/* Callgraph handling code.
   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008
   Free Software Foundation, Inc.
   Contributed by Jan Hubicka

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/>.  */

#ifndef GCC_CGRAPH_H
#define GCC_CGRAPH_H
#include "tree.h"
#include "basic-block.h"

enum availability
{
  /* Not yet set by cgraph_function_body_availability.  */
  AVAIL_UNSET,
  /* Function body/variable initializer is unknown.  */
  AVAIL_NOT_AVAILABLE,
  /* Function body/variable initializer is known but might be replaced
     by a different one from other compilation unit and thus needs to
     be dealt with a care.  Like AVAIL_NOT_AVAILABLE it can have
     arbitrary side effects on escaping variables and functions, while
     like AVAILABLE it might access static variables.  */
  AVAIL_OVERWRITABLE,
  /* Function body/variable initializer is known and will be used in final
     program.  */
  AVAIL_AVAILABLE,
  /* Function body/variable initializer is known and all it's uses are explicitly
     visible within current unit (ie it's address is never taken and it is not
     exported to other units).
     Currently used only for functions.  */
  AVAIL_LOCAL
};

extern const char * const cgraph_availability_names[];

/* Information about the function collected locally.
   Available after function is analyzed.  */

struct cgraph_local_info GTY(())
{
  /* Estimated stack frame consumption by the function.  */
  HOST_WIDE_INT estimated_self_stack_size;

  /* Size of the function before inlining.  */
  int self_insns;

  /* Set when function function is visible in current compilation unit only
     and its address is never taken.  */
  unsigned local : 1;

  /* Set when function is visible by other units.  */
  unsigned externally_visible : 1;

  /* Set once it has been finalized so we consider it to be output.  */
  unsigned finalized : 1;

  /* False when there something makes inlining impossible (such as va_arg).  */
  unsigned inlinable : 1;

  /* True when function should be inlined independently on its size.  */
  unsigned disregard_inline_limits : 1;

  /* True when the function has been originally extern inline, but it is
     redefined now.  */
  unsigned redefined_extern_inline : 1;

  /* True if statics_read_for_function and
     statics_written_for_function contain valid data.  */
  unsigned for_functions_valid : 1;

  /* True if the function is going to be emitted in some other translation
     unit, referenced from vtable.  */
  unsigned vtable_method : 1;
};

/* Information about the function that needs to be computed globally
   once compilation is finished.  Available only with -funit-at-time.  */

struct cgraph_global_info GTY(())
{
  /* Estimated stack frame consumption by the function.  */
  HOST_WIDE_INT estimated_stack_size;
  /* Expected offset of the stack frame of inlined function.  */
  HOST_WIDE_INT stack_frame_offset;

  /* For inline clones this points to the function they will be inlined into.  */
  struct cgraph_node *inlined_to;

  /* Estimated size of the function after inlining.  */
  int insns;

  /* Estimated growth after inlining.  INT_MIN if not computed.  */
  int estimated_growth;

  /* Set iff the function has been inlined at least once.  */
  bool inlined;
};

/* Information about the function that is propagated by the RTL backend.
   Available only for functions that has been already assembled.  */

struct cgraph_rtl_info GTY(())
{
   int preferred_incoming_stack_boundary;
};

/* The cgraph data structure.
   Each function decl has assigned cgraph_node listing callees and callers.  */

struct cgraph_node GTY((chain_next ("%h.next"), chain_prev ("%h.previous")))
{
  tree decl;
  struct cgraph_edge *callees;
  struct cgraph_edge *callers;
  struct cgraph_node *next;
  struct cgraph_node *previous;
  /* For nested functions points to function the node is nested in.  */
  struct cgraph_node *origin;
  /* Points to first nested function, if any.  */
  struct cgraph_node *nested;
  /* Pointer to the next function with same origin, if any.  */
  struct cgraph_node *next_nested;
  /* Pointer to the next function in cgraph_nodes_queue.  */
  struct cgraph_node *next_needed;
  /* Pointer to the next clone.  */
  struct cgraph_node *next_clone;
  struct cgraph_node *prev_clone;
  /* Pointer to a single unique cgraph node for this function.  If the
     function is to be output, this is the copy that will survive.  */
  struct cgraph_node *master_clone;
  /* For functions with many calls sites it holds map from call expression
     to the edge to speed up cgraph_edge function.  */
  htab_t GTY((param_is (struct cgraph_edge))) call_site_hash;

