Add gcc-4.6. Synced to @180989

Change-Id: Ie3676586e1d8e3c8cd9f07d022f450d05fa08439
svn://gcc.gnu.org/svn/gcc/branches/google/gcc-4_6-mobile

1 files changed, 1586 insertions, 0 deletions

diff --git a/gcc-4.6/gcc/fortran/openmp.c b/gcc-4.6/gcc/fortran/openmp.c
new file mode 100644
index 000000000..2b70c69a9
--- /dev/null
+++ b/gcc-4.6/gcc/fortran/openmp.c
@@ -0,0 +1,1586 @@
+/* OpenMP directive matching and resolving.
+   Copyright (C) 2005, 2006, 2007, 2008, 2010
+   Free Software Foundation, Inc.
+   Contributed by Jakub Jelinek
+
+This file is part of GCC.
+
+GCC 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, or (at your option) any later
+version.
+
+GCC 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 GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "flags.h"
+#include "gfortran.h"
+#include "match.h"
+#include "parse.h"
+#include "pointer-set.h"
+
+/* Match an end of OpenMP directive.  End of OpenMP directive is optional
+   whitespace, followed by '\n' or comment '!'.  */
+
+match
+gfc_match_omp_eos (void)
+{
+  locus old_loc;
+  char c;
+
+  old_loc = gfc_current_locus;
+  gfc_gobble_whitespace ();
+
+  c = gfc_next_ascii_char ();
+  switch (c)
+    {
+    case '!':
+      do
+	c = gfc_next_ascii_char ();
+      while (c != '\n');
+      /* Fall through */
+
+    case '\n':
+      return MATCH_YES;
+    }
+
+  gfc_current_locus = old_loc;
+  return MATCH_NO;
+}
+
+/* Free an omp_clauses structure.  */
+
+void
+gfc_free_omp_clauses (gfc_omp_clauses *c)
+{
+  int i;
+  if (c == NULL)
+    return;
+
+  gfc_free_expr (c->if_expr);
+  gfc_free_expr (c->num_threads);
+  gfc_free_expr (c->chunk_size);
+  for (i = 0; i < OMP_LIST_NUM; i++)
+    gfc_free_namelist (c->lists[i]);
+  gfc_free (c);
+}
+
+/* Match a variable/common block list and construct a namelist from it.  */
+
+static match
+gfc_match_omp_variable_list (const char *str, gfc_namelist **list,
+			     bool allow_common)
+{
+  gfc_namelist *head, *tail, *p;
+  locus old_loc;
+  char n[GFC_MAX_SYMBOL_LEN+1];
+  gfc_symbol *sym;
+  match m;
+  gfc_symtree *st;
+
+  head = tail = NULL;
+
+  old_loc = gfc_current_locus;
+
+  m = gfc_match (str);
+  if (m != MATCH_YES)
+    return m;
+
+  for (;;)
+    {
+      m = gfc_match_symbol (&sym, 1);
+      switch (m)
+	{
+	case MATCH_YES:
+	  gfc_set_sym_referenced (sym);
+	  p = gfc_get_namelist ();
+	  if (head == NULL)
+	    head = tail = p;
+	  else
+	    {
+	      tail->next = p;
+	      tail = tail->next;
+	    }
+	  tail->sym = sym;
+	  goto next_item;
+	case MATCH_NO:
+	  break;
+	case MATCH_ERROR:
+	  goto cleanup;
+	}
+
+      if (!allow_common)
+	goto syntax;
+
+      m = gfc_match (" / %n /", n);
+      if (m == MATCH_ERROR)
+	goto cleanup;
+      if (m == MATCH_NO)
+	goto syntax;
+
+      st = gfc_find_symtree (gfc_current_ns->common_root, n);
+      if (st == NULL)
+	{
+	  gfc_error ("COMMON block /%s/ not found at %C", n);
+	  goto cleanup;
+	}
+      for (sym = st->n.common->head; sym; sym = sym->common_next)
+	{
+	  gfc_set_sym_referenced (sym);
+	  p = gfc_get_namelist ();
+	  if (head == NULL)
+	    head = tail = p;
+	  else
+	    {
+	      tail->next = p;
+	      tail = tail->next;
+	    }
+	  tail->sym = sym;
+	}
+
+    next_item:
+      if (gfc_match_char (')') == MATCH_YES)
+	break;
+      if (gfc_match_char (',') != MATCH_YES)
+	goto syntax;
+    }
+
+  while (*list)
+    list = &(*list)->next;
+
+  *list = head;
+  return MATCH_YES;
+
+syntax:
+  gfc_error ("Syntax error in OpenMP variable list at %C");
+
+cleanup:
+  gfc_free_namelist (head);
+  gfc_current_locus = old_loc;
+  return MATCH_ERROR;
+}
+
+#define OMP_CLAUSE_PRIVATE	(1 << 0)
+#define OMP_CLAUSE_FIRSTPRIVATE	(1 << 1)
+#define OMP_CLAUSE_LASTPRIVATE	(1 << 2)
+#define OMP_CLAUSE_COPYPRIVATE	(1 << 3)
+#define OMP_CLAUSE_SHARED	(1 << 4)
+#define OMP_CLAUSE_COPYIN	(1 << 5)
+#define OMP_CLAUSE_REDUCTION	(1 << 6)
+#define OMP_CLAUSE_IF		(1 << 7)
+#define OMP_CLAUSE_NUM_THREADS	(1 << 8)
+#define OMP_CLAUSE_SCHEDULE	(1 << 9)
+#define OMP_CLAUSE_DEFAULT	(1 << 10)
+#define OMP_CLAUSE_ORDERED	(1 << 11)
+#define OMP_CLAUSE_COLLAPSE	(1 << 12)
+#define OMP_CLAUSE_UNTIED	(1 << 13)
+
+/* Match OpenMP directive clauses. MASK is a bitmask of
+   clauses that are allowed for a particular directive.  */
+
+static match
+gfc_match_omp_clauses (gfc_omp_clauses **cp, int mask)
+{
+  gfc_omp_clauses *c = gfc_get_omp_clauses ();
+  locus old_loc;
+  bool needs_space = true, first = true;
+
+  *cp = NULL;
+  while (1)
+    {
+      if ((first || gfc_match_char (',') != MATCH_YES)
+	  && (needs_space && gfc_match_space () != MATCH_YES))
+	break;
+      needs_space = false;
+      first = false;
+      gfc_gobble_whitespace ();
+      if ((mask & OMP_CLAUSE_IF) && c->if_expr == NULL
+	  && gfc_match ("if ( %e )", &c->if_expr) == MATCH_YES)
+	continue;
+      if ((mask & OMP_CLAUSE_NUM_THREADS) && c->num_threads == NULL
+	  && gfc_match ("num_threads ( %e )", &c->num_threads) == MATCH_YES)
+	continue;
+      if ((mask & OMP_CLAUSE_PRIVATE)
+	  && gfc_match_omp_variable_list ("private (",
+					  &c->lists[OMP_LIST_PRIVATE], true)
+	     == MATCH_YES)
+	continue;
+      if ((mask & OMP_CLAUSE_FIRSTPRIVATE)
+	  && gfc_match_omp_variable_list ("firstprivate (",
+					  &c->lists[OMP_LIST_FIRSTPRIVATE],
+					  true)
+	     == MATCH_YES)
+	continue;
