3 files changed, 37 insertions, 7 deletions

diff --git a/gcc/d/d-target.cc b/gcc/d/d-target.cc
index a1dc2ee..f1814df 100644
--- a/gcc/d/d-target.cc
+++ b/gcc/d/d-target.cc
@@ -435,11 +435,21 @@ TargetCPP::derivedClassOffset(ClassDeclaration *base_class)
   return base_class->structsize;
 }
 
-/* Return the default system linkage for the target.  */
+/* Return the default `extern (System)' linkage for the target.  */
 
 LINK
 Target::systemLinkage (void)
 {
+  unsigned link_system, link_windows;
+
+  if (targetdm.d_has_stdcall_convention (&link_system, &link_windows))
+    {
+      /* In [attribute/linkage], `System' is the same as `Windows' on Windows
+	 platforms, and `C' on other platforms.  */
+      if (link_system)
+	return LINKwindows;
+    }
+
   return LINKc;
 }
 
diff --git a/gcc/d/d-target.def b/gcc/d/d-target.def
index d1426a1..f79ffb9 100644
--- a/gcc/d/d-target.def
+++ b/gcc/d/d-target.def
@@ -71,5 +71,18 @@ as the name of the symbol indicating the end address of the module info\n\
 section",
  const char *, NULL)
 
+/* The "stdcall" convention is really supported on 32-bit x86/Windows only.
+   The following hook is a helper to determine whether to apply the attribute
+   on declarations with `extern(System)' and `extern(Windows)' linkage.  */
+DEFHOOK
+(d_has_stdcall_convention,
+ "Returns @code{true} if the target supports the stdcall calling convention.\n\
+The hook should also set @var{link_system} to @code{1} if the @code{stdcall}\n\
+attribute should be applied to functions with @code{extern(System)} linkage,\n\
+and @var{link_windows} to @code{1} to apply @code{stdcall} to functions with\n\
+@code{extern(Windows)} linkage.",
+ bool, (unsigned int *link_system, unsigned int *link_windows),
+ hook_bool_uintp_uintp_false)
+
 /* Close the 'struct gcc_targetdm' definition.  */
 HOOK_VECTOR_END (C90_EMPTY_HACK)
diff --git a/gcc/d/types.cc b/gcc/d/types.cc
index ec61740..3b121f5 100644
--- a/gcc/d/types.cc
+++ b/gcc/d/types.cc
@@ -40,6 +40,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "attribs.h"
 
 #include "d-tree.h"
+#include "d-target.h"
 
 
 /* Return the signed or unsigned version of TYPE, an integral type, the
@@ -800,13 +801,19 @@ public:
     switch (t->linkage)
       {
       case LINKwindows:
-	/* [attribute/linkage]
+	{
+	  /* [attribute/linkage]
 
-	   The Windows convention is distinct from the C convention only
-	   on Win32, where it is equivalent to the stdcall convention.  */
-	if (!global.params.is64bit)
-	  t->ctype = insert_type_attribute (t->ctype, "stdcall");
-	break;
+	     The Windows convention is distinct from the C convention only
+	     on Win32, where it is equivalent to the stdcall convention.  */
+	  unsigned link_system, link_windows;
+	  if (targetdm.d_has_stdcall_convention (&link_system, &link_windows))
+	    {
+	      if (link_windows)
+		t->ctype = insert_type_attribute (t->ctype, "stdcall");
+	    }
+	  break;
+	}
 
       case LINKc:
       case LINKcpp: