/*
-* Copyright (C) 1998 - 2000 by Universitaet Karlsruhe
-* All rights reserved.
-*
-*/
+ * Project: libFIRM
+ * File name: ir/tr/entity.h
+ * Purpose: Representation of all program known entities.
+ * Author: Martin Trapp, Christian Schaefer
+ * Modified by: Goetz Lindenmaier
+ * Created:
+ * CVS-ID: $Id$
+ * Copyright: (c) 1998-2003 Universität Karlsruhe
+ * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ */
/**
-* @file entity.h
-*
-* Entities represent all program known objects.
-*
-* @author Martin Trapp, Christian Schaefer
-* @author Goetz Lindenmaier
-*
-* An entity is the representation of program known objects in Firm.
-* The primary concept of entities is to represent members of complex
-* types, i.e., fields and methods of classes. As not all programming
-* language model all variables and methods as members of some class,
-* the concept of entities is extended to cover also local and global
-* variables, and arbitrary procedures.
-*
-* An entity always specifies the type of the object it represents and
-* the type of the object it is a part of, the owner of the entity.
-* Originally this is the type of the class of which the entity is a
-* member.
-* The owner of local variables is the procedure they are defined in.
-* The owner of global variables and procedures visible in the whole
-* program is a universally defined class type "GlobalType". The owner
-* of procedures defined in the scope of an other procedure is the
-* enclosing procedure.
-*
-* In detail the datastructure entity has the following fields:
-*
-* - ident *name: Name of this entity as specified in the source code.
-* Only unequivocal in conjuction with scope.
-* - ident *ld_name: Unique name of this entity, i.e., the mangled
-* name. E.g., for a class `A' with field `a' this
-* is the ident for `A_a'.
-* - type *type: The type of this entity, e.g., a method type, a
-* basic type of the language or a class itself.
-* - type *owner: The class this entity belongs to. In case of local
-* variables the method they are defined in.
-* - int offset: Offset in byte for this entity. Fixed when layout
-* of owner is determined.
-* - ir_graph *irg: If (type == method_type) this is the corresponding irg.
-* The ir_graph constructor automatically sets this field.
-* If (type != method_type) access of this field will cause
-* an assertion.
-*/
-
-/* $Id$ */
-
-# ifndef _ENTITY_H_
-# define _ENTITY_H_
-
-# include "ident.h"
-# include "type.h"
-# include "dbginfo.h"
+ * @file entity.h
+ *
+ * Entities represent all program known objects.
+ *
+ * @author Martin Trapp, Christian Schaefer
+ * @author Goetz Lindenmaier
+ *
+ * An entity is the representation of program known objects in Firm.
+ * The primary concept of entities is to represent members of complex
+ * types, i.e., fields and methods of classes. As not all programming
+ * language model all variables and methods as members of some class,
+ * the concept of entities is extended to cover also local and global
+ * variables, and arbitrary procedures.
+ *
+ * An entity always specifies the type of the object it represents and
+ * the type of the object it is a part of, the owner of the entity.
+ * Originally this is the type of the class of which the entity is a
+ * member.
+ * The owner of local variables is the procedure they are defined in.
+ * The owner of global variables and procedures visible in the whole
+ * program is a universally defined class type "GlobalType". The owner
+ * of procedures defined in the scope of an other procedure is the
+ * enclosing procedure.
+ *
+ * In detail the datastructure entity has the following fields:
+ *
+ * - ident *name: Name of this entity as specified in the source code.
+ * Only unequivocal in conjuction with scope.
+ * - ident *ld_name: Unique name of this entity, i.e., the mangled
+ * name. E.g., for a class `A' with field `a' this
+ * is the ident for `A_a'.
+ * - ir_type *type: The type of this entity, e.g., a method type, a
+ * basic type of the language or a class itself.
+ * - ir_type *owner: The class this entity belongs to. In case of local
+ * variables the method they are defined in.
