commit f1d42e628ed611297731b2a78bbee69d2f45f8e1
Author: Richard Henderson <rth@redhat.com>
Date:   Thu Sep 25 20:14:37 2014 -0700

    Always use libffi for libgo

	* Makefile.am (LIBFFI, LIBFFIINCS): Define directly
	(go_reflect_makefunc_file, go_reflect_makefunc_s_file): Remove.
	(reflect/makefunc.lo): Remove.
	* configure.ac (--with-libffi): Remove option.
	(LIBFFI, LIBFFIINCS): Remove subst.
	* Makefile.in, configure: Rebuild.
	* go/reflect/makefunc.go (MakeFunc): Don't check runtime.GOARCH.
	(makeValueMethod): Likewise.
	* go/reflect/makefunc_ffi_c.c: Don't check USE_LIBFFI.
	* runtime/go-ffi.c: Likewise.
	* runtime/go-ffi.h: Likewise.
	* runtime/go-reflect-call.c: Likewise.
	* go/reflect/value.go (makeFuncStubFn, makeFuncStubCode): Remove.
	(Value.call): Don't compare against makeFuncStubCode.
	(Value.Pointer): Return a dummy value for methods.
	* go/reflect/makefunc_386.S: Remove file.
	* go/reflect/makefunc_amd64.S: Remove file.
	* go/reflect/makefunc_dummy.c: Remove file.
	* go/reflect/makefuncgo_386.go: Remove file.
	* go/reflect/makefuncgo_amd64.go: Remove file.


diff --git a/libgo/Makefile.am b/libgo/Makefile.am
index 6d00bcc..06ce555 100644
--- a/libgo/Makefile.am
+++ b/libgo/Makefile.am
@@ -27,8 +27,8 @@ toolexecdir = $(glibgo_toolexecdir)
 toolexeclibdir = $(glibgo_toolexeclibdir)
 toolexeclibgodir = $(nover_glibgo_toolexeclibdir)/go/$(gcc_version)/$(target_alias)
 
-LIBFFI = @LIBFFI@
-LIBFFIINCS = @LIBFFIINCS@
+LIBFFI = ../libffi/libffi_convenience.la
+LIBFFIINCS = -I$(top_srcdir)/../libffi/include -I../libffi/include
 
 LIBATOMIC = @LIBATOMIC@
 
@@ -931,29 +931,10 @@ go_path_files = \
 	go/path/match.go \
 	go/path/path.go
 
-if LIBGO_IS_X86_64
-go_reflect_makefunc_file = \
-	go/reflect/makefuncgo_amd64.go
-go_reflect_makefunc_s_file = \
-	go/reflect/makefunc_amd64.S
-else
-if LIBGO_IS_386
-go_reflect_makefunc_file = \
-	go/reflect/makefuncgo_386.go
-go_reflect_makefunc_s_file = \
-	go/reflect/makefunc_386.S
-else
-go_reflect_makefunc_file =
-go_reflect_makefunc_s_file = \
-	go/reflect/makefunc_dummy.c
-endif
-endif
-
 go_reflect_files = \
 	go/reflect/deepequal.go \
 	go/reflect/makefunc.go \
 	go/reflect/makefunc_ffi.go \
-	$(go_reflect_makefunc_file) \
 	go/reflect/type.go \
 	go/reflect/value.go
 go_reflect_makefunc_c_file = \
@@ -1852,7 +1833,6 @@ libgo_go_objs = \
 	os.lo \
 	path.lo \
 	reflect-go.lo \
-	reflect/makefunc.lo \
 	reflect/makefunc_ffi_c.lo \
 	regexp.lo \
 	runtime-go.lo \
@@ -2254,9 +2234,6 @@ reflect-go.lo: $(go_reflect_files)
 	$(BUILDPACKAGE)
 reflect/check: $(CHECK_DEPS)
 	@$(CHECK)
-reflect/makefunc.lo: $(go_reflect_makefunc_s_file)
-	@$(MKDIR_P) reflect
-	$(LTCOMPILE) -c -o $@ $<
 reflect/makefunc_ffi_c.lo: $(go_reflect_makefunc_c_file)
 	@$(MKDIR_P) reflect
 	$(LTCOMPILE) -c -o $@ $<
diff --git a/libgo/config.h.in b/libgo/config.h.in
index 9e622c6..e243e11 100644
--- a/libgo/config.h.in
+++ b/libgo/config.h.in
@@ -374,9 +374,6 @@
 /* Define to 1 if you have the ANSI C header files. */
 #undef STDC_HEADERS
 
