// Copyright(c) 2006 to 2020 ZettaScale Technology and others
//
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License v. 2.0 which is available at
// http://www.eclipse.org/legal/epl-2.0, or the Eclipse Distribution License
// v. 1.0 which is available at
// http://www.eclipse.org/org/documents/edl-v10.php.
//
// SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause

#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <stdbool.h>

#include "dds/ddsrt/heap.h"
#include "dds/ddsrt/misc.h"
#include "dds/ddsrt/string.h"
#include "dds/ddsrt/xmlparser.h"

#define TOK_EOF -1
#define TOK_OPEN_TAG -2
#define TOK_ID -3
#define TOK_STRING -4
#define TOK_CLOSE_TAG -5
#define TOK_SHORTHAND_CLOSE_TAG -6
#define TOK_ERROR -7
#define TOK_CDATA -8

#define NOMARKER (~(size_t)0)

static const char *cdata_magic = "<![CDATA[";

struct ddsrt_xmlp_state {
  size_t cbufp; /**< current position in cbuf */
  size_t cbufn; /**< number of bytes in cbuf (cbufp <= cbufn) */
  size_t cbufmax; /**< allocated size of cbuf (cbufn <= cbufmax) */
  size_t cbufmark; /**< NORMARKER or marker position (cbufmark <= cbufp) for rewinding */
  bool eof; /**< fake EOF (for treating missing close tags as EOF) */
  unsigned char *cbuf; /**< parser input buffer */
  FILE *fp; /**< file to refill cbuf from, or NULL if parsing a string */
  int line; /**< current line number */
  int prevline; /**< line number at last token */
  int linemark; /**< line number at marker */
  int peektok; /**< token lookahead (peek token when no next token available) */
  char *peekpayload; /**< payload associated with lookahead */
  bool error; /**< error flag to call error callback only once */
  size_t tpp; /**< length of token payload */
  size_t tpsz; /**< allocated size of tp */
  char *tp; /**< token payload buffer */
  size_t tpescp; /**< still escape sequences in tpescp .. tpp */
  int nest; /**< current nesting level */
  void *varg; /**< user argument to callback functions */
  uint32_t options; /**< parser options (see `DDSRT_XMLP_...` macros in header */
  struct ddsrt_xmlp_callbacks cb; /**< user-supplied callbacks (or stubs) */
};

static int cb_null_elem_open (void *varg, uintptr_t parentinfo, uintptr_t *eleminfo, const char *name, int line)
{
  DDSRT_UNUSED_ARG (varg);
  DDSRT_UNUSED_ARG (parentinfo);
  DDSRT_UNUSED_ARG (eleminfo);
  DDSRT_UNUSED_ARG (name);
  DDSRT_UNUSED_ARG (line);
  return 0;
}

static int cb_null_attr (void *varg, uintptr_t eleminfo, const char *name, const char *value, int line)
{
  DDSRT_UNUSED_ARG (varg);
  DDSRT_UNUSED_ARG (eleminfo);
  DDSRT_UNUSED_ARG (name);
  DDSRT_UNUSED_ARG (value);
  DDSRT_UNUSED_ARG (line);
  return 0;
}

static int cb_null_elem_data (void *varg, uintptr_t eleminfo, const char *data, int line)
{
  DDSRT_UNUSED_ARG (varg);
  DDSRT_UNUSED_ARG (eleminfo);
  DDSRT_UNUSED_ARG (data);
  DDSRT_UNUSED_ARG (line);
  return 0;
}

static int cb_null_elem_close (void *varg, uintptr_t eleminfo, int line)
{
  DDSRT_UNUSED_ARG (varg);
  DDSRT_UNUSED_ARG (eleminfo);
  DDSRT_UNUSED_ARG (line);
  return 0;
}

static void cb_null_error (void *varg, const char *msg, int line)
{
  DDSRT_UNUSED_ARG (varg);
  DDSRT_UNUSED_ARG (msg);
  DDSRT_UNUSED_ARG (line);
}