+ * - int offset: Offset in bits for this entity. Fixed when layout
+ * of owner is determined.
+ * - ir_graph *irg: If (type == method_type) this is the corresponding irg.
+ * The ir_graph constructor automatically sets this field.
+ * If (type != method_type) access of this field will cause
+ * an assertion.
+ * - unsigned irg_add_properties:
+ * If (type == method_type) this mirrors the additional flags
+ * of the corresponding irg if set or is an own set for
+ * this entity. This construction allows to specify these
+ * flags even if no graph is available.
+ * If (type != method_type) access of this field will cause
+ * an assertion.
+ */
+#ifndef _ENTITY_H_
+#define _ENTITY_H_
-/*-----------------------------------------------------------------*/
-/* general */
-/*-----------------------------------------------------------------*/
+#include "firm_types.h"
+#include "dbginfo.h"
-/** Initalize entity module. */
-void init_entity (void);
+#include "tr_inheritance.h"
/*-----------------------------------------------------------------*/
/* ENTITY */
/*-----------------------------------------------------------------*/
-/* to resolve recursion between entity.h and irgraph.h */
-#ifndef _IR_GRAPH_TYPEDEF_
-#define _IR_GRAPH_TYPEDEF_
-typedef struct ir_graph ir_graph;
-#endif
-
/**
*
- * An abstract data type to represent program entites.
+ * An abstract data type to represent program entities.
*
* @param owner A compound type this entity is a part of.
* @param type The type of this entity.
* @param visibility A flag indicating the visibility of this entity (values: local,
* external_visible, external_allocated)
* @param variability A flag indicating the variability of this entity (values:
- * uninitialized, initalized, part_constant, constant)
+ * uninitialized, initialized, part_constant, constant)
* @param volatility @@@
- * @param offset The offset of the entity within the compound object. Only set
+ * @param offset The offset of the entity within the compound object in bits. Only set
* if the owner in the state "layout_fixed".
* @param overwrites A list of entities overwritten by this entity. This list is only
* existent if the owner of this entity is a class. The members in
* Creates a new entity.
*
* Automatically inserts the entity as a member of owner.
- * Entity is automatic_allocated and uninitialize except if the type
+ * Entity is automatic_allocated and uninitialized except if the type
* is type_method, then it is static_allocated and constant. The constant
* value is a pointer to the method.
* Visibility is local, offset -1, and it is not volatile.
*/
-entity *new_entity (type *owner, ident *name, type *tp);
+entity *new_entity (ir_type *owner, ident *name, ir_type *tp);
/**
* Creates a new entity.
*
* Automatically inserts the entity as a member of owner.
- * Entity is automatic_allocated and uninitialize except if the type
- * is type_method, then it is static_allocated and constant. The constant
+ * The entity is automatic allocated and uninitialized except if the type
+ * is type_method, then it is static allocated and constant. The constant
* value is a pointer to the method.
* Visibility is local, offset -1, and it is not volatile.
*/
-entity *new_d_entity (type *owner, ident *name, type *tp, dbg_info *db);
+entity *new_d_entity (ir_type *owner, ident *name, ir_type *tp, dbg_info *db);
/**
* Copies the entity if the new_owner is different from the
*
* Automatically inserts the new entity as a member of owner.
* Resets the overwrites/overwritten_by fields.
+ * Keeps the old atomic value.
+ * @@@ Maybe we should change this. If peculiarity of a method
+ * is existent, we should add a new SymConst that points to
+ * itself and not to the origin. Right now we have to change
+ * the peculiarity and then set a new atomic value by hand.
*/
-entity *copy_entity_own (entity *old, type *new_owner);
+entity *copy_entity_own (entity *old, ir_type *new_owner);
/**
* Copies the entity if the new_name is different from the
*
* Automatically inserts the new entity as a member of owner.
* The mangled name ld_name is set to NULL.
+ * Overwrites relation is copied from old.
