llama.cpp verification source 2026-05-22

common/unicode.cpp

@@ -0,0 +1,124 @@
+#include "unicode.h"
+
+#include <algorithm>
+#include <cassert>
+#include <stdexcept>
+#include <string>
+#include <vector>
+
+// implementation adopted from src/unicode.cpp
+
+size_t common_utf8_sequence_length(unsigned char first_byte) {
+    const size_t lookup[] = { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 4 };
+    uint8_t highbits = static_cast<uint8_t>(first_byte) >> 4;
+    return lookup[highbits];
+}
+
+utf8_parse_result common_parse_utf8_codepoint(std::string_view input, size_t offset) {
+    if (offset >= input.size()) {
+        return utf8_parse_result(utf8_parse_result::INCOMPLETE);
+    }
+
+    // ASCII fast path
+    if (!(input[offset] & 0x80)) {
+        return utf8_parse_result(utf8_parse_result::SUCCESS, input[offset], 1);
+    }
+
+    // Invalid: continuation byte as first byte
+    if (!(input[offset] & 0x40)) {
+        return utf8_parse_result(utf8_parse_result::INVALID);
+    }
+
+    // 2-byte sequence
+    if (!(input[offset] & 0x20)) {
+        if (offset + 1 >= input.size()) {
+            return utf8_parse_result(utf8_parse_result::INCOMPLETE);
+        }
+        if ((input[offset + 1] & 0xc0) != 0x80) {
+            return utf8_parse_result(utf8_parse_result::INVALID);
+        }
+        auto result = ((input[offset] & 0x1f) << 6) | (input[offset + 1] & 0x3f);
+        return utf8_parse_result(utf8_parse_result::SUCCESS, result, 2);
+    }
+
+    // 3-byte sequence
+    if (!(input[offset] & 0x10)) {
+        if (offset + 2 >= input.size()) {
+            return utf8_parse_result(utf8_parse_result::INCOMPLETE);
+        }
+        if ((input[offset + 1] & 0xc0) != 0x80 || (input[offset + 2] & 0xc0) != 0x80) {
+            return utf8_parse_result(utf8_parse_result::INVALID);
+        }
+        auto result = ((input[offset] & 0x0f) << 12) | ((input[offset + 1] & 0x3f) << 6) | (input[offset + 2] & 0x3f);
+        return utf8_parse_result(utf8_parse_result::SUCCESS, result, 3);
+    }
+
+    // 4-byte sequence
+    if (!(input[offset] & 0x08)) {
+        if (offset + 3 >= input.size()) {
+            return utf8_parse_result(utf8_parse_result::INCOMPLETE);
+        }
+        if ((input[offset + 1] & 0xc0) != 0x80 || (input[offset + 2] & 0xc0) != 0x80 || (input[offset + 3] & 0xc0) != 0x80) {
+            return utf8_parse_result(utf8_parse_result::INVALID);
+        }
+        auto result = ((input[offset] & 0x07) << 18) | ((input[offset + 1] & 0x3f) << 12) | ((input[offset + 2] & 0x3f) << 6) | (input[offset + 3] & 0x3f);
+        return utf8_parse_result(utf8_parse_result::SUCCESS, result, 4);
+    }
+
+    // Invalid first byte
+    return utf8_parse_result(utf8_parse_result::INVALID);
+}
+
+bool common_utf8_is_complete(const std::string & s) {
+    if (s.empty()) {
+        return true;
+    }
+    for (int i = 1; i <= std::min(4, (int)s.size()); i++) {
+        unsigned char c = s[s.size() - i];
+        if ((c & 0xC0) != 0x80) {
+            int expected = (c >= 0xF0) ? 4 : (c >= 0xE0) ? 3 : (c >= 0xC0) ? 2 : 1;
+            return i >= expected;
+        }
+    }
+    return false;
+}
+
+std::string common_unicode_cpts_to_utf8(const std::vector<uint32_t> & cps) {
+    std::string result;
+    for (size_t i = 0; i < cps.size(); ++i) {
+        result.append(common_unicode_cpt_to_utf8(cps[i]));
+    }
+    return result;
+}
+
+std::string common_unicode_cpt_to_utf8(uint32_t cpt) {
+    std::string result;
+
+    if (/* 0x00 <= cpt && */ cpt <= 0x7f) {
+        result.push_back(cpt);
+        return result;
+    }
+    if (0x80 <= cpt && cpt <= 0x7ff) {
+        result.push_back(0xc0 | ((cpt >> 6) & 0x1f));
+        result.push_back(0x80 | (cpt & 0x3f));
+        return result;
+    }
+    if (0x800 <= cpt && cpt <= 0xffff) {
+        result.push_back(0xe0 | ((cpt >> 12) & 0x0f));
+        result.push_back(0x80 | ((cpt >> 6) & 0x3f));
+        result.push_back(0x80 | (cpt & 0x3f));
+        return result;
+    }
+    if (0x10000 <= cpt && cpt <= 0x10ffff) {
+        result.push_back(0xf0 | ((cpt >> 18) & 0x07));
+        result.push_back(0x80 | ((cpt >> 12) & 0x3f));
+        result.push_back(0x80 | ((cpt >> 6) & 0x3f));
+        result.push_back(0x80 | (cpt & 0x3f));
+        return result;
+    }
+
+    throw std::invalid_argument("invalid codepoint");
+}
+
+
+