Fix a few more cases of ignored return values in regex.

3 files changed, 145 insertions, 129 deletions

diff --git a/posix/regcomp.c b/posix/regcomp.c
index 542b848f14..63ef7683ca 100644
--- a/posix/regcomp.c
+++ b/posix/regcomp.c
@@ -999,7 +999,11 @@ create_initial_state (re_dfa_t *dfa)
 	    int dest_idx = dfa->edests[node_idx].elems[0];
 	    if (!re_node_set_contains (&init_nodes, dest_idx))
 	      {
-		re_node_set_merge (&init_nodes, dfa->eclosures + dest_idx);
+		reg_errcode_t err = re_node_set_merge (&init_nodes,
+						       dfa->eclosures
+						       + dest_idx);
+		if (err != REG_NOERROR)
+		  return err;
 		i = 0;
 	      }
 	  }
@@ -1414,7 +1418,7 @@ link_nfa_nodes (void *extra, bin_tree_t *node)
     case OP_BACK_REF:
       dfa->nexts[idx] = node->next->node_idx;
       if (node->token.type == OP_BACK_REF)
-	re_node_set_init_1 (dfa->edests + idx, dfa->nexts[idx]);
+	err = re_node_set_init_1 (dfa->edests + idx, dfa->nexts[idx]);
       break;
 
     default:
@@ -1690,7 +1694,9 @@ calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, int node, int root)
 	else
 	  eclosure_elem = dfa->eclosures[edest];
 	/* Merge the epsilon closure of `edest'.  */
-	re_node_set_merge (&eclosure, &eclosure_elem);
+	err = re_node_set_merge (&eclosure, &eclosure_elem);
+	if (BE (err != REG_NOERROR, 0))
+	  return err;
 	/* If the epsilon closure of `edest' is incomplete,
 	   the epsilon closure of this node is also incomplete.  */
 	if (dfa->eclosures[edest].nelem == 0)
diff --git a/posix/regex_internal.c b/posix/regex_internal.c
index c9da2b961c..ff28e5fcb9 100644
--- a/posix/regex_internal.c
+++ b/posix/regex_internal.c
@@ -1,5 +1,5 @@
 /* Extended regular expression matching and search library.
-   Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+   Copyright (C) 2002-2006, 2010 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
 