+      if ((mask & OMP_CLAUSE_LASTPRIVATE)
+	  && gfc_match_omp_variable_list ("lastprivate (",
+					  &c->lists[OMP_LIST_LASTPRIVATE],
+					  true)
+	     == MATCH_YES)
+	continue;
+      if ((mask & OMP_CLAUSE_COPYPRIVATE)
+	  && gfc_match_omp_variable_list ("copyprivate (",
+					  &c->lists[OMP_LIST_COPYPRIVATE],
+					  true)
+	     == MATCH_YES)
+	continue;
+      if ((mask & OMP_CLAUSE_SHARED)
+	  && gfc_match_omp_variable_list ("shared (",
+					  &c->lists[OMP_LIST_SHARED], true)
+	     == MATCH_YES)
+	continue;
+      if ((mask & OMP_CLAUSE_COPYIN)
+	  && gfc_match_omp_variable_list ("copyin (",
+					  &c->lists[OMP_LIST_COPYIN], true)
+	     == MATCH_YES)
+	continue;
+      old_loc = gfc_current_locus;
+      if ((mask & OMP_CLAUSE_REDUCTION)
+	  && gfc_match ("reduction ( ") == MATCH_YES)
+	{
+	  int reduction = OMP_LIST_NUM;
+	  char buffer[GFC_MAX_SYMBOL_LEN + 1];
+	  if (gfc_match_char ('+') == MATCH_YES)
+	    reduction = OMP_LIST_PLUS;
+	  else if (gfc_match_char ('*') == MATCH_YES)
+	    reduction = OMP_LIST_MULT;
+	  else if (gfc_match_char ('-') == MATCH_YES)
+	    reduction = OMP_LIST_SUB;
+	  else if (gfc_match (".and.") == MATCH_YES)
+	    reduction = OMP_LIST_AND;
+	  else if (gfc_match (".or.") == MATCH_YES)
+	    reduction = OMP_LIST_OR;
+	  else if (gfc_match (".eqv.") == MATCH_YES)
+	    reduction = OMP_LIST_EQV;
+	  else if (gfc_match (".neqv.") == MATCH_YES)
+	    reduction = OMP_LIST_NEQV;
+	  else if (gfc_match_name (buffer) == MATCH_YES)
+	    {
+	      gfc_symbol *sym;
+	      const char *n = buffer;
+
+	      gfc_find_symbol (buffer, NULL, 1, &sym);
+	      if (sym != NULL)
+		{
+		  if (sym->attr.intrinsic)
+		    n = sym->name;
+		  else if ((sym->attr.flavor != FL_UNKNOWN
+			    && sym->attr.flavor != FL_PROCEDURE)
+			   || sym->attr.external
+			   || sym->attr.generic
+			   || sym->attr.entry
+			   || sym->attr.result
+			   || sym->attr.dummy
+			   || sym->attr.subroutine
+			   || sym->attr.pointer
+			   || sym->attr.target
+			   || sym->attr.cray_pointer
+			   || sym->attr.cray_pointee
+			   || (sym->attr.proc != PROC_UNKNOWN
+			       && sym->attr.proc != PROC_INTRINSIC)
+			   || sym->attr.if_source != IFSRC_UNKNOWN
+			   || sym == sym->ns->proc_name)
+		    {
+		      gfc_error_now ("%s is not INTRINSIC procedure name "
+				     "at %C", buffer);
+		      sym = NULL;
+		    }
+		  else
+		    n = sym->name;
+		}
+	      if (strcmp (n, "max") == 0)
+		reduction = OMP_LIST_MAX;
+	      else if (strcmp (n, "min") == 0)
+		reduction = OMP_LIST_MIN;
+	      else if (strcmp (n, "iand") == 0)
+		reduction = OMP_LIST_IAND;
+	      else if (strcmp (n, "ior") == 0)
+		reduction = OMP_LIST_IOR;
+	      else if (strcmp (n, "ieor") == 0)
+		reduction = OMP_LIST_IEOR;
+	      if (reduction != OMP_LIST_NUM
+		  && sym != NULL
+		  && ! sym->attr.intrinsic
+		  && ! sym->attr.use_assoc
+		  && ((sym->attr.flavor == FL_UNKNOWN
+		       && gfc_add_flavor (&sym->attr, FL_PROCEDURE,
+					  sym->name, NULL) == FAILURE)
+		      || gfc_add_intrinsic (&sym->attr, NULL) == FAILURE))
+		{
+		  gfc_free_omp_clauses (c);
+		  return MATCH_ERROR;
+		}
+	    }
+	  if (reduction != OMP_LIST_NUM
+	      && gfc_match_omp_variable_list (" :", &c->lists[reduction],
+					      false)
+		 == MATCH_YES)
+	    continue;
+	  else
+	    gfc_current_locus = old_loc;
+	}
+      if ((mask & OMP_CLAUSE_DEFAULT)
+	  && c->default_sharing == OMP_DEFAULT_UNKNOWN)
+	{
+	  if (gfc_match ("default ( shared )") == MATCH_YES)
+	    c->default_sharing = OMP_DEFAULT_SHARED;
+	  else if (gfc_match ("default ( private )") == MATCH_YES)
+	    c->default_sharing = OMP_DEFAULT_PRIVATE;
+	  else if (gfc_match ("default ( none )") == MATCH_YES)
+	    c->default_sharing = OMP_DEFAULT_NONE;
+	  else if (gfc_match ("default ( firstprivate )") == MATCH_YES)
+	    c->default_sharing = OMP_DEFAULT_FIRSTPRIVATE;
+	  if (c->default_sharing != OMP_DEFAULT_UNKNOWN)
+	    continue;
+	}
+      old_loc = gfc_current_locus;
+      if ((mask & OMP_CLAUSE_SCHEDULE)
+	  && c->sched_kind == OMP_SCHED_NONE
+	  && gfc_match ("schedule ( ") == MATCH_YES)
+	{
+	  if (gfc_match ("static") == MATCH_YES)
+	    c->sched_kind = OMP_SCHED_STATIC;
+	  else if (gfc_match ("dynamic") == MATCH_YES)
+	    c->sched_kind = OMP_SCHED_DYNAMIC;
+	  else if (gfc_match ("guided") == MATCH_YES)
+	    c->sched_kind = OMP_SCHED_GUIDED;
+	  else if (gfc_match ("runtime") == MATCH_YES)
+	    c->sched_kind = OMP_SCHED_RUNTIME;
+	  else if (gfc_match ("auto") == MATCH_YES)
+	    c->sched_kind = OMP_SCHED_AUTO;
+	  if (c->sched_kind != OMP_SCHED_NONE)
+	    {
+	      match m = MATCH_NO;
+	      if (c->sched_kind != OMP_SCHED_RUNTIME
+		  && c->sched_kind != OMP_SCHED_AUTO)
+		m = gfc_match (" , %e )", &c->chunk_size);
+	      if (m != MATCH_YES)
+		m = gfc_match_char (')');
+	      if (m != MATCH_YES)
+		c->sched_kind = OMP_SCHED_NONE;
+	    }
+	  if (c->sched_kind != OMP_SCHED_NONE)
+	    continue;
+	  else
+	    gfc_current_locus = old_loc;
+	}
+      if ((mask & OMP_CLAUSE_ORDERED) && !c->ordered
+	  && gfc_match ("ordered") == MATCH_YES)
+	{
+	  c->ordered = needs_space = true;
+	  continue;
+	}
+      if ((mask & OMP_CLAUSE_UNTIED) && !c->untied
+	  && gfc_match ("untied") == MATCH_YES)
+	{
+	  c->untied = needs_space = true;
+	  continue;
+	}