static void ddsrt_xmlp_new_common (struct ddsrt_xmlp_state *st)
{
  st->cbufp = 0;
  st->cbufmark = NOMARKER;
  st->eof = false;
  st->tpp = 0;
  st->tpescp = 0;
  st->tpsz = 1024;
  st->tp = ddsrt_malloc (st->tpsz);
  st->line = 1;
  st->prevline = 1;
  st->linemark = 0;
  st->peektok = 0;
  st->peekpayload = NULL;
  st->nest = 0;
  st->error = false;
  st->options = DDSRT_XMLP_REQUIRE_EOF;
}

static void ddsrt_xmlp_new_setCB (struct ddsrt_xmlp_state *st, void *varg, const struct ddsrt_xmlp_callbacks *cb)
{
  st->varg = varg;
  st->cb = *cb;
  if (st->cb.attr == NULL) st->cb.attr = cb_null_attr;
  if (st->cb.elem_open == NULL) st->cb.elem_open = cb_null_elem_open;
  if (st->cb.elem_data == NULL) st->cb.elem_data = cb_null_elem_data;
  if (st->cb.elem_close == NULL) st->cb.elem_close = cb_null_elem_close;
  if (st->cb.error == NULL) st->cb.error = cb_null_error;
}

struct ddsrt_xmlp_state *ddsrt_xmlp_new_file (FILE *fp, void *varg, const struct ddsrt_xmlp_callbacks *cb)
{
  struct ddsrt_xmlp_state *st;
  st = ddsrt_malloc (sizeof (*st));
  st->cbufn = 0;
  st->cbufmax = 8192;
  st->cbuf = ddsrt_malloc (st->cbufmax);
  st->fp = fp;
  ddsrt_xmlp_new_common (st);
  ddsrt_xmlp_new_setCB (st, varg, cb);
  return st;
}

struct ddsrt_xmlp_state *ddsrt_xmlp_new_string (const char *string, void *varg, const struct ddsrt_xmlp_callbacks *cb)
{
  struct ddsrt_xmlp_state *st;
  st = ddsrt_malloc (sizeof (*st));
  st->cbufn = strlen (string);
  st->cbufmax = st->cbufn;
  st->cbuf = (unsigned char *) string;
  st->fp = NULL;
  ddsrt_xmlp_new_common (st);
  ddsrt_xmlp_new_setCB (st, varg, cb);
  return st;
}

void ddsrt_xmlp_set_options (struct ddsrt_xmlp_state *st, uint32_t options)
{
  st->options = options;
}

size_t ddsrt_xmlp_get_bufpos (const struct ddsrt_xmlp_state *st)
{
  return st->cbufp;
}

void ddsrt_xmlp_free (struct ddsrt_xmlp_state *st)
{
    if (st->fp != NULL) {
        ddsrt_free (st->cbuf);
    }
    ddsrt_free (st->tp);
    ddsrt_free (st);
}

static bool make_chars_available (struct ddsrt_xmlp_state *st, size_t nmin)
{
  size_t n, pos;
  if (st->eof) {
    return false;
  }
  pos = (st->cbufmark != NOMARKER) ? st->cbufmark : st->cbufp;
  assert (st->cbufn >= st->cbufp);
  assert (st->cbufmax >= st->cbufn);
  assert (st->cbufmark == NOMARKER || st->cbufmark <= st->cbufp);
  /* fast-path available chars */
  if (st->cbufn - st->cbufp >= nmin) {
    return true;
  }
  /* ensure buffer space is available */
  if (st->fp != NULL) {
    if (pos + nmin > st->cbufmax) {
      memmove (st->cbuf, st->cbuf + pos, st->cbufn - pos);
      st->cbufn -= pos;
      st->cbufp -= pos;
      if (st->cbufmark != NOMARKER) {
        st->cbufmark -= pos;
      }
    }
    /* buffer is owned by caller if fp = NULL, and by us if fp != NULL */
    if (st->cbufmax < st->cbufp + nmin) {
      st->cbufmax = st->cbufp + nmin;
      st->cbuf = ddsrt_realloc (st->cbuf, st->cbufmax);
    }
    /* try to refill buffer if a backing file is present; eof (or end-of-string) is
     reached when this doesn't add any bytes to the buffer */
    n = fread (st->cbuf + st->cbufn, 1, st->cbufmax - st->cbufn, st->fp);
    st->cbufn += n;
  }
  return (st->cbufn - st->cbufp >= nmin);
}