@@ -36,7 +36,7 @@ static re_dfastate_t *create_cd_newstate (const re_dfa_t *dfa,
    re_string_reconstruct before using the object.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 re_string_allocate (re_string_t *pstr, const char *str, int len, int init_len,
 		    RE_TRANSLATE_TYPE trans, int icase, const re_dfa_t *dfa)
 {
@@ -64,7 +64,7 @@ re_string_allocate (re_string_t *pstr, const char *str, int len, int init_len,
 /* This function allocate the buffers, and initialize them.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 re_string_construct (re_string_t *pstr, const char *str, int len,
 		     RE_TRANSLATE_TYPE trans, int icase, const re_dfa_t *dfa)
 {
@@ -127,7 +127,7 @@ re_string_construct (re_string_t *pstr, const char *str, int len,
 /* Helper functions for re_string_allocate, and re_string_construct.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 re_string_realloc_buffers (re_string_t *pstr, int new_buf_len)
 {
 #ifdef RE_ENABLE_I18N
@@ -260,7 +260,7 @@ build_wcs_buffer (re_string_t *pstr)
    but for REG_ICASE.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 build_wcs_upper_buffer (re_string_t *pstr)
 {
   mbstate_t prev_st;
@@ -423,8 +423,8 @@ build_wcs_upper_buffer (re_string_t *pstr)
 		    src_idx += mbclen;
 		    continue;
 		  }
-                else
-                  memcpy (pstr->mbs + byte_idx, p, mbclen);
+		else
+		  memcpy (pstr->mbs + byte_idx, p, mbclen);
 	      }
 	    else
 	      memcpy (pstr->mbs + byte_idx, p, mbclen);
@@ -559,7 +559,7 @@ re_string_translate_buffer (re_string_t *pstr)
    convert to upper case in case of REG_ICASE, apply translation.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 re_string_reconstruct (re_string_t *pstr, int idx, int eflags)
 {
   int offset = idx - pstr->raw_mbs_idx;
@@ -951,7 +951,7 @@ re_string_context_at (const re_string_t *input, int idx, int eflags)
 /* Functions for set operation.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 re_node_set_alloc (re_node_set *set, int size)
 {
   set->alloc = size;
@@ -963,7 +963,7 @@ re_node_set_alloc (re_node_set *set, int size)
 }
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 re_node_set_init_1 (re_node_set *set, int elem)
 {
   set->alloc = 1;
@@ -979,7 +979,7 @@ re_node_set_init_1 (re_node_set *set, int elem)
 }
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 re_node_set_init_2 (re_node_set *set, int elem1, int elem2)
 {
   set->alloc = 2;
@@ -1009,7 +1009,7 @@ re_node_set_init_2 (re_node_set *set, int elem1, int elem2)
 }
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 re_node_set_init_copy (re_node_set *dest, const re_node_set *src)
 {
   dest->nelem = src->nelem;
@@ -1034,7 +1034,7 @@ re_node_set_init_copy (re_node_set *dest, const re_node_set *src)
    Note: We assume dest->elems is NULL, when dest->alloc is 0.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 re_node_set_add_intersect (re_node_set *dest, const re_node_set *src1,
 			   const re_node_set *src2)
 {
@@ -1049,7 +1049,7 @@ re_node_set_add_intersect (re_node_set *dest, const re_node_set *src1,
       int new_alloc = src1->nelem + src2->nelem + dest->alloc;
       int *new_elems = re_realloc (dest->elems, int, new_alloc);
       if (BE (new_elems == NULL, 0))
-        return REG_ESPACE;
+	return REG_ESPACE;
       dest->elems = new_elems;
       dest->alloc = new_alloc;
     }
@@ -1068,8 +1068,8 @@ re_node_set_add_intersect (re_node_set *dest, const re_node_set *src1,
 	  while (id >= 0 && dest->elems[id] > src1->elems[i1])
 	    --id;
 
-          if (id < 0 || dest->elems[id] != src1->elems[i1])
-            dest->elems[--sbase] = src1->elems[i1];
+	  if (id < 0 || dest->elems[id] != src1->elems[i1])
+	    dest->elems[--sbase] = src1->elems[i1];
 
 	  if (--i1 < 0 || --i2 < 0)
 	    break;
@@ -1099,20 +1099,20 @@ re_node_set_add_intersect (re_node_set *dest, const re_node_set *src1,
   if (delta > 0 && id >= 0)
     for (;;)
       {
-        if (dest->elems[is] > dest->elems[id])
-          {
-            /* Copy from the top.  */
-            dest->elems[id + delta--] = dest->elems[is--];
-            if (delta == 0)
-              break;
-          }
-        else
-          {
-            /* Slide from the bottom.  */
-            dest->elems[id + delta] = dest->elems[id];
-            if (--id < 0)
-              break;
-          }
+	if (dest->elems[is] > dest->elems[id])
+	  {
+	    /* Copy from the top.  */
+	    dest->elems[id + delta--] = dest->elems[is--];
+	    if (delta == 0)
+	      break;
+	  }
+	else
+	  {
+	    /* Slide from the bottom.  */
+	    dest->elems[id + delta] = dest->elems[id];
+	    if (--id < 0)
+	      break;
+	  }
       }
 
   /* Copy remaining SRC elements.  */
@@ -1125,7 +1125,7 @@ re_node_set_add_intersect (re_node_set *dest, const re_node_set *src1,
    DEST. Return value indicate the error code or REG_NOERROR if succeeded.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 re_node_set_init_union (re_node_set *dest, const re_node_set *src1,
 			const re_node_set *src2)
 {
@@ -1178,7 +1178,7 @@ re_node_set_init_union (re_node_set *dest, const re_node_set *src1,
    DEST. Return value indicate the error code or REG_NOERROR if succeeded.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 re_node_set_merge (re_node_set *dest, const re_node_set *src)
 {
   int is, id, sbase, delta;
@@ -1207,11 +1207,11 @@ re_node_set_merge (re_node_set *dest, const re_node_set *src)
        is = src->nelem - 1, id = dest->nelem - 1; is >= 0 && id >= 0; )
     {
       if (dest->elems[id] == src->elems[is])
-        is--, id--;
+	is--, id--;
       else if (dest->elems[id] < src->elems[is])
-        dest->elems[--sbase] = src->elems[is--];
+	dest->elems[--sbase] = src->elems[is--];
       else /* if (dest->elems[id] > src->elems[is]) */
-        --id;
+	--id;
     }
 
