *utf8_to_utf16(const char *s, size_t length) {
+        char16_t *n, *p;
+        size_t i;
+        int r;
+
+        assert(s);
+
+        n = new(char16_t, length + 1);
+        if (!n)
+                return NULL;
+
+        p = n;
+
+        for (i = 0; i < length;) {
+                char32_t unichar;
+                size_t e;
+
+                e = utf8_encoded_expected_len(s[i]);
+                if (e <= 1) /* Invalid and single byte characters are copied as they are */
+                        goto copy;
+
+                if (i + e > length) /* sequence longer than input buffer, then copy as-is */
+                        goto copy;
+
+                r = utf8_encoded_to_unichar(s + i, &unichar);
+                if (r < 0) /* sequence invalid, then copy as-is */
+                        goto copy;
+
+                p += utf16_encode_unichar(p, unichar);
+                i += e;
+                continue;
+
+        copy:
+                *(p++) = htole16(s[i++]);
+        }
+
+        *p = 0;
+        return n;
+}
+
+size_t char16_strlen(const char16_t *s) {
+        size_t n = 0;
+
+        assert(s);
+
+        while (*s != 0)
+                n++, s++;
+
+        return n;
+}
+
+/* expected size used to encode one unicode char */
+static int utf8_unichar_to_encoded_len(char32_t unichar) {
+
+        if (unichar < 0x80)
+                return 1;
+        if (unichar < 0x800)
+                return 2;
+        if (unichar < 0x10000)
+                return 3;
+        if (unichar < 0x200000)
+                return 4;
+        if (unichar < 0x4000000)
+                return 5;
+
+        return 6;
+}
+
+/* validate one encoded unicode char and return its length */
+int utf8_encoded_valid_unichar(const char *str, size_t length /* bytes */) {
+        char32_t unichar;
+        size_t len, i;
+        int r;
+
+        assert(str);
+        assert(length > 0);
+
+        /* We read until NUL, at most length bytes. (size_t) -1 may be used to disable the length check. */
+
+        len = utf8_encoded_expected_len(str[0]);
+        if (len == 0)
+                return -EINVAL;
+
+        /* Do we have a truncated multi-byte character? */
+        if (len > length)
+                return -EINVAL;
+
+        /* ascii is valid */
+        if (len == 1)
+                return 1;
+
+        /* check if expected encoded chars are available */
+        for (i = 0; i < len; i++)
+                if ((str[i] & 0x80) != 0x80)
+                        return -EINVAL;
+
+        r = utf8_encoded_to_unichar(str, &unichar);
+        if (r < 0)
+                return r;
+
+        /* check if encoded length matches encoded value */
+        if (utf8_unichar_to_encoded_len(unichar) != (int) len)
+                return -EINVAL;
+
+        /* check if value has valid range */
+        if (!unichar_is_valid(unichar))
+                return -EINVAL;
+
+        return (int) len;
+}
+
+size_t utf8_n_codepoints(const char *str) {
+        size_t n = 0;
+
+        /* Returns the number of UTF-8 codepoints in this string, or (size_t) -1 if the string is not valid UTF-8. */
+
+        while (*str != 0) {
+                int k;
+
+                k = utf8_encoded_valid_unichar(str, (size_t) -1);
+                if (k < 0)
+                        return (size_t) -1;
+
+                str += k;
+                n++;
+        }
+
+        return n;
+}
+
+size_t utf8_console_width(const char *str) {
+        size_t n = 0;
+
+        /* Returns the approximate width a string will take on screen when printed on a character cell
+         * terminal/console. */
+
+        while (*str) {
+                int w;
+
+                w = utf8_char_console_width(str);
+                if (w < 0)
+                        return (size_t) -1;
+
+                n += w;
+                str = utf8_next_char(str);
+        }
+
+        return n;
+}