-/* Define if we're to use libffi. */
-#undef USE_LIBFFI
-
 /* Define if the compiler supports -fsplit-stack */
 #undef USING_SPLIT_STACK
 
diff --git a/libgo/configure.ac b/libgo/configure.ac
index 5e1e4d9..568188d 100644
--- a/libgo/configure.ac
+++ b/libgo/configure.ac
@@ -103,25 +103,6 @@ AC_SUBST(glibgo_toolexecdir)
 AC_SUBST(glibgo_toolexeclibdir)
 AC_SUBST(nover_glibgo_toolexeclibdir)
 
-# See if the user wants to configure without libffi.  Some
-# architectures don't support it.  FIXME: We should set a default
-# based on the host.
-AC_ARG_WITH(libffi,
-  AS_HELP_STRING([--without-libffi],
-                 [don't use libffi]),
-  [:],
-  [with_libffi=${with_libffi_default-yes}])
-
-LIBFFI=
-LIBFFIINCS=
-if test "$with_libffi" != no; then
-   AC_DEFINE(USE_LIBFFI, 1, [Define if we're to use libffi.])
-   LIBFFI=../libffi/libffi_convenience.la
-   LIBFFIINCS='-I$(top_srcdir)/../libffi/include -I../libffi/include'
-fi
-AC_SUBST(LIBFFI)
-AC_SUBST(LIBFFIINCS)
-
 # See if the user wants to configure without libatomic. This is useful if we are
 # on an architecture for which libgo does not need an atomic support library and
 # libatomic does not support our C compiler.
diff --git a/libgo/go/reflect/makefunc.go b/libgo/go/reflect/makefunc.go
index 736ac36..6549f33 100644
--- a/libgo/go/reflect/makefunc.go
+++ b/libgo/go/reflect/makefunc.go
@@ -7,7 +7,6 @@
 package reflect
 
 import (
-	"runtime"
 	"unsafe"
 )
 
@@ -58,18 +57,7 @@ func MakeFunc(typ Type, fn func(args []Value) (results []Value)) Value {
 	t := typ.common()
 	ftyp := (*funcType)(unsafe.Pointer(t))
 
-	var code uintptr
-	var ffi *ffiData
-	switch runtime.GOARCH {
-	case "amd64", "386":
-		// Indirect Go func value (dummy) to obtain actual
-		// code address. (A Go func value is a pointer to a C
-		// function pointer. http://golang.org/s/go11func.)
-		dummy := makeFuncStub
-		code = **(**uintptr)(unsafe.Pointer(&dummy))
-	default:
-		code, ffi = makeFuncFFI(ftyp, fn)
-	}
+	code, ffi := makeFuncFFI(ftyp, fn)
 
 	impl := &makeFuncImpl{
 		code:   code,
@@ -117,22 +105,11 @@ func makeMethodValue(op string, v Value) Value {
 	ftyp := (*funcType)(unsafe.Pointer(t))
 	method := int(v.flag) >> flagMethodShift
 
-	var code uintptr
-	var ffi *ffiData
-	switch runtime.GOARCH {
-	case "amd64", "386":
-		// Indirect Go func value (dummy) to obtain actual
-		// code address. (A Go func value is a pointer to a C
-		// function pointer. http://golang.org/s/go11func.)
-		dummy := makeFuncStub
-		code = **(**uintptr)(unsafe.Pointer(&dummy))
-	default:
-		code, ffi = makeFuncFFI(ftyp,
-			func(in []Value) []Value {
-				m := rcvr.Method(method)
-				return m.Call(in)
-			})
-	}
+	code, ffi := makeFuncFFI(ftyp,
+		func(in []Value) []Value {
+			m := rcvr.Method(method)
+			return m.Call(in)
+		})
 
 	fv := &makeFuncImpl{
 		code:   code,
@@ -160,21 +137,10 @@ func makeValueMethod(v Value) Value {
 	t := typ.common()
 	ftyp := (*funcType)(unsafe.Pointer(t))
 