+      if ((mask & OMP_CLAUSE_COLLAPSE) && !c->collapse)
+	{
+	  gfc_expr *cexpr = NULL;
+	  match m = gfc_match ("collapse ( %e )", &cexpr);
+
+	  if (m == MATCH_YES)
+	    {
+	      int collapse;
+	      const char *p = gfc_extract_int (cexpr, &collapse);
+	      if (p)
+		{
+		  gfc_error_now (p);
+		  collapse = 1;
+		}
+	      else if (collapse <= 0)
+		{
+		  gfc_error_now ("COLLAPSE clause argument not"
+				 " constant positive integer at %C");
+		  collapse = 1;
+		}
+	      c->collapse = collapse;
+	      gfc_free_expr (cexpr);
+	      continue;
+	    }
+	}
+
+      break;
+    }
+
+  if (gfc_match_omp_eos () != MATCH_YES)
+    {
+      gfc_free_omp_clauses (c);
+      return MATCH_ERROR;
+    }
+
+  *cp = c;
+  return MATCH_YES;
+}
+
+#define OMP_PARALLEL_CLAUSES \
+  (OMP_CLAUSE_PRIVATE | OMP_CLAUSE_FIRSTPRIVATE | OMP_CLAUSE_SHARED	\
+   | OMP_CLAUSE_COPYIN | OMP_CLAUSE_REDUCTION | OMP_CLAUSE_IF		\
+   | OMP_CLAUSE_NUM_THREADS | OMP_CLAUSE_DEFAULT)
+#define OMP_DO_CLAUSES \
+  (OMP_CLAUSE_PRIVATE | OMP_CLAUSE_FIRSTPRIVATE				\
+   | OMP_CLAUSE_LASTPRIVATE | OMP_CLAUSE_REDUCTION			\
+   | OMP_CLAUSE_SCHEDULE | OMP_CLAUSE_ORDERED | OMP_CLAUSE_COLLAPSE)
+#define OMP_SECTIONS_CLAUSES \
+  (OMP_CLAUSE_PRIVATE | OMP_CLAUSE_FIRSTPRIVATE				\
+   | OMP_CLAUSE_LASTPRIVATE | OMP_CLAUSE_REDUCTION)
+#define OMP_TASK_CLAUSES \
+  (OMP_CLAUSE_PRIVATE | OMP_CLAUSE_FIRSTPRIVATE | OMP_CLAUSE_SHARED	\
+   | OMP_CLAUSE_IF | OMP_CLAUSE_DEFAULT | OMP_CLAUSE_UNTIED)
+
+match
+gfc_match_omp_parallel (void)
+{
+  gfc_omp_clauses *c;
+  if (gfc_match_omp_clauses (&c, OMP_PARALLEL_CLAUSES) != MATCH_YES)
+    return MATCH_ERROR;
+  new_st.op = EXEC_OMP_PARALLEL;
+  new_st.ext.omp_clauses = c;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_task (void)
+{
+  gfc_omp_clauses *c;
+  if (gfc_match_omp_clauses (&c, OMP_TASK_CLAUSES) != MATCH_YES)
+    return MATCH_ERROR;
+  new_st.op = EXEC_OMP_TASK;
+  new_st.ext.omp_clauses = c;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_taskwait (void)
+{
+  if (gfc_match_omp_eos () != MATCH_YES)
+    {
+      gfc_error ("Unexpected junk after TASKWAIT clause at %C");
+      return MATCH_ERROR;
+    }
+  new_st.op = EXEC_OMP_TASKWAIT;
+  new_st.ext.omp_clauses = NULL;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_critical (void)
+{
+  char n[GFC_MAX_SYMBOL_LEN+1];
+
+  if (gfc_match (" ( %n )", n) != MATCH_YES)
+    n[0] = '\0';
+  if (gfc_match_omp_eos () != MATCH_YES)
+    {
+      gfc_error ("Unexpected junk after $OMP CRITICAL statement at %C");
+      return MATCH_ERROR;
+    }
+  new_st.op = EXEC_OMP_CRITICAL;
+  new_st.ext.omp_name = n[0] ? xstrdup (n) : NULL;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_do (void)
+{
+  gfc_omp_clauses *c;
+  if (gfc_match_omp_clauses (&c, OMP_DO_CLAUSES) != MATCH_YES)
+    return MATCH_ERROR;
+  new_st.op = EXEC_OMP_DO;
+  new_st.ext.omp_clauses = c;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_flush (void)
+{
+  gfc_namelist *list = NULL;
+  gfc_match_omp_variable_list (" (", &list, true);
+  if (gfc_match_omp_eos () != MATCH_YES)
+    {
+      gfc_error ("Unexpected junk after $OMP FLUSH statement at %C");
+      gfc_free_namelist (list);
+      return MATCH_ERROR;
+    }
+  new_st.op = EXEC_OMP_FLUSH;
+  new_st.ext.omp_namelist = list;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_threadprivate (void)
+{
+  locus old_loc;
+  char n[GFC_MAX_SYMBOL_LEN+1];
+  gfc_symbol *sym;
+  match m;
+  gfc_symtree *st;
+
+  old_loc = gfc_current_locus;
+
+  m = gfc_match (" (");
+  if (m != MATCH_YES)
+    return m;
+
+  for (;;)
+    {
+      m = gfc_match_symbol (&sym, 0);
+      switch (m)
+	{
+	case MATCH_YES:
+	  if (sym->attr.in_common)
+	    gfc_error_now ("Threadprivate variable at %C is an element of "
+			   "a COMMON block");
+	  else if (gfc_add_threadprivate (&sym->attr, sym->name,
+		   &sym->declared_at) == FAILURE)
+	    goto cleanup;
+	  goto next_item;
+	case MATCH_NO:
+	  break;
+	case MATCH_ERROR:
+	  goto cleanup;
+	}
+
+      m = gfc_match (" / %n /", n);
+      if (m == MATCH_ERROR)
+	goto cleanup;
+      if (m == MATCH_NO || n[0] == '\0')
+	goto syntax;
+
+      st = gfc_find_symtree (gfc_current_ns->common_root, n);
+      if (st == NULL)
+	{
+	  gfc_error ("COMMON block /%s/ not found at %C", n);
+	  goto cleanup;
+	}
+      st->n.common->threadprivate = 1;
+      for (sym = st->n.common->head; sym; sym = sym->common_next)
+	if (gfc_add_threadprivate (&sym->attr, sym->name,
+				   &sym->declared_at) == FAILURE)
+	  goto cleanup;
+
+    next_item:
+      if (gfc_match_char (')') == MATCH_YES)
+	break;
+      if (gfc_match_char (',') != MATCH_YES)
+	goto syntax;
+    }
+
+  return MATCH_YES;
+
+syntax:
+  gfc_error ("Syntax error in !$OMP THREADPRIVATE list at %C");
+
+cleanup:
+  gfc_current_locus = old_loc;
+  return MATCH_ERROR;
+}
+
+
+match
+gfc_match_omp_parallel_do (void)
+{
+  gfc_omp_clauses *c;
+  if (gfc_match_omp_clauses (&c, OMP_PARALLEL_CLAUSES | OMP_DO_CLAUSES)
+      != MATCH_YES)
+    return MATCH_ERROR;
+  new_st.op = EXEC_OMP_PARALLEL_DO;
+  new_st.ext.omp_clauses = c;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_parallel_sections (void)
+{
+  gfc_omp_clauses *c;
+  if (gfc_match_omp_clauses (&c, OMP_PARALLEL_CLAUSES | OMP_SECTIONS_CLAUSES)
+      != MATCH_YES)
+    return MATCH_ERROR;
