Added support for type alias

Doc/Manual/CPlusPlus11.html

@@ -29,7 +29,7 @@
 <li><a href="#CPlusPlus11_strongly_typed_enumerations">Strongly typed enumerations</a>
 <li><a href="#CPlusPlus11_double_angle_brackets">Double angle brackets</a>
 <li><a href="#CPlusPlus11_explicit_conversion_operators">Explicit conversion operators</a>
-<li><a href="#CPlusPlus11_alias_templates">Alias templates</a>
+<li><a href="#CPlusPlus11_alias_templates">Type alias and alias templates</a>
 <li><a href="#CPlusPlus11_unrestricted_unions">Unrestricted unions</a>
 <li><a href="#CPlusPlus11_variadic_templates">Variadic templates</a>
 <li><a href="#CPlusPlus11_new_string_literals">New string literals</a>
@@ -603,8 +603,27 @@ Conversion operators either with or without <tt>explicit</tt> need renaming to a
 them available as a normal proxy method.
 </p>
 
-<H3><a name="CPlusPlus11_alias_templates">7.2.16 Alias templates</a></H3>
+<H3><a name="CPlusPlus11_alias_templates">7.2.16 Type alias and alias templates</a></H3>
 
+<p>
+A type alias is a statement of the form:
+</p>
+
+<div class="code"><pre>
+using PFD = void (*)(double); // New introduced syntax
+</pre></div>
+
+<p>
+which is equivalent to the old style typedef:
+</p>
+
+<div class="code"><pre>
+typedef void (*PFD)(double);  // The old style
+</pre></div>
+
+<p>
+SWIG supports this kind of statements.
+</p>
 
 <p>
 The following is an example of an alias template:
@@ -632,31 +651,6 @@ example.i:13: Warning 342: The 'using' keyword in template aliasing is not fully
 </pre>
 </div>
 
-<p>
-Similarly for non-template type aliasing:
-</p>
-
-<div class="code"><pre>
-using PFD = void (*)(double); // New introduced syntax
-</pre></div>
-
-<p>
-A warning will be issued:
-</p>
-
-<div class="shell">
-<pre>
-example.i:17: Warning 341: The 'using' keyword in type aliasing is not fully supported yet.
-</pre>
-</div>
-
-
-<p>The equivalent old style typedefs can be used as a workaround:</p>
-
-<div class="code"><pre>
-typedef void (*PFD)(double);  // The old style
-</pre></div>
-
 <H3><a name="CPlusPlus11_unrestricted_unions">7.2.17 Unrestricted unions</a></H3>
 
 

Examples/test-suite/cpp11_type_aliasing.i

@@ -2,15 +2,6 @@
 
 // Type aliasing seg fault : Github issue #424
 
-%warnfilter(SWIGWARN_CPP11_ALIAS_DECLARATION) Target;
-%warnfilter(SWIGWARN_CPP11_ALIAS_DECLARATION) Int;
-%warnfilter(SWIGWARN_CPP11_ALIAS_DECLARATION) IntRef;
-%warnfilter(SWIGWARN_CPP11_ALIAS_DECLARATION) IntPtrRef;
-%warnfilter(SWIGWARN_CPP11_ALIAS_DECLARATION) IntRValueRef;
-%warnfilter(SWIGWARN_CPP11_ALIAS_DECLARATION) IntArray;
-%warnfilter(SWIGWARN_CPP11_ALIAS_DECLARATION) HalideTargetPtr1;
-%warnfilter(SWIGWARN_CPP11_ALIAS_DECLARATION) HalideTargetPtr2;
-
 %inline %{
 namespace Halide {
 
@@ -53,14 +44,69 @@ public:
 