  PTR GTY ((skip)) aux;

  struct cgraph_local_info local;
  struct cgraph_global_info global;
  struct cgraph_rtl_info rtl;

  /* Expected number of executions: calculated in profile.c.  */
  gcov_type count;
  /* Unique id of the node.  */
  int uid;
  /* Ordering of all cgraph nodes.  */
  int order;

  /* Set when function must be output - it is externally visible
     or its address is taken.  */
  unsigned needed : 1;
  /* Set when decl is an abstract function pointed to by the
     ABSTRACT_DECL_ORIGIN of a reachable function.  */
  unsigned abstract_and_needed : 1;
  /* Set when function is reachable by call from other function
     that is either reachable or needed.  */
  unsigned reachable : 1;
  /* Set once the function is lowered (i.e. its CFG is built).  */
  unsigned lowered : 1;
  /* Set once the function has been instantiated and its callee
     lists created.  */
  unsigned analyzed : 1;
  /* Set when function is scheduled to be assembled.  */
  unsigned output : 1;
  /* Set for aliases once they got through assemble_alias.  */
  unsigned alias : 1;

  /* In non-unit-at-a-time mode the function body of inline candidates is saved
     into clone before compiling so the function in original form can be
     inlined later.  This pointer points to the clone.  */
  tree inline_decl;

  /* unique id for profiling. pid is not suitable because of different
     number of cfg nodes with -fprofile-generate and -fprofile-use */
  int pid;
};

struct cgraph_edge GTY((chain_next ("%h.next_caller"), chain_prev ("%h.prev_caller")))
{
  struct cgraph_node *caller;
  struct cgraph_node *callee;
  struct cgraph_edge *prev_caller;
  struct cgraph_edge *next_caller;
  struct cgraph_edge *prev_callee;
  struct cgraph_edge *next_callee;
  tree call_stmt;
  PTR GTY ((skip (""))) aux;
  /* When NULL, inline this call.  When non-NULL, points to the explanation
     why function was not inlined.  */
  const char *inline_failed;
  /* Expected number of executions: calculated in profile.c.  */
  gcov_type count;
  /* Expected frequency of executions within the function. 
     When set to CGRAPH_FREQ_BASE, the edge is expected to be called once
     per function call.  The range is 0 to CGRAPH_FREQ_MAX.  */
  int frequency;
  /* Depth of loop nest, 1 means no loop nest.  */
  int loop_nest;
};

#define CGRAPH_FREQ_BASE 1000
#define CGRAPH_FREQ_MAX 100000

typedef struct cgraph_edge *cgraph_edge_p;

DEF_VEC_P(cgraph_edge_p);
DEF_VEC_ALLOC_P(cgraph_edge_p,heap);

/* The varpool data structure.
   Each static variable decl has assigned varpool_node.  */

struct varpool_node GTY(())
{
  tree decl;
  /* Pointer to the next function in varpool_nodes.  */
  struct varpool_node *next;
  /* Pointer to the next function in varpool_nodes_queue.  */
  struct varpool_node *next_needed;
  /* Ordering of all cgraph nodes.  */
  int order;

