Now CBMC supports the wrap-entry-point-in-while flag correctly.

Author: NlightNFotis

src/ansi-c/ansi_c_entry_point.cpp

@@ -25,6 +25,7 @@ Author: Daniel Kroening, [email protected]
 #include <linking/static_lifetime_init.h>
 
 #include "ansi_c_entry_point.h"
+#include "ansi_c_language.h"
 #include "c_nondet_symbol_factory.h"
 
 exprt::operandst build_function_environment(
@@ -121,7 +122,8 @@ void record_function_outputs(
 bool ansi_c_entry_point(
   symbol_tablet &symbol_table,
   const std::string &standard_main,
-  message_handlert &message_handler)
+  message_handlert &message_handler,
+  bool wrap_entry_point)
 {
   // check if entry point is already there
   if(symbol_table.symbols.find(goto_functionst::entry_point())!=
@@ -444,7 +446,12 @@ bool ansi_c_entry_point(
         message_handler);
   }
 
-  init_code.move_to_operands(call_main);
+  if (wrap_entry_point) {
+    auto wrapped_main = wrap_entry_point_in_while(call_main);
+    init_code.move_to_operands(wrapped_main);
+  } else {
+    init_code.move_to_operands(call_main);
+  }
 
   // TODO: add read/modified (recursively in call graph) globals as INPUT/OUTPUT
 
@@ -471,3 +478,16 @@ bool ansi_c_entry_point(
 
   return false;
 }
+
+// Build and return a while(true) statement nesting the function call
+// passed as a parameter.
+code_whilet wrap_entry_point_in_while(code_function_callt &call_main)
+{
+  exprt true_expr;
+  code_whilet while_expr;
+  true_expr.make_true();
+  while_expr.cond() = true_expr;
+  while_expr.body() = call_main;
+
+  return while_expr;
+}

src/ansi-c/ansi_c_entry_point.h

@@ -12,10 +12,15 @@ Author: Daniel Kroening, [email protected]
 
 #include <util/symbol_table.h>
 #include <util/message.h>
+#include <util/std_code.h>
 
 bool ansi_c_entry_point(
   symbol_tablet &symbol_table,
   const std::string &standard_main,
-  message_handlert &message_handler);
+  message_handlert &message_handler,
+  bool wrap_entry_point);
+
+code_whilet wrap_entry_point_in_while(
+  code_function_callt &call_main);
 
 #endif // CPROVER_ANSI_C_ANSI_C_ENTRY_POINT_H

src/ansi-c/ansi_c_language.cpp

@@ -13,6 +13,7 @@ Author: Daniel Kroening, [email protected]
 
 #include <util/config.h>
 #include <util/get_base_name.h>
+#include <util/cmdline.h>
 
 #include <linking/linking.h>
 #include <linking/remove_internal_symbols.h>
@@ -26,6 +27,14 @@ Author: Daniel Kroening, [email protected]
 #include "ansi_c_internal_additions.h"
 #include "type2name.h"
 
+void ansi_c_languaget::get_language_options(const cmdlinet &cmd)
+{
+    if (cmd.isset("wrap-entry-point-in-while"))
+    {
+      wrap_entry_point = true;
+    }
+}
+
 std::set<std::string> ansi_c_languaget::extensions() const
 {
   return { "c", "i" };
@@ -126,7 +135,8 @@ bool ansi_c_languaget::typecheck(
 
 bool ansi_c_languaget::final(symbol_tablet &symbol_table)
 {
-  if(ansi_c_entry_point(symbol_table, "main", get_message_handler()))
+  if(ansi_c_entry_point(symbol_table, "main", get_message_handler(),
+                        wrap_entry_point_in_while()))
     return true;
 
   return false;
@@ -211,7 +221,6 @@ bool ansi_c_languaget::to_expr(
      expr.type().id()==ID_empty &&
      expr.operands().size()==1)
     expr=expr.op0();
-
   return result;
 }
 

src/ansi-c/ansi_c_language.h

@@ -22,6 +22,9 @@ Author: Daniel Kroening, [email protected]
 class ansi_c_languaget:public languaget
 {
 public:
+  virtual void get_language_options(
+    const cmdlinet &) override;
+
   bool preprocess(
     std::istream &instream,
     const std::string &path,
@@ -67,6 +70,9 @@ class ansi_c_languaget:public languaget
   languaget *new_language() override
   { return new ansi_c_languaget; }
 