static void set_input_marker (struct ddsrt_xmlp_state *st)
{
  assert (st->cbufmark == NOMARKER);
  st->cbufmark = st->cbufp;
  st->linemark = st->line;
}

static void discard_input_marker (struct ddsrt_xmlp_state *st)
{
  assert (st->cbufmark != NOMARKER);
  st->cbufmark = NOMARKER;
  st->linemark = 0;
}

static bool have_input_marker (struct ddsrt_xmlp_state *st)
{
  return (st->cbufmark != NOMARKER);
}

static void rewind_to_input_marker (struct ddsrt_xmlp_state *st)
{
  assert (st->cbufmark != NOMARKER);
  st->cbufp = st->cbufmark;
  st->line = st->linemark;
  discard_input_marker (st);
}

static int next_char (struct ddsrt_xmlp_state *st)
{
  unsigned char c;
  if (!make_chars_available (st, 1)) {
    return TOK_EOF;
  }
  c = st->cbuf[st->cbufp++];
  if (c == '\n') {
    st->line++;
  }
  return c;
}

static int peek_char (struct ddsrt_xmlp_state *st)
{
  if (!make_chars_available (st, 1)) {
    return TOK_EOF;
  }
  return st->cbuf[st->cbufp];
}

static bool peek_chars_impl (struct ddsrt_xmlp_state *st, const char *seq, size_t n, int consume)
{
  if (!make_chars_available (st, n)) {
    return false;
  }
  if (st->cbuf[st->cbufp] != seq[0] || memcmp (st->cbuf + st->cbufp, seq, n) != 0) {
    return false;
  } else {
    if (consume) st->cbufp += n;
    return true;
  }
}

static bool peek_chars (struct ddsrt_xmlp_state *st, const char *seq, int consume)
{
  return peek_chars_impl (st, seq, strlen (seq), consume);
}

static bool qq_isspace (int x)
{
  return x == ' ' || x == '\t' || x == '\v' || x == '\r' || x == '\n';
}

static bool qq_isidentfirst (int x)
{
  return (x >= 'A' && x <= 'Z') || (x >= 'a' && x <= 'z');
}

static bool qq_isidentcont (int x)
{
  return qq_isidentfirst (x) || (x >= '0' && x <= '9') || x == '_' || x == '-' || x == ':';
}

static char *unescape_into_utf8 (char *dst, unsigned cp)
{
  if (cp < 0x80) {
    *dst++ = (char) cp;
  } else if (cp <= 0x7ff) {
    *dst++ = (char) ((cp >> 6) + 0xc0);
    *dst++ = (char) ((cp & 0x3f) + 0x80);
  } else if (cp <= 0xffff) {
    *dst++ = (char) ((cp >> 12) + 0xe0);
    *dst++ = (char) (((cp >> 6) & 0x3f) + 0x80);
    *dst++ = (char) ((cp & 0x3f) + 0x80);
  } else if (cp <= 0x10ffff) {
    *dst++ = (char) ((cp >> 18) + 0xf0);
    *dst++ = (char) (((cp >> 12) & 0x3f) + 0x80);
    *dst++ = (char) (((cp >> 6) & 0x3f) + 0x80);
    *dst++ = (char) ((cp & 0x3f) + 0x80);
  } else {
    dst = NULL;
  }
  return dst;
}