*/
entity *copy_entity_name (entity *old, ident *new_name);
void free_entity (entity *ent);
/** Returns the name of an entity. */
-const char *get_entity_name (entity *ent);
+const char *get_entity_name (const entity *ent);
/** Returns the ident of an entity. */
-ident *get_entity_ident (entity *ent);
+ident *get_entity_ident (const entity *ent);
/** Returns the mangled name of the entity.
*
void set_entity_ld_ident (entity *ent, ident *ld_ident);
/** Returns the mangled name of the entity as a string. */
-const char *get_entity_ld_name (entity *end);
+const char *get_entity_ld_name (entity *ent);
/** Returns the owner of the entity. */
-type *get_entity_owner (entity *ent);
+ir_type *get_entity_owner (entity *ent);
/** Sets the owner field in entity to owner. Don't forget to add
ent to owner!! */
-void set_entity_owner (entity *ent, type *owner);
+void set_entity_owner (entity *ent, ir_type *owner);
-/** Asserts if the type owner is neither a compound type or an array */
-INLINE void assert_legal_owner_of_ent(type *owner);
+/** Asserts if the type owner is either a compound type or an array */
+void assert_legal_owner_of_ent(ir_type *owner);
/** Returns the type of an entity. */
-type *get_entity_type (entity *ent);
+ir_type *get_entity_type (entity *ent);
/** Sets the type of an entity. */
-void set_entity_type (entity *ent, type *tp);
+void set_entity_type (entity *ent, ir_type *tp);
/** The allocation type. */
typedef enum {
- automatic_allocated, /**< The entity is allocated during runtime, implicitly
- as component of a compound type. This is the default. */
- parameter_allocated, /**< The entity is a parameter. It is also automatic allocated.
- We distinguish the allocation of paramters from the allocation
- of local variables as their placement depends on the calling
- conventions. */
- dynamic_allocated, /**< The entity is allocated during runtime, explicitly
- by an Alloc node. */
- static_allocated /**< The entity is allocated statically. We can use a
- SymConst(?) as address of the entity. */
+ allocation_automatic, /**< The entity is allocated during runtime, implicitly
+ as component of a compound type. This is the default. */
+ allocation_parameter, /**< The entity is a parameter. It is also automatic allocated.
+ We distinguish the allocation of parameters from the allocation
+ of local variables as their placement depends on the calling
+ conventions. */
+ allocation_dynamic, /**< The entity is allocated during runtime, explicitly
+ by an Alloc node. */
+ allocation_static /**< The entity is allocated statically. We can use a
+ Const as address of the entity. */
} ent_allocation;
/** Returns the allocation type of an entity. */
-ent_allocation get_entity_allocation (entity *ent);
+ent_allocation get_entity_allocation (const entity *ent);
/** Sets the allocation type of an entity. */
void set_entity_allocation (entity *ent, ent_allocation al);
-/** Return the name of the visibility */
+/** Return the name of the allocation type. */
const char *get_allocation_name(ent_allocation vis);
-/**
- * This enumeration flags the visibility of entities. This is necessary
- * for partial compilation.
- */
-typedef enum {
- local, /**< The entity is only visible locally. This is the default. */
- external_visible, /**< The entity is visible to other external program parts, but
- it is defined here. It may not be optimized away. The entity must
- be static_allocated. */
- external_allocated /**< The entity is defined and allocated externally. This compilation
- must not allocate memory for this entity. The entity must
- be static_allocated. This can also be an external defined
- method. */
-} ent_visibility;
-
/** Returns the visibility of an entity. */
-ent_visibility get_entity_visibility (entity *ent);
+visibility get_entity_visibility (const entity *ent);
/** Sets the visibility of an entity. */
-void set_entity_visibility (entity *ent, ent_visibility vis);
+void set_entity_visibility (entity *ent, visibility vis);
/** Return the name of the visibility */
-const char *get_visibility_name(ent_visibility vis);
+const char *get_visibility_name(visibility vis);
/** This enumeration flags the variability of entities. */
typedef enum {
- uninitialized, /**< The content of the entity is completely unknown. */
- initialized, /**< After allocation the entity is initalized with the
- value given somewhere in the entity. */
- part_constant, /**< For entities of compound types. Some members of the entity
- are constant. The others are uninitialized. Those members
- given a value for are constant. */
- constant /**< The entity is constant. */
+ variability_uninitialized, /**< The content of the entity is completely unknown. Default. */
+ variability_initialized, /**< After allocation the entity is initialized with the
+ value given somewhere in the entity. */
+ variability_part_constant, /**< For entities of compound types.
