cprover
mm_io.cpp
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1 /*******************************************************************\
2 
3 Module: Perform Memory-mapped I/O instrumentation
4 
5 Author: Daniel Kroening
6 
7 Date: April 2017
8 
9 \*******************************************************************/
10 
13 
14 #include "mm_io.h"
15 
18 #include <util/replace_expr.h>
19 
20 #include "remove_returns.h"
21 
23  const exprt &src,
24  std::set<dereference_exprt> &dest)
25 {
26  if(src.id()==ID_dereference)
27  dest.insert(to_dereference_expr(src));
28 
29  for(const auto & op : src.operands())
30  collect_deref_expr(op, dest); // recursive call
31 }
32 
33 void mm_io(
34  const exprt &mm_io_r,
35  const exprt &mm_io_w,
36  goto_functionst::goto_functiont &goto_function,
37  const namespacet &ns)
38 {
39  for(goto_programt::instructionst::iterator it=
40  goto_function.body.instructions.begin();
41  it!=goto_function.body.instructions.end();
42  it++)
43  {
44  std::set<dereference_exprt> deref_expr_w, deref_expr_r;
45 
46  if(it->is_assign())
47  {
48  auto &a=to_code_assign(it->code);
49  collect_deref_expr(a.rhs(), deref_expr_r);
50 
51  if(mm_io_r.is_not_nil())
52  {
53  if(deref_expr_r.size()==1)
54  {
55  const dereference_exprt &d=*deref_expr_r.begin();
56  source_locationt source_location=it->source_location;
57  irep_idt function=it->function;
58  const code_typet &ct=to_code_type(mm_io_r.type());
59 
60  irep_idt identifier=to_symbol_expr(mm_io_r).get_identifier();
61  irep_idt r_identifier=id2string(identifier)+RETURN_VALUE_SUFFIX;
62  symbol_exprt return_value(r_identifier, ct.return_type());
63  if_exprt if_expr(integer_address(d.pointer()), return_value, d);
64  replace_expr(d, if_expr, a.rhs());
65 
66  const typet &pt=ct.parameters()[0].type();
67  const typet &st=ct.parameters()[1].type();
68  exprt size=size_of_expr(d.type(), ns);
69  const code_function_callt fc(
70  mm_io_r,
71  {typecast_exprt(d.pointer(), pt), typecast_exprt(size, st)});
72  goto_function.body.insert_before_swap(it);
73  it->make_function_call(fc);
74  it->source_location=source_location;
75  it->function=function;
76  it++;
77  }
78  }
79 
80  if(mm_io_w.is_not_nil())
81  {
82  if(a.lhs().id()==ID_dereference)
83  {
84  const dereference_exprt &d=to_dereference_expr(a.lhs());
85  source_locationt source_location=it->source_location;
86  irep_idt function=it->function;
87  const code_typet &ct=to_code_type(mm_io_w.type());
88  const typet &pt=ct.parameters()[0].type();
89  const typet &st=ct.parameters()[1].type();
90  const typet &vt=ct.parameters()[2].type();
91  exprt size=size_of_expr(d.type(), ns);
92  const code_function_callt fc(
93  mm_io_w,
94  {typecast_exprt(d.pointer(), pt),
95  typecast_exprt(size, st),
96  typecast_exprt(a.rhs(), vt)});
97  goto_function.body.insert_before_swap(it);
98  it->make_function_call(fc);
99  it->source_location=source_location;
100  it->function=function;
101  it++;
102  }
103  }
104  }
105  }
106 }
107 
108 void mm_io(
109  const symbol_tablet &symbol_table,
110  goto_functionst &goto_functions)
111 {
112  const namespacet ns(symbol_table);
113  exprt mm_io_r=nil_exprt(), mm_io_w=nil_exprt();
114 
115  irep_idt id_r=CPROVER_PREFIX "mm_io_r";
116  irep_idt id_w=CPROVER_PREFIX "mm_io_w";
117 
118  auto maybe_symbol=symbol_table.lookup(id_r);
119  if(maybe_symbol)
120  mm_io_r=maybe_symbol->symbol_expr();
121 
122  maybe_symbol=symbol_table.lookup(id_w);
123  if(maybe_symbol)
124  mm_io_w=maybe_symbol->symbol_expr();
125 
126  for(auto & f : goto_functions.function_map)
127  mm_io(mm_io_r, mm_io_w, f.second, ns);
128 }
129 
130 void mm_io(goto_modelt &model)
131 {
132  mm_io(model.symbol_table, model.goto_functions);
133 }
dstringt
dstringt has one field, an unsigned integer no which is an index into a static table of strings.