static int unescape_insitu (char *buffer, size_t *n)
{
  DDSRT_WARNING_MSVC_OFF(4996);
  const char *src = buffer;
  char const * const srcend = buffer + *n;
  char *dst = buffer;
  while (src < srcend)
  {
    if (*src != '&') {
      *dst++ = *src++;
    } else if (src + 1 == srcend) {
      return -1;
    } else {
      char tmp[16], *ptmp = tmp;
      src++;
      while (ptmp < tmp + sizeof (tmp) && src < srcend) {
        char c = *src++;
        *ptmp++ = c;
        if (c == ';') {
          break;
        }
      }
      if (ptmp == tmp || *(ptmp-1) != ';') {
        return -1;
      }
      *--ptmp = 0;
      if (tmp[0] == '#') {
        unsigned cp;
        int pos;
        if (sscanf (tmp, "#x%x%n", &cp, &pos) == 1 && tmp[pos] == 0) {
          ;
        } else if (sscanf (tmp, "#%u%n", &cp, &pos) == 1 && tmp[pos] == 0) {
          ;
        } else {
          return -1;
        }
        if ((dst = unescape_into_utf8(dst, cp)) == NULL) {
          return -1;
        }
      } else if (strcmp (tmp, "lt") == 0) {
        *dst++ = '<';
      } else if (strcmp (tmp, "gt") == 0) {
        *dst++ = '>';
      } else if (strcmp (tmp, "amp") == 0) {
        *dst++ = '&';
      } else if (strcmp (tmp, "apos") == 0) {
        *dst++ = '\'';
      } else if (strcmp (tmp, "quot") == 0) {
        *dst++ = '"';
      } else {
        return -1;
      }
    }
  }
  *n = (size_t) (dst - buffer);
  return 0;
  DDSRT_WARNING_MSVC_ON(4996);
}

static void discard_payload (struct ddsrt_xmlp_state *st)
{
  st->tpp = 0;
  st->tpescp = 0;
}

static dds_return_t append_to_payload (struct ddsrt_xmlp_state *st, int c)
{
  st->tp[st->tpp++] = (char) c;
  if (st->tpp == st->tpsz) {
    st->tpsz += 1024;
    void *tp_realloc = ddsrt_realloc_s (st->tp, st->tpsz);
    if (tp_realloc == NULL) {
      return DDS_RETCODE_OUT_OF_RESOURCES;
    } else {
      st->tp = tp_realloc;
    }
  }

  return DDS_RETCODE_OK;
}

static int append_to_payload_no_unescape (struct ddsrt_xmlp_state *st, int c)
{
  if (st->tpescp < st->tpp) {
    size_t n = st->tpp - st->tpescp;
    if (unescape_insitu (st->tp + st->tpescp, &n) < 0) {
      discard_payload (st);
      return -1;
    }
    st->tpp = st->tpescp + n;
  }
  int result = append_to_payload (st, c);
  st->tpescp = st->tpp;

  if (result < 0) {
    discard_payload (st);
    return -1;
  } else {
    return 0;
  }
}

static int save_payload (char **payload, struct ddsrt_xmlp_state *st, int trim)
{
  char *p;
  if (st->tpescp < st->tpp) {
    size_t n = st->tpp - st->tpescp;
    if (unescape_insitu (st->tp + st->tpescp, &n) < 0) {
      discard_payload (st);
      return -1;
    }
    st->tpp = st->tpescp + n;
  }
  if (payload == NULL) {
    p = NULL;
  } else if (st->tpp == 0) {
    p = ddsrt_strdup("");
  } else {
    size_t first = 0, last = st->tpp - 1;
    if (trim) {
      while (first <= last && qq_isspace (st->tp[first])) {
        first++;
      }
      while (first <= last && qq_isspace (st->tp[last]) && last > 0) {
        last--;
      }
    }
    if (first > last) {
      p = ddsrt_strdup("");
    } else {
      p = ddsrt_malloc (last - first + 2);
      /* Could be improved, parser error will be "invalid char sequence" if malloc fails. */
      memcpy (p, st->tp + first, last - first + 1);
      p[last - first + 1] = 0;
    }
  }
  discard_payload (st);
  if (payload) {
    *payload = p;
  }
  return 0;
}