+  new_st.op = EXEC_OMP_PARALLEL_SECTIONS;
+  new_st.ext.omp_clauses = c;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_parallel_workshare (void)
+{
+  gfc_omp_clauses *c;
+  if (gfc_match_omp_clauses (&c, OMP_PARALLEL_CLAUSES) != MATCH_YES)
+    return MATCH_ERROR;
+  new_st.op = EXEC_OMP_PARALLEL_WORKSHARE;
+  new_st.ext.omp_clauses = c;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_sections (void)
+{
+  gfc_omp_clauses *c;
+  if (gfc_match_omp_clauses (&c, OMP_SECTIONS_CLAUSES) != MATCH_YES)
+    return MATCH_ERROR;
+  new_st.op = EXEC_OMP_SECTIONS;
+  new_st.ext.omp_clauses = c;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_single (void)
+{
+  gfc_omp_clauses *c;
+  if (gfc_match_omp_clauses (&c, OMP_CLAUSE_PRIVATE | OMP_CLAUSE_FIRSTPRIVATE)
+      != MATCH_YES)
+    return MATCH_ERROR;
+  new_st.op = EXEC_OMP_SINGLE;
+  new_st.ext.omp_clauses = c;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_workshare (void)
+{
+  if (gfc_match_omp_eos () != MATCH_YES)
+    {
+      gfc_error ("Unexpected junk after $OMP WORKSHARE statement at %C");
+      return MATCH_ERROR;
+    }
+  new_st.op = EXEC_OMP_WORKSHARE;
+  new_st.ext.omp_clauses = gfc_get_omp_clauses ();
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_master (void)
+{
+  if (gfc_match_omp_eos () != MATCH_YES)
+    {
+      gfc_error ("Unexpected junk after $OMP MASTER statement at %C");
+      return MATCH_ERROR;
+    }
+  new_st.op = EXEC_OMP_MASTER;
+  new_st.ext.omp_clauses = NULL;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_ordered (void)
+{
+  if (gfc_match_omp_eos () != MATCH_YES)
+    {
+      gfc_error ("Unexpected junk after $OMP ORDERED statement at %C");
+      return MATCH_ERROR;
+    }
+  new_st.op = EXEC_OMP_ORDERED;
+  new_st.ext.omp_clauses = NULL;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_atomic (void)
+{
+  if (gfc_match_omp_eos () != MATCH_YES)
+    {
+      gfc_error ("Unexpected junk after $OMP ATOMIC statement at %C");
+      return MATCH_ERROR;
+    }
+  new_st.op = EXEC_OMP_ATOMIC;
+  new_st.ext.omp_clauses = NULL;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_barrier (void)
+{
+  if (gfc_match_omp_eos () != MATCH_YES)
+    {
+      gfc_error ("Unexpected junk after $OMP BARRIER statement at %C");
+      return MATCH_ERROR;
+    }
+  new_st.op = EXEC_OMP_BARRIER;
+  new_st.ext.omp_clauses = NULL;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_end_nowait (void)
+{
+  bool nowait = false;
+  if (gfc_match ("% nowait") == MATCH_YES)
+    nowait = true;
+  if (gfc_match_omp_eos () != MATCH_YES)
+    {
+      gfc_error ("Unexpected junk after NOWAIT clause at %C");
+      return MATCH_ERROR;
+    }
+  new_st.op = EXEC_OMP_END_NOWAIT;
+  new_st.ext.omp_bool = nowait;
+  return MATCH_YES;
+}
+
+
+match
+gfc_match_omp_end_single (void)
+{
+  gfc_omp_clauses *c;
+  if (gfc_match ("% nowait") == MATCH_YES)
+    {
+      new_st.op = EXEC_OMP_END_NOWAIT;
+      new_st.ext.omp_bool = true;
+      return MATCH_YES;
+    }
+  if (gfc_match_omp_clauses (&c, OMP_CLAUSE_COPYPRIVATE) != MATCH_YES)
+    return MATCH_ERROR;
+  new_st.op = EXEC_OMP_END_SINGLE;
+  new_st.ext.omp_clauses = c;
+  return MATCH_YES;
+}
+
+
+/* OpenMP directive resolving routines.  */
+
+static void
+resolve_omp_clauses (gfc_code *code)
+{
+  gfc_omp_clauses *omp_clauses = code->ext.omp_clauses;
+  gfc_namelist *n;
+  int list;
+  static const char *clause_names[]
+    = { "PRIVATE", "FIRSTPRIVATE", "LASTPRIVATE", "COPYPRIVATE", "SHARED",
+	"COPYIN", "REDUCTION" };
+
+  if (omp_clauses == NULL)
+    return;
+
+  if (omp_clauses->if_expr)
+    {
+      gfc_expr *expr = omp_clauses->if_expr;
+      if (gfc_resolve_expr (expr) == FAILURE
+	  || expr->ts.type != BT_LOGICAL || expr->rank != 0)
+	gfc_error ("IF clause at %L requires a scalar LOGICAL expression",
+		   &expr->where);
+    }
+  if (omp_clauses->num_threads)
+    {
+      gfc_expr *expr = omp_clauses->num_threads;
+      if (gfc_resolve_expr (expr) == FAILURE
+	  || expr->ts.type != BT_INTEGER || expr->rank != 0)
+	gfc_error ("NUM_THREADS clause at %L requires a scalar "
+		   "INTEGER expression", &expr->where);
+    }
+  if (omp_clauses->chunk_size)
+    {
+      gfc_expr *expr = omp_clauses->chunk_size;
+      if (gfc_resolve_expr (expr) == FAILURE
+	  || expr->ts.type != BT_INTEGER || expr->rank != 0)
+	gfc_error ("SCHEDULE clause's chunk_size at %L requires "
+		   "a scalar INTEGER expression", &expr->where);
+    }
+
+  /* Check that no symbol appears on multiple clauses, except that
+     a symbol can appear on both firstprivate and lastprivate.  */
+  for (list = 0; list < OMP_LIST_NUM; list++)
+    for (n = omp_clauses->lists[list]; n; n = n->next)
+      {
+	n->sym->mark = 0;
+	if (n->sym->attr.flavor == FL_VARIABLE)
+	  continue;
+	if (n->sym->attr.flavor == FL_PROCEDURE
+	    && n->sym->result == n->sym
+	    && n->sym->attr.function)
+	  {
+	    if (gfc_current_ns->proc_name == n->sym
+		|| (gfc_current_ns->parent
+		    && gfc_current_ns->parent->proc_name == n->sym))
+	      continue;
+	    if (gfc_current_ns->proc_name->attr.entry_master)
+	      {
+		gfc_entry_list *el = gfc_current_ns->entries;
+		for (; el; el = el->next)
+		  if (el->sym == n->sym)
+		    break;
+		if (el)
+		  continue;
+	      }
+	    if (gfc_current_ns->parent
