Patch for building libffi v3.2.1 with MSVC

0001-Support-MSVC.patch

From f0627cd357082ba27e914810bdfbc47e80e37c92 Mon Sep 17 00:00:00 2001
From: "K.Takata" <kentkt@csc.jp>
Date: Sat, 25 Jul 2015 21:09:11 +0900
Subject: [PATCH] Support MSVC

Based on Ruby 2.2's patch:
https://github.com/ruby/ruby/blob/ruby_2_2/ext/fiddle/win32/libffi-3.2.1-mswin.patch
---
 src/x86/ffi.c       | 21 +++++++++++++++------
 src/x86/ffitarget.h |  2 ++
 src/x86/win64.S     | 25 ++++++++++++-------------
 3 files changed, 29 insertions(+), 19 deletions(-)

diff --git a/src/x86/ffi.c b/src/x86/ffi.c
index 006c95d..9345677 100644
--- a/src/x86/ffi.c
+++ b/src/x86/ffi.c
@@ -99,11 +99,13 @@ unsigned int ffi_prep_args(char *stack, extended_cif *ecif)
        i != 0;
        i--, p_arg += dir, p_argv += dir)
     {
+      size_t z;
+
       /* Align if necessary */
       if ((sizeof(void*) - 1) & (size_t) argp)
         argp = (char *) ALIGN(argp, sizeof(void*));
 
-      size_t z = (*p_arg)->size;
+      z = (*p_arg)->size;
 
 #ifdef X86_WIN64
       if (z > FFI_SIZEOF_ARG
@@ -202,6 +204,8 @@ unsigned int ffi_prep_args(char *stack, extended_cif *ecif)
      on top of stack, so that those can be moved to registers by call-handler.  */
   if (stack_args_count > 0)
     {
+      int i;
+
       if (dir < 0 && stack_args_count > 1)
         {
           /* Reverse order if iterating arguments backwards */
@@ -210,7 +214,6 @@ unsigned int ffi_prep_args(char *stack, extended_cif *ecif)
           *(ffi_arg*) p_stack_data[stack_args_count - 1] = tmp;
         }
       
-      int i;
       for (i = 0; i < stack_args_count; i++)
         {
           if (p_stack_data[i] != argp2)
@@ -569,11 +572,13 @@ ffi_prep_incoming_args(char *stack, void **rvalue, void **avalue,
        i < cif->nargs && passed_regs < max_stack_count;
        i++, p_arg++)
     {
+      size_t sz;
+
       if ((*p_arg)->type == FFI_TYPE_FLOAT
          || (*p_arg)->type == FFI_TYPE_STRUCT)
         continue;
 
-      size_t sz = (*p_arg)->size;
+      sz = (*p_arg)->size;
       if(sz == 0 || sz > FFI_SIZEOF_ARG)
         continue;
 
@@ -599,11 +604,13 @@ ffi_prep_incoming_args(char *stack, void **rvalue, void **avalue,
        i != 0;
        i--, p_arg += dir, p_argv += dir)
     {
+      size_t z;
+
       /* Align if necessary */
       if ((sizeof(void*) - 1) & (size_t) argp)
         argp = (char *) ALIGN(argp, sizeof(void*));
 
-      size_t z = (*p_arg)->size;
+      z = (*p_arg)->size;
 
 #ifdef X86_WIN64
       if (z > FFI_SIZEOF_ARG
@@ -642,7 +649,7 @@ ffi_prep_incoming_args(char *stack, void **rvalue, void **avalue,
 #endif
     }
 
-  return (size_t)argp - (size_t)stack;
+  return (int)((size_t)argp - (size_t)stack);
 }
 
 #define FFI_INIT_TRAMPOLINE_WIN64(TRAMP,FUN,CTX,MASK) \
@@ -855,11 +862,13 @@ ffi_prep_args_raw(char *stack, extended_cif *ecif)
   
   for (i = 0; i < cif->nargs && passed_regs <= max_regs; i++)
     {
+      size_t sz;
+
       if (cif->arg_types[i]->type == FFI_TYPE_FLOAT
          || cif->arg_types[i]->type == FFI_TYPE_STRUCT)
         continue;
 