  /* Set when function must be output - it is externally visible
     or its address is taken.  */
  unsigned needed : 1;
  /* Needed variables might become dead by optimization.  This flag
     forces the variable to be output even if it appears dead otherwise.  */
  unsigned force_output : 1;
  /* Set once the variable has been instantiated and its callee
     lists created.  */
  unsigned analyzed : 1;
  /* Set once it has been finalized so we consider it to be output.  */
  unsigned finalized : 1;
  /* Set when variable is scheduled to be assembled.  */
  unsigned output : 1;
  /* Set when function is visible by other units.  */
  unsigned externally_visible : 1;
  /* Set for aliases once they got through assemble_alias.  */
  unsigned alias : 1;
};

/* Every top level asm statement is put into a cgraph_asm_node.  */

struct cgraph_asm_node GTY(())
{
  /* Next asm node.  */
  struct cgraph_asm_node *next;
  /* String for this asm node.  */
  tree asm_str;
  /* Ordering of all cgraph nodes.  */
  int order;
};

extern GTY(()) struct cgraph_node *cgraph_nodes;
extern GTY(()) int cgraph_n_nodes;
extern GTY(()) int cgraph_max_uid;
extern GTY(()) int cgraph_max_pid;
extern bool cgraph_global_info_ready;
enum cgraph_state
{
  /* Callgraph is being constructed.  It is safe to add new functions.  */
  CGRAPH_STATE_CONSTRUCTION,
  /* Callgraph is built and IPA passes are being run.  */
  CGRAPH_STATE_IPA,
  /* Callgraph is built and all functions are transformed to SSA form.  */
  CGRAPH_STATE_IPA_SSA,
  /* Functions are now ordered and being passed to RTL expanders.  */
  CGRAPH_STATE_EXPANSION,
  /* All cgraph expansion is done.  */
  CGRAPH_STATE_FINISHED
};
extern enum cgraph_state cgraph_state;
extern bool cgraph_function_flags_ready;
extern GTY(()) struct cgraph_node *cgraph_nodes_queue;
extern GTY(()) struct cgraph_node *cgraph_new_nodes;

extern GTY(()) struct cgraph_asm_node *cgraph_asm_nodes;
extern GTY(()) int cgraph_order;

/* In cgraph.c  */
void dump_cgraph (FILE *);
void debug_cgraph (void);
void dump_cgraph_node (FILE *, struct cgraph_node *);
void debug_cgraph_node (struct cgraph_node *);
void cgraph_insert_node_to_hashtable (struct cgraph_node *node);
void cgraph_remove_edge (struct cgraph_edge *);
void cgraph_remove_node (struct cgraph_node *);
void cgraph_release_function_body (struct cgraph_node *);
void cgraph_node_remove_callees (struct cgraph_node *node);
struct cgraph_edge *cgraph_create_edge (struct cgraph_node *,
					struct cgraph_node *,
					tree, gcov_type, int, int);
struct cgraph_node *cgraph_node (tree);
struct cgraph_node *cgraph_node_for_asm (tree asmname);
struct cgraph_edge *cgraph_edge (struct cgraph_node *, tree);
void cgraph_set_call_stmt (struct cgraph_edge *, tree);
void cgraph_update_edges_for_call_stmt (tree, tree, tree);
struct cgraph_local_info *cgraph_local_info (tree);
struct cgraph_global_info *cgraph_global_info (tree);
struct cgraph_rtl_info *cgraph_rtl_info (tree);
const char * cgraph_node_name (struct cgraph_node *);
struct cgraph_edge * cgraph_clone_edge (struct cgraph_edge *,
					struct cgraph_node *,
					tree, gcov_type, int, int, bool);
struct cgraph_node * cgraph_clone_node (struct cgraph_node *, gcov_type, int,
					int, bool);

void cgraph_redirect_edge_callee (struct cgraph_edge *, struct cgraph_node *);

struct cgraph_asm_node *cgraph_add_asm_node (tree);

bool cgraph_function_possibly_inlined_p (tree);
void cgraph_unnest_node (struct cgraph_node *);

enum availability cgraph_function_body_availability (struct cgraph_node *);
bool cgraph_is_master_clone (struct cgraph_node *);
struct cgraph_node *cgraph_master_clone (struct cgraph_node *);
void cgraph_add_new_function (tree, bool);

