cprover
convert_java_nondet.cpp
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1 /*******************************************************************\
2 
3 Module: Convert side_effect_expr_nondett expressions
4 
5 Author: Reuben Thomas, reuben.thomas@diffblue.com
6 
7 \*******************************************************************/
8 
11 
12 #include "convert_java_nondet.h"
13 
17 
18 #include "java_object_factory.h" // gen_nondet_init
20 #include "java_utils.h"
21 
24 static bool is_nondet_pointer(exprt expr)
25 {
26  // If the expression type doesn't have a subtype then I guess it's primitive
27  // and we do not want to convert it. If the type is a ptr-to-void or a
28  // function pointer then we also do not want to convert it.
29  const typet &type = expr.type();
30  const bool non_void_non_function_pointer = type.id() == ID_pointer &&
31  type.subtype().id() != ID_empty &&
32  type.subtype().id() != ID_code;
34  non_void_non_function_pointer;
35 }
36 
40  const symbol_exprt &aux_symbol_expr,
41  const source_locationt &source_loc,
42  symbol_table_baset &symbol_table,
43  message_handlert &message_handler,
44  const java_object_factory_parameterst &object_factory_parameters,
45  const irep_idt &mode)
46 {
47  code_blockt gen_nondet_init_code;
48  const bool skip_classid = true;
50  aux_symbol_expr,
51  gen_nondet_init_code,
52  symbol_table,
53  source_loc,
54  skip_classid,
56  object_factory_parameters,
58  message_handler);
59 
60  goto_programt instructions;
62  gen_nondet_init_code, symbol_table, instructions, message_handler, mode);
63  return instructions;
64 }
65 
79 static std::pair<goto_programt::targett, bool> insert_nondet_init_code(
80  const irep_idt &function_identifier,
81  goto_programt &goto_program,
82  const goto_programt::targett &target,
83  symbol_table_baset &symbol_table,
84  message_handlert &message_handler,
85  java_object_factory_parameterst object_factory_parameters,
86  const irep_idt &mode)
87 {
88  const auto next_instr = std::next(target);
89 
90  // We only expect to find nondets in the rhs of an assignments, and in return
91  // statements if remove_returns has not been run, but we do a more general
92  // check on all operands in case this changes
93  for(exprt &op : target->code_nonconst().operands())
94  {
95  if(!is_nondet_pointer(op))
96  {
97  continue;
98  }
99 
100  const auto &nondet_expr = to_side_effect_expr_nondet(op);
101 
102  if(!nondet_expr.get_nullable())
103  object_factory_parameters.min_null_tree_depth = 1;
104 
105  const source_locationt &source_loc = target->source_location();
106 
107  // Currently the code looks like this
108  // target: instruction containing op
109  // When we are done it will look like this
110  // target : declare aux_symbol
111  // . <gen_nondet_init_instructions - many lines>
112  // . <gen_nondet_init_instructions - many lines>
113  // . <gen_nondet_init_instructions - many lines>
114  // target2: instruction containing op, with op replaced by aux_symbol
115  // dead aux_symbol
116 
117  symbolt &aux_symbol = fresh_java_symbol(
118  op.type(), "nondet_tmp", source_loc, function_identifier, symbol_table);
119 
120  const symbol_exprt aux_symbol_expr = aux_symbol.symbol_expr();
121  op = aux_symbol_expr;
122 
123  // Insert an instruction declaring `aux_symbol` before `target`, being
124  // careful to preserve jumps to `target`
125  goto_programt::instructiont decl_aux_symbol =
126  goto_programt::make_decl(code_declt(aux_symbol_expr), source_loc);
127  goto_program.insert_before_swap(target, decl_aux_symbol);
128 
129  // Keep track of the new location of the instruction containing op.
