Use vector instead of list for get_value_set result

vectors are generally more efficient than list, unless we use
concatenation or insertion which doesn't appear to be case here.

Author: romainbrenguier

src/goto-symex/postcondition.cpp

@@ -160,16 +160,13 @@ bool postconditiont::is_used(
   else if(expr.id()==ID_dereference)
   {
     // aliasing may happen here
-    value_setst::valuest expr_set =
+    std::vector<exprt> expr_set =
       value_set.get_value_set(to_dereference_expr(expr).pointer(), ns);
     std::unordered_set<irep_idt> symbols;
 
-    for(value_setst::valuest::const_iterator
-        it=expr_set.begin();
-        it!=expr_set.end();
-        it++)
+    for(const exprt &e : expr_set)
     {
-      const exprt tmp = get_original_name(*it);
+      const exprt tmp = get_original_name(e);
       find_symbols(tmp, symbols);
     }
 

src/goto-symex/precondition.cpp

@@ -112,15 +112,12 @@ void preconditiont::compute_rec(exprt &dest)
 
     // aliasing may happen here
 
-    value_setst::valuest expr_set = value_sets.get_values(
+    const std::vector<exprt> expr_set = value_sets.get_values(
       SSA_step.source.function_id, target, deref_expr.pointer());
     std::unordered_set<irep_idt> symbols;
 
-    for(value_setst::valuest::const_iterator
-        it=expr_set.begin();
-        it!=expr_set.end();
-        it++)
-      find_symbols(*it, symbols);
+    for(const exprt &e : expr_set)
+      find_symbols(e, symbols);
 
     if(symbols.find(lhs_identifier)!=symbols.end())
     {

src/goto-symex/symex_dereference_state.cpp

@@ -105,7 +105,7 @@ void symex_dereference_statet::get_value_set(
 }
 
 /// Just forwards a value-set query to `state.value_set`
-value_setst::valuest
+std::vector<exprt>
 symex_dereference_statet::get_value_set(const exprt &expr) const
 {
   return state.value_set.get_value_set(expr, ns);

src/goto-symex/symex_dereference_state.h

@@ -38,7 +38,7 @@ class symex_dereference_statet:
   void get_value_set(const exprt &expr, value_setst::valuest &value_set)
     const override;
 
-  value_setst::valuest get_value_set(const exprt &expr) const override;
+  std::vector<exprt> get_value_set(const exprt &expr) const override;
 
   const symbolt *get_or_create_failed_symbol(const exprt &expr) override;
 };

src/pointer-analysis/dereference_callback.h

@@ -33,7 +33,7 @@ class dereference_callbackt
   virtual void
   get_value_set(const exprt &expr, value_setst::valuest &value_set) const = 0;
 
-  virtual value_setst::valuest get_value_set(const exprt &expr) const = 0;
+  virtual std::vector<exprt> get_value_set(const exprt &expr) const = 0;
 
   virtual const symbolt *get_or_create_failed_symbol(const exprt &expr) = 0;
 };

src/pointer-analysis/goto_program_dereference.cpp

@@ -151,7 +151,7 @@ void goto_program_dereferencet::get_value_set(
 /// expression \p expr.
 /// \param expr: an expression
 /// \return the value set
-std::list<exprt>
+std::vector<exprt>
 goto_program_dereferencet::get_value_set(const exprt &expr) const
 {
   return value_sets.get_values(current_function, current_target, expr);

src/pointer-analysis/goto_program_dereference.h

@@ -65,11 +65,11 @@ class goto_program_dereferencet:protected dereference_callbackt
 
   const symbolt *get_or_create_failed_symbol(const exprt &expr) override;
 
-  DEPRECATED(SINCE(2019, 05, 22, "use list returning version instead"))
+  DEPRECATED(SINCE(2019, 05, 22, "use vector returning version instead"))
   void
   get_value_set(const exprt &expr, value_setst::valuest &dest) const override;
 
-  std::list<exprt> get_value_set(const exprt &expr) const override;
+  std::vector<exprt> get_value_set(const exprt &expr) const override;
 
   void dereference_instruction(
     goto_programt::targett target,

src/pointer-analysis/value_set.cpp

@@ -370,7 +370,7 @@ void value_sett::get_value_set(
   #endif
 }
 
-std::list<exprt>
+std::vector<exprt>
 value_sett::get_value_set(exprt expr, const namespacet &ns) const
 {
   const object_mapt object_map = get_value_set(std::move(expr), ns, false);

src/pointer-analysis/value_set.h

@@ -276,7 +276,8 @@ class value_sett
   /// \param expr: query expression
   /// \param ns: global namespace
   /// \return list of expressions that `expr` may point to
-  std::list<exprt> get_value_set(exprt expr, const namespacet &ns) const;
+  std::vector<exprt>
+  get_value_set(exprt expr, const namespacet &ns) const;
 
   /// Appears to be unimplemented.
   DEPRECATED(SINCE(2019, 05, 22, "Unimplemented"))

src/pointer-analysis/value_set_analysis.h

@@ -76,7 +76,7 @@ class value_set_analysis_templatet:
   }
 
   // interface value_sets
-  std::list<exprt>
+  std::vector<exprt>
   get_values(const irep_idt &, locationt l, const exprt &expr) override
   {
     return (*this)[l].value_set.get_value_set(expr, baset::ns);