-	var code uintptr
-	var ffi *ffiData
-	switch runtime.GOARCH {
-	case "amd64", "386":
-		// Indirect Go func value (dummy) to obtain actual
-		// code address. (A Go func value is a pointer to a C
-		// function pointer. http://golang.org/s/go11func.)
-		dummy := makeFuncStub
-		code = **(**uintptr)(unsafe.Pointer(&dummy))
-	default:
-		code, ffi = makeFuncFFI(ftyp,
-			func(in []Value) []Value {
-				return v.Call(in)
-			})
-	}
+	code, ffi := makeFuncFFI(ftyp,
+		func(in []Value) []Value {
+			return v.Call(in)
+		})
 
 	impl := &makeFuncImpl{
 		code:   code,
diff --git a/libgo/go/reflect/makefunc_ffi_c.c b/libgo/go/reflect/makefunc_ffi_c.c
index fba269d..d05f82b 100644
--- a/libgo/go/reflect/makefunc_ffi_c.c
+++ b/libgo/go/reflect/makefunc_ffi_c.c
@@ -5,17 +5,8 @@
 #include "runtime.h"
 #include "go-type.h"
 #include "go-panic.h"
-
-#ifdef USE_LIBFFI
-
 #include "go-ffi.h"
 
-#if FFI_CLOSURES
-#define USE_LIBFFI_CLOSURES
-#endif
-
-#endif /* defined(USE_LIBFFI) */
-
 /* Declare C functions with the names used to call from Go.  */
 
 struct ffi_ret {
@@ -30,8 +21,6 @@ struct ffi_ret ffi(const struct __go_func_type *ftyp, FuncVal *callback)
 void ffiFree(void *data)
   __asm__ (GOSYM_PREFIX "reflect.ffiFree");
 
-#ifdef USE_LIBFFI_CLOSURES
-
 /* The function that we pass to ffi_prep_closure_loc.  This calls the
    Go callback function (passed in user_data) with the pointer to the
    arguments and the results area.  */
@@ -116,20 +105,3 @@ ffiFree (void *data)
 {
   ffi_closure_free (data);
 }
-
-#else /* !defined(USE_LIBFFI_CLOSURES) */
-
-struct ffi_ret
-ffi(const struct __go_func_type *ftyp, FuncVal *callback)
-{
-  runtime_panicstring ("libgo built without FFI does not support "
-		       "reflect.MakeFunc");
-}
-
-void ffiFree(void *data)
-{
-  runtime_panicstring ("libgo built without FFI does not support "
-		       "reflect.MakeFunc");
-}
-
-#endif
diff --git a/libgo/go/reflect/value.go b/libgo/go/reflect/value.go
index c390b8e..0a4c5e1 100644
--- a/libgo/go/reflect/value.go
+++ b/libgo/go/reflect/value.go
@@ -427,9 +427,6 @@ func (v Value) CallSlice(in []Value) []Value {
 
 var callGC bool // for testing; see TestCallMethodJump
 
-var makeFuncStubFn = makeFuncStub
-var makeFuncStubCode = **(**uintptr)(unsafe.Pointer(&makeFuncStubFn))
-
 func (v Value) call(op string, in []Value) []Value {
 	// Get function pointer, type.
 	t := v.typ
@@ -507,17 +504,6 @@ func (v Value) call(op string, in []Value) []Value {
 	}
 	nout := t.NumOut()
 