+ The members of the entity are mixed constant,
+ initialized or uninitialized. */
+ variability_constant /**< The entity is constant. */
} ent_variability;
/** Returns the variability of an entity. */
-ent_variability get_entity_variability (entity *ent);
+ent_variability get_entity_variability (const entity *ent);
/** Sets the variability of an entity. */
void set_entity_variability (entity *ent, ent_variability var);
-/** Return the name of the variablity. */
+/** Return the name of the variability. */
const char *get_variability_name(ent_variability var);
/** This enumeration flags the volatility of entities. */
typedef enum {
- non_volatile, /**< The entity is not volatile */
- is_volatile /**< The entity is volatile */
+ volatility_non_volatile, /**< The entity is not volatile. Default. */
+ volatility_is_volatile /**< The entity is volatile */
} ent_volatility;
/** Returns the volatility of an entity. */
-ent_volatility get_entity_volatility (entity *ent);
+ent_volatility get_entity_volatility (const entity *ent);
/** Sets the volatility of an entity. */
void set_entity_volatility (entity *ent, ent_volatility vol);
-/* Return the name of the volatility. */
+/** Return the name of the volatility. */
const char *get_volatility_name(ent_volatility var);
-/** Returns the offset of an entity (in a compound). Only set if layout = fixed. */
-int get_entity_offset (entity *ent);
+/** This enumeration flags the stickyness of an entity. */
+typedef enum {
+ stickyness_unsticky, /**< The entity can be removed from
+ the program, unless contraindicated
+ by other attributes. Default. */
+ stickyness_sticky /**< The entity must remain in the
+ program in any case. */
+} ent_stickyness;
+
+/** Get the entity's stickyness */
+ent_stickyness get_entity_stickyness(const entity *ent);
+
+/** Set the entity's stickyness */
+void set_entity_stickyness(entity *ent, ent_stickyness stickyness);
+
+/** Returns the offset of an entity (in a compound) in bytes. Only set if layout = fixed. */
+int get_entity_offset_bytes(const entity *ent);
+
+/** Returns the offset of an entity (in a compound) in bits. Only set if layout = fixed. */
+int get_entity_offset_bits(const entity *ent);
+
+/** Sets the offset of an entity (in a compound) in bytes. */
+void set_entity_offset_bytes(entity *ent, int offset);
-/** Sets the offset of an entity (in a compound). */
-void set_entity_offset (entity *ent, int offset);
+/** Sets the offset of an entity (in a compound) in bits. */
+void set_entity_offset_bits(entity *ent, int offset);
/** Returns the stored intermediate information. */
-void* get_entity_link(entity *ent);
+void* get_entity_link(const entity *ent);
/** Stores new intermediate information. */
void set_entity_link(entity *ent, void *l);
/* -- Fields of method entities -- */
-/* The entity knows the corresponding irg if the entity is a method.
+/** The entity knows the corresponding irg if the entity is a method.
This allows to get from a Call to the called irg.
