gimplify.c

/* Tree lowering pass.  This pass converts the GENERIC functions-as-trees
   tree representation into the GIMPLE form.
   Copyright (C) 2002-2013 Free Software Foundation, Inc.
   Major work done by Sebastian Pop <s.pop@laposte.net>,
   Diego Novillo <dnovillo@redhat.com> and Jason Merrill <jason@redhat.com>.

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 "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "gimple.h"
#include "tree-iterator.h"
#include "tree-inline.h"
#include "tree-pretty-print.h"
#include "langhooks.h"
#include "tree-flow.h"
#include "cgraph.h"
#include "timevar.h"
#include "hashtab.h"
#include "flags.h"
#include "function.h"
#include "ggc.h"
#include "diagnostic-core.h"
#include "target.h"
#include "pointer-set.h"
#include "splay-tree.h"
#include "vec.h"

#include "langhooks-def.h"	/* FIXME: for lhd_set_decl_assembler_name */
#include "tree-pass.h"		/* FIXME: only for PROP_gimple_any */

enum gimplify_omp_var_data
{
  GOVD_SEEN = 1,
  GOVD_EXPLICIT = 2,
  GOVD_SHARED = 4,
  GOVD_PRIVATE = 8,
  GOVD_FIRSTPRIVATE = 16,
  GOVD_LASTPRIVATE = 32,
  GOVD_REDUCTION = 64,
  GOVD_LOCAL = 128,
  GOVD_DEBUG_PRIVATE = 256,
  GOVD_PRIVATE_OUTER_REF = 512,
  GOVD_DATA_SHARE_CLASS = (GOVD_SHARED | GOVD_PRIVATE | GOVD_FIRSTPRIVATE
			   | GOVD_LASTPRIVATE | GOVD_REDUCTION | GOVD_LOCAL)
};


enum omp_region_type
{
  ORT_WORKSHARE = 0,
  ORT_PARALLEL = 2,
  ORT_COMBINED_PARALLEL = 3,
  ORT_TASK = 4,
  ORT_UNTIED_TASK = 5
};

struct gimplify_omp_ctx
{
  struct gimplify_omp_ctx *outer_context;
  splay_tree variables;
  struct pointer_set_t *privatized_types;
  location_t location;
  enum omp_clause_default_kind default_kind;
  enum omp_region_type region_type;
};

static struct gimplify_ctx *gimplify_ctxp;
static struct gimplify_omp_ctx *gimplify_omp_ctxp;


/* Forward declaration.  */
static enum gimplify_status gimplify_compound_expr (tree *, gimple_seq *, bool);

/* Mark X addressable.  Unlike the langhook we expect X to be in gimple
   form and we don't do any syntax checking.  */

void
mark_addressable (tree x)
{
  while (handled_component_p (x))
    x = TREE_OPERAND (x, 0);
  if (TREE_CODE (x) == MEM_REF
      && TREE_CODE (TREE_OPERAND (x, 0)) == ADDR_EXPR)
    x = TREE_OPERAND (TREE_OPERAND (x, 0), 0);
  if (TREE_CODE (x) != VAR_DECL
      && TREE_CODE (x) != PARM_DECL
      && TREE_CODE (x) != RESULT_DECL)
    return;
  TREE_ADDRESSABLE (x) = 1;

  /* Also mark the artificial SSA_NAME that points to the partition of X.  */
  if (TREE_CODE (x) == VAR_DECL
      && !DECL_EXTERNAL (x)
      && !TREE_STATIC (x)
      && cfun->gimple_df != NULL
      && cfun->gimple_df->decls_to_pointers != NULL)
    {
      void *namep
	= pointer_map_contains (cfun->gimple_df->decls_to_pointers, x); 
      if (namep)
	TREE_ADDRESSABLE (*(tree *)namep) = 1;
    }
}

/* Link gimple statement GS to the end of the sequence *SEQ_P.  If
   *SEQ_P is NULL, a new sequence is allocated.  This function is
   similar to gimple_seq_add_stmt, but does not scan the operands.
   During gimplification, we need to manipulate statement sequences
   before the def/use vectors have been constructed.  */

void
gimple_seq_add_stmt_without_update (gimple_seq *seq_p, gimple gs)
{
  gimple_stmt_iterator si;

  if (gs == NULL)
    return;

  si = gsi_last (*seq_p);
  gsi_insert_after_without_update (&si, gs, GSI_NEW_STMT);
}

/* Shorter alias name for the above function for use in gimplify.c
   only.  */

static inline void
gimplify_seq_add_stmt (gimple_seq *seq_p, gimple gs)
{
  gimple_seq_add_stmt_without_update (seq_p, gs);
}

/* Append sequence SRC to the end of sequence *DST_P.  If *DST_P is
   NULL, a new sequence is allocated.   This function is
   similar to gimple_seq_add_seq, but does not scan the operands.
   During gimplification, we need to manipulate statement sequences
   before the def/use vectors have been constructed.  */

static void
gimplify_seq_add_seq (gimple_seq *dst_p, gimple_seq src)
{
  gimple_stmt_iterator si;

  if (src == NULL)
    return;

  si = gsi_last (*dst_p);
  gsi_insert_seq_after_without_update (&si, src, GSI_NEW_STMT);
}

/* Set up a context for the gimplifier.  */

void
push_gimplify_context (struct gimplify_ctx *c)
{
  memset (c, '\0', sizeof (*c));
  c->prev_context = gimplify_ctxp;
  gimplify_ctxp = c;
}

/* Tear down a context for the gimplifier.  If BODY is non-null, then
   put the temporaries into the outer BIND_EXPR.  Otherwise, put them
   in the local_decls.

   BODY is not a sequence, but the first tuple in a sequence.  */

void
pop_gimplify_context (gimple body)
{
  struct gimplify_ctx *c = gimplify_ctxp;

  gcc_assert (c
              && (!c->bind_expr_stack.exists ()
		  || c->bind_expr_stack.is_empty ()));
  c->bind_expr_stack.release ();
  gimplify_ctxp = c->prev_context;

  if (body)
    declare_vars (c->temps, body, false);
  else
    record_vars (c->temps);

  if (c->temp_htab.is_created ())