Definition: dstring.h:35
pointer_offset_size.h
symbol_tablet
The symbol table.
Definition: symbol_table.h:19
typet
The type of an expression, extends irept.
Definition: type.h:27
mm_io
void mm_io(const exprt &mm_io_r, const exprt &mm_io_w, goto_functionst::goto_functiont &goto_function, const namespacet &ns)
Definition: mm_io.cpp:33
dereference_exprt
Operator to dereference a pointer.
Definition: std_expr.h:3355
if_exprt
The trinary if-then-else operator.
Definition: std_expr.h:3427
pointer_predicates.h
exprt
Base class for all expressions.
Definition: expr.h:54
goto_modelt
Definition: goto_model.h:24
goto_functionst::function_map
function_mapt function_map
Definition: goto_functions.h:27
symbol_exprt
Expression to hold a symbol (variable)
Definition: std_expr.h:143
namespacet
A namespacet is essentially one or two symbol tables bound together, to allow for symbol lookups in t...
Definition: namespace.h:93
exprt::type
typet & type()
Return the type of the expression.
Definition: expr.h:68
code_function_callt
codet representation of a function call statement.
Definition: std_code.h:1036
irept::is_not_nil
bool is_not_nil() const
Definition: irep.h:173
collect_deref_expr
void collect_deref_expr(const exprt &src, std::set< dereference_exprt > &dest)
Definition: mm_io.cpp:22
to_code_type
const code_typet & to_code_type(const typet &type)
Cast a typet to a code_typet.
Definition: std_types.h:982
mm_io.h
size_of_expr
exprt size_of_expr(const typet &type, const namespacet &ns)
Definition: pointer_offset_size.cpp:292
id2string
const std::string & id2string(const irep_idt &d)
Definition: irep.h:44
symbol_exprt::get_identifier
const irep_idt & get_identifier() const
Definition: std_expr.h:176
nil_exprt
The NIL expression.
Definition: std_expr.h:4461
dereference_exprt::pointer
exprt & pointer()
Definition: std_expr.h:3380
symbolt::symbol_expr
class symbol_exprt symbol_expr() const
Produces a symbol_exprt for a symbol.
Definition: symbol.cpp:121
integer_address
exprt integer_address(const exprt &pointer)
Definition: pointer_predicates.cpp:128
to_symbol_expr
const symbol_exprt & to_symbol_expr(const exprt &expr)
Cast an exprt to a symbol_exprt.
Definition: std_expr.h:251
code_typet
Base type of functions.
Definition: std_types.h:751
irept::id
const irep_idt & id() const
Definition: irep.h:259
code_typet::parameters
const parameterst & parameters() const
Definition: std_types.h:893
RETURN_VALUE_SUFFIX
#define RETURN_VALUE_SUFFIX
Definition: remove_returns.h:21
remove_returns.h
source_locationt
Definition: source_location.h:20
goto_functionst::goto_functiont
::goto_functiont goto_functiont
Definition: goto_functions.h:25
goto_functionst
A collection of goto functions.
Definition: goto_functions.h:22
to_dereference_expr
const dereference_exprt & to_dereference_expr(const exprt &expr)
Cast an exprt to a dereference_exprt.
Definition: std_expr.h:3397
goto_modelt::goto_functions
goto_functionst goto_functions
GOTO functions.
Definition: goto_model.h:32
to_code_assign
const code_assignt & to_code_assign(const codet &code)
Definition: std_code.h:334
replace_expr
bool replace_expr(const exprt &what, const exprt &by, exprt &dest)
Definition: replace_expr.cpp:12
CPROVER_PREFIX
#define CPROVER_PREFIX
Definition: cprover_prefix.h:14
symbol_table_baset::lookup
const symbolt * lookup(const irep_idt &name) const
Find a symbol in the symbol table for read-only access.
Definition: symbol_table_base.h:86
code_typet::return_type
const typet & return_type() const
Definition: std_types.h:883
replace_expr.h
exprt::operands
operandst & operands()
Definition: expr.h:78
typecast_exprt
Semantic type conversion.
Definition: std_expr.h:2277
exprt::source_location
const source_locationt & source_location() const
Definition: expr.h:228
goto_modelt::symbol_table
symbol_tablet symbol_table
Symbol table.
Definition: goto_model.h:29