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", 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   package->set_is_imported();
  36
  37   this->imports_.insert(std::make_pair("unsafe", package));
  38
  39   Bindings* bindings = package->bindings();
  40
  41   // The type may have already been created by an import.
  42   Named_object* no = package->bindings()->lookup("Pointer");
  43   if (no == NULL)
  44     {
  45       Type* type = Type::make_pointer_type(Type::make_void_type());
  46       no = bindings->add_type("Pointer", package, type,
  47                               Linemap::unknown_location());
  48     }
  49   else
  50     {
  51       go_assert(no->package() == package);
  52       go_assert(no->is_type());
  53       go_assert(no->type_value()->is_unsafe_pointer_type());
  54       no->type_value()->set_is_visible();
  55     }
  56   Named_type* pointer_type = no->type_value();
  57   if (add_to_globals)
  58     this->add_named_type(pointer_type);
  59
  60   Type* uintptr_type = Type::lookup_integer_type("uintptr");
  61
  62   // Sizeof.
  63   Typed_identifier_list* results = new Typed_identifier_list;
  64   results->push_back(Typed_identifier("", uintptr_type, bloc));
  65   Function_type* fntype = Type::make_function_type(NULL, NULL, results, bloc);
  66   fntype->set_is_builtin();
  67   no = bindings->add_function_declaration("Sizeof", package, fntype, bloc);
  68   if (add_to_globals)
  69     this->add_dot_import_object(no);
  70
  71   // Offsetof.
  72   results = new Typed_identifier_list;
  73   results->push_back(Typed_identifier("", uintptr_type, bloc));
  74   fntype = Type::make_function_type(NULL, NULL, results, bloc);
  75   fntype->set_is_varargs();
  76   fntype->set_is_builtin();
  77   no = bindings->add_function_declaration("Offsetof", package, fntype, bloc);
  78   if (add_to_globals)
  79     this->add_dot_import_object(no);
  80
  81   // Alignof.
  82   results = new Typed_identifier_list;
  83   results->push_back(Typed_identifier("", uintptr_type, bloc));
  84   fntype = Type::make_function_type(NULL, NULL, results, bloc);
  85   fntype->set_is_varargs();
  86   fntype->set_is_builtin();
  87   no = bindings->add_function_declaration("Alignof", package, fntype, bloc);
  88   if (add_to_globals)
  89     this->add_dot_import_object(no);
  90
  91   if (!this->imported_unsafe_)
  92     {
  93       go_imported_unsafe();
  94       this->imported_unsafe_ = true;
  95     }
  96 }