   if (is >= 0)
@@ -1233,21 +1233,21 @@ re_node_set_merge (re_node_set *dest, const re_node_set *src)
   for (;;)
     {
       if (dest->elems[is] > dest->elems[id])
-        {
+	{
 	  /* Copy from the top.  */
-          dest->elems[id + delta--] = dest->elems[is--];
+	  dest->elems[id + delta--] = dest->elems[is--];
 	  if (delta == 0)
 	    break;
 	}
       else
-        {
-          /* Slide from the bottom.  */
-          dest->elems[id + delta] = dest->elems[id];
+	{
+	  /* Slide from the bottom.  */
+	  dest->elems[id + delta] = dest->elems[id];
 	  if (--id < 0)
 	    {
 	      /* Copy remaining SRC elements.  */
 	      memcpy (dest->elems, dest->elems + sbase,
-	              delta * sizeof (int));
+		      delta * sizeof (int));
 	      break;
 	    }
 	}
@@ -1261,7 +1261,7 @@ re_node_set_merge (re_node_set *dest, const re_node_set *src)
    return -1 if an error is occured, return 1 otherwise.  */
 
 static int
-internal_function
+internal_function __attribute_warn_unused_result__
 re_node_set_insert (re_node_set *set, int elem)
 {
   int idx;
@@ -1299,12 +1299,12 @@ re_node_set_insert (re_node_set *set, int elem)
     {
       idx = 0;
       for (idx = set->nelem; idx > 0; idx--)
-        set->elems[idx] = set->elems[idx - 1];
+	set->elems[idx] = set->elems[idx - 1];
     }
   else
     {
       for (idx = set->nelem; set->elems[idx - 1] > elem; idx--)
-        set->elems[idx] = set->elems[idx - 1];
+	set->elems[idx] = set->elems[idx - 1];
     }
 
   /* Insert the new element.  */
@@ -1318,7 +1318,7 @@ re_node_set_insert (re_node_set *set, int elem)
    Return -1 if an error is occured, return 1 otherwise.  */
 
 static int
-internal_function
+internal_function __attribute_warn_unused_result__
 re_node_set_insert_last (re_node_set *set, int elem)
 {
   /* Realloc if we need.  */
@@ -1458,7 +1458,7 @@ calc_state_hash (const re_node_set *nodes, unsigned int context)
 	   optimization.  */
 
 static re_dfastate_t *
-internal_function
+internal_function __attribute_warn_unused_result__
 re_acquire_state (reg_errcode_t *err, const re_dfa_t *dfa,
 		  const re_node_set *nodes)
 {
@@ -1502,7 +1502,7 @@ re_acquire_state (reg_errcode_t *err, const re_dfa_t *dfa,
 	   optimization.  */
 
 static re_dfastate_t *
-internal_function
+internal_function __attribute_warn_unused_result__
 re_acquire_state_context (reg_errcode_t *err, const re_dfa_t *dfa,
 			  const re_node_set *nodes, unsigned int context)
 {
@@ -1539,6 +1539,7 @@ re_acquire_state_context (reg_errcode_t *err, const re_dfa_t *dfa,
    indicates the error code if failed.  */
 
 static reg_errcode_t
+__attribute_warn_unused_result__
 register_state (const re_dfa_t *dfa, re_dfastate_t *newstate,
 		unsigned int hash)
 {
@@ -1554,7 +1555,8 @@ register_state (const re_dfa_t *dfa, re_dfastate_t *newstate,
     {
       int elem = newstate->nodes.elems[i];
       if (!IS_EPSILON_NODE (dfa->nodes[elem].type))
-        re_node_set_insert_last (&newstate->non_eps_nodes, elem);
+	if (re_node_set_insert_last (&newstate->non_eps_nodes, elem) < 0)
+	  return REG_ESPACE;
     }
 