Only entities of peculiarity "existent" can have a corresponding irg,
else the field is fixed to NULL. (Get returns NULL, set asserts.) */
-ir_graph *get_entity_irg(entity *ent);
+ir_graph *get_entity_irg(const entity *ent);
void set_entity_irg(entity *ent, ir_graph *irg);
/** Return the peculiarity of an entity. */
-peculiarity get_entity_peculiarity (entity *ent);
+peculiarity get_entity_peculiarity (const entity *ent);
/** Sets the peculiarity of an entity. */
void set_entity_peculiarity (entity *ent, peculiarity pec);
/** Return the name of the peculiarity. */
const char *get_peculiarity_name(peculiarity var);
-/* -- Representation of constant values of entites -- */
+/* -- Representation of constant values of entities -- */
+/** Returns true if the the node is representable as code on
+ * const_code_irg. */
+int is_irn_const_expression(ir_node *n);
/* Set current_ir_graph to get_const_code_irg() to generate a constant
expression. */
-/* Copies a firm subgraph that complies to the restrictions for
- constant expressions to current_block in current_ir_graph. */
-ir_node *copy_const_value(ir_node *n);
+
+/**
+ * Copies a firm subgraph that complies to the restrictions for
+ * constant expressions to current_block in current_ir_graph.
+ */
+ir_node *copy_const_value(dbg_info *dbg, ir_node *n);
/* Set has no effect for existent entities of type method. */
ir_node *get_atomic_ent_value(entity *ent);
void set_atomic_ent_value(entity *ent, ir_node *val);
-/* The following type describes a path to a leave in the compound graph.
- Node 0 in the path must be an entity of type tp given in the constructor. If
- the type of this element is compound, the path node 1 is an element of the type
- of node 0 an so forth, until an entity of atomic type is reached. */
+/**
+ * The following type describes a path to a leave in the compound graph.
+ * Node 0 in the path must be an entity of type tp given in the constructor. If
+ * the type of this element is compound, the path node 1 is an element of the type
+ * of node 0 an so forth, until an entity of atomic type is reached.
+ */
#ifndef _COMPOUND_GRAPH_PATH_TYPEDEF_
#define _COMPOUND_GRAPH_PATH_TYPEDEF_
typedef struct compound_graph_path compound_graph_path;
#endif /* _COMPOUND_GRAPH_PATH_TYPEDEF_ */
-compound_graph_path *new_compound_graph_path(type *tp, int length);
+
+/** Creates a new compound graph path. */
+compound_graph_path *new_compound_graph_path(ir_type *tp, int length);
+
+/** Returns non-zero if an object is a compound graph path */
int is_compound_graph_path(void *thing);
+
+/** Frees a graph path object */
void free_compound_graph_path (compound_graph_path *gr);
+
+/** Returns the length of a graph path */
int get_compound_graph_path_length(compound_graph_path *gr);
+
entity *get_compound_graph_path_node(compound_graph_path *gr, int pos);
void set_compound_graph_path_node(compound_graph_path *gr, int pos, entity *node);
+int get_compound_graph_path_array_index(compound_graph_path *gr, int pos);
+void set_compound_graph_path_array_index(compound_graph_path *gr, int pos, int index);
+
+/** Checks whether the path up to pos is correct. If the path contains a NULL,
+ * assumes the path is not complete and returns non-zero. */
+int is_proper_compound_graph_path(compound_graph_path *gr, int pos);
/* A value of a compound entity is a pair of a value and the description of the
corresponding access path to the member of the compound. */
void add_compound_ent_value_w_path(entity *ent, ir_node *val, compound_graph_path *path);
void set_compound_ent_value_w_path(entity *ent, ir_node *val, compound_graph_path *path, int pos);
+/** Returns the number of constant values needed to initialize the entity.
+ *
+ * Asserts if the entity has variability_uninitialized.
+ * */
int get_compound_ent_n_values(entity *ent);
+/** Returns a constant value given the position. */
ir_node *get_compound_ent_value(entity *ent, int pos);
+/** Returns the access path for value at position pos. */
compound_graph_path *get_compound_ent_value_path(entity *ent, int pos);
-/* Removes all constant entries where the path ends at value_ent. Does not
+/** Returns the position of a value with the given path.