-	// If target is makeFuncStub, short circuit the unpack onto stack /
-	// pack back into []Value for the args and return values.  Just do the
-	// call directly.
-	// We need to do this here because otherwise we have a situation where
-	// reflect.callXX calls makeFuncStub, neither of which knows the
-	// layout of the args.  That's bad for precise gc & stack copying.
-	x := (*makeFuncImpl)(fn)
-	if x.code == makeFuncStubCode {
-		return x.call(in)
-	}
-
 	if v.flag&flagMethod != 0 {
 		nin++
 	}
@@ -1313,12 +1299,14 @@ func (v Value) Pointer() uintptr {
 		if v.flag&flagMethod != 0 {
 			// As the doc comment says, the returned pointer is an
 			// underlying code pointer but not necessarily enough to
-			// identify a single function uniquely. All method expressions
-			// created via reflect have the same underlying code pointer,
-			// so their Pointers are equal. The function used here must
-			// match the one used in makeMethodValue.
-			f := makeFuncStub
-			return **(**uintptr)(unsafe.Pointer(&f))
+			// identify a single function uniquely.
+			// ??? Prior to the use of libffi, all method expressions
+			// created via reflect had the same underlying code pointer,
+			// so their Pointers were equal.  Since we now create ffi
+			// thunks, we have no way to remember the thunk value for
+			// any method, so we have no way at all to generate pointer
+			// equality.  The best we can do is some non-zero quantity.
+			return 0xdeadbeef
 		}
 		p := v.pointer()
 		// Non-nil func value points at data block.
diff --git a/libgo/runtime/go-ffi.c b/libgo/runtime/go-ffi.c
index 21879b9..42f8134 100644
--- a/libgo/runtime/go-ffi.c
+++ b/libgo/runtime/go-ffi.c
@@ -12,9 +12,6 @@
 #include "go-alloc.h"
 #include "go-assert.h"
 #include "go-type.h"
-
-#ifdef USE_LIBFFI
-
 #include "ffi.h"
 
 /* The functions in this file are only called from reflect_call and
@@ -334,5 +331,3 @@ __go_func_to_cif (const struct __go_func_type *func, _Bool is_interface,
   status = ffi_prep_cif (cif, FFI_DEFAULT_ABI, num_args, rettype, args);
   __go_assert (status == FFI_OK);
 }
-
-#endif /* defined(USE_LIBFFI) */
diff --git a/libgo/runtime/go-ffi.h b/libgo/runtime/go-ffi.h
index afae4b6..1b4f523 100644
--- a/libgo/runtime/go-ffi.h
+++ b/libgo/runtime/go-ffi.h
@@ -6,11 +6,6 @@
 
 #include "config.h"
 #include "go-type.h"
-
-#ifdef USE_LIBFFI
-
 #include "ffi.h"
 
 void __go_func_to_cif (const struct __go_func_type *, _Bool, _Bool, ffi_cif *);
-
-#endif
diff --git a/libgo/runtime/go-reflect-call.c b/libgo/runtime/go-reflect-call.c
index dfc703e..8018183 100644
--- a/libgo/runtime/go-reflect-call.c
+++ b/libgo/runtime/go-reflect-call.c
@@ -12,9 +12,6 @@
 #include "go-alloc.h"
 #include "go-assert.h"
 #include "go-type.h"
-
-#ifdef USE_LIBFFI
-
 #include "go-ffi.h"
 
 /* The functions in this file are only called from reflect_call.  As
@@ -232,20 +229,3 @@ reflect_call (const struct __go_func_type *func_type, FuncVal *func_val,
 
   free (call_result);
 }
-
-#else /* !defined(USE_LIBFFI) */
-
-void
-reflect_call (const struct __go_func_type *func_type __attribute__ ((unused)),
-	      FuncVal *func_val __attribute__ ((unused)),
-	      _Bool is_interface __attribute__ ((unused)),
-	      _Bool is_method __attribute__ ((unused)),
-	      void **params __attribute__ ((unused)),
-	      void **results __attribute__ ((unused)))
-{
-  /* Without FFI there is nothing we can do.  */
-  runtime_throw("libgo built without FFI does not support "
-		"reflect.Call or runtime.SetFinalizer");
-}
-
-#endif /* !defined(USE_LIBFFI) */