[pypy-commit] cffi default: Attempt to get rid of USE_C_LIBFFI_MSVC by really fixing libffi_msvc.

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: 
Changeset: r1284:541a90941078
Date: 2013-07-18 20:57 +0200
http://bitbucket.org/cffi/cffi/changeset/541a90941078/

Log:	Attempt to get rid of USE_C_LIBFFI_MSVC by really fixing
	libffi_msvc.

diff --git a/c/_cffi_backend.c b/c/_cffi_backend.c
--- a/c/_cffi_backend.c
+++ b/c/_cffi_backend.c
@@ -3885,19 +3885,6 @@
         }
         assert(cf == NULL);
 
-#ifdef USE_C_LIBFFI_MSVC
-        /* MSVC returns small structures in registers.  Pretend int32 or
-           int64 return type.  This is needed as a workaround for what
-           is really a bug of libffi_msvc seen as an independent library
-           (ctypes has a similar workaround). */
-        if (is_result_type) {
-            if (ct->ct_size <= 4)
-                return &ffi_type_sint32;
-            if (ct->ct_size <= 8)
-                return &ffi_type_sint64;
-        }
-#endif
-
         /* next, allocate and fill the flattened list */
         elements = fb_alloc(fb, (nflat + 1) * sizeof(ffi_type*));
         nflat = 0;
diff --git a/c/libffi_msvc/ffi.c b/c/libffi_msvc/ffi.c
--- a/c/libffi_msvc/ffi.c
+++ b/c/libffi_msvc/ffi.c
@@ -46,7 +46,7 @@
   register ffi_type **p_arg;
 
   argp = stack;
-  if (ecif->cif->rtype->type == FFI_TYPE_STRUCT)
+  if (ecif->cif->flags == FFI_TYPE_STRUCT)
     {
       *(void **) argp = ecif->rvalue;
       argp += sizeof(void *);
@@ -124,7 +124,6 @@
   switch (cif->rtype->type)
     {
     case FFI_TYPE_VOID:
-    case FFI_TYPE_STRUCT:
     case FFI_TYPE_SINT64:
     case FFI_TYPE_FLOAT:
     case FFI_TYPE_DOUBLE:
@@ -132,6 +131,18 @@
       cif->flags = (unsigned) cif->rtype->type;
       break;
 
+    case FFI_TYPE_STRUCT:
+      /* MSVC returns small structures in registers.  Put in cif->flags
+         the value FFI_TYPE_STRUCT only if the structure is big enough;
+         otherwise, put the 4- or 8-bytes integer type. */
+      if (cif->rtype->size <= 4)
+        cif->flags = FFI_TYPE_INT;
+      else if (cif->rtype->size <= 8)
+        cif->flags = FFI_TYPE_SINT64;
+      else
+        cif->flags = FFI_TYPE_STRUCT;
+      break;
+
     case FFI_TYPE_UINT64:
 #ifdef _WIN64
     case FFI_TYPE_POINTER:
@@ -180,7 +191,7 @@
   /* value address then we need to make one		        */
 
   if ((rvalue == NULL) && 
-      (cif->rtype->type == FFI_TYPE_STRUCT))
+      (cif->flags == FFI_TYPE_STRUCT))
     {
       /*@-sysunrecog@*/
       ecif.rvalue = alloca(cif->rtype->size);
@@ -338,7 +349,7 @@
 
   argp = stack;
 
-  if ( cif->rtype->type == FFI_TYPE_STRUCT ) {
+  if ( cif->flags == FFI_TYPE_STRUCT ) {
     *rvalue = *(void **) argp;
     argp += 4;
   }
diff --git a/c/libffi_msvc/prep_cif.c b/c/libffi_msvc/prep_cif.c
--- a/c/libffi_msvc/prep_cif.c
+++ b/c/libffi_msvc/prep_cif.c
@@ -116,9 +116,9 @@
 #if !defined M68K && !defined __x86_64__ && !defined S390
   /* Make space for the return structure pointer */
   if (cif->rtype->type == FFI_TYPE_STRUCT
-      /* MSVC returns small structures in registers.  But we have a different
-      workaround: pretend int32 or int64 return type, and converting to
-      structure afterwards. */
+#ifdef _WIN32
+      && (cif->rtype->size > 8)  /* MSVC returns small structs in registers */
+#endif
 #ifdef SPARC
       && (cif->abi != FFI_V9 || cif->rtype->size > 32)
 #endif
diff --git a/setup.py b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -72,7 +72,6 @@
         extra_link_args.append(os.path.join(COMPILE_LIBFFI, 'win64.obj'))
     sources.extend(os.path.join(COMPILE_LIBFFI, filename)
                    for filename in _filenames)
-    define_macros.append(('USE_C_LIBFFI_MSVC', '1'))
 else:
     use_pkg_config()