+		&& gfc_current_ns->parent->proc_name->attr.entry_master)
+	      {
+		gfc_entry_list *el = gfc_current_ns->parent->entries;
+		for (; el; el = el->next)
+		  if (el->sym == n->sym)
+		    break;
+		if (el)
+		  continue;
+	      }
+	    if (n->sym->attr.proc_pointer)
+	      continue;
+	  }
+	gfc_error ("Object '%s' is not a variable at %L", n->sym->name,
+		   &code->loc);
+      }
+
+  for (list = 0; list < OMP_LIST_NUM; list++)
+    if (list != OMP_LIST_FIRSTPRIVATE && list != OMP_LIST_LASTPRIVATE)
+      for (n = omp_clauses->lists[list]; n; n = n->next)
+	{
+	  if (n->sym->mark)
+	    gfc_error ("Symbol '%s' present on multiple clauses at %L",
+		       n->sym->name, &code->loc);
+	  else
+	    n->sym->mark = 1;
+	}
+
+  gcc_assert (OMP_LIST_LASTPRIVATE == OMP_LIST_FIRSTPRIVATE + 1);
+  for (list = OMP_LIST_FIRSTPRIVATE; list <= OMP_LIST_LASTPRIVATE; list++)
+    for (n = omp_clauses->lists[list]; n; n = n->next)
+      if (n->sym->mark)
+	{
+	  gfc_error ("Symbol '%s' present on multiple clauses at %L",
+		     n->sym->name, &code->loc);
+	  n->sym->mark = 0;
+	}
+
+  for (n = omp_clauses->lists[OMP_LIST_FIRSTPRIVATE]; n; n = n->next)
+    {
+      if (n->sym->mark)
+	gfc_error ("Symbol '%s' present on multiple clauses at %L",
+		   n->sym->name, &code->loc);
+      else
+	n->sym->mark = 1;
+    }
+  for (n = omp_clauses->lists[OMP_LIST_LASTPRIVATE]; n; n = n->next)
+    n->sym->mark = 0;
+
+  for (n = omp_clauses->lists[OMP_LIST_LASTPRIVATE]; n; n = n->next)
+    {
+      if (n->sym->mark)
+	gfc_error ("Symbol '%s' present on multiple clauses at %L",
+		   n->sym->name, &code->loc);
+      else
+	n->sym->mark = 1;
+    }
+  for (list = 0; list < OMP_LIST_NUM; list++)
+    if ((n = omp_clauses->lists[list]) != NULL)
+      {
+	const char *name;
+
+	if (list < OMP_LIST_REDUCTION_FIRST)
+	  name = clause_names[list];
+	else if (list <= OMP_LIST_REDUCTION_LAST)
+	  name = clause_names[OMP_LIST_REDUCTION_FIRST];
+	else
+	  gcc_unreachable ();
+
+	switch (list)
+	  {
+	  case OMP_LIST_COPYIN:
+	    for (; n != NULL; n = n->next)
+	      {
+		if (!n->sym->attr.threadprivate)
+		  gfc_error ("Non-THREADPRIVATE object '%s' in COPYIN clause"
+			     " at %L", n->sym->name, &code->loc);
+		if (n->sym->ts.type == BT_DERIVED && n->sym->ts.u.derived->attr.alloc_comp)
+		  gfc_error ("COPYIN clause object '%s' at %L has ALLOCATABLE components",
+			     n->sym->name, &code->loc);
+	      }
+	    break;
+	  case OMP_LIST_COPYPRIVATE:
+	    for (; n != NULL; n = n->next)
+	      {
+		if (n->sym->as && n->sym->as->type == AS_ASSUMED_SIZE)
+		  gfc_error ("Assumed size array '%s' in COPYPRIVATE clause "
+			     "at %L", n->sym->name, &code->loc);
+		if (n->sym->ts.type == BT_DERIVED && n->sym->ts.u.derived->attr.alloc_comp)
+		  gfc_error ("COPYPRIVATE clause object '%s' at %L has ALLOCATABLE components",
+			     n->sym->name, &code->loc);
+	      }
+	    break;
+	  case OMP_LIST_SHARED:
+	    for (; n != NULL; n = n->next)
+	      {
+		if (n->sym->attr.threadprivate)
+		  gfc_error ("THREADPRIVATE object '%s' in SHARED clause at "
+			     "%L", n->sym->name, &code->loc);
+		if (n->sym->attr.cray_pointee)
+		  gfc_error ("Cray pointee '%s' in SHARED clause at %L",
+			    n->sym->name, &code->loc);
+	      }
+	    break;
+	  default:
+	    for (; n != NULL; n = n->next)
+	      {
+		if (n->sym->attr.threadprivate)
+		  gfc_error ("THREADPRIVATE object '%s' in %s clause at %L",
+			     n->sym->name, name, &code->loc);
+		if (n->sym->attr.cray_pointee)
+		  gfc_error ("Cray pointee '%s' in %s clause at %L",
+			    n->sym->name, name, &code->loc);
+		if (list != OMP_LIST_PRIVATE)
+		  {
+		    if (n->sym->attr.pointer)
+		      gfc_error ("POINTER object '%s' in %s clause at %L",
+				 n->sym->name, name, &code->loc);
+		    /* Variables in REDUCTION-clauses must be of intrinsic type (flagged below).  */
+		    if ((list < OMP_LIST_REDUCTION_FIRST || list > OMP_LIST_REDUCTION_LAST) &&
+		        n->sym->ts.type == BT_DERIVED && n->sym->ts.u.derived->attr.alloc_comp)
+		      gfc_error ("%s clause object '%s' has ALLOCATABLE components at %L",
+				 name, n->sym->name, &code->loc);
+		    if (n->sym->attr.cray_pointer)
+		      gfc_error ("Cray pointer '%s' in %s clause at %L",
+				 n->sym->name, name, &code->loc);
+		  }
+		if (n->sym->as && n->sym->as->type == AS_ASSUMED_SIZE)
+		  gfc_error ("Assumed size array '%s' in %s clause at %L",
+			     n->sym->name, name, &code->loc);
+		if (n->sym->attr.in_namelist
+		    && (list < OMP_LIST_REDUCTION_FIRST
+			|| list > OMP_LIST_REDUCTION_LAST))
+		  gfc_error ("Variable '%s' in %s clause is used in "
+			     "NAMELIST statement at %L",
+			     n->sym->name, name, &code->loc);
+		switch (list)
+		  {
+		  case OMP_LIST_PLUS:
+		  case OMP_LIST_MULT:
+		  case OMP_LIST_SUB:
+		    if (!gfc_numeric_ts (&n->sym->ts))
+		      gfc_error ("%c REDUCTION variable '%s' at %L must be of numeric type, got %s",
+				 list == OMP_LIST_PLUS ? '+'
+				 : list == OMP_LIST_MULT ? '*' : '-',
+				 n->sym->name, &code->loc,
+				 gfc_typename (&n->sym->ts));
+		    break;
+		  case OMP_LIST_AND:
+		  case OMP_LIST_OR:
+		  case OMP_LIST_EQV:
+		  case OMP_LIST_NEQV:
+		    if (n->sym->ts.type != BT_LOGICAL)
+		      gfc_error ("%s REDUCTION variable '%s' must be LOGICAL "
+				 "at %L",
+				 list == OMP_LIST_AND ? ".AND."