static int next_token_ident (struct ddsrt_xmlp_state *st, char **payload)
{
  while (qq_isidentcont (peek_char (st))) {
    if (append_to_payload (st, next_char(st)) < 0) {
      return TOK_ERROR;
    }
  }
  if (save_payload (payload, st, 0) < 0) {
    return TOK_ERROR;
  } else {
    return TOK_ID;
  }
}

static int next_token_tag_withoutclose (struct ddsrt_xmlp_state *st, char **payload)
{
  if (peek_chars (st, "<![CDATA[", 0)) {
    return next_char (st);
  } else {
    int tok = TOK_OPEN_TAG;
    /* pre: peek_char(st) == '<' */
    (void) next_char (st);
    if (peek_char (st) == '/') {
      tok = TOK_CLOSE_TAG;
      (void) next_char (st);
    }
    /* we only do tag names that are identifiers */
    if (peek_char (st) == '>' && (st->options & DDSRT_XMLP_ANONYMOUS_CLOSE_TAG)) {
      return TOK_SHORTHAND_CLOSE_TAG;
    } else if (!qq_isidentfirst (peek_char (st))) {
      return TOK_ERROR;
    } else {
      next_token_ident (st, payload);
      return tok;
    }
  }
}

static int next_token_string (struct ddsrt_xmlp_state *st, char **payload, const char *endm)
{
  const size_t endm_len = strlen (endm);
  /* positioned at first character of string */
  while (!peek_chars_impl (st, endm, endm_len, 0) && peek_char (st) != TOK_EOF) {
    if (append_to_payload (st, next_char (st)) < 0) {
      return TOK_ERROR;
    }
  }
  if (!peek_chars (st, endm, 1)) {
    discard_payload (st);
    return TOK_ERROR;
  } else if (save_payload (payload, st, 0) < 0) {
    return TOK_ERROR;
  } else {
    return TOK_STRING;
  }
}

static int skip_comment (struct ddsrt_xmlp_state *st)
{
  if (!peek_chars (st, "<!--", 1)) {
    return 0;
  }
  while (peek_char (st) != TOK_EOF && (peek_char (st) != '-' || !peek_chars (st, "-->", 0))) {
    (void) next_char (st);
  }
  if (peek_chars (st, "-->", 1)) {
    return 1;
  } else {
    return TOK_ERROR;
  }
}

static void processing_instruction (struct ddsrt_xmlp_state *st, const char *end)
{
  /* just after <?; skip everything up to and include ?> */
  while (peek_char (st) != TOK_EOF && !peek_chars (st, end, 1)) {
    (void) next_char (st);
  }
}

static void drop_peek_token (struct ddsrt_xmlp_state *st)
{
  st->peektok = 0;
  if (st->peekpayload) {
    ddsrt_free (st->peekpayload);
    st->peekpayload = NULL;
  }
}

