cprover
std_types.cpp
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1 /*******************************************************************\
2 
3 Module: Pre-defined types
4 
5 Author: Daniel Kroening, kroening@kroening.com
6  Maria Svorenova, maria.svorenova@diffblue.com
7 
8 \*******************************************************************/
9 
12 
13 #include "std_types.h"
14 
15 #include "c_types.h"
16 #include "namespace.h"
17 #include "std_expr.h"
18 
19 void array_typet::check(const typet &type, const validation_modet vm)
20 {
21  PRECONDITION(type.id() == ID_array);
23  const array_typet &array_type = static_cast<const array_typet &>(type);
24  if(array_type.size().is_nil())
25  {
26  DATA_CHECK(
27  vm,
28  array_type.size() == nil_exprt{},
29  "nil array size must be exactly nil");
30  }
31 }
32 
34 {
35  // we may wish to make the index type part of the array type
36  return c_index_type();
37 }
38 
41  const irep_idt &component_name) const
42 {
43  std::size_t number=0;
44 
45  for(const auto &c : components())
46  {
47  if(c.get_name() == component_name)
48  return number;
49 
50  number++;
51  }
52 
54 }
55 
58  const irep_idt &component_name) const
59 {
60  for(const auto &c : components())
61  {
62  if(c.get_name() == component_name)
63  return c;
64  }
65 
66  return static_cast<const componentt &>(get_nil_irep());
67 }
68 
69 const typet &
70 struct_union_typet::component_type(const irep_idt &component_name) const
71 {
72  const auto &c = get_component(component_name);
73  CHECK_RETURN(c.is_not_nil());
74  return c.type();
75 }
76 
78 {
80 }
81 
83 {
85 }
86 
88  : exprt(ID_base, std::move(base))
89 {
90 }
91 
93 {
94  bases().push_back(baset(base));
95 }
96 
98 {
99  for(const auto &b : bases())
100  {
101  if(to_struct_tag_type(b.type()).get_identifier() == id)
102  return b;
103  }
104  return {};
105 }
106 
111 bool struct_typet::is_prefix_of(const struct_typet &other) const
112 {
113  const componentst &ot_components=other.components();
114  const componentst &tt_components=components();
115 
116  if(ot_components.size()<
117  tt_components.size())
118  return false;
119 
120  componentst::const_iterator
121  ot_it=ot_components.begin();
122 
123  for(const auto &tt_c : tt_components)
124  {
125  if(ot_it->type() != tt_c.type() || ot_it->get_name() != tt_c.get_name())
126  {
127  return false; // they just don't match
128  }
129 
130  ot_it++;
131  }
132 
133  return true; // ok, *this is a prefix of ot
134 }
135 
137 bool is_reference(const typet &type)
138 {
139  return type.id()==ID_pointer &&
140  type.get_bool(ID_C_reference);
141 }
142 
144 bool is_rvalue_reference(const typet &type)
145 {
146  return type.id()==ID_pointer &&
147  type.get_bool(ID_C_rvalue_reference);
148 }
149 
151 {
152  set(ID_from, integer2string(from));
153 }
154 
156 {
157  set(ID_to, integer2string(to));
158 }
159 
161 {
162  return string2integer(get_string(ID_from));
163 }
164 
166 {
167  return string2integer(get_string(ID_to));
168 }
169 
180  const typet &type,
181  const namespacet &ns)
182 {
183  // Helper function to avoid the code duplication in the branches
184  // below.
185  const auto has_constant_components = [&ns](const typet &subtype) -> bool {
186  if(subtype.id() == ID_struct || subtype.id() == ID_union)
187  {
188  const auto &struct_union_type = to_struct_union_type(subtype);
189  for(const auto &component : struct_union_type.components())
190  {
192  return true;
193  }
194  }
195  return false;
196  };
197 
198  // There are 4 possibilities the code below is handling.
199  // The possibilities are enumerated as comments, to show
200  // what each code is supposed to be handling. For more
201  // comprehensive test case for this, take a look at
202  // regression/cbmc/no_nondet_static/main.c
203 
204  // const int a;
205  if(type.get_bool(ID_C_constant))
206  return true;
207 
208  // This is a termination condition to break the recursion
209  // for recursive types such as the following:
210  // struct list { const int datum; struct list * next; };
211  // NOTE: the difference between this condition and the previous
212  // one is that this one always returns.
213  if(type.id() == ID_pointer)
214  return type.get_bool(ID_C_constant);
215 
216  // When we have a case like the following, we don't immediately
217  // see the struct t. Instead, we only get to see symbol t1, which
218  // we have to use the namespace to resolve to its definition:
219  // struct t { const int a; };
220  // struct t t1;
221  if(type.id() == ID_struct_tag || type.id() == ID_union_tag)
222  {
223  const auto &resolved_type = ns.follow(type);
224  return has_constant_components(resolved_type);
225  }
226 
227  // In a case like this, where we see an array (b[3] here), we know that
228  // the array contains subtypes. We get the first one, and
229  // then resolve it to its definition through the usage of the namespace.
230  // struct contains_constant_pointer { int x; int * const p; };
231  // struct contains_constant_pointer b[3] = { {23, &y}, {23, &y}, {23, &y} };
232  if(type.has_subtype())
233  {
234  const auto &subtype = to_type_with_subtype(type).subtype();
236  }
237 
238  return false;
239 }
240 
241 vector_typet::vector_typet(const typet &_subtype, const constant_exprt &_size)
242  : type_with_subtypet(ID_vector, _subtype)
243 {
244  size() = _size;
245 }
246 
248 {
249  // we may wish to make the index type part of the vector type
250  return c_index_type();
251 }
252 
254 {
255  return static_cast<const constant_exprt &>(find(ID_size));
256 }
257 
259 {
260  return static_cast<constant_exprt &>(add(ID_size));
261 }
bitvector_typet c_index_type()
Definition: c_types.cpp:16
Arrays with given size.