+				 : list == OMP_LIST_OR ? ".OR."
+				 : list == OMP_LIST_EQV ? ".EQV." : ".NEQV.",
+				 n->sym->name, &code->loc);
+		    break;
+		  case OMP_LIST_MAX:
+		  case OMP_LIST_MIN:
+		    if (n->sym->ts.type != BT_INTEGER
+			&& n->sym->ts.type != BT_REAL)
+		      gfc_error ("%s REDUCTION variable '%s' must be "
+				 "INTEGER or REAL at %L",
+				 list == OMP_LIST_MAX ? "MAX" : "MIN",
+				 n->sym->name, &code->loc);
+		    break;
+		  case OMP_LIST_IAND:
+		  case OMP_LIST_IOR:
+		  case OMP_LIST_IEOR:
+		    if (n->sym->ts.type != BT_INTEGER)
+		      gfc_error ("%s REDUCTION variable '%s' must be INTEGER "
+				 "at %L",
+				 list == OMP_LIST_IAND ? "IAND"
+				 : list == OMP_LIST_MULT ? "IOR" : "IEOR",
+				 n->sym->name, &code->loc);
+		    break;
+		  /* Workaround for PR middle-end/26316, nothing really needs
+		     to be done here for OMP_LIST_PRIVATE.  */
+		  case OMP_LIST_PRIVATE:
+		    gcc_assert (code->op != EXEC_NOP);
+		  default:
+		    break;
+		  }
+	      }
+	    break;
+	  }
+      }
+}
+
+
+/* Return true if SYM is ever referenced in EXPR except in the SE node.  */
+
+static bool
+expr_references_sym (gfc_expr *e, gfc_symbol *s, gfc_expr *se)
+{
+  gfc_actual_arglist *arg;
+  if (e == NULL || e == se)
+    return false;
+  switch (e->expr_type)
+    {
+    case EXPR_CONSTANT:
+    case EXPR_NULL:
+    case EXPR_VARIABLE:
+    case EXPR_STRUCTURE:
+    case EXPR_ARRAY:
+      if (e->symtree != NULL
+	  && e->symtree->n.sym == s)
+	return true;
+      return false;
+    case EXPR_SUBSTRING:
+      if (e->ref != NULL
+	  && (expr_references_sym (e->ref->u.ss.start, s, se)
+	      || expr_references_sym (e->ref->u.ss.end, s, se)))
+	return true;
+      return false;
+    case EXPR_OP:
+      if (expr_references_sym (e->value.op.op2, s, se))
+	return true;
+      return expr_references_sym (e->value.op.op1, s, se);
+    case EXPR_FUNCTION:
+      for (arg = e->value.function.actual; arg; arg = arg->next)
+	if (expr_references_sym (arg->expr, s, se))
+	  return true;
+      return false;
+    default:
+      gcc_unreachable ();
+    }
+}
+
+
+/* If EXPR is a conversion function that widens the type
+   if WIDENING is true or narrows the type if WIDENING is false,
+   return the inner expression, otherwise return NULL.  */
+
+static gfc_expr *
+is_conversion (gfc_expr *expr, bool widening)
+{
+  gfc_typespec *ts1, *ts2;
+
+  if (expr->expr_type != EXPR_FUNCTION
+      || expr->value.function.isym == NULL
+      || expr->value.function.esym != NULL
+      || expr->value.function.isym->id != GFC_ISYM_CONVERSION)
+    return NULL;
+
+  if (widening)
+    {
+      ts1 = &expr->ts;
+      ts2 = &expr->value.function.actual->expr->ts;
+    }
+  else
+    {
+      ts1 = &expr->value.function.actual->expr->ts;
+      ts2 = &expr->ts;
+    }
+
+  if (ts1->type > ts2->type
+      || (ts1->type == ts2->type && ts1->kind > ts2->kind))
+    return expr->value.function.actual->expr;
+
+  return NULL;
+}
+
+
+static void
+resolve_omp_atomic (gfc_code *code)
+{
+  gfc_symbol *var;
+  gfc_expr *expr2;
+
+  code = code->block->next;
+  gcc_assert (code->op == EXEC_ASSIGN);
+  gcc_assert (code->next == NULL);
+
+  if (code->expr1->expr_type != EXPR_VARIABLE
+      || code->expr1->symtree == NULL
+      || code->expr1->rank != 0
+      || (code->expr1->ts.type != BT_INTEGER
+	  && code->expr1->ts.type != BT_REAL
+	  && code->expr1->ts.type != BT_COMPLEX
+	  && code->expr1->ts.type != BT_LOGICAL))
+    {
+      gfc_error ("!$OMP ATOMIC statement must set a scalar variable of "
+		 "intrinsic type at %L", &code->loc);
+      return;
+    }
+
+  var = code->expr1->symtree->n.sym;
+  expr2 = is_conversion (code->expr2, false);
+  if (expr2 == NULL)
+    expr2 = code->expr2;
+
+  if (expr2->expr_type == EXPR_OP)
+    {
+      gfc_expr *v = NULL, *e, *c;
+      gfc_intrinsic_op op = expr2->value.op.op;
+      gfc_intrinsic_op alt_op = INTRINSIC_NONE;
+
+      switch (op)
+	{
+	case INTRINSIC_PLUS:
+	  alt_op = INTRINSIC_MINUS;
+	  break;
+	case INTRINSIC_TIMES:
+	  alt_op = INTRINSIC_DIVIDE;
+	  break;
+	case INTRINSIC_MINUS:
+	  alt_op = INTRINSIC_PLUS;
+	  break;
+	case INTRINSIC_DIVIDE:
+	  alt_op = INTRINSIC_TIMES;
+	  break;
+	case INTRINSIC_AND:
+	case INTRINSIC_OR:
+	  break;
+	case INTRINSIC_EQV:
+	  alt_op = INTRINSIC_NEQV;
+	  break;
+	case INTRINSIC_NEQV:
+	  alt_op = INTRINSIC_EQV;
+	  break;
+	default:
+	  gfc_error ("!$OMP ATOMIC assignment operator must be "
+		     "+, *, -, /, .AND., .OR., .EQV. or .NEQV. at %L",
+		     &expr2->where);
+	  return;
+	}
+
+      /* Check for var = var op expr resp. var = expr op var where
+	 expr doesn't reference var and var op expr is mathematically
+	 equivalent to var op (expr) resp. expr op var equivalent to
+	 (expr) op var.  We rely here on the fact that the matcher
+	 for x op1 y op2 z where op1 and op2 have equal precedence
+	 returns (x op1 y) op2 z.  */
+      e = expr2->value.op.op2;
+      if (e->expr_type == EXPR_VARIABLE
+	  && e->symtree != NULL
+	  && e->symtree->n.sym == var)
+	v = e;
+      else if ((c = is_conversion (e, true)) != NULL
+	       && c->expr_type == EXPR_VARIABLE
+	       && c->symtree != NULL
+	       && c->symtree->n.sym == var)
+	v = c;
+      else
+	{
+	  gfc_expr **p = NULL, **q;
+	  for (q = &expr2->value.op.op1; (e = *q) != NULL; )
+	    if (e->expr_type == EXPR_VARIABLE
+		&& e->symtree != NULL
+		&& e->symtree->n.sym == var)
+	      {
+		v = e;
+		break;
+	      }
