c3-lang/libffi

diff --git a/configure.host b/configure.host
index 257b784..2682671 100644
--- a/configure.host
+++ b/configure.host
@@ -32,7 +32,9 @@ case "${host}" in
 
   arm*-*-cygwin* | arm*-*-mingw* | arm*-*-win* )
 	TARGET=ARM_WIN32; TARGETDIR=arm
-	MSVC=1
+	if test "${ax_cv_c_compiler_vendor}" = "microsoft"; then
+	  MSVC=1
+	fi
 	;;
 
   arm*-*-*)
@@ -264,7 +266,11 @@ esac
 # ... but some of the cases above share configury.
 case "${TARGET}" in
   ARM_WIN32)
-	SOURCES="ffi.c sysv_msvc_arm32.S"
+	if test "$MSVC" = 1; then
+		SOURCES="ffi.c sysv_msvc_arm32.S"
+	else
+		SOURCES="ffi.c sysv.S"
+	fi
 	;;
   ARM_WIN64)
 	if test "$MSVC" = 1; then
diff --git a/src/arm/ffi.c b/src/arm/ffi.c
index b2f60d1..593ab4d 100644
--- a/src/arm/ffi.c
+++ b/src/arm/ffi.c
@@ -37,7 +37,7 @@
 #include <tramp.h>
 #include "internal.h"
 
-#if defined(_MSC_VER) && defined(_M_ARM)
+#if defined(_WIN32)
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 #endif
@@ -49,10 +49,13 @@
 #endif
 
 #else
-#ifndef _M_ARM
+#ifndef _WIN32
 extern unsigned int ffi_arm_trampoline[2] FFI_HIDDEN;
 #else
-extern unsigned int ffi_arm_trampoline[3] FFI_HIDDEN;
+// Declare this as an array of char, instead of array of int,
+// otherwise Clang optimizes out the "& 0xFFFFFFFE" for clearing
+// the thumb bit.
+extern unsigned char ffi_arm_trampoline[12] FFI_HIDDEN;
 #endif
 #endif
 
@@ -104,13 +107,13 @@ ffi_put_arg (ffi_type *ty, void *src, void *dst)
     case FFI_TYPE_SINT32:
     case FFI_TYPE_UINT32:
     case FFI_TYPE_POINTER:
-#ifndef _MSC_VER
+#ifndef _WIN32
     case FFI_TYPE_FLOAT:
 #endif
       *(UINT32 *)dst = *(UINT32 *)src;
       break;
 
-#ifdef _MSC_VER
+#ifdef _WIN32
     // casting a float* to a UINT32* doesn't work on Windows
     case FFI_TYPE_FLOAT:
         *(uintptr_t *)dst = 0;
@@ -633,7 +636,7 @@ ffi_prep_closure_loc (ffi_closure * closure,
 #endif
 
   /* Initialize the dynamic trampoline. */
-#ifndef _M_ARM
+#ifndef _WIN32
   memcpy(closure->tramp, ffi_arm_trampoline, 8);
 #else
   // cast away function type so MSVC doesn't set the lower bit of the function pointer
@@ -643,13 +646,13 @@ ffi_prep_closure_loc (ffi_closure * closure,
 #if defined (__QNX__)
   msync(closure->tramp, 8, 0x1000000);	/* clear data map */
   msync(codeloc, 8, 0x1000000);	/* clear insn map */
-#elif defined(_MSC_VER)
+#elif defined(_WIN32)
   FlushInstructionCache(GetCurrentProcess(), closure->tramp, FFI_TRAMPOLINE_SIZE);
 #else
   __clear_cache(closure->tramp, closure->tramp + 8);	/* clear data map */
   __clear_cache(codeloc, codeloc + 8);			/* clear insn map */
 #endif
-#ifdef _M_ARM
+#ifdef _WIN32
   *(void(**)(void))(closure->tramp + FFI_TRAMPOLINE_CLOSURE_FUNCTION) = closure_func;
 #else
   *(void (**)(void))(closure->tramp + 8) = closure_func;
diff --git a/src/arm/ffitarget.h b/src/arm/ffitarget.h
index cb57b84..12d5d20 100644
--- a/src/arm/ffitarget.h
+++ b/src/arm/ffitarget.h
@@ -43,7 +43,7 @@ typedef enum ffi_abi {
   FFI_SYSV,
   FFI_VFP,
   FFI_LAST_ABI,
-#if defined(__ARM_PCS_VFP) || defined(_M_ARM)
+#if defined(__ARM_PCS_VFP) || defined(_WIN32)
   FFI_DEFAULT_ABI = FFI_VFP,
 #else
   FFI_DEFAULT_ABI = FFI_SYSV,
@@ -57,7 +57,7 @@ typedef enum ffi_abi {
   signed char vfp_args[16]			\
 
