introduce __CPROVER_map type

This introduces C syntax for a type

  __CPROVER_map domain -> codomain

where domain is a list of types and codomain is a type.  The type is
internal, for modeling purposes.  It replaces arrays with size
__CPROVER_infinity, which are now deprecated.

Author: kroening

src/ansi-c/c_typecheck_base.h

@@ -21,6 +21,7 @@ Author: Daniel Kroening, [email protected]
 
 class ansi_c_declarationt;
 class c_bit_field_typet;
+class mathematical_function_typet;
 class shift_exprt;
 
 class c_typecheck_baset:
@@ -237,6 +238,7 @@ class c_typecheck_baset:
   virtual void typecheck_code_type(code_typet &type);
   virtual void typecheck_typedef_type(typet &type);
   virtual void typecheck_c_bit_field_type(c_bit_field_typet &type);
+  virtual void typecheck_map_type(mathematical_function_typet &);
   virtual void typecheck_typeof_type(typet &type);
   virtual void typecheck_array_type(array_typet &type);
   virtual void typecheck_vector_type(typet &type);

src/ansi-c/c_typecheck_type.cpp

@@ -114,6 +114,10 @@ void c_typecheck_baset::typecheck_type(typet &type)
   {
     typecheck_vector_type(type);
   }
+  else if(type.id() == ID_mathematical_function)
+  {
+    typecheck_map_type(to_mathematical_function_type(type));
+  }
   else if(type.id()==ID_custom_unsignedbv ||
           type.id()==ID_custom_signedbv ||
           type.id()==ID_custom_floatbv ||
@@ -728,7 +732,6 @@ void c_typecheck_baset::typecheck_vector_type(typet &type)
     error() << "type had size 0: '" << to_string(subtype) << "'" << eom;
     throw 0;
   }
-
   // adjust by width of base type
   if(s % *sub_size != 0)
   {
@@ -748,6 +751,14 @@ void c_typecheck_baset::typecheck_vector_type(typet &type)
   type = new_type;
 }
 
+void c_typecheck_baset::typecheck_map_type(mathematical_function_typet &type)
+{
+  for(auto &t : type.domain())
+    typecheck_type(t);
+
+  typecheck_type(type.codomain());
+}
+
 void c_typecheck_baset::typecheck_compound_type(struct_union_typet &type)
 {
   // These get replaced by symbol types later.

src/ansi-c/expr2c.cpp

@@ -613,6 +613,27 @@ std::string expr2ct::convert_rec(
 
     return q+dest+d;
   }
+  else if(src.id() == ID_mathematical_function)
+  {
+    const mathematical_function_typet &function_type =
+      to_mathematical_function_type(src);
+    std::string dest = "__CPROVER_map ";
+    bool first = true;
+    for(auto &t : function_type.domain())
+    {
+      if(first)
+        first = false;
+      else
+        dest += ", ";
+
+      dest += convert(t);
+    }
+
+    dest += " -> ";
+    dest += convert(function_type.codomain());
+
+    return q + dest + d;
+  }
   else if(src.id()==ID_constructor ||
           src.id()==ID_destructor)
   {

src/ansi-c/parser.y

@@ -195,6 +195,7 @@ extern char *yyansi_ctext;
 %token TOK_CPROVER_BITVECTOR "__CPROVER_bitvector"
 %token TOK_CPROVER_FLOATBV "__CPROVER_floatbv"
 %token TOK_CPROVER_FIXEDBV "__CPROVER_fixedbv"
+%token TOK_CPROVER_MAP "__CPROVER_map"
 %token TOK_CPROVER_ATOMIC "__CPROVER_atomic"
 %token TOK_CPROVER_BOOL "__CPROVER_bool"
 %token TOK_CPROVER_THROW "__CPROVER_throw"
@@ -1090,6 +1091,7 @@ type_specifier:
         | typedef_type_specifier
         | typeof_type_specifier
         | atomic_type_specifier
+        | map_type_specifier
         ;
 
 declaration_qualifier_list:
@@ -1533,6 +1535,18 @@ array_of_construct:
         { $$=$1; stack_type($$).subtype().swap(parser_stack($2)); }
         ;
 
+map_type_specifier:
+          TOK_CPROVER_MAP type_specifier TOK_ARROW type_specifier
+        {
+          $$=$1;
+          parser_stack($$).id(ID_mathematical_function);
+          irept domain;
+          domain.move_to_sub(parser_stack($2));
+          parser_stack($$).move_to_sub(domain);
+          mts($$, $4);
+        }
+        ;
+
 pragma_packed:
         {
           init($$);

src/ansi-c/scanner.l

@@ -1281,6 +1281,7 @@ __decltype          { if(PARSER.cpp98 &&
 {CPROVER_PREFIX}"bitvector"    { loc(); return TOK_CPROVER_BITVECTOR; }
 {CPROVER_PREFIX}"floatbv"      { loc(); return TOK_CPROVER_FLOATBV; }
 {CPROVER_PREFIX}"fixedbv"      { loc(); return TOK_CPROVER_FIXEDBV; }
+{CPROVER_PREFIX}"map"          { loc(); return TOK_CPROVER_MAP; }
 {CPROVER_PREFIX}"bool"         { loc(); return TOK_CPROVER_BOOL; }
 {CPROVER_PREFIX}"throw"        { loc(); return TOK_CPROVER_THROW; }
 {CPROVER_PREFIX}"catch"        { loc(); return TOK_CPROVER_CATCH; }