+ * The path must contain array indicees for all array element entities. */
+int get_compound_ent_pos_by_path(entity *ent, compound_graph_path *path);
+/** Returns a constant value given the access path.
+ * The path must contain array indicees for all array element entities. */
+ir_node *get_compound_ent_value_by_path(entity *ent, compound_graph_path *path);
+
+/** Removes all constant entries where the path ends at value_ent. Does not
free the memory of the paths. (The same path might be used for several
constant entities. */
void remove_compound_ent_value(entity *ent, entity *value_ent);
direct, atomic member of the constant entities type. In this case the
corresponding entity can be accessed directly. The following functions
allow direct access. */
-/* generates a Path with length 1 */
+
+/** generates a Path with length 1 */
void add_compound_ent_value(entity *ent, ir_node *val, entity *member);
-/* Returns the last member in the path */
-entity *get_compound_ent_value_member(entity *ent, int pos);
-/* Sets the path at pos 0 */
-void set_compound_ent_value(entity *ent, ir_node *val, entity *member, int pos);
+/** Returns the last member in the path */
+entity *get_compound_ent_value_member(entity *ent, int pos);
+/** Sets the path at pos 0 */
+void set_compound_ent_value(entity *ent, ir_node *val, entity *member, int pos);
-/** Inits the entity ent witch must be of a one dimensional
+/** Initializes the entity ent which must be of a one dimensional
array type with the values given in the values array.
The array must have a lower and an upper bound. Keeps the
order of values. Does not test whether the number of values
values have the proper mode for the array. */
void set_array_entity_values(entity *ent, tarval **values, int num_vals);
+/** Return the overall offset of value at position pos in bits.
+ *
+ * This requires that the layout of all concerned types is fixed.
+ *
+ * @param ent Any entity of compound type with at least pos initialization values.
+ * @param pos The position of the value for which the offset is requested.
+ */
+int get_compound_ent_value_offset_bits(entity *ent, int pos);
+
+/** Return the overall offset of value at position pos in bytes.
+ *
+ * This requires that the layout of all concerned types is fixed.
+ * Asserts if bit offset is not byte aligned.
+ *
+ * @param ent Any entity of compound type with at least pos initialization values.
+ * @param pos The position of the value for which the offset is requested.
+ */
+int get_compound_ent_value_offset_bytes(entity *ent, int pos);
+
+/** Compute the array indicees in compound graph paths of initialized entities.
+ *
+ * All arrays must have fixed lower and upper bounds. One array can
+ * have an open upper bound. If there are several open bounds, we do
+ * nothing. There must be initializer elements for all array
+ * elements. Uses the link field in the array element entities. The
+ * array bounds must be representable as integers.
+ *
+ * @param ent Any entity.
+ */
+void compute_compound_ent_array_indicees(entity *ent);
+
+/** Sort the values of the compound entity by their overall offset.
+ *
+ * This requires that the layout of all concerned types is fixed.
+ * If the entity has no initialization information the method just
+ * returns. This is needed to dump the entity in a backend.
+ *
+ * @param ent Any entity.
+ */
+void sort_compound_ent_values(entity *ent);
+
+
/* --- Fields of entities with a class type as owner --- */
/* Overwrites is a field that specifies that an access to the overwritten
entity in the supertype must use this entity. It's a list as with
- multiple inheritance several enitites can be overwritten. This field
+ multiple inheritance several entities can be overwritten. This field
is mostly useful for method entities.
If a Sel node selects an entity that is overwritten by other entities it
must return a pointer to the entity of the dynamic type of the pointer
* @return
* true if the thing is an entity, else false
*/
-int is_entity (void *thing);
+int is_entity (const void *thing);
/** Returns true if the type of the entity is a primitive, pointer
enumeration or method type. */
array or union type. */
int is_compound_entity(entity *ent);
-/** Returns true if ent1 and ent2 have are equal except for their owner.
+/** Returns non-zero if ent1 and ent2 have are equal except for their owner.