 #define FFI_TARGET_SPECIFIC_VARIADIC
-#ifndef _M_ARM
+#ifndef _WIN32
 #define FFI_TARGET_HAS_COMPLEX_TYPE
 #endif
 
@@ -77,7 +77,7 @@ typedef enum ffi_abi {
 #endif
 
 #else
-#ifdef _MSC_VER
+#ifdef _WIN32
 #define FFI_TRAMPOLINE_SIZE 16
 #define FFI_TRAMPOLINE_CLOSURE_FUNCTION 12
 #else
diff --git a/src/arm/sysv.S b/src/arm/sysv.S
index e816e32..fb36213 100644
--- a/src/arm/sysv.S
+++ b/src/arm/sysv.S
@@ -92,9 +92,25 @@
 #define ARM_FUNC_END(name) \
 	SIZE(name)
 
+	.text
+	.syntax unified
+#if defined(_WIN32)
+	/* Windows on ARM is thumb-only */
+	.thumb
+#else
+	/* Keep the assembly in ARM mode in other cases, for simplicity
+	 * (to avoid interworking issues). */
+#undef __thumb__
+	.arm
+#endif
+
 /* Aid in defining a jump table with 8 bytes between entries.  */
+#ifdef __thumb__
+/* In thumb mode, instructions can be shorter than expected in arm mode, so
+ * we need to align the start of each case. */
+# define E(index) .align 3
+#elif defined(__clang__)
 /* ??? The clang assembler doesn't handle .if with symbolic expressions.  */
-#ifdef __clang__
 # define E(index)
 #else
 # define E(index)				\
@@ -103,9 +119,6 @@
 	.endif
 #endif
 
-	.text
-	.syntax unified
-	.arm
 
 #ifndef __clang__
 	/* We require interworking on LDM, which implies ARMv5T,
@@ -128,6 +141,7 @@ ARM_FUNC_START(ffi_call_VFP)
 	cfi_startproc
 
 	cmp	r3, #3			@ load only d0 if possible
+	ite	le
 #ifdef __clang__
 	vldrle d0, [r0]
 	vldmgt r0, {d0-d7}
@@ -167,9 +181,16 @@ ARM_FUNC_START(ffi_call_SYSV)
 	cfi_def_cfa_register(sp)
 
 	@ Store values stored in registers.
+#ifndef __thumb__
 	.align	3
 	add	pc, pc, r3, lsl #3
 	nop
+#else
+	adr	ip, 0f
+	add	ip, ip, r3, lsl #3
+	mov	pc, ip
+	.align	3
+#endif
 0:
 E(ARM_TYPE_VFP_S)
 #ifdef __clang__
@@ -228,6 +249,9 @@ ARM_FUNC_END(ffi_go_closure_SYSV)
 ARM_FUNC_START(ffi_closure_SYSV)
 	UNWIND(.fnstart)
 	cfi_startproc
+#ifdef _WIN32
+	ldmfd	sp!, {r0, ip}			@ restore fp (r0 is used for stack alignment)
+#endif
 	stmdb	sp!, {r0-r3}			@ save argument regs
 	cfi_adjust_cfa_offset(16)
 