/* In cgraphunit.c  */
void cgraph_finalize_function (tree, bool);
void cgraph_finalize_compilation_unit (void);
void cgraph_optimize (void);
void cgraph_mark_needed_node (struct cgraph_node *);
void cgraph_mark_reachable_node (struct cgraph_node *);
bool cgraph_inline_p (struct cgraph_edge *, const char **reason);
bool cgraph_preserve_function_body_p (tree);
void verify_cgraph (void);
void verify_cgraph_node (struct cgraph_node *);
void cgraph_build_static_cdtor (char which, tree body, int priority);
void cgraph_reset_static_var_maps (void);
void init_cgraph (void);
struct cgraph_node *cgraph_function_versioning (struct cgraph_node *,
						VEC(cgraph_edge_p,heap)*,
						varray_type);
void cgraph_analyze_function (struct cgraph_node *);
struct cgraph_node *save_inline_function_body (struct cgraph_node *);
void record_references_in_initializer (tree);
bool cgraph_process_new_functions (void);

/* In cgraphbuild.c  */
unsigned int rebuild_cgraph_edges (void);

/* In ipa.c  */
bool cgraph_remove_unreachable_nodes (bool, FILE *);
int cgraph_postorder (struct cgraph_node **);

/* In varpool.c  */

extern GTY(()) struct varpool_node *varpool_nodes_queue;
extern GTY(()) struct varpool_node *varpool_nodes;

struct varpool_node *varpool_node (tree);
struct varpool_node *varpool_node_for_asm (tree asmname);
void varpool_mark_needed_node (struct varpool_node *);
void dump_varpool (FILE *);
void dump_varpool_node (FILE *, struct varpool_node *);

void varpool_finalize_decl (tree);
bool decide_is_variable_needed (struct varpool_node *, tree);
enum availability cgraph_variable_initializer_availability (struct varpool_node *);

bool varpool_assemble_pending_decls (void);
bool varpool_assemble_decl (struct varpool_node *node);
bool varpool_analyze_pending_decls (void);
void varpool_output_debug_info (void);
void varpool_remove_unreferenced_decls (void);

/* Walk all reachable static variables.  */
#define FOR_EACH_STATIC_VARIABLE(node) \
   for ((node) = varpool_nodes_queue; (node); (node) = (node)->next_needed)

/* Return first reachable static variable with initializer.  */
static inline struct varpool_node *
varpool_first_static_initializer (void)
{
  struct varpool_node *node;
  for (node = varpool_nodes_queue; node; node = node->next_needed)
    {
      gcc_assert (TREE_CODE (node->decl) == VAR_DECL);
      if (DECL_INITIAL (node->decl))
	return node;
    }
  return NULL;
}

/* Return next reachable static variable with initializer after NODE.  */
static inline struct varpool_node *
varpool_next_static_initializer (struct varpool_node *node)
{
  for (node = node->next_needed; node; node = node->next_needed)
    {
      gcc_assert (TREE_CODE (node->decl) == VAR_DECL);
      if (DECL_INITIAL (node->decl))
	return node;
    }
  return NULL;
}

/* Walk all static variables with initializer set.  */
#define FOR_EACH_STATIC_INITIALIZER(node) \
   for ((node) = varpool_first_static_initializer (); (node); \
        (node) = varpool_next_static_initializer (node))

/* In ipa-inline.c  */
void cgraph_clone_inlined_nodes (struct cgraph_edge *, bool, bool);
void cgraph_mark_inline_edge (struct cgraph_edge *, bool);
bool cgraph_default_inline_p (struct cgraph_node *, const char **);


/* Create a new static variable of type TYPE.  */
tree add_new_static_var (tree type);

#endif  /* GCC_CGRAPH_H  */