backport fix for go hash function names to 4.8

backport fix for go hash function names to 4.8

[Michael Hudson-Doyle]

Hi,

This patch brings the recent fix for the generated hash functions of
types that are aliases for structures containing unexported fields to
the 4.8 branch.

Cheers,
mwh

diff --git a/gcc/go/gofrontend/types.cc b/gcc/go/gofrontend/types.cc
index 59247d6..36383de 100644
--- a/gcc/go/gofrontend/types.cc
+++ b/gcc/go/gofrontend/types.cc
@@ -1834,7 +1834,9 @@ Type::write_specific_type_functions(Gogo* gogo, Named_type* name,
 					       bloc);
   gogo->start_block(bloc);
 
-  if (this->struct_type() != NULL)
+  if (name != NULL && name->real_type()->named_type() != NULL)
+    this->write_named_hash(gogo, name, hash_fntype, equal_fntype);
+  else if (this->struct_type() != NULL)
     this->struct_type()->write_hash_function(gogo, name, hash_fntype,
 					     equal_fntype);
   else if (this->array_type() != NULL)
@@ -1852,7 +1854,9 @@ Type::write_specific_type_functions(Gogo* gogo, Named_type* name,
 						false, bloc);
   gogo->start_block(bloc);
 
-  if (this->struct_type() != NULL)
+  if (name != NULL && name->real_type()->named_type() != NULL)
+    this->write_named_equal(gogo, name);
+  else if (this->struct_type() != NULL)
     this->struct_type()->write_equal_function(gogo, name);
   else if (this->array_type() != NULL)
     this->array_type()->write_equal_function(gogo, name);
@@ -1865,6 +1869,100 @@ Type::write_specific_type_functions(Gogo* gogo, Named_type* name,
   gogo->finish_function(bloc);
 }
 
+// Write a hash function that simply calls the hash function for a
+// named type.  This is used when one named type is defined as
+// another.  This ensures that this case works when the other named
+// type is defined in another package and relies on calling hash
+// functions defined only in that package.
+
+void
+Type::write_named_hash(Gogo* gogo, Named_type* name,
+		       Function_type* hash_fntype, Function_type* equal_fntype)
+{
+  Location bloc = Linemap::predeclared_location();
+
+  Named_type* base_type = name->real_type()->named_type();
+  go_assert(base_type != NULL);
+
+  // The pointer to the type we are going to hash.  This is an
+  // unsafe.Pointer.
+  Named_object* key_arg = gogo->lookup("key", NULL);
+  go_assert(key_arg != NULL);
+
+  // The size of the type we are going to hash.
+  Named_object* keysz_arg = gogo->lookup("key_size", NULL);
+  go_assert(keysz_arg != NULL);
+
+  Named_object* hash_fn;
+  Named_object* equal_fn;
+  name->real_type()->type_functions(gogo, base_type, hash_fntype, equal_fntype,
+				    &hash_fn, &equal_fn);
+
+  // Call the hash function for the base type.
+  Expression* key_ref = Expression::make_var_reference(key_arg, bloc);
+  Expression* keysz_ref = Expression::make_var_reference(keysz_arg, bloc);
+  Expression_list* args = new Expression_list();
+  args->push_back(key_ref);
+  args->push_back(keysz_ref);
+  Expression* func = Expression::make_func_reference(hash_fn, NULL, bloc);
+  Expression* call = Expression::make_call(func, args, false, bloc);
+
+  // Return the hash of the base type.
+  Expression_list* vals = new Expression_list();
+  vals->push_back(call);
+  Statement* s = Statement::make_return_statement(vals, bloc);
+  gogo->add_statement(s);
+}
+
+// Write an equality function that simply calls the equality function
+// for a named type.  This is used when one named type is defined as
+// another.  This ensures that this case works when the other named
+// type is defined in another package and relies on calling equality
+// functions defined only in that package.
+
+void
+Type::write_named_equal(Gogo* gogo, Named_type* name)
+{
+  Location bloc = Linemap::predeclared_location();
+
+  // The pointers to the types we are going to compare.  These have
+  // type unsafe.Pointer.
+  Named_object* key1_arg = gogo->lookup("key1", NULL);
+  Named_object* key2_arg = gogo->lookup("key2", NULL);
+  go_assert(key1_arg != NULL && key2_arg != NULL);
+
+  Named_type* base_type = name->real_type()->named_type();
+  go_assert(base_type != NULL);
+
+  // Build temporaries with the base type.
+  Type* pt = Type::make_pointer_type(base_type);
+
+  Expression* ref = Expression::make_var_reference(key1_arg, bloc);
+  ref = Expression::make_cast(pt, ref, bloc);
+  Temporary_statement* p1 = Statement::make_temporary(pt, ref, bloc);
+  gogo->add_statement(p1);
+
+  ref = Expression::make_var_reference(key2_arg, bloc);
+  ref = Expression::make_cast(pt, ref, bloc);
+  Temporary_statement* p2 = Statement::make_temporary(pt, ref, bloc);
+  gogo->add_statement(p2);
+
+  // Compare the values for equality.
+  Expression* t1 = Expression::make_temporary_reference(p1, bloc);
+  t1 = Expression::make_unary(OPERATOR_MULT, t1, bloc);
+
+  Expression* t2 = Expression::make_temporary_reference(p2, bloc);
+  t2 = Expression::make_unary(OPERATOR_MULT, t2, bloc);
+
+  Expression* cond = Expression::make_binary(OPERATOR_EQEQ, t1, t2, bloc);
+
+  // Return the equality comparison.
+  Expression_list* vals = new Expression_list();
+  vals->push_back(cond);
+  Statement* s = Statement::make_return_statement(vals, bloc);
+  gogo->add_statement(s);
+}
+
 // Return a composite literal for the type descriptor for a plain type
 // of kind RUNTIME_TYPE_KIND named NAME.
 
diff --git a/gcc/go/gofrontend/types.h b/gcc/go/gofrontend/types.h
index ed01d9c..c8af711 100644
--- a/gcc/go/gofrontend/types.h
+++ b/gcc/go/gofrontend/types.h
@@ -1138,6 +1138,13 @@ class Type
 			  Function_type* equal_fntype, Named_object** hash_fn,
 			  Named_object** equal_fn);
 
+  void
+  write_named_hash(Gogo*, Named_type*, Function_type* hash_fntype,
+		   Function_type* equal_fntype);
+
+  void
+  write_named_equal(Gogo*, Named_type*);
+
   // Build a composite literal for the uncommon type information.
   Expression*
   uncommon_type_constructor(Gogo*, Type* uncommon_type,

Re: backport fix for go hash function names to 4.8

[Ian Lance Taylor]

On Wed, Nov 27, 2013 at 3:04 PM, Michael Hudson-Doyle
<michael.hudson@linaro.org> wrote:
>
> This patch brings the recent fix for the generated hash functions of
> types that are aliases for structures containing unexported fields to
> the 4.8 branch.

Thanks.  Committed to 4.8 branch.

Ian