Definition: std_types.h:763
static void check(const typet &type, const validation_modet vm=validation_modet::INVARIANT)
Definition: std_types.cpp:19
typet index_type() const
The type of the index expressions into any instance of this type.
Definition: std_types.cpp:33
const exprt & size() const
Definition: std_types.h:790
A constant literal expression.
Definition: std_expr.h:2807
dstringt has one field, an unsigned integer no which is an index into a static table of strings.
Definition: dstring.h:37
Base class for all expressions.
Definition: expr.h:54
typet & type()
Return the type of the expression.
Definition: expr.h:82
bool get_bool(const irep_idt &name) const
Definition: irep.cpp:58
const irept & find(const irep_idt &name) const
Definition: irep.cpp:106
tree_implementationt baset
Definition: irep.h:374
void set(const irep_idt &name, const irep_idt &value)
Definition: irep.h:420
const irep_idt & id() const
Definition: irep.h:396
const std::string & get_string(const irep_idt &name) const
Definition: irep.h:409
irept & add(const irep_idt &name)
Definition: irep.cpp:116
bool is_nil() const
Definition: irep.h:376
const typet & follow(const typet &) const
Resolve type symbol to the type it points to.
Definition: namespace.cpp:49
A namespacet is essentially one or two symbol tables bound together, to allow for symbol lookups in t...
Definition: namespace.h:91
The NIL expression.
Definition: std_expr.h:2874
void set_to(const mp_integer &to)
Definition: std_types.cpp:155
void set_from(const mp_integer &_from)
Definition: std_types.cpp:150
mp_integer get_to() const
Definition: std_types.cpp:165
mp_integer get_from() const
Definition: std_types.cpp:160
A struct tag type, i.e., struct_typet with an identifier.
Definition: std_types.h:449
struct_tag_typet & type()
Definition: std_types.cpp:77
Structure type, corresponds to C style structs.
Definition: std_types.h:231
bool is_prefix_of(const struct_typet &other) const
Returns true if the struct is a prefix of other, i.e., if this struct has n components then the compo...
Definition: std_types.cpp:111
void add_base(const struct_tag_typet &base)
Add a base class/struct.
Definition: std_types.cpp:92
const basest & bases() const
Get the collection of base classes/structs.
Definition: std_types.h:262
optionalt< baset > get_base(const irep_idt &id) const
Return the base with the given name, if exists.
Definition: std_types.cpp:97
const typet & component_type(const irep_idt &component_name) const
Definition: std_types.cpp:70
const componentt & get_component(const irep_idt &component_name) const
Get the reference to a component with given name.
Definition: std_types.cpp:57
const componentst & components() const
Definition: std_types.h:147
std::size_t component_number(const irep_idt &component_name) const
Return the sequence number of the component with given name.
Definition: std_types.cpp:40
std::vector< componentt > componentst
Definition: std_types.h:140
const irep_idt & get_identifier() const
Definition: std_types.h:410
Type with a single subtype.
Definition: type.h:149
const typet & subtype() const
Definition: type.h:156
static void check(const typet &type, const validation_modet vm=validation_modet::INVARIANT)
Definition: type.h:168
The type of an expression, extends irept.
Definition: type.h:29
const typet & subtype() const
Definition: type.h:48
bool has_subtype() const
Definition: type.h:66
vector_typet(const typet &_subtype, const constant_exprt &_size)
Definition: std_types.cpp:241
const constant_exprt & size() const
Definition: std_types.cpp:253
typet index_type() const
The type of any index expression into an instance of this type.
Definition: std_types.cpp:247
const irept & get_nil_irep()
Definition: irep.cpp:20
const mp_integer string2integer(const std::string &n, unsigned base)
Definition: mp_arith.cpp:54
const std::string integer2string(const mp_integer &n, unsigned base)
Definition: mp_arith.cpp:103
nonstd::optional< T > optionalt
Definition: optional.h:35
BigInt mp_integer
Definition: smt_terms.h:12
#define CHECK_RETURN(CONDITION)
Definition: invariant.h:495
#define UNREACHABLE
This should be used to mark dead code.
Definition: invariant.h:503
#define PRECONDITION(CONDITION)
Definition: invariant.h:463
auto component(T &struct_expr, const irep_idt &name, const namespacet &ns) -> decltype(struct_expr.op0())
Definition: std_expr.cpp:48
API to expression classes.
bool is_constant_or_has_constant_components(const typet &type, const namespacet &ns)
Identify whether a given type is constant itself or contains constant components.
Definition: std_types.cpp:179
bool is_reference(const typet &type)
Returns true if the type is a reference.
Definition: std_types.cpp:137
bool is_rvalue_reference(const typet &type)
Returns if the type is an R value reference.
Definition: std_types.cpp:144
Pre-defined types.
const struct_union_typet & to_struct_union_type(const typet &type)
Cast a typet to a struct_union_typet.
Definition: std_types.h:214
const struct_tag_typet & to_struct_tag_type(const typet &type)
Cast a typet to a struct_tag_typet.
Definition: std_types.h:474
const type_with_subtypet & to_type_with_subtype(const typet &type)
Definition: type.h:177
#define DATA_CHECK(vm, condition, message)
This macro takes a condition which denotes a well-formedness criterion on goto programs,...
Definition: validate.h:22
validation_modet