static int next_token (struct ddsrt_xmlp_state *st, char **payload)
{
  /* Always return a valid pointer to allocated memory or a null
     pointer, regardless of token type */
  if (payload) {
    *payload = NULL;
  }
  if (st->error) {
    return TOK_ERROR;
  } else if (st->peektok) {
    int tok = st->peektok;
    st->peektok = 0;
    if (payload) {
      *payload = st->peekpayload;
    } else if (st->peekpayload) {
      ddsrt_free (st->peekpayload);
      st->peekpayload = NULL;
    }
    return tok;
  } else {
    int cmt, tok;
    st->prevline = st->line;
    do {
      while (qq_isspace (peek_char (st))) {
        (void) next_char (st);
      }
    } while ((cmt = skip_comment (st)) > 0);
    if (cmt == TOK_ERROR) {
      tok = TOK_ERROR;
    } else if (peek_chars (st, "<?", 1)) {
      processing_instruction (st, "?>");
      return next_token (st, payload);
    } else if (peek_chars (st, cdata_magic, 0)) {
      tok = TOK_CDATA;
    } else if (peek_chars (st, "<!", 1)) {
      processing_instruction (st, ">");
      return next_token (st, payload);
    } else {
      int n = peek_char (st);
      if (n == '<') {
        tok = next_token_tag_withoutclose (st, payload);
      } else if (n == '"' || n == '\'') {
        const unsigned char c = (unsigned char) next_char (st);
        const unsigned char endm[2] = { c, 0 };
        tok = next_token_string (st, payload, (const char *) endm);
      } else if (n == 0xe2 && (peek_chars (st, "\xe2\x80\x9c", 0) || peek_chars (st, "\xe2\x80\x98", 0))) {
        /* allow fancy unicode quotes (U+201c .. U+201d and U+2018 ... U+2019) in
           UTF-8 representation because email clients like to rewrite plain ones,
           and this has caused people trouble several times already */
        (void) next_char (st); (void) next_char (st);
        const unsigned char c = (unsigned char) next_char (st);
        const unsigned char endm[4] = { 0xe2, 0x80, (unsigned char) (c + 1), 0 };
        tok = next_token_string (st, payload, (const char *) endm);
      } else if (qq_isidentfirst (n)) {
        tok = next_token_ident (st, payload);
      } else if (peek_chars (st, "/>", 1)) {
        tok = TOK_SHORTHAND_CLOSE_TAG;
      } else {
        tok = next_char (st);
      }
    }
    if (tok == TOK_ERROR) {
      char msg[512];
      (void) snprintf (msg, sizeof (msg), "invalid token encountered");
      st->cb.error (st->varg, msg, st->line);
      st->error = true;
    }
    return tok;
  }
}

static int peek_token (struct ddsrt_xmlp_state *st)
{
  int tok;
  char *payload;
  tok = next_token (st, &payload);
  st->peektok = tok;
  st->peekpayload = payload;
  return tok;
}

static int parse_element (struct ddsrt_xmlp_state *st, uintptr_t parentinfo)
{
#define PE_ERROR2(c,c1,c2) do { errc = (c); errc1 = (c1); errc2 = (c2); goto err; } while (0)
#define PE_ERROR(c,c1) PE_ERROR2(c,c1,0)
#define PE_LOCAL_ERROR(c,c1) do { ret = -1; PE_ERROR ((c), (c1)); } while (0)
  char *name = NULL, *aname = NULL, *ename = NULL;
  const char *errc = NULL, *errc1 = NULL, *errc2 = NULL;
  uintptr_t eleminfo;
  int ret = 0, tok;

  if (next_token (st, &name) != TOK_OPEN_TAG) {
    PE_LOCAL_ERROR ("expecting '<'", 0);
  }

  if ((ret = st->cb.elem_open (st->varg, parentinfo, &eleminfo, name, st->line)) < 0) {
    PE_ERROR ("failed in element open callback", name);
  }

  while (peek_token (st) == TOK_ID) {
    char *content;
    next_token (st, &aname);
    if (next_token (st, NULL) != '=') {
      PE_LOCAL_ERROR ("expecting '=' following attribute name", aname);
    }
    if (next_token (st, &content) != TOK_STRING) {
      ddsrt_free (content);
      PE_LOCAL_ERROR ("expecting string value for attribute", aname);
    }
    ret = st->cb.attr (st->varg, eleminfo, aname, content, st->line);
    ddsrt_free (content);
    if (ret < 0) {
      PE_ERROR2 ("failed in attribute callback", name, aname);
    }
    ddsrt_free (aname);
    aname = NULL;
  }

