From 8dfb763782a673461c039e793e3b42bd5f0cc284 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Beno=C3=AEt=20Minisini?= <gambas@users.sourceforge.net>
Date: Sun, 4 Mar 2012 23:43:07 +0000
Subject: [PATCH] [INTERPRETER] * NEW: GOSUB can be recursive now, by saving
 the control variables, and   restoring them on RETURN.

[COMPILER]
* NEW: GOSUB can be used on any top-level labels.


git-svn-id: svn://localhost/gambas/trunk@4534 867c0c6c-44f3-4631-809d-bfa615b0a4ec
---
 main/gbc/gbc_trans_ctrl.c |  6 ++--
 main/gbx/gbx_exec_loop.c  | 62 +++++++++++++++++++++++++++------------
 main/gbx/gbx_stack.c      | 17 +++++++----
 main/gbx/gbx_stack.h      |  9 ++----
 4 files changed, 62 insertions(+), 32 deletions(-)

diff --git a/main/gbc/gbc_trans_ctrl.c b/main/gbc/gbc_trans_ctrl.c
index 0fa0a03c7..41ffa4556 100644
--- a/main/gbc/gbc_trans_ctrl.c
+++ b/main/gbc/gbc_trans_ctrl.c
@@ -337,7 +337,7 @@ void TRANS_control_exit()
 			
 			if (goto_info[i].gosub)
 			{
-				if (label->ctrl_id || goto_info[i].pos > label->pos)
+				if (label->ctrl_id)
 					THROW("Forbidden GOSUB");
 			}
 			else
@@ -1074,7 +1074,7 @@ void TRANS_catch(void)
 void TRANS_label(void)
 {
 	CLASS_SYMBOL *sym;
-	int sym_index, i;
+	int sym_index;
 	TRANS_LABEL *label;
 
 	sym_index = PATTERN_index(*JOB->current);
@@ -1101,6 +1101,7 @@ void TRANS_label(void)
 	/* on saute le ':' */
 	JOB->current++;
 	
+	/*
 	// A new set of control stack slots must be used for a GOSUB subroutine
 	
 	for (i = 0; i < ARRAY_count(goto_info); i++)
@@ -1111,6 +1112,7 @@ void TRANS_label(void)
 			return;
 		}
 	}
+	*/
 }
 
 
diff --git a/main/gbx/gbx_exec_loop.c b/main/gbx/gbx_exec_loop.c
index ad1da36ff..ab90add39 100644
--- a/main/gbx/gbx_exec_loop.c
+++ b/main/gbx/gbx_exec_loop.c
@@ -849,19 +849,29 @@ _NEW:
 
 _GOSUB:
 	
-	if (!GP)
 	{
-		ALLOC_ZERO(&GP, sizeof(STACK_GOSUB), "EXEC_loop");
-	}
+		STACK_GOSUB *gp;
+		VALUE *ctrl;
+		int i;
+		
+		if (!GP)
+			ARRAY_create(&GP);
 	
-	if (GP->level == MAX_GOSUB_LEVEL)
-	{
-		ALLOC_ZERO(&GP->next, sizeof(STACK_GOSUB), "EXEC_loop");
-		GP->next->prev = GP;
-		GP = GP->next;
+		gp = ARRAY_add(&GP);
+		gp->pc = PC - FP->code;
+		if (FP->n_ctrl)
+		{
+			ALLOC(&gp->ctrl, sizeof(VALUE) * FP->n_ctrl, "EXEC_loop._GOSUB");
+			ctrl = &BP[FP->n_local];
+			for (i = 0; i < FP->n_ctrl; i++)
+			{
+				gp->ctrl[i] = ctrl[i];
+				ctrl[i].type = T_NULL;
+			}
+		}
+		else
+			gp->ctrl = NULL;
 	}
-	
-	GP->pc[GP->level++] = PC - FP->code;
 
 /*-----------------------------------------------*/
 
@@ -903,6 +913,9 @@ _RETURN:
 		static const void *return_jump[] = { &&__RETURN_GOSUB, &&__RETURN_VALUE, &&__RETURN_VOID };
 		
 		TYPE type;
+		STACK_GOSUB *gp;
+		VALUE *ctrl;
+		int i, n;
 		
 		goto *return_jump[GET_UX()];
 		
@@ -910,18 +923,29 @@ _RETURN:
 		
 		if (!GP)
 			goto __RETURN_VOID;
+		
+		n = ARRAY_count(GP);
+		if (n == 0)
+			goto __RETURN_VOID;
 
-		if (GP->level == 0)
+		gp = &GP[n - 1];
+		PC = FP->code + gp->pc + 2;
+		if (FP->n_ctrl)
 		{
-			STACK_GOSUB *prev = GP->prev;
-			IFREE(GP, "EXEC_loop");
-			GP = prev;
-			if (!prev)
-				goto __RETURN_VOID;
+			ctrl = &BP[FP->n_local];
+			for (i = 0; i < FP->n_ctrl; i++)
+			{
+				RELEASE(&ctrl[i]);
+				ctrl[i] = gp->ctrl[i];
+			}
+			FREE(&gp->ctrl, "EXEC_loop._RETURN");
 		}
-			
-		GP->level--;
-		PC = FP->code + GP->pc[GP->level] + 2;
+		
+		if (n == 1)
+			ARRAY_delete(&GP);
+		else
+			ARRAY_remove_last(&GP);
+		
 		goto _MAIN;
 
 	__RETURN_VALUE:
diff --git a/main/gbx/gbx_stack.c b/main/gbx/gbx_stack.c
index 3435593c1..e47cc3ed3 100644
--- a/main/gbx/gbx_stack.c
+++ b/main/gbx/gbx_stack.c
@@ -268,12 +268,19 @@ STACK_BACKTRACE *STACK_get_backtrace(void)
 
 void STACK_free_gosub_stack(STACK_GOSUB *gosub)
 {
+	int i, j;
 	STACK_GOSUB *p;
 	
-	while (gosub)
+	if (FP->n_ctrl)
 	{
-		p = gosub;
-		gosub = gosub->next;
-		IFREE(p, "STACK_free_gosub_stack");
+		for (i = 0, p = gosub; i < ARRAY_count(gosub); i++, p++)
+		{
+			for (j = 0; j < FP->n_ctrl; j++)
+				RELEASE(&p->ctrl[j]);
+			
+			FREE(&p->ctrl, "STACK_free_gosub_stack");
+		}
 	}
-}
\ No newline at end of file
+	
+	ARRAY_delete(&gosub);
+}
diff --git a/main/gbx/gbx_stack.h b/main/gbx/gbx_stack.h
index 69752c2ce..e6739d19b 100644
--- a/main/gbx/gbx_stack.h
+++ b/main/gbx/gbx_stack.h
@@ -36,16 +36,13 @@ typedef
 	PACKED
 	STACK_BACKTRACE;
 
-#define MAX_GOSUB_LEVEL 119
+//#define MAX_GOSUB_LEVEL 119
 
 typedef
 	struct _STACK_GOSUB {
-		ushort level;
-		ushort pc[MAX_GOSUB_LEVEL];
-		struct _STACK_GOSUB *next;
-		struct _STACK_GOSUB *prev;
+		ushort pc;
+		VALUE *ctrl;
 	}
-	PACKED
 	STACK_GOSUB;
 
 typedef