+  bool wrap_entry_point_in_while()
+  { return wrap_entry_point; }
+
   std::string id() const override { return "C"; }
   std::string description() const override { return "ANSI-C 99"; }
   std::set<std::string> extensions() const override;
@@ -76,6 +82,9 @@ class ansi_c_languaget:public languaget
 protected:
   ansi_c_parse_treet parse_tree;
   std::string parse_path;
+
+private:
+  bool wrap_entry_point;
 };
 
 languaget *new_ansi_c_language();

src/cbmc/cbmc_parse_options.cpp

@@ -57,12 +57,16 @@ Author: Daniel Kroening, [email protected]
 
 #include <langapi/mode.h>
 
+#include <ansi-c/ansi_c_language.h>
+
 #include "cbmc_solvers.h"
 #include "cbmc_parse_options.h"
 #include "bmc.h"
 #include "version.h"
 #include "xml_interface.h"
 
+
+
 cbmc_parse_optionst::cbmc_parse_optionst(int argc, const char **argv):
   parse_options_baset(CBMC_OPTIONS, argc, argv),
   xml_interfacet(cmdline),
@@ -181,6 +185,9 @@ void cbmc_parse_optionst::get_command_line_options(optionst &options)
       cmdline.get_value("localize-faults-method"));
   }
 
+  if (cmdline.isset("wrap-entry-point-in-while"))
+    options.set_option("wrap-entry-point-in-while", true);
+
   if(cmdline.isset("unwind"))
     options.set_option("unwind", cmdline.get_value("unwind"));
 
@@ -597,7 +604,6 @@ int cbmc_parse_optionst::get_goto_program(
       }
 
       language->set_message_handler(get_message_handler());
-
       status() << "Parsing " << filename << eom;
 
       if(language->parse(infile, filename))

src/cbmc/cbmc_parse_options.h

@@ -63,6 +63,7 @@ class optionst;
   "(java-cp-include-files):" \
   "(localize-faults)(localize-faults-method):" \
   "(lazy-methods)" \
+  "(wrap-entry-point-in-while)" \
   "(test-invariant-failure)" \
   "(fixedbv)(floatbv)(all-claims)(all-properties)" // legacy, and will eventually disappear // NOLINT(whitespace/line_length)
 

src/cpp/cpp_language.cpp

@@ -16,7 +16,7 @@ Author: Daniel Kroening, [email protected]
 #include <util/config.h>
 #include <util/replace_symbol.h>
 #include <util/get_base_name.h>
-
+#include <util/cmdline.h>
 #include <linking/linking.h>
 
 #include <ansi-c/ansi_c_entry_point.h>
@@ -29,6 +29,14 @@ Author: Daniel Kroening, [email protected]
 #include "cpp_typecheck.h"
 #include "cpp_type2name.h"
 
+void cpp_languaget::get_language_options(const cmdlinet &cmd)
+{
+    if (cmd.isset("wrap-entry-point-in-while"))
+    {
+      wrap_entry_point = true;
+    }
+}
+
 std::set<std::string> cpp_languaget::extensions() const
 {
   std::set<std::string> s;
@@ -135,7 +143,8 @@ bool cpp_languaget::typecheck(
 
 bool cpp_languaget::final(symbol_tablet &symbol_table)
 {
-  if(ansi_c_entry_point(symbol_table, "main", get_message_handler()))
+  if(ansi_c_entry_point(symbol_table, "main", get_message_handler(),
+                        wrap_entry_point_in_while()))
     return true;
 
   return false;

src/cpp/cpp_language.h

@@ -24,6 +24,9 @@ Author: Daniel Kroening, [email protected]
 class cpp_languaget:public languaget
 {
 public:
+  virtual void get_language_options(
+    const cmdlinet &cmd) override;
+
   bool preprocess(
     std::istream &instream,
     const std::string &path,
@@ -85,6 +88,9 @@ class cpp_languaget:public languaget
 
   void modules_provided(std::set<std::string> &modules) override;
 
+  bool wrap_entry_point_in_while()
+  { return wrap_entry_point; }
+
 protected:
   cpp_parse_treet cpp_parse_tree;
   std::string parse_path;
@@ -95,6 +101,9 @@ class cpp_languaget:public languaget
   {
     return "main";
   }
+
+private:
+  bool wrap_entry_point;
 };
 
 languaget *new_cpp_language();

src/goto-cc/compile.cpp

@@ -368,7 +368,7 @@ bool compilet::link()
     symbol_table.remove(goto_functionst::entry_point());
     compiled_functions.function_map.erase(goto_functionst::entry_point());
 
-    if(ansi_c_entry_point(symbol_table, "main", get_message_handler()))
+    if(ansi_c_entry_point(symbol_table, "main", get_message_handler(), false))
       return true;
 
     // entry_point may (should) add some more functions.