gcc/go/gofrontend/unsafe.cc

   1 // unsafe.cc -- Go frontend builtin unsafe package.
   2
   3 // Copyright 2009 The Go Authors. All rights reserved.
   4 // Use of this source code is governed by a BSD-style
   5 // license that can be found in the LICENSE file.
   6
   7 #include "go-system.h"
   8
   9 #include "go-c.h"
  10 #include "types.h"
  11 #include "gogo.h"
  12
  13 // Set up the builtin unsafe package.  This should probably be driven
  14 // by a table.
  15
  16 void
  17 Gogo::import_unsafe(const std::string& local_name, bool is_local_name_exported,
  18                     Location location)
  19 {
  20   Location bloc = Linemap::predeclared_location();
  21
  22   bool add_to_globals;
  23   Package* package = this->add_imported_package("unsafe", local_name,
  24                                                 is_local_name_exported,
  25                                                 "unsafe", "unsafe", location,
  26                                                 &add_to_globals);
  27
  28   if (package == NULL)
  29     {
  30       go_assert(saw_errors());
  31       return;
  32     }
  33
  34   package->set_location(location);
  35   this->imports_.insert(std::make_pair("unsafe", package));
  36
  37   Bindings* bindings = package->bindings();
  38
  39   // The type may have already been created by an import.
  40   Named_object* no = package->bindings()->lookup("Pointer");
  41   if (no == NULL)
  42     {
  43       Type* type = Type::make_pointer_type(Type::make_void_type());
  44       no = bindings->add_type("Pointer", package, type,
  45                               Linemap::unknown_location());
  46     }
  47   else
  48     {
  49       go_assert(no->package() == package);
  50       go_assert(no->is_type());
  51       go_assert(no->type_value()->is_unsafe_pointer_type());
  52       no->type_value()->set_is_visible();
  53     }
  54   Named_type* pointer_type = no->type_value();
  55   if (add_to_globals)
  56     this->add_named_type(pointer_type);
  57
  58   Type* uintptr_type = Type::lookup_integer_type("uintptr");
  59
  60   // Sizeof.
  61   Typed_identifier_list* results = new Typed_identifier_list;
  62   results->push_back(Typed_identifier("", uintptr_type, bloc));
  63   Function_type* fntype = Type::make_function_type(NULL, NULL, results, bloc);
  64   fntype->set_is_builtin();
  65   no = bindings->add_function_declaration("Sizeof", package, fntype, bloc);
  66   if (add_to_globals)
  67     this->add_dot_import_object(no);
  68
  69   // Offsetof.
  70   results = new Typed_identifier_list;
  71   results->push_back(Typed_identifier("", uintptr_type, bloc));
  72   fntype = Type::make_function_type(NULL, NULL, results, bloc);
  73   fntype->set_is_varargs();
  74   fntype->set_is_builtin();
  75   no = bindings->add_function_declaration("Offsetof", package, fntype, bloc);
  76   if (add_to_globals)
  77     this->add_dot_import_object(no);
  78
  79   // Alignof.
  80   results = new Typed_identifier_list;
  81   results->push_back(Typed_identifier("", uintptr_type, bloc));
  82   fntype = Type::make_function_type(NULL, NULL, results, bloc);
  83   fntype->set_is_varargs();
  84   fntype->set_is_builtin();
  85   no = bindings->add_function_declaration("Alignof", package, fntype, bloc);
  86   if (add_to_globals)
  87     this->add_dot_import_object(no);
  88
  89   if (!this->imported_unsafe_)
  90     {
  91       go_imported_unsafe();
  92       this->imported_unsafe_ = true;
  93     }
  94 }