  tok = next_token (st, NULL);
  switch (tok)
  {
    case TOK_SHORTHAND_CLOSE_TAG:
      ret = st->cb.elem_close (st->varg, eleminfo, st->line);
      goto ok;
    case '>':
      st->nest++;
      set_input_marker (st);
      if (peek_token (st) == TOK_OPEN_TAG) {
        /* child elements */
        discard_input_marker (st);
        while (peek_token (st) == TOK_OPEN_TAG) {
          if ((ret = parse_element (st, eleminfo)) < 0) {
            PE_ERROR ("parse children", 0);
          }
        }
      } else {
        /* text */
        char *content;
        int cmt = 0;
        rewind_to_input_marker (st);
        drop_peek_token (st);
        do {
          /* gobble up content until EOF or markup */
          while (peek_char (st) != '<' && peek_char (st) != TOK_EOF) {
            if (append_to_payload (st, next_char (st)) < 0) {
              PE_LOCAL_ERROR ("invalid character sequence", 0);
            }
          }
          /* if the mark-up happens to be a CDATA, consume it, and gobble up characters
             until the closing marker is reached, which then also gets consumed */
          if (peek_chars (st, cdata_magic, 1)) {
            while (!peek_chars (st, "]]>", 1) && peek_char (st) != TOK_EOF) {
              if (append_to_payload_no_unescape (st, next_char (st)) < 0) {
                PE_LOCAL_ERROR ("invalid character sequence", 0);
              }
            }
          }
          /* then, if the markup is a comment, skip it and try again */
        } while ((peek_char (st) != '<' || (cmt = skip_comment (st)) > 0) && make_chars_available (st, sizeof(cdata_magic) - 1));
        if (cmt == TOK_ERROR) {
          discard_payload (st);
          PE_LOCAL_ERROR ("invalid comment", 0);
        }
        if (save_payload (&content, st, 1) < 0) {
          PE_ERROR ("invalid character sequence", 0);
        } else if (content != NULL) {
          if (*content != '\0') {
            ret = st->cb.elem_data (st->varg, eleminfo, content, st->line);
            ddsrt_free (content);
            if (ret < 0) {
              PE_ERROR ("failed in data callback", 0);
            }
          } else {
            ddsrt_free (content);
          }
        }
      }
      st->nest--;
      set_input_marker (st);
      if (((tok = next_token (st, &ename)) != TOK_CLOSE_TAG && tok != TOK_SHORTHAND_CLOSE_TAG) || next_char (st) != '>') {
        if (!(st->options & DDSRT_XMLP_MISSING_CLOSE_AS_EOF)) {
          PE_LOCAL_ERROR ("expecting closing tag", name);
        } else {
          rewind_to_input_marker (st);
          st->eof = true;
          tok = TOK_SHORTHAND_CLOSE_TAG;
        }
      }
      if (tok != TOK_SHORTHAND_CLOSE_TAG && strcmp (name, ename) != 0) {
        PE_LOCAL_ERROR ("open/close tag mismatch", ename);
      }
      if (have_input_marker (st)) {
        discard_input_marker (st);
      }
      ret = st->cb.elem_close (st->varg, eleminfo, st->line);
      goto ok;
    default:
      PE_LOCAL_ERROR ("expecting '/>' or '>'", 0);
  }

err:
  if (!st->error) {
    char msg[512];
    (void) snprintf (msg, sizeof (msg), "%s (%s%s%s)", errc, errc1 ? errc1 : "", errc1 && errc2 ? ", " : "", errc2 ? errc2 : "");
    st->cb.error (st->varg, msg, st->prevline);
    st->error = true;
  }
ok:
  ddsrt_free (name);
  ddsrt_free (aname);
  ddsrt_free (ename);
  return ret;
#undef PE_LOCAL_ERROR
#undef PE_ERROR
#undef PE_ERROR2
}

int ddsrt_xmlp_parse (struct ddsrt_xmlp_state *st)
{
  if (peek_token (st) == TOK_EOF) {
    return 0;
  } else {
    int ret = parse_element (st, 0);
    if (ret < 0|| !(st->options & DDSRT_XMLP_REQUIRE_EOF) || next_token (st, NULL) == TOK_EOF ) {
      return ret;
    } else {
      return -1;
    }
  }
}