-      size_t sz = cif->arg_types[i]->size;
+      sz = cif->arg_types[i]->size;
       if (sz == 0 || sz > FFI_SIZEOF_ARG)
         continue;
 
diff --git a/src/x86/ffitarget.h b/src/x86/ffitarget.h
index a236677..28618d0 100644
--- a/src/x86/ffitarget.h
+++ b/src/x86/ffitarget.h
@@ -50,7 +50,9 @@
 #endif
 
 #define FFI_TARGET_SPECIFIC_STACK_SPACE_ALLOCATION
+#if !defined(_MSC_VER) || _MSC_VER >= 1800
 #define FFI_TARGET_HAS_COMPLEX_TYPE
+#endif
 
 /* ---- Generic type definitions ----------------------------------------- */
 
diff --git a/src/x86/win64.S b/src/x86/win64.S
index 687f97c..347a26a 100644
--- a/src/x86/win64.S
+++ b/src/x86/win64.S
@@ -127,7 +127,7 @@ ret_struct4b$:
 
 	mov	rcx, QWORD PTR RVALUE[rbp]
 	mov	DWORD PTR [rcx], eax
-	jmp	ret_void$
+	jmp	SHORT ret_void$
 
 ret_struct2b$:
  	cmp	DWORD PTR CIF_FLAGS[rbp], FFI_TYPE_SMALL_STRUCT_2B
@@ -135,7 +135,7 @@ ret_struct2b$:
 
 	mov	rcx, QWORD PTR RVALUE[rbp]
 	mov	WORD PTR [rcx], ax
-	jmp	ret_void$
+	jmp	SHORT ret_void$
 
 ret_struct1b$:
  	cmp	DWORD PTR CIF_FLAGS[rbp], FFI_TYPE_SMALL_STRUCT_1B
@@ -143,7 +143,7 @@ ret_struct1b$:
 
 	mov	rcx, QWORD PTR RVALUE[rbp]
 	mov	BYTE PTR [rcx], al
-	jmp	ret_void$
+	jmp	SHORT ret_void$
 
 ret_uint8$:
  	cmp	DWORD PTR CIF_FLAGS[rbp], FFI_TYPE_UINT8
@@ -152,7 +152,7 @@ ret_uint8$:
 	mov	rcx, QWORD PTR RVALUE[rbp]
 	movzx   rax, al
 	mov	QWORD PTR [rcx], rax
-	jmp	ret_void$
+	jmp	SHORT ret_void$
 
 ret_sint8$:
  	cmp	DWORD PTR CIF_FLAGS[rbp], FFI_TYPE_SINT8
@@ -161,7 +161,7 @@ ret_sint8$:
 	mov	rcx, QWORD PTR RVALUE[rbp]
 	movsx   rax, al
 	mov	QWORD PTR [rcx], rax
-	jmp	ret_void$
+	jmp	SHORT ret_void$
 
 ret_uint16$:
  	cmp	DWORD PTR CIF_FLAGS[rbp], FFI_TYPE_UINT16
@@ -188,7 +188,13 @@ ret_uint32$:
 	mov	rcx, QWORD PTR RVALUE[rbp]
 	mov     eax, eax
 	mov	QWORD PTR [rcx], rax
-	jmp	SHORT ret_void$
+
+ret_void$:
+	xor	rax, rax
+
+	lea	rsp, QWORD PTR [rbp+16]
+	pop	rbp
+	ret	0
 
 ret_sint32$:
  	cmp	DWORD PTR CIF_FLAGS[rbp], FFI_TYPE_SINT32
@@ -247,13 +253,6 @@ ret_int$:
 	cdqe
 	mov	QWORD PTR [rcx], rax
  	jmp	SHORT ret_void$
-
-ret_void$:
-	xor	rax, rax
-
-	lea	rsp, QWORD PTR [rbp+16]
-	pop	rbp
-	ret	0
 ffi_call_win64 ENDP
 _TEXT	ENDS
 END
-- 
2.4.5