Two entities are equal if
- they have the same type (the same C-struct)
- ...?
*/
-bool equal_entity(entity *ent1, entity *ent2);
-
+int equal_entity(entity *ent1, entity *ent2);
/** Outputs a unique number for this entity if libfirm is compiled for
- debugging, (configure with --enable-debug) else returns 0. */
-INLINE long get_entity_nr(entity *ent);
+ * debugging, (configure with --enable-debug) else returns the address
+ * of the type cast to long.
+ */
+long get_entity_nr(entity *ent);
-/** Returns the entitys visited count. */
+/** Returns the entities visited count. */
unsigned long get_entity_visited(entity *ent);
-/** Sets the entitys visited count. */
+/** Sets the entities visited count. */
void set_entity_visited(entity *ent, unsigned long num);
/** Sets visited field in entity to entity_visited. */
void mark_entity_visited(entity *ent);
/** Returns true if this entity was visited. */
-bool entity_visited(entity *ent);
+int entity_visited(entity *ent);
/** Returns true if this entity was not visited. */
-bool entity_not_visited(entity *ent);
+int entity_not_visited(entity *ent);
-# endif /* _ENTITY_H_ */
+/**
+ * Returns the mask of the additional entity properties.
+ * The properties are automatically inherited from the irg if available
+ * or from the method type if they were not set using
+ * set_entity_additional_properties() or
+ * set_entity_additional_property().
+ */
+unsigned get_entity_additional_properties(entity *ent);
+
+/** Sets the mask of the additional graph properties. */
+void set_entity_additional_properties(entity *ent, unsigned property_mask);
+
+/** Sets one additional graph property. */
+void set_entity_additional_property(entity *ent, mtp_additional_property flag);
+
+/**
+ * @page unknown_entity
+ *
+ * This entity is an auxiliary entity dedicated to support analyses.
+ *
+ * The unknown entity represents that there could be an entity, but it is not
+ * known. This entity can be used to initialize fields before an analysis (not known
+ * yet) or to represent the top of a lattice (could not be determined). There exists
+ * exactly one entity unknown. This entity has as owner and as type the unknown type. It is
+ * allocated when initializing the entity module.
+ *
+ * The entity can take the role of any entity, also methods. It returns default
+ * values in these cases.
+ *
+ * The following values are set:
+ * name = "unknown_entity"
+ * ld_name = "unknown_entity"
+ * owner = unknown_type
+ * type = unknown_type
+ * allocation = allocation_automatic
+ * visibility = visibility_external_allocated
+ * offset = -1
+ * variability = variability_uninitialized
+ * value = SymConst(unknown_entity)
+ * values = NULL
+ * val_paths = NULL
+ * peculiarity = peculiarity_existent
+ * volatility = volatility_non_volatile
+ * stickyness = stickyness_unsticky
+ * ld_name = NULL
+ * overwrites = NULL
+ * overwrittenby = NULL
+ * irg = NULL
+ * link = NULL
+ */
+/* A variable that contains the only unknown entity. */
+extern entity *unknown_entity;
+
+/** Returns the unknown entity */
+entity *get_unknown_entity(void);
+
+/** Encodes how a pointer parameter is accessed. */
+typedef enum acc_bits {
+ ptr_access_none = 0, /**< no access */
+ ptr_access_read = 1, /**< read access */
+ ptr_access_write = 2, /**< write access */
+ ptr_access_rw = ptr_access_read|ptr_access_write, /**< read AND write access */
+ ptr_access_store = 4, /**< the pointer is stored */
+ ptr_access_all = ptr_access_rw|ptr_access_store /**< all possible access */
+} ptr_access_kind;
+
+#define IS_READ(a) ((a) & ptr_access_read)
+#define IS_WRITTEN(a) ((a) & ptr_access_write)
+#define IS_STORED(a) ((a) & ptr_access_store)
+
+#endif /* _ENTITY_H_ */