130  const goto_programt::targett target2 = std::next(target);
131 
132  goto_programt gen_nondet_init_instructions =
134  aux_symbol_expr,
135  source_loc,
136  symbol_table,
137  message_handler,
138  object_factory_parameters,
139  mode);
140  goto_program.destructive_insert(target2, gen_nondet_init_instructions);
141 
142  goto_program.insert_after(
143  target2, goto_programt::make_dead(aux_symbol_expr, source_loc));
144 
145  // In theory target could have more than one operand which should be
146  // replaced by convert_nondet, so we return target2 so that it
147  // will be checked again
148  return std::make_pair(target2, true);
149  }
150 
151  return std::make_pair(next_instr, false);
152 }
153 
165  const irep_idt &function_identifier,
166  goto_programt &goto_program,
167  symbol_table_baset &symbol_table,
168  message_handlert &message_handler,
169  const java_object_factory_parameterst &user_object_factory_parameters,
170  const irep_idt &mode)
171 {
172  java_object_factory_parameterst object_factory_parameters =
173  user_object_factory_parameters;
174  object_factory_parameters.function_id = function_identifier;
175 
176  bool changed = false;
177  auto instruction_iterator = goto_program.instructions.begin();
178 
179  while(instruction_iterator != goto_program.instructions.end())
180  {
181  auto ret = insert_nondet_init_code(
182  function_identifier,
183  goto_program,
184  instruction_iterator,
185  symbol_table,
186  message_handler,
187  object_factory_parameters,
188  mode);
189  instruction_iterator = ret.first;
190  changed |= ret.second;
191  }
192 
193  if(changed)
194  {
195  goto_program.update();
196  }
197 }
198 
200  goto_model_functiont &function,
201  message_handlert &message_handler,
202  const java_object_factory_parameterst &object_factory_parameters,
203  const irep_idt &mode)
204 {
206  function.get_function_id(),
207  function.get_goto_function().body,
208  function.get_symbol_table(),
209  message_handler,
210  object_factory_parameters,
211  mode);
212 
213  function.compute_location_numbers();
214 }
215 
217  goto_functionst &goto_functions,
218  symbol_table_baset &symbol_table,
219  message_handlert &message_handler,
220  const java_object_factory_parameterst &object_factory_parameters)
221 {
222  const namespacet ns(symbol_table);
223 
224  for(auto &f_it : goto_functions.function_map)
225  {
226  const symbolt &symbol=ns.lookup(f_it.first);
227 
228  if(symbol.mode==ID_java)
229  {
231  f_it.first,
232  f_it.second.body,
233  symbol_table,
234  message_handler,
235  object_factory_parameters,
236  symbol.mode);
237  }
238  }
239 
240  goto_functions.compute_location_numbers();
241 
242  remove_skip(goto_functions);
243 }
244 
246  goto_modelt &goto_model,
247  message_handlert &message_handler,
248  const java_object_factory_parameterst &object_factory_parameters)
249 {
251  goto_model.goto_functions,
252  goto_model.symbol_table,
253  message_handler,
254  object_factory_parameters);
255 }
@ DYNAMIC
Allocate dynamic objects (using ALLOCATE)
A codet representing sequential composition of program statements.
Definition: std_code.h:130
A codet representing the declaration of a local variable.
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
operandst & operands()
Definition: expr.h:92
A collection of goto functions.
function_mapt function_map
void compute_location_numbers()
Interface providing access to a single function in a GOTO model, plus its associated symbol table.
Definition: goto_model.h:183
symbol_tablet symbol_table
Symbol table.
Definition: goto_model.h:30
goto_functionst goto_functions
GOTO functions.
Definition: goto_model.h:33
This class represents an instruction in the GOTO intermediate representation.
Definition: goto_program.h:180
A generic container class for the GOTO intermediate representation of one function.
Definition: goto_program.h:73
instructionst instructions
The list of instructions in the goto program.
Definition: goto_program.h:598
static instructiont make_dead(const symbol_exprt &symbol, const source_locationt &l=source_locationt::nil())
Definition: goto_program.h:956
void update()
Update all indices.
void insert_before_swap(targett target)
Insertion that preserves jumps to "target".