 
 %inline %{
-using Int = int;
-using IntRef = int&;
-using IntPtrRef = int*&;
-using IntRValueRef = int&&;
-using IntArray = int[];
-
 using HalideTargetPtr1 = Halide::Target*;
 namespace Halide {
   using HalideTargetPtr2 = Target*;
 }
 %}
+
+// Define some types
+
+%inline %{
+using Int = int;
+using IntPtr = Int*;
+using IntRef = Int&;
+using IntPtrRef = Int*&;
+using IntRValueRef = Int&&;
+using IntArray = Int[];
+%}
+
+// Test that SWIG understands these new types
+
+%callback("%s_cb");
+Int mult2(Int x);
+%nocallback;
+
+%inline %{
+Int mult2(Int x) { return x * 2; }
+IntPtr allocate_int() { return new Int(12); }
+void free_int(int* ptr) { delete ptr; }
+void inplace_mult2(IntRef x) { x *= 2; }
+Int read_int(IntPtr ptr) { return *ptr; }
+
+template <typename T> class Pair {
+public:
+  using data_t = T;
+
+  data_t a, b;
+
+  Pair() : a(), b() { }
+  Pair(data_t a, data_t b) : a(a), b(b) { }
+  data_t first() { return a; }
+  data_t second() { return b; }
+};
+%}
+
+%template(int_pair) Pair<Int>;
+
+%inline %{
+using PairInt = Pair<Int>;
+
+class PairSubclass : public PairInt {
+public:
+  PairSubclass(data_t a, data_t b) : PairInt(a, b) { }
+
+  using const_ref_data_t = const data_t&;
+};
+
+PairSubclass::data_t plus1(PairSubclass::const_ref_data_t x) { return x + 1; }
+%}
+
+// Test function pointers
+
+%inline %{
+using callback_t = int(*)(int);
+
+callback_t get_callback() { return mult2; }
+int call(callback_t func, int param) { return func(param); }
+%}

Examples/test-suite/errors/cpp_using_type_aliasing.stderr

@@ -1,3 +0,0 @@
-cpp_using_type_aliasing.i:8: Warning 341: The 'using' keyword in type aliasing is not fully supported yet.
-cpp_using_type_aliasing.i:8: Warning 315: Nothing known about 'Okay< int >'.
-cpp_using_type_aliasing.i:8: Warning 315: Nothing known about 'Okay< int >'.

Examples/test-suite/python/cpp11_type_aliasing_runme.py

@@ -0,0 +1,32 @@
+from cpp11_type_aliasing import *
+
+if get_host_target().bits != 32:
+    raise RuntimeError("get_host_target().bits should return 32")
+
+if mult2(10) != 20:
+    raise RuntimeError("mult2(10) should return 20")
+
+int_ptr = allocate_int()
+inplace_mult2(int_ptr)
+if read_int(int_ptr) != 24:
+    raise RuntimeError("read_int should return 24")
+free_int(int_ptr)
+
+pair = PairSubclass(3, 4)
+if pair.first() != 3:
+    raise RuntimeError("pair.first() should return 3")
+
+if pair.second() != 4:
+    raise RuntimeError("pair.second() should return 4")
+
+if pair.a != 3:
+    raise RuntimeError("pair.a should be 3")
+
+if plus1(5) != 6:
+    raise RuntimeError("plus1(5) should return 6")
+
+if call(mult2_cb, 7) != 14:
+    raise RuntimeError("call(mult2_cb, 7) should return 14")
+
+if call(get_callback(), 7) != 14:
+    raise RuntimeError("call(get_callback(), 7) should return 14")

Source/CParse/parser.y

@@ -2899,16 +2899,15 @@ c_declaration   : c_decl {
 		  SWIG_WARN_NODE_END($$);
 		}
                 | USING idcolon EQUAL type plain_declarator SEMI {
-		  $$ = new_node("using");
-		  Setattr($$,"name",$2);
+		  /* Convert using statement to a typedef statement */
+		  $$ = new_node("cdecl");
 		  SwigType_push($4,$5.type);
-		  Setattr($$,"uname",$4);
+		  Setattr($$,"type",$4);
+		  Setattr($$,"storage","typedef");
+		  Setattr($$,"name",$2);
+		  Setattr($$,"decl","");
+		  SetFlag($$,"typealias");
 		  add_symbols($$);
-		  SWIG_WARN_NODE_BEGIN($$);
-		  Swig_warning(WARN_CPP11_ALIAS_DECLARATION, cparse_file, cparse_line, "The 'using' keyword in type aliasing is not fully supported yet.\n");
-		  SWIG_WARN_NODE_END($$);
-
-		  $$ = 0; /* TODO - ignored for now */
 		}
                 | TEMPLATE LESSTHAN template_parms GREATERTHAN USING idcolon EQUAL type plain_declarator SEMI {
 		  $$ = new_node("using");