1 files changed, 112 insertions, 0 deletions
diff --git a/src/read_utf8.c b/src/read_utf8.c
new file mode 100644
index 00000000..614ea14f
--- /dev/null
+++ b/src/read_utf8.c
@@ -0,0 +1,112 @@
+/*
+  Copyright 2011-2021 David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "read_utf8.h"
+#include "reader.h"
+
+#include "string_utils.h"
+
+#include <stdio.h>
+
+static SerdStatus
+skip_invalid_utf8(SerdReader* const reader)
+{
+  for (int b = peek_byte(reader); b != EOF && ((uint8_t)b & 0x80);) {
+    eat_byte_safe(reader, b);
+    b = peek_byte(reader);
+  }
+
+  return reader->strict ? SERD_ERR_BAD_SYNTAX : SERD_FAILURE;
+}
+
+static SerdStatus
+bad_char(SerdReader* const reader, const char* const fmt, const uint8_t c)
+{
+  r_err(reader, SERD_ERR_BAD_SYNTAX, fmt, c);
+  return skip_invalid_utf8(reader);
+}
+
+static SerdStatus
+read_utf8_continuation_bytes(SerdReader* const reader,
+                             uint8_t           bytes[4],
+                             uint32_t* const   size,
+                             const uint8_t     lead)
+{
+  *size = utf8_num_bytes(lead);
+  if (*size < 1 || *size > 4) {
+    return bad_char(reader, "0x%X is not a UTF-8 leading byte", lead);
+  }
+
+  bytes[0] = lead;
+
+  for (uint32_t i = 1u; i < *size; ++i) {
+    const int b = peek_byte(reader);
+    if (b == EOF) {
+      return r_err(reader, SERD_ERR_NO_DATA, "unexpected end of input");
+    }
+
+    const uint8_t byte = (uint8_t)b;
+    if (!(byte & 0x80u)) {
+      return bad_char(reader, "0x%X is not a UTF-8 continuation byte", byte);
+    }
+
+    eat_byte_safe(reader, b);
+    bytes[i] = byte;
+  }
+
+  return SERD_SUCCESS;
+}
+
+SerdStatus
+read_utf8_continuation(SerdReader* const reader,
+                       SerdNode* const   dest,
+                       const uint8_t     lead)
+{
+  uint32_t size     = 0;
+  uint8_t  bytes[4] = {0, 0, 0, 0};
+
+  SerdStatus st = read_utf8_continuation_bytes(reader, bytes, &size, lead);
+  if (st) {
+    return reader->strict ? st : push_bytes(reader, dest, replacement_char, 3);
+  }
+
+  return push_bytes(reader, dest, bytes, size);
+}
+
+SerdStatus
+read_utf8_code_point(SerdReader* const reader,
+                     SerdNode* const   dest,
+                     uint32_t* const   code,
+                     const uint8_t     lead)
+{
+  uint32_t size     = 0u;
+  uint8_t  bytes[4] = {lead, 0u, 0u, 0u};
+
+  *code = 0u;
+
+  eat_byte_safe(reader, lead);
+
+  SerdStatus st = read_utf8_continuation_bytes(reader, bytes, &size, lead);
+  if (st) {
+    return reader->strict ? st : push_bytes(reader, dest, replacement_char, 3);
+  }
+
+  if (!(st = push_bytes(reader, dest, bytes, size))) {
+    *code = parse_counted_utf8_char(bytes, size);
+  }
+
+  return st;
+}