+	    else if ((c = is_conversion (e, true)) != NULL)
+	      q = &e->value.function.actual->expr;
+	    else if (e->expr_type != EXPR_OP
+		     || (e->value.op.op != op
+			 && e->value.op.op != alt_op)
+		     || e->rank != 0)
+	      break;
+	    else
+	      {
+		p = q;
+		q = &e->value.op.op1;
+	      }
+
+	  if (v == NULL)
+	    {
+	      gfc_error ("!$OMP ATOMIC assignment must be var = var op expr "
+			 "or var = expr op var at %L", &expr2->where);
+	      return;
+	    }
+
+	  if (p != NULL)
+	    {
+	      e = *p;
+	      switch (e->value.op.op)
+		{
+		case INTRINSIC_MINUS:
+		case INTRINSIC_DIVIDE:
+		case INTRINSIC_EQV:
+		case INTRINSIC_NEQV:
+		  gfc_error ("!$OMP ATOMIC var = var op expr not "
+			     "mathematically equivalent to var = var op "
+			     "(expr) at %L", &expr2->where);
+		  break;
+		default:
+		  break;
+		}
+
+	      /* Canonicalize into var = var op (expr).  */
+	      *p = e->value.op.op2;
+	      e->value.op.op2 = expr2;
+	      e->ts = expr2->ts;
+	      if (code->expr2 == expr2)
+		code->expr2 = expr2 = e;
+	      else
+		code->expr2->value.function.actual->expr = expr2 = e;
+
+	      if (!gfc_compare_types (&expr2->value.op.op1->ts, &expr2->ts))
+		{
+		  for (p = &expr2->value.op.op1; *p != v;
+		       p = &(*p)->value.function.actual->expr)
+		    ;
+		  *p = NULL;
+		  gfc_free_expr (expr2->value.op.op1);
+		  expr2->value.op.op1 = v;
+		  gfc_convert_type (v, &expr2->ts, 2);
+		}
+	    }
+	}
+
+      if (e->rank != 0 || expr_references_sym (code->expr2, var, v))
+	{
+	  gfc_error ("expr in !$OMP ATOMIC assignment var = var op expr "
+		     "must be scalar and cannot reference var at %L",
+		     &expr2->where);
+	  return;
+	}
+    }
+  else if (expr2->expr_type == EXPR_FUNCTION
+	   && expr2->value.function.isym != NULL
+	   && expr2->value.function.esym == NULL
+	   && expr2->value.function.actual != NULL
+	   && expr2->value.function.actual->next != NULL)
+    {
+      gfc_actual_arglist *arg, *var_arg;
+
+      switch (expr2->value.function.isym->id)
+	{
+	case GFC_ISYM_MIN:
+	case GFC_ISYM_MAX:
+	  break;
+	case GFC_ISYM_IAND:
+	case GFC_ISYM_IOR:
+	case GFC_ISYM_IEOR:
+	  if (expr2->value.function.actual->next->next != NULL)
+	    {
+	      gfc_error ("!$OMP ATOMIC assignment intrinsic IAND, IOR "
+			 "or IEOR must have two arguments at %L",
+			 &expr2->where);
+	      return;
+	    }
+	  break;
+	default:
+	  gfc_error ("!$OMP ATOMIC assignment intrinsic must be "
+		     "MIN, MAX, IAND, IOR or IEOR at %L",
+		     &expr2->where);
+	  return;
+	}
+
+      var_arg = NULL;
+      for (arg = expr2->value.function.actual; arg; arg = arg->next)
+	{
+	  if ((arg == expr2->value.function.actual
+	       || (var_arg == NULL && arg->next == NULL))
+	      && arg->expr->expr_type == EXPR_VARIABLE
+	      && arg->expr->symtree != NULL
+	      && arg->expr->symtree->n.sym == var)
+	    var_arg = arg;
+	  else if (expr_references_sym (arg->expr, var, NULL))
+	    gfc_error ("!$OMP ATOMIC intrinsic arguments except one must not "
+		       "reference '%s' at %L", var->name, &arg->expr->where);
+	  if (arg->expr->rank != 0)
+	    gfc_error ("!$OMP ATOMIC intrinsic arguments must be scalar "
+		       "at %L", &arg->expr->where);
+	}
+
+      if (var_arg == NULL)
+	{
+	  gfc_error ("First or last !$OMP ATOMIC intrinsic argument must "
+		     "be '%s' at %L", var->name, &expr2->where);
+	  return;
+	}
+
+      if (var_arg != expr2->value.function.actual)
+	{
+	  /* Canonicalize, so that var comes first.  */
+	  gcc_assert (var_arg->next == NULL);
+	  for (arg = expr2->value.function.actual;
+	       arg->next != var_arg; arg = arg->next)
+	    ;
+	  var_arg->next = expr2->value.function.actual;
+	  expr2->value.function.actual = var_arg;
+	  arg->next = NULL;
+	}
+    }
+  else
+    gfc_error ("!$OMP ATOMIC assignment must have an operator or intrinsic "
+	       "on right hand side at %L", &expr2->where);
+}
+
+
+struct omp_context
+{
+  gfc_code *code;
+  struct pointer_set_t *sharing_clauses;
+  struct pointer_set_t *private_iterators;
+  struct omp_context *previous;
+} *omp_current_ctx;
+static gfc_code *omp_current_do_code;
+static int omp_current_do_collapse;
+
+void
+gfc_resolve_omp_do_blocks (gfc_code *code, gfc_namespace *ns)
+{
+  if (code->block->next && code->block->next->op == EXEC_DO)
+    {
+      int i;
+      gfc_code *c;
+
+      omp_current_do_code = code->block->next;
+      omp_current_do_collapse = code->ext.omp_clauses->collapse;
+      for (i = 1, c = omp_current_do_code; i < omp_current_do_collapse; i++)
+	{
+	  c = c->block;
+	  if (c->op != EXEC_DO || c->next == NULL)
+	    break;
+	  c = c->next;
+	  if (c->op != EXEC_DO)
+	    break;
+	}
+      if (i < omp_current_do_collapse || omp_current_do_collapse <= 0)
+	omp_current_do_collapse = 1;
+    }
+  gfc_resolve_blocks (code->block, ns);
+  omp_current_do_collapse = 0;
+  omp_current_do_code = NULL;
+}
+
+
+void
+gfc_resolve_omp_parallel_blocks (gfc_code *code, gfc_namespace *ns)
+{
+  struct omp_context ctx;
+  gfc_omp_clauses *omp_clauses = code->ext.omp_clauses;
+  gfc_namelist *n;
+  int list;
+
+  ctx.code = code;
+  ctx.sharing_clauses = pointer_set_create ();
+  ctx.private_iterators = pointer_set_create ();
+  ctx.previous = omp_current_ctx;
+  omp_current_ctx = &ctx;
+
+  for (list = 0; list < OMP_LIST_NUM; list++)
+    for (n = omp_clauses->lists[list]; n; n = n->next)
+      pointer_set_insert (ctx.sharing_clauses, n->sym);
+
+  if (code->op == EXEC_OMP_PARALLEL_DO)