Definition: goto_program.h:619
void destructive_insert(const_targett target, goto_programt &p)
Inserts the given program p before target.
Definition: goto_program.h:706
instructionst::iterator targett
Definition: goto_program.h:592
targett insert_after(const_targett target)
Insertion after the instruction pointed-to by the given instruction iterator target.
Definition: goto_program.h:684
static instructiont make_decl(const symbol_exprt &symbol, const source_locationt &l=source_locationt::nil())
Definition: goto_program.h:949
const irep_idt & id() const
Definition: irep.h:396
A namespacet is essentially one or two symbol tables bound together, to allow for symbol lookups in t...
Definition: namespace.h:91
bool lookup(const irep_idt &name, const symbolt *&symbol) const override
See documentation for namespace_baset::lookup().
Definition: namespace.cpp:138
Expression to hold a symbol (variable)
Definition: std_expr.h:80
The symbol table base class interface.
Symbol table entry.
Definition: symbol.h:28
class symbol_exprt symbol_expr() const
Produces a symbol_exprt for a symbol.
Definition: symbol.cpp:121
irep_idt mode
Language mode.
Definition: symbol.h:49
The type of an expression, extends irept.
Definition: type.h:29
const typet & subtype() const
Definition: type.h:48
static bool is_nondet_pointer(exprt expr)
Returns true if expr is a nondet pointer that isn't a function pointer or a void* pointer as these ca...
static goto_programt get_gen_nondet_init_instructions(const symbol_exprt &aux_symbol_expr, const source_locationt &source_loc, symbol_table_baset &symbol_table, message_handlert &message_handler, const java_object_factory_parameterst &object_factory_parameters, const irep_idt &mode)
Populate instructions with goto instructions to nondet init aux_symbol_expr
void convert_nondet(const irep_idt &function_identifier, goto_programt &goto_program, symbol_table_baset &symbol_table, message_handlert &message_handler, const java_object_factory_parameterst &user_object_factory_parameters, const irep_idt &mode)
For each instruction in the goto program, checks if it is an assignment from nondet and replaces it w...
static std::pair< goto_programt::targett, bool > insert_nondet_init_code(const irep_idt &function_identifier, goto_programt &goto_program, const goto_programt::targett &target, symbol_table_baset &symbol_table, message_handlert &message_handler, java_object_factory_parameterst object_factory_parameters, const irep_idt &mode)
Checks an instruction to see whether it contains an assignment from side_effect_expr_nondet.
Convert side_effect_expr_nondett expressions using java_object_factory.
void goto_convert(const codet &code, symbol_table_baset &symbol_table, goto_programt &dest, message_handlert &message_handler, const irep_idt &mode)
Program Transformation.
Symbol Table + CFG.
void gen_nondet_init(const exprt &expr, code_blockt &init_code, symbol_table_baset &symbol_table, const source_locationt &loc, bool skip_classid, lifetimet lifetime, const java_object_factory_parameterst &object_factory_parameters, const select_pointer_typet &pointer_type_selector, update_in_placet update_in_place, message_handlert &log)
Initializes a primitive-typed or reference-typed object tree rooted at expr, allocating child objects...
This module is responsible for the synthesis of code (in the form of a sequence of codet statements) ...
symbolt & fresh_java_symbol(const typet &type, const std::string &basename_prefix, const source_locationt &source_location, const irep_idt &function_name, symbol_table_baset &symbol_table)
Definition: java_utils.cpp:558
void remove_skip(goto_programt &goto_program, goto_programt::targett begin, goto_programt::targett end)
remove unnecessary skip statements
Definition: remove_skip.cpp:88
Program Transformation.
bool can_cast_expr< side_effect_expr_nondett >(const exprt &base)
Definition: std_code.h:1540
side_effect_expr_nondett & to_side_effect_expr_nondet(exprt &expr)
Definition: std_code.h:1548
irep_idt function_id
Function id, used as a prefix for identifiers of temporaries.
size_t min_null_tree_depth
To force a certain depth of non-null objects.