compiler, runtime: Use function descriptors.

This changes the representation of a Go value of function type
from being a pointer to function code (like a C function
pointer) to being a pointer to a struct.  The first field of
the struct points to the function code.  The remaining fields,
if any, are the addresses of variables referenced in enclosing
functions.  For each call to a function, the address of the
function descriptor is passed as the last argument.

This lets us avoid generating trampolines, and removes the use
of writable/executable sections of the heap.

From-SVN: r200181

1 files changed, 4 insertions, 4 deletions

diff --git a/libgo/runtime/mfinal.c b/libgo/runtime/mfinal.c
index 7c906da..407092b 100644
--- a/libgo/runtime/mfinal.c
+++ b/libgo/runtime/mfinal.c
@@ -11,7 +11,7 @@ enum { debug = 0 };
 typedef struct Fin Fin;
 struct Fin
 {
-	void (*fn)(void*);
+	FuncVal *fn;
 	const struct __go_func_type *ft;
 };
 
@@ -42,7 +42,7 @@ static struct {
 } fintab[TABSZ];
 
 static void
-addfintab(Fintab *t, void *k, void (*fn)(void*), const struct __go_func_type *ft)
+addfintab(Fintab *t, void *k, FuncVal *fn, const struct __go_func_type *ft)
 {
 	int32 i, j;
 
@@ -137,7 +137,7 @@ resizefintab(Fintab *tab)
 }
 
 bool
-runtime_addfinalizer(void *p, void (*f)(void*), const struct __go_func_type *ft)
+runtime_addfinalizer(void *p, FuncVal *f, const struct __go_func_type *ft)
 {
 	Fintab *tab;
 	byte *base;
@@ -175,7 +175,7 @@ runtime_addfinalizer(void *p, void (*f)(void*), const struct __go_func_type *ft)
 // get finalizer; if del, delete finalizer.
 // caller is responsible for updating RefHasFinalizer (special) bit.
 bool
-runtime_getfinalizer(void *p, bool del, void (**fn)(void*), const struct __go_func_type **ft)
+runtime_getfinalizer(void *p, bool del, FuncVal **fn, const struct __go_func_type **ft)
 {
 	Fintab *tab;
 	bool res;