C++ front-end: various fixes and DEBUG

Author: tautschnig

src/ansi-c/scanner.l

@@ -1458,7 +1458,7 @@ __decltype          { if(PARSER.cpp98 &&
 "_Atomic"{ws}"(" { // put back all but _Atomic
                    yyless(7);
 
-                   if(!PARSER.cpp98 &&
+                   if((!PARSER.cpp98 || PARSER.cpp11) &&
                       (PARSER.mode==configt::ansi_ct::flavourt::GCC ||
                        PARSER.mode==configt::ansi_ct::flavourt::CLANG ||
                        PARSER.mode==configt::ansi_ct::flavourt::ARM))

src/cpp/cpp_typecheck_template.cpp

@@ -20,6 +20,8 @@ Author: Daniel Kroening, kroening@cs.cmu.edu
 #include "cpp_type2name.h"
 #include "cpp_typecheck.h"
 
+#include <iostream>
+
 void cpp_typecheckt::salvage_default_arguments(
   const template_typet &old_type,
   template_typet &new_type)
@@ -714,6 +716,7 @@ cpp_scopet &cpp_typecheckt::typecheck_template_parameters(
   // put template parameters into this scope
   template_typet::template_parameterst &parameters=
     type.template_parameters();
+  std::cerr << type.pretty() << std::endl;
 
   unsigned anon_count=0;
 
@@ -730,6 +733,7 @@ cpp_scopet &cpp_typecheckt::typecheck_template_parameters(
     cpp_declarator_convertert cpp_declarator_converter(*this);
 
     // there must be _one_ declarator
+    std::cerr << declaration.pretty() << std::endl;
     PRECONDITION(declaration.declarators().size() == 1);
 
     cpp_declaratort &declarator=declaration.declarators().front();

src/cpp/parse.cpp

@@ -778,7 +778,7 @@ bool Parser::isTypeSpecifier()
          t == TOK_CPROVER_BOOL || t == TOK_CLASS || t == TOK_STRUCT ||
          t == TOK_UNION || t == TOK_ENUM || t == TOK_INTERFACE ||
          t == TOK_TYPENAME || t == TOK_TYPEOF || t == TOK_DECLTYPE ||
-         t == TOK_UNDERLYING_TYPE;
+         t == TOK_UNDERLYING_TYPE || t == TOK_ATOMIC_TYPE_SPECIFIER;
 }
 
 /*
@@ -1343,7 +1343,7 @@ bool Parser::rTempArgDeclaration(cpp_declarationt &declaration)
     if(lex.get_token(tk1) != TOK_CLASS)
       return false;
 
-    if(lex.LookAhead(0) == ',')
+    if(lex.LookAhead(0) == ',' || lex.LookAhead(0) == '>')
       return true;
 
     if(!is_identifier(lex.get_token(tk2)))
@@ -2502,6 +2502,17 @@ bool Parser::optAttribute(typet &t)
         break;
       }
 
+      case TOK_GCC_IDENTIFIER:
+        if(tk.text == "clang" && lex.LookAhead(0) == TOK_SCOPE)
+        {
+          exprt discarded;
+          if(!rExpression(discarded, false))
+            return false;
+        }
+        else
+          return false;
+        break;
+
     default:
       // TODO: way may wish to change this: GCC, Clang, Visual Studio merely
       // warn when they see an attribute that they don't recognize
@@ -2737,8 +2748,34 @@ bool Parser::optIntegralTypeOrClassSpec(typet &p)
 
     return true;
   }
+  else if(t == TOK_ATOMIC_TYPE_SPECIFIER)
+  {
+#ifdef DEBUG
+    std::cout << std::string(__indent, ' ')
+              << "Parser::optIntegralTypeOrClassSpec 9\n";
+#endif // DEBUG
+    cpp_tokent atomic_tk;
+    lex.get_token(atomic_tk);
+
+    cpp_tokent tk;
+    if(lex.get_token(tk)!='(')
+      return false;
+
+    // the argument is always a type
+    if(!rTypeSpecifier(p, false))
+      return false;
+
+    if(lex.get_token(tk)!=')')
+      return false;
+
+    return true;
+  }
   else
   {
+#ifdef DEBUG
+    std::cout << std::string(__indent, ' ')
+              << "Parser::optIntegralTypeOrClassSpec 10\n";
+#endif // DEBUG
     p.make_nil();
     return true;
   }
@@ -4549,6 +4586,9 @@ bool Parser::rEnumSpec(typet &spec)
     spec.set(ID_C_class, true);
   }
 
+  if(!optAttribute(spec))
+    return false;
+
   if(lex.LookAhead(0)!='{' &&
      lex.LookAhead(0)!=':')
   {
@@ -7903,7 +7943,9 @@ std::optional<codet> Parser::rStatement()
       if(!rUsing(cpp_using))
         return {};
 
-      UNIMPLEMENTED;
+      codet statement(ID_cpp_using);
+      // UNIMPLEMENTED;
+      return std::move(statement);
     }
 
   case TOK_STATIC_ASSERT:
@@ -7920,6 +7962,14 @@ std::optional<codet> Parser::rStatement()
       return std::move(statement);
     }
 
+  case '[':
+    {
+      typet discard;
+      if(!optAttribute(discard))
+        return {};
+      return code_blockt{};
+    }
+
   default:
     return rExprStatement();
   }