+    gfc_resolve_omp_do_blocks (code, ns);
+  else
+    gfc_resolve_blocks (code->block, ns);
+
+  omp_current_ctx = ctx.previous;
+  pointer_set_destroy (ctx.sharing_clauses);
+  pointer_set_destroy (ctx.private_iterators);
+}
+
+
+/* Save and clear openmp.c private state.  */
+
+void
+gfc_omp_save_and_clear_state (struct gfc_omp_saved_state *state)
+{
+  state->ptrs[0] = omp_current_ctx;
+  state->ptrs[1] = omp_current_do_code;
+  state->ints[0] = omp_current_do_collapse;
+  omp_current_ctx = NULL;
+  omp_current_do_code = NULL;
+  omp_current_do_collapse = 0;
+}
+
+
+/* Restore openmp.c private state from the saved state.  */
+
+void
+gfc_omp_restore_state (struct gfc_omp_saved_state *state)
+{
+  omp_current_ctx = (struct omp_context *) state->ptrs[0];
+  omp_current_do_code = (gfc_code *) state->ptrs[1];
+  omp_current_do_collapse = state->ints[0];
+}
+
+
+/* Note a DO iterator variable.  This is special in !$omp parallel
+   construct, where they are predetermined private.  */
+
+void
+gfc_resolve_do_iterator (gfc_code *code, gfc_symbol *sym)
+{
+  int i = omp_current_do_collapse;
+  gfc_code *c = omp_current_do_code;
+
+  if (sym->attr.threadprivate)
+    return;
+
+  /* !$omp do and !$omp parallel do iteration variable is predetermined
+     private just in the !$omp do resp. !$omp parallel do construct,
+     with no implications for the outer parallel constructs.  */
+
+  while (i-- >= 1)
+    {
+      if (code == c)
+	return;
+
+      c = c->block->next;
+    }
+
+  if (omp_current_ctx == NULL)
+    return;
+
+  if (pointer_set_contains (omp_current_ctx->sharing_clauses, sym))
+    return;
+
+  if (! pointer_set_insert (omp_current_ctx->private_iterators, sym))
+    {
+      gfc_omp_clauses *omp_clauses = omp_current_ctx->code->ext.omp_clauses;
+      gfc_namelist *p;
+
+      p = gfc_get_namelist ();
+      p->sym = sym;
+      p->next = omp_clauses->lists[OMP_LIST_PRIVATE];
+      omp_clauses->lists[OMP_LIST_PRIVATE] = p;
+    }
+}
+
+
+static void
+resolve_omp_do (gfc_code *code)
+{
+  gfc_code *do_code, *c;
+  int list, i, collapse;
+  gfc_namelist *n;
+  gfc_symbol *dovar;
+
+  if (code->ext.omp_clauses)
+    resolve_omp_clauses (code);
+
+  do_code = code->block->next;
+  collapse = code->ext.omp_clauses->collapse;
+  if (collapse <= 0)
+    collapse = 1;
+  for (i = 1; i <= collapse; i++)
+    {
+      if (do_code->op == EXEC_DO_WHILE)
+	{
+	  gfc_error ("!$OMP DO cannot be a DO WHILE or DO without loop control "
+		     "at %L", &do_code->loc);
+	  break;
+	}
+      gcc_assert (do_code->op == EXEC_DO);
+      if (do_code->ext.iterator->var->ts.type != BT_INTEGER)
+	gfc_error ("!$OMP DO iteration variable must be of type integer at %L",
+		   &do_code->loc);
+      dovar = do_code->ext.iterator->var->symtree->n.sym;
+      if (dovar->attr.threadprivate)
+	gfc_error ("!$OMP DO iteration variable must not be THREADPRIVATE "
+		   "at %L", &do_code->loc);
+      if (code->ext.omp_clauses)
+	for (list = 0; list < OMP_LIST_NUM; list++)
+	  if (list != OMP_LIST_PRIVATE && list != OMP_LIST_LASTPRIVATE)
+	    for (n = code->ext.omp_clauses->lists[list]; n; n = n->next)
+	      if (dovar == n->sym)
+		{
+		  gfc_error ("!$OMP DO iteration variable present on clause "
+			     "other than PRIVATE or LASTPRIVATE at %L",
+			     &do_code->loc);
+		  break;
+		}
+      if (i > 1)
+	{
+	  gfc_code *do_code2 = code->block->next;
+	  int j;
+
+	  for (j = 1; j < i; j++)
+	    {
+	      gfc_symbol *ivar = do_code2->ext.iterator->var->symtree->n.sym;
+	      if (dovar == ivar
+		  || gfc_find_sym_in_expr (ivar, do_code->ext.iterator->start)
+		  || gfc_find_sym_in_expr (ivar, do_code->ext.iterator->end)
+		  || gfc_find_sym_in_expr (ivar, do_code->ext.iterator->step))
+		{
+		  gfc_error ("!$OMP DO collapsed loops don't form rectangular iteration space at %L",
+			     &do_code->loc);
+		  break;
+		}
+	      if (j < i)
+		break;
+	      do_code2 = do_code2->block->next;
+	    }
+	}
+      if (i == collapse)
+	break;
+      for (c = do_code->next; c; c = c->next)
+	if (c->op != EXEC_NOP && c->op != EXEC_CONTINUE)
+	  {
+	    gfc_error ("collapsed !$OMP DO loops not perfectly nested at %L",
+		       &c->loc);
+	    break;
+	  }
+      if (c)
+	break;
+      do_code = do_code->block;
+      if (do_code->op != EXEC_DO && do_code->op != EXEC_DO_WHILE)
+	{
+	  gfc_error ("not enough DO loops for collapsed !$OMP DO at %L",
+		     &code->loc);
+	  break;
+	}
+      do_code = do_code->next;
+      if (do_code == NULL
+	  || (do_code->op != EXEC_DO && do_code->op != EXEC_DO_WHILE))
+	{
+	  gfc_error ("not enough DO loops for collapsed !$OMP DO at %L",
+		     &code->loc);
+	  break;
+	}
+    }
+}
+
+
+/* Resolve OpenMP directive clauses and check various requirements
+   of each directive.  */
+
+void
+gfc_resolve_omp_directive (gfc_code *code, gfc_namespace *ns ATTRIBUTE_UNUSED)
+{
+  if (code->op != EXEC_OMP_ATOMIC)
+    gfc_maybe_initialize_eh ();
+
+  switch (code->op)
+    {
+    case EXEC_OMP_DO:
+    case EXEC_OMP_PARALLEL_DO:
+      resolve_omp_do (code);
+      break;
+    case EXEC_OMP_WORKSHARE:
+    case EXEC_OMP_PARALLEL_WORKSHARE:
+    case EXEC_OMP_PARALLEL:
+    case EXEC_OMP_PARALLEL_SECTIONS:
+    case EXEC_OMP_SECTIONS:
+    case EXEC_OMP_SINGLE:
+    case EXEC_OMP_TASK:
+      if (code->ext.omp_clauses)
+	resolve_omp_clauses (code);
+      break;
+    case EXEC_OMP_ATOMIC:
+      resolve_omp_atomic (code);
+      break;
+    default:
+      break;
+    }
+}