   spot = dfa->state_table + (hash & dfa->state_hash_mask);
@@ -1592,7 +1594,7 @@ free_state (re_dfastate_t *state)
    Return the new state if succeeded, otherwise return NULL.  */
 
 static re_dfastate_t *
-internal_function
+internal_function __attribute_warn_unused_result__
 create_ci_newstate (const re_dfa_t *dfa, const re_node_set *nodes,
 		    unsigned int hash)
 {
@@ -1642,7 +1644,7 @@ create_ci_newstate (const re_dfa_t *dfa, const re_node_set *nodes,
    Return the new state if succeeded, otherwise return NULL.  */
 
 static re_dfastate_t *
-internal_function
+internal_function __attribute_warn_unused_result__
 create_cd_newstate (const re_dfa_t *dfa, const re_node_set *nodes,
 		    unsigned int context, unsigned int hash)
 {
@@ -1691,7 +1693,9 @@ create_cd_newstate (const re_dfa_t *dfa, const re_node_set *nodes,
 		  free_state (newstate);
 		  return NULL;
 		}
-	      re_node_set_init_copy (newstate->entrance_nodes, nodes);
+	      if (re_node_set_init_copy (newstate->entrance_nodes, nodes)
+		  != REG_NOERROR)
+		return NULL;
 	      nctx_nodes = 0;
 	      newstate->has_constraint = 1;
 	    }
diff --git a/posix/regexec.c b/posix/regexec.c
index 7bf0c08a78..b8db74062b 100644
--- a/posix/regexec.c
+++ b/posix/regexec.c
@@ -1,5 +1,5 @@
 /* Extended regular expression matching and search library.
-   Copyright (C) 2002, 2003, 2004, 2005, 2007, 2009 Free Software Foundation, Inc.
+   Copyright (C) 2002-2005, 2007, 2009, 2010 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
 
@@ -617,6 +617,7 @@ re_exec (s)
    (START + RANGE >= 0 && START + RANGE <= LENGTH)  */
 
 static reg_errcode_t
+__attribute_warn_unused_result__
 re_search_internal (preg, string, length, start, range, stop, nmatch, pmatch,
 		    eflags)
     const regex_t *preg;
@@ -668,7 +669,7 @@ re_search_internal (preg, string, length, start, range, stop, nmatch, pmatch,
 	  || !preg->newline_anchor))
     {
       if (start != 0 && start + range != 0)
-        return REG_NOMATCH;
+	return REG_NOMATCH;
       start = range = 0;
     }
 
@@ -800,10 +801,10 @@ re_search_internal (preg, string, length, start, range, stop, nmatch, pmatch,
 		break;
 	      match_first += incr;
 	      if (match_first < left_lim || match_first > right_lim)
-	        {
-	          err = REG_NOMATCH;
-	          goto free_return;
-	        }
+		{
+		  err = REG_NOMATCH;
+		  goto free_return;
+		}
 	    }
 	  break;
 	}
@@ -917,14 +918,14 @@ re_search_internal (preg, string, length, start, range, stop, nmatch, pmatch,
 	}
 
       if (dfa->subexp_map)
-        for (reg_idx = 0; reg_idx + 1 < nmatch; reg_idx++)
-          if (dfa->subexp_map[reg_idx] != reg_idx)
-            {
-              pmatch[reg_idx + 1].rm_so
-                = pmatch[dfa->subexp_map[reg_idx] + 1].rm_so;
-              pmatch[reg_idx + 1].rm_eo
-                = pmatch[dfa->subexp_map[reg_idx] + 1].rm_eo;
-            }
+	for (reg_idx = 0; reg_idx + 1 < nmatch; reg_idx++)
+	  if (dfa->subexp_map[reg_idx] != reg_idx)
+	    {
+	      pmatch[reg_idx + 1].rm_so
+		= pmatch[dfa->subexp_map[reg_idx] + 1].rm_so;
+	      pmatch[reg_idx + 1].rm_eo
+		= pmatch[dfa->subexp_map[reg_idx] + 1].rm_eo;
+	    }
     }
 
