From 67941d7acbdbf8342251359811bbbcc324262247 Mon Sep 17 00:00:00 2001
From: Ali Gholami Rudi <ali@rudi.ir>
Date: Fri, 28 May 2010 10:15:56 +0430
Subject: [PATCH] handle initializer for local variables

---
 gen.c | 14 +++++++++++
 gen.h |  1 +
 ncc.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------
 3 files changed, 94 insertions(+), 9 deletions(-)

diff --git a/gen.c b/gen.c
index a629078..4d591c8 100644
--- a/gen.c
+++ b/gen.c
@@ -952,6 +952,20 @@ void o_memcpy(int sz)
 	o_tmpdrop(2);
 }
 
+void o_memset(int x, int sz)
+{
+	struct tmp *t0 = &tmp[ntmp + 1];
+	struct tmp *t1 = &tmp[ntmp];
+	struct tmp *t2 = &tmp[ntmp - 1];
+	o_num(sz, 4);
+	o_num(x, 4);
+	tmp_to(t0, R_RAX);
+	tmp_to(t1, R_RCX);
+	tmp_to(t2, R_RDI);
+	os("\xf3\xaa", 2);		/* rep stosb */
+	o_tmpdrop(2);
+}
+
 long o_mklabel(void)
 {
 	return codeaddr();
diff --git a/gen.h b/gen.h
index e336084..17ce48b 100644
--- a/gen.h
+++ b/gen.h
@@ -53,6 +53,7 @@ long o_jmp(long addr);
 void o_filljmp(long addr);
 void o_filljmp2(long addr, long jmpdst);
 void o_memcpy(int sz);
+void o_memset(int x, int sz);
 
 long o_func_beg(char *name, int global);
 void o_func_end(void);
diff --git a/ncc.c b/ncc.c
index 8f01bd5..e4449c3 100644
--- a/ncc.c
+++ b/ncc.c
@@ -1017,17 +1017,22 @@ static void opassign(void (*bop)(void (*op)(void)), void (*op)(void))
 	o_assign(bt);
 }
 
+static void doassign(void)
+{
+	struct type t;
+	ts_pop(&t);
+	if (!t.ptr && t.flags & T_STRUCT)
+		o_memcpy(type_totsz(&t));
+	else
+		o_assign(TYPE_BT(&ts[nts - 1]));
+}
+
 static void readexpr(void)
 {
 	readcexpr();
 	if (!tok_jmp('=')) {
-		struct type t;
 		readexpr();
-		ts_pop(&t);
-		if (t.flags & (T_STRUCT))
-			o_memcpy(type_totsz(&t));
-		else
-			o_assign(TYPE_BT(&ts[nts - 1]));
+		doassign();
 		return;
 	}
 	if (!tok_jmp(TOK2("+="))) {
@@ -1090,6 +1095,68 @@ static void globaldef(void *data, struct name *name, unsigned flags)
 	global_add(name);
 }
 
+static void o_localoff(long addr, int off, unsigned bt)
+{
+	o_local(addr, bt);
+	if (off) {
+		o_addr();
+		o_num(off, 4);
+		o_add();
+		o_deref(bt);
+	}
+}
+
+static void initexpr(struct type *t, long addr, int off)
+{
+	if (tok_jmp('{')) {
+		o_localoff(addr, off, TYPE_BT(t));
+		ts_push(t);
+		readexpr();
+		doassign();
+		ts_pop(NULL);
+		o_tmpdrop(1);
+		return;
+	}
+	if (!t->ptr && t->flags & T_STRUCT) {
+		struct structinfo *si = &structs[t->id];
+		int i;
+		for (i = 0; i < si->nfields; i++) {
+			struct name *field = &si->fields[i];
+			if (!tok_jmp('.')) {
+				tok_expect(TOK_NAME);
+				field = struct_field(t->id, tok_id());
+				tok_expect('=');
+			}
+			initexpr(&field->type, addr, off + field->addr);
+			if (tok_jmp(',') || tok_see() == '}')
+				break;
+		}
+	} else {
+		struct type t_de;
+		int i;
+		int sz;
+		memcpy(&t_de, t, sizeof(*t));
+		if (t->flags & T_ARRAY)
+			array2ptr(&t_de);
+		t_de.ptr--;
+		sz = type_totsz(&t_de);
+		for (i = 0; ; i++) {
+			long idx = i;
+			if (!tok_jmp('[')) {
+				readexpr();
+				o_popnum(&idx);
+				ts_pop(NULL);
+				tok_expect(']');
+				tok_expect('=');
+			}
+			initexpr(&t_de, addr, off + sz * idx);
+			if (tok_jmp(',') || tok_see() == '}')
+				break;
+		}
+	}
+	tok_expect('}');
+}
+
 static void localdef(void *data, struct name *name, unsigned flags)
 {
 	if (flags & F_STATIC) {
@@ -1100,9 +1167,12 @@ static void localdef(void *data, struct name *name, unsigned flags)
 	local_add(name);
 	if (flags & F_INIT) {
 		struct type *t = &name->type;
-		o_local(locals[nlocals - 1].addr, TYPE_BT(t));
-		readexpr();
-		o_assign(TYPE_BT(t));
+		if (tok_see() == '{') {
+			o_local(name->addr, TYPE_BT(t));
+			o_memset(0, type_totsz(t));
+			o_tmpdrop(1);
+		}
+		initexpr(t, name->addr, 0);
 	}
 }
 
-- 
2.11.4.GIT