@@ -256,7 +280,12 @@ ARM_FUNC_START(ffi_closure_SYSV)
 	@ Load values returned in registers.
 	add	r2, sp, #8+64			@ load result
 	adr	r3, CNAME(ffi_closure_ret)
+#ifndef __thumb__
 	add	pc, r3, r0, lsl #3
+#else
+	add	r3, r3, r0, lsl #3
+	mov	pc, r3
+#endif
 	cfi_endproc
 	UNWIND(.fnend)
 ARM_FUNC_END(ffi_closure_SYSV)
@@ -275,6 +304,9 @@ ARM_FUNC_END(ffi_go_closure_VFP)
 ARM_FUNC_START(ffi_closure_VFP)
 	UNWIND(.fnstart)
 	cfi_startproc
+#ifdef _WIN32
+	ldmfd	sp!, {r0, ip}			@ restore fp (r0 is used for stack alignment)
+#endif
 	stmdb	sp!, {r0-r3}			@ save argument regs
 	cfi_adjust_cfa_offset(16)
 
@@ -306,7 +338,12 @@ ARM_FUNC_START(ffi_closure_VFP)
 	@ Load values returned in registers.
 	add	r2, sp, #8+64			@ load result
 	adr	r3, CNAME(ffi_closure_ret)
+#ifndef __thumb__
 	add	pc, r3, r0, lsl #3
+#else
+	add	r3, r3, r0, lsl #3
+	mov	pc, r3
+#endif
 	cfi_endproc
 	UNWIND(.fnend)
 ARM_FUNC_END(ffi_closure_VFP)
@@ -326,32 +363,40 @@ E(ARM_TYPE_VFP_S)
 #else
 	ldc	p10, cr0, [r2]			@ vldr s0, [r2]
 #endif
-	ldm	sp, {sp,pc}
+	b	call_epilogue
 E(ARM_TYPE_VFP_D)
 #ifdef __clang__
 	vldr d0, [r2]
 #else
 	ldc	p11, cr0, [r2]			@ vldr d0, [r2]
 #endif
-	ldm	sp, {sp,pc}
+	b	call_epilogue
 E(ARM_TYPE_VFP_N)
 #ifdef __clang__
 	vldm r2, {d0-d3}
 #else
 	ldc	p11, cr0, [r2], {8}		@ vldm r2, {d0-d3}
 #endif
-	ldm	sp, {sp,pc}
+	b	call_epilogue
 E(ARM_TYPE_INT64)
 	ldr	r1, [r2, #4]
 	nop
 E(ARM_TYPE_INT)
 	ldr	r0, [r2]
-	ldm	sp, {sp,pc}
+	b	call_epilogue
 E(ARM_TYPE_VOID)
-	ldm	sp, {sp,pc}
+	b	call_epilogue
 	nop
 E(ARM_TYPE_STRUCT)
+	b	call_epilogue
+call_epilogue:
+#ifndef __thumb__
 	ldm	sp, {sp,pc}
+#else
+	ldm	sp, {ip,lr}
+	mov	sp, ip
+	bx	lr
+#endif
 	cfi_endproc
 ARM_FUNC_END(ffi_closure_ret)
 
@@ -419,6 +464,15 @@ ARM_FUNC_START(ffi_closure_trampoline_table_page)
 ARM_FUNC_END(ffi_closure_trampoline_table_page)
 #endif
 
+#elif defined(_WIN32)
+
+ARM_FUNC_START(ffi_arm_trampoline)
+0:	adr	ip, 0b
+	stmdb	sp!, {r0, ip}
+	ldr	pc, 1f
+1:	.long	0
+ARM_FUNC_END(ffi_arm_trampoline)
+
 #else
 
 ARM_FUNC_START(ffi_arm_trampoline)