  free_return:
@@ -936,6 +937,7 @@ re_search_internal (preg, string, length, start, range, stop, nmatch, pmatch,
 }
 
 static reg_errcode_t
+__attribute_warn_unused_result__
 prune_impossible_nodes (mctx)
      re_match_context_t *mctx;
 {
@@ -1069,7 +1071,7 @@ acquire_init_state_context (reg_errcode_t *err, const re_match_context_t *mctx,
    index of the buffer.  */
 
 static int
-internal_function
+internal_function __attribute_warn_unused_result__
 check_matching (re_match_context_t *mctx, int fl_longest_match,
 		int *p_match_first)
 {
@@ -1108,7 +1110,7 @@ check_matching (re_match_context_t *mctx, int fl_longest_match,
 	    {
 	      err = transit_state_bkref (mctx, &cur_state->nodes);
 	      if (BE (err != REG_NOERROR, 0))
-	        return err;
+		return err;
 	    }
 	}
     }
@@ -1135,16 +1137,16 @@ check_matching (re_match_context_t *mctx, int fl_longest_match,
       int next_char_idx = re_string_cur_idx (&mctx->input) + 1;
 
       if (BE (next_char_idx >= mctx->input.bufs_len, 0)
-          || (BE (next_char_idx >= mctx->input.valid_len, 0)
-              && mctx->input.valid_len < mctx->input.len))
-        {
-          err = extend_buffers (mctx);
-          if (BE (err != REG_NOERROR, 0))
+	  || (BE (next_char_idx >= mctx->input.valid_len, 0)
+	      && mctx->input.valid_len < mctx->input.len))
+	{
+	  err = extend_buffers (mctx);
+	  if (BE (err != REG_NOERROR, 0))
 	    {
 	      assert (err == REG_ESPACE);
 	      return -2;
 	    }
-        }
+	}
 
       cur_state = transit_state (&err, mctx, cur_state);
       if (mctx->state_log != NULL)
@@ -1263,20 +1265,20 @@ proceed_next_node (const re_match_context_t *mctx, int nregs, regmatch_t *regs,
 	  int candidate = edests->elems[i];
 	  if (!re_node_set_contains (cur_nodes, candidate))
 	    continue;
-          if (dest_node == -1)
+	  if (dest_node == -1)
 	    dest_node = candidate;
 
-          else
+	  else
 	    {
 	      /* In order to avoid infinite loop like "(a*)*", return the second
-	         epsilon-transition if the first was already considered.  */
+		 epsilon-transition if the first was already considered.  */
 	      if (re_node_set_contains (eps_via_nodes, dest_node))
-	        return candidate;
+		return candidate;
 
 	      /* Otherwise, push the second epsilon-transition on the fail stack.  */
 	      else if (fs != NULL
 		       && push_fail_stack (fs, *pidx, candidate, nregs, regs,
-				           eps_via_nodes))
+					   eps_via_nodes))
 		return -2;
 
 	      /* We know we are going to exit.  */
@@ -1342,7 +1344,7 @@ proceed_next_node (const re_match_context_t *mctx, int nregs, regmatch_t *regs,
 }
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 push_fail_stack (struct re_fail_stack_t *fs, int str_idx, int dest_node,
 		 int nregs, regmatch_t *regs, re_node_set *eps_via_nodes)
 {
@@ -1389,7 +1391,7 @@ pop_fail_stack (struct re_fail_stack_t *fs, int *pidx, int nregs,
    pmatch[i].rm_so == pmatch[i].rm_eo == -1 for 0 < i < nmatch.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 set_regs (const regex_t *preg, const re_match_context_t *mctx, size_t nmatch,
 	  regmatch_t *pmatch, int fl_backtrack)
 {
@@ -1624,7 +1626,7 @@ sift_states_backward (const re_match_context_t *mctx, re_sift_context_t *sctx)
       if (mctx->state_log[str_idx])
 	{
 	  err = build_sifted_states (mctx, sctx, str_idx, &cur_dest);
-          if (BE (err != REG_NOERROR, 0))
+	  if (BE (err != REG_NOERROR, 0))
 	    goto free_return;
 	}
 
