Adding upstream version 8.32.upstream/8.32upstream

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

1 files changed, 195 insertions, 0 deletions

diff --git a/lib/readtokens.c b/lib/readtokens.c
new file mode 100644
index 0000000..b884d81
--- /dev/null
+++ b/lib/readtokens.c
@@ -0,0 +1,195 @@
+/* readtokens.c  -- Functions for reading tokens from an input stream.
+
+   Copyright (C) 1990-1991, 1999-2004, 2006, 2009-2020 Free Software
+   Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+   Written by Jim Meyering. */
+
+/* This almost supersedes xreadline stuff -- using delim="\n"
+   gives the same functionality, except that these functions
+   would never return empty lines. */
+
+#include <config.h>
+
+#include "readtokens.h"
+
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+
+#include "xalloc.h"
+
+#if USE_UNLOCKED_IO
+# include "unlocked-io.h"
+#endif
+
+/* Initialize a tokenbuffer. */
+
+void
+init_tokenbuffer (token_buffer *tokenbuffer)
+{
+  tokenbuffer->size = 0;
+  tokenbuffer->buffer = NULL;
+}
+
+typedef size_t word;
+enum { bits_per_word = sizeof (word) * CHAR_BIT };
+
+static bool
+get_nth_bit (size_t n, word const *bitset)
+{
+  return bitset[n / bits_per_word] >> n % bits_per_word & 1;
+}
+
+static void
+set_nth_bit (size_t n, word *bitset)
+{
+  size_t one = 1;
+  bitset[n / bits_per_word] |= one << n % bits_per_word;
+}
+
+/* Read a token from STREAM into TOKENBUFFER.
+   A token is delimited by any of the N_DELIM bytes in DELIM.
+   Upon return, the token is in tokenbuffer->buffer and
+   has a trailing '\0' instead of any original delimiter.
+   The function value is the length of the token not including
+   the final '\0'.  Upon EOF (i.e. on the call after the last
+   token is read) or error, return -1 without modifying tokenbuffer.
+   The EOF and error conditions may be distinguished in the caller
+   by testing ferror (STREAM).
+
+   This function works properly on lines containing NUL bytes
+   and on files that do not end with a delimiter.  */
+
+size_t
+readtoken (FILE *stream,
+           const char *delim,
+           size_t n_delim,
+           token_buffer *tokenbuffer)
+{
+  char *p;
+  int c;
+  size_t i, n;
+  word isdelim[(UCHAR_MAX + bits_per_word) / bits_per_word];
+
+  memset (isdelim, 0, sizeof isdelim);
+  for (i = 0; i < n_delim; i++)
+    {
+      unsigned char ch = delim[i];
+      set_nth_bit (ch, isdelim);
+    }
+
+  /* skip over any leading delimiters */
+  for (c = getc (stream); c >= 0 && get_nth_bit (c, isdelim); c = getc (stream))
+    {
+      /* empty */
+    }
+
+  p = tokenbuffer->buffer;
+  n = tokenbuffer->size;
+  i = 0;
+  for (;;)
+    {
+      if (c < 0 && i == 0)
+        return -1;
+
+      if (i == n)
+        p = x2nrealloc (p, &n, sizeof *p);
+
+      if (c < 0)
+        {
+          p[i] = 0;
+          break;
+        }
+      if (get_nth_bit (c, isdelim))
+        {
+          p[i] = 0;
+          break;
+        }
+      p[i++] = c;
+      c = getc (stream);
+    }
+
+  tokenbuffer->buffer = p;
+  tokenbuffer->size = n;
+  return i;
+}
+
+/* Build a NULL-terminated array of pointers to tokens
+   read from STREAM.  Return the number of tokens read.
+   All storage is obtained through calls to xmalloc-like functions.
+
+   %%% Question: is it worth it to do a single
+   %%% realloc() of 'tokens' just before returning? */
+
+size_t
+readtokens (FILE *stream,
+            size_t projected_n_tokens,
+            const char *delim,
+            size_t n_delim,
+            char ***tokens_out,
+            size_t **token_lengths)
+{
+  token_buffer tb, *token = &tb;
+  char **tokens;
+  size_t *lengths;
+  size_t sz;
+  size_t n_tokens;
+
+  if (projected_n_tokens == 0)
+    projected_n_tokens = 64;
+  else
+    projected_n_tokens++;       /* add one for trailing NULL pointer */
+
+  sz = projected_n_tokens;
+  tokens = xnmalloc (sz, sizeof *tokens);
+  lengths = xnmalloc (sz, sizeof *lengths);
+
+  n_tokens = 0;
+  init_tokenbuffer (token);
+  for (;;)
+    {
+      char *tmp;
+      size_t token_length = readtoken (stream, delim, n_delim, token);
+      if (n_tokens >= sz)
+        {
+          tokens = x2nrealloc (tokens, &sz, sizeof *tokens);
+          lengths = xnrealloc (lengths, sz, sizeof *lengths);
+        }
+
+      if (token_length == (size_t) -1)
+        {
+          /* don't increment n_tokens for NULL entry */
+          tokens[n_tokens] = NULL;
+          lengths[n_tokens] = 0;
+          break;
+        }
+      tmp = xnmalloc (token_length + 1, sizeof *tmp);
+      lengths[n_tokens] = token_length;
+      tokens[n_tokens] = memcpy (tmp, token->buffer, token_length + 1);
+      n_tokens++;
+    }
+
+  free (token->buffer);
+  *tokens_out = tokens;
+  if (token_lengths != NULL)
+    *token_lengths = lengths;
+  else
+    free (lengths);
+  return n_tokens;
+}