@@ -1643,7 +1645,7 @@ sift_states_backward (const re_match_context_t *mctx, re_sift_context_t *sctx)
 }
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 build_sifted_states (const re_match_context_t *mctx, re_sift_context_t *sctx,
 		     int str_idx, re_node_set *cur_dest)
 {
@@ -1805,7 +1807,7 @@ update_cur_sifted_state (const re_match_context_t *mctx,
 }
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 add_epsilon_src_nodes (const re_dfa_t *dfa, re_node_set *dest_nodes,
 		       const re_node_set *candidates)
 {
@@ -1820,10 +1822,14 @@ add_epsilon_src_nodes (const re_dfa_t *dfa, re_node_set *dest_nodes,
     {
       err = re_node_set_alloc (&state->inveclosure, dest_nodes->nelem);
       if (BE (err != REG_NOERROR, 0))
-        return REG_ESPACE;
+	return REG_ESPACE;
       for (i = 0; i < dest_nodes->nelem; i++)
-        re_node_set_merge (&state->inveclosure,
-			   dfa->inveclosures + dest_nodes->elems[i]);
+	{
+	  err = re_node_set_merge (&state->inveclosure,
+				   dfa->inveclosures + dest_nodes->elems[i]);
+	  if (BE (err != REG_NOERROR, 0))
+	    return REG_ESPACE;
+	}
     }
   return re_node_set_add_intersect (dest_nodes, candidates,
 				    &state->inveclosure);
@@ -1935,7 +1941,7 @@ check_dst_limits_calc_pos_1 (const re_match_context_t *mctx, int boundaries,
 	    {
 	      struct re_backref_cache_entry *ent = mctx->bkref_ents + bkref_idx;
 	      do
-	        {
+		{
 		  int dst, cpos;
 
 		  if (ent->node != node)
@@ -1956,9 +1962,9 @@ check_dst_limits_calc_pos_1 (const re_match_context_t *mctx, int boundaries,
 		  if (dst == from_node)
 		    {
 		      if (boundaries & 1)
-		        return -1;
+			return -1;
 		      else /* if (boundaries & 2) */
-		        return 0;
+			return 0;
 		    }
 
 		  cpos =
@@ -1972,7 +1978,7 @@ check_dst_limits_calc_pos_1 (const re_match_context_t *mctx, int boundaries,
 		  if (subexp_idx < BITSET_WORD_BITS)
 		    ent->eps_reachable_subexps_map
 		      &= ~((bitset_word_t) 1 << subexp_idx);
-	        }
+		}
 	      while (ent++->more);
 	    }
 	  break;
@@ -2114,7 +2120,7 @@ check_subexp_limits (const re_dfa_t *dfa, re_node_set *dest_nodes,
 }
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 sift_states_bkref (const re_match_context_t *mctx, re_sift_context_t *sctx,
 		   int str_idx, const re_node_set *candidates)
 {
@@ -2197,7 +2203,7 @@ sift_states_bkref (const re_match_context_t *mctx, re_sift_context_t *sctx,
 	  re_node_set_remove (&local_sctx.limits, enabled_idx);
 
 	  /* mctx->bkref_ents may have changed, reload the pointer.  */
-          entry = mctx->bkref_ents + enabled_idx;
+	  entry = mctx->bkref_ents + enabled_idx;
 	}
       while (enabled_idx++, entry++->more);
     }
@@ -2244,7 +2250,7 @@ sift_states_iter_mb (const re_match_context_t *mctx, re_sift_context_t *sctx,
    update the destination of STATE_LOG.  */
 
 static re_dfastate_t *
-internal_function
+internal_function __attribute_warn_unused_result__
 transit_state (reg_errcode_t *err, re_match_context_t *mctx,
 	       re_dfastate_t *state)
 {
@@ -2278,7 +2284,7 @@ transit_state (reg_errcode_t *err, re_match_context_t *mctx,
 
       trtable = state->word_trtable;
       if (BE (trtable != NULL, 1))
-        {
+	{
 	  unsigned int context;
 	  context
 	    = re_string_context_at (&mctx->input,
@@ -2324,21 +2330,21 @@ merge_state_with_log (reg_errcode_t *err, re_match_context_t *mctx,
       unsigned int context;
       re_node_set next_nodes, *log_nodes, *table_nodes = NULL;
       /* If (state_log[cur_idx] != 0), it implies that cur_idx is
-         the destination of a multibyte char/collating element/
-         back reference.  Then the next state is the union set of
-         these destinations and the results of the transition table.  */
+	 the destination of a multibyte char/collating element/
+	 back reference.  Then the next state is the union set of
+	 these destinations and the results of the transition table.  */
       pstate = mctx->state_log[cur_idx];
       log_nodes = pstate->entrance_nodes;
       if (next_state != NULL)
-        {
-          table_nodes = next_state->entrance_nodes;
-          *err = re_node_set_init_union (&next_nodes, table_nodes,
+	{
+	  table_nodes = next_state->entrance_nodes;
+	  *err = re_node_set_init_union (&next_nodes, table_nodes,
 					     log_nodes);
-          if (BE (*err != REG_NOERROR, 0))
+	  if (BE (*err != REG_NOERROR, 0))
 	    return NULL;
-        }
+	}
       else
-        next_nodes = *log_nodes;
+	next_nodes = *log_nodes;
       /* Note: We already add the nodes of the initial state,
 	 then we don't need to add them here.  */
 
@@ -2346,12 +2352,12 @@ merge_state_with_log (reg_errcode_t *err, re_match_context_t *mctx,
 				      re_string_cur_idx (&mctx->input) - 1,
 				      mctx->eflags);
       next_state = mctx->state_log[cur_idx]
-        = re_acquire_state_context (err, dfa, &next_nodes, context);
+	= re_acquire_state_context (err, dfa, &next_nodes, context);
       /* We don't need to check errors here, since the return value of
-         this function is next_state and ERR is already set.  */
+	 this function is next_state and ERR is already set.  */
 
       if (table_nodes != NULL)
-        re_node_set_free (&next_nodes);
+	re_node_set_free (&next_nodes);
     }
 
   if (BE (dfa->nbackref, 0) && next_state != NULL)
@@ -2392,9 +2398,9 @@ find_recover_state (reg_errcode_t *err, re_match_context_t *mctx)
 
       do
 	{
-          if (++cur_str_idx > max)
-            return NULL;
-          re_string_skip_bytes (&mctx->input, 1);
+	  if (++cur_str_idx > max)
+	    return NULL;
+	  re_string_skip_bytes (&mctx->input, 1);
 	}
       while (mctx->state_log[cur_str_idx] == NULL);
 
@@ -2501,7 +2507,7 @@ transit_state_mb (re_match_context_t *mctx, re_dfastate_t *pstate)
       re_dfastate_t *dest_state;
 
       if (!dfa->nodes[cur_node_idx].accept_mb)
-        continue;
+	continue;
 
       if (dfa->nodes[cur_node_idx].constraint)
 	{
@@ -2669,7 +2675,7 @@ transit_state_bkref (re_match_context_t *mctx, const re_node_set *nodes)
    delay these checking for prune_impossible_nodes().  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 get_subexp (re_match_context_t *mctx, int bkref_node, int bkref_str_idx)
 {
   const re_dfa_t *const dfa = mctx->dfa;
@@ -2682,7 +2688,7 @@ get_subexp (re_match_context_t *mctx, int bkref_node, int bkref_str_idx)
       const struct re_backref_cache_entry *entry
 	= mctx->bkref_ents + cache_idx;
       do
-        if (entry->node == bkref_node)
+	if (entry->node == bkref_node)
 	  return REG_NOERROR; /* We already checked it.  */
       while (entry++->more);
     }
@@ -2869,7 +2875,7 @@ find_subexp_node (const re_dfa_t *dfa, const re_node_set *nodes,
    Return REG_NOERROR if it can arrive, or REG_NOMATCH otherwise.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 check_arrival (re_match_context_t *mctx, state_array_t *path, int top_node,
 	       int top_str, int last_node, int last_str, int type)
 {
@@ -3030,7 +3036,7 @@ check_arrival (re_match_context_t *mctx, state_array_t *path, int top_node,
 	 Can't we unify them?  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 check_arrival_add_next_nodes (re_match_context_t *mctx, int str_idx,
 			      re_node_set *cur_nodes, re_node_set *next_nodes)
 {
@@ -3162,7 +3168,7 @@ check_arrival_expand_ecl (const re_dfa_t *dfa, re_node_set *cur_nodes,
    problematic append it to DST_NODES.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 check_arrival_expand_ecl_sub (const re_dfa_t *dfa, re_node_set *dst_nodes,
 			      int target, int ex_subexp, int type)
 {
@@ -3206,7 +3212,7 @@ check_arrival_expand_ecl_sub (const re_dfa_t *dfa, re_node_set *dst_nodes,
    in MCTX->BKREF_ENTS.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 expand_bkref_cache (re_match_context_t *mctx, re_node_set *cur_nodes,
 		    int cur_str, int subexp_num, int type)
 {
@@ -3564,13 +3570,13 @@ group_nodes_into_DFAstates (const re_dfa_t *dfa, const re_dfastate_t *state,
 	}
 #ifdef RE_ENABLE_I18N
       else if (type == OP_UTF8_PERIOD)
-        {
+	{
 	  memset (accepts, '\xff', sizeof (bitset_t) / 2);
 	  if (!(dfa->syntax & RE_DOT_NEWLINE))
 	    bitset_clear (accepts, '\n');
 	  if (dfa->syntax & RE_DOT_NOT_NULL)
 	    bitset_clear (accepts, '\0');
-        }
+	}
 #endif
       else
 	continue;
@@ -3775,7 +3781,7 @@ check_node_accept_bytes (const re_dfa_t *dfa, int node_idx,
   if (node->type == OP_PERIOD)
     {
       if (char_len <= 1)
-        return 0;
+	return 0;
       /* FIXME: I don't think this if is needed, as both '\n'
 	 and '\0' are char_len == 1.  */
       /* '.' accepts any one character except the following two cases.  */
@@ -4025,18 +4031,18 @@ check_node_accept (const re_match_context_t *mctx, const re_token_t *node,
     {
     case CHARACTER:
       if (node->opr.c != ch)
-        return 0;
+	return 0;
       break;
 
     case SIMPLE_BRACKET:
       if (!bitset_contain (node->opr.sbcset, ch))
-        return 0;
+	return 0;
       break;
 
 #ifdef RE_ENABLE_I18N
     case OP_UTF8_PERIOD:
       if (ch >= 0x80)
-        return 0;
+	return 0;
       /* FALLTHROUGH */
 #endif
     case OP_PERIOD:
@@ -4065,7 +4071,7 @@ check_node_accept (const re_match_context_t *mctx, const re_token_t *node,
 /* Extend the buffers, if the buffers have run out.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 extend_buffers (re_match_context_t *mctx)
 {
   reg_errcode_t ret;
@@ -4124,7 +4130,7 @@ extend_buffers (re_match_context_t *mctx)
 /* Initialize MCTX.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 match_ctx_init (re_match_context_t *mctx, int eflags, int n)
 {
   mctx->eflags = eflags;
@@ -4197,7 +4203,7 @@ match_ctx_free (re_match_context_t *mctx)
 */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 match_ctx_add_entry (re_match_context_t *mctx, int node, int str_idx, int from,
 		     int to)
 {
@@ -4269,7 +4275,7 @@ search_cur_bkref_entry (const re_match_context_t *mctx, int str_idx)
    at STR_IDX.  */
 
 static reg_errcode_t
-internal_function
+internal_function __attribute_warn_unused_result__
 match_ctx_add_subtop (re_match_context_t *mctx, int node, int str_idx)
 {
 #ifdef DEBUG