From a43a2e343e4620c10b1a383f419b2d7b2714f78b Mon Sep 17 00:00:00 2001
From: Hugo Villeneuve <hugo@hugovil.com>
Date: Wed, 5 Feb 2014 22:02:43 -0500
Subject: [PATCH] Add new value range check when writing register in CLI
 version

The GUI version also had this check, so the functionality has been merged.
---
 src/common/sfr.c | 17 ++++++++++++++--
 src/common/sfr.h |  2 +-
 src/gtk/regwin.c | 50 ++++++++++++++++--------------------------------
 3 files changed, 33 insertions(+), 36 deletions(-)

diff --git a/src/common/sfr.c b/src/common/sfr.c
index 165ba2e..8d74dcf 100644
--- a/src/common/sfr.c
+++ b/src/common/sfr.c
@@ -317,9 +317,20 @@ regwin_read(int row)
 	return val;
 }
 
-void
+int
 regwin_write(struct regwin_infos_t *p, int new)
 {
+	int max_value;
+
+	max_value = (1 << (4 * p->w)) - 1; /* 16^w - 1 */
+
+	/* Check that the new value is not too large for the register type. */
+	if (new > max_value) {
+		/* Display message for CLI version */
+		printf("Value out of range\n");
+		return -1;
+	}
+
 	if (p->write_func == NULL) {
 		/*
 		 * Write register value using generic 8 or 16 bits write
@@ -330,6 +341,8 @@ regwin_write(struct regwin_infos_t *p, int new)
 		/* Write register value using custom function pointer. */
 		p->write_func(p->param, new);
 	}
+
+	return 0;
 }
 
 struct regwin_infos_t *
@@ -342,7 +355,7 @@ sfr_get_infos(const char *regname)
 			return &regwin_infos[row];
 	}
 
-	return NULL; /* Programming error. */
+	return NULL; /* Register not found. */
 }
 
 struct regwin_infos_t *
diff --git a/src/common/sfr.h b/src/common/sfr.h
index fe552dd..4d4d511 100644
--- a/src/common/sfr.h
+++ b/src/common/sfr.h
@@ -34,7 +34,7 @@ struct regwin_infos_t {
 int
 regwin_read(int row);
 
-void
+int
 regwin_write(struct regwin_infos_t *p, int new);
 
 struct regwin_infos_t *
diff --git a/src/gtk/regwin.c b/src/gtk/regwin.c
index 8b470a9..a2b0f6e 100644
--- a/src/gtk/regwin.c
+++ b/src/gtk/regwin.c
@@ -80,6 +80,7 @@ regwin_cell_edited(GtkCellRendererText *cell, gchar *path_string,
 	int old;
 	int new;
 	char *str;
+	int rc;
 	struct regwin_infos_t *regwin_infos;
 
 	(void) cell; /* Remove compiler warning about unused variables. */
@@ -96,47 +97,30 @@ regwin_cell_edited(GtkCellRendererText *cell, gchar *path_string,
 
 	log_info("Register: %s", str);
 	regwin_infos = sfr_get_infos(str);
+	log_info("  width:     %d bits", 4 * regwin_infos->w);
 
 	/* Read current (old) value. */
 	gtk_tree_model_get(model, &iter, COL_VAL, &str, -1);
 
 	old = asciihex2int(str);
-
-	if (regwin_infos->w == 2)
-		log_info("  old value: $%02X", old);
-	else if (regwin_infos->w == 4)
-		log_info("  old value: $%04X", old);
+	log_info("  old value: $%04X", old);
 
 	new = asciihex2int(new_str);
-
-	if (regwin_infos->w == 2) {
-		if ((new < 0) || (new > 0xFF)) {
-			log_info("  new value: out of range");
-			new = old; /* Put back old value... */
-		} else {
-			log_info("  new value: $%02X", new);
-		}
-	} else if (regwin_infos->w == 4) {
-		if ((new < 0) || (new > 0xFFFF)) {
-			log_info("  new value: out of range");
-			new = old; /* Put back old value... */
-		} else {
-			log_info("  new value: $%04X", new);
-		}
+	log_info("  new value: $%04X", new);
+
+	/* Store new value in emulator register (if in range). */
+	rc = regwin_write(regwin_infos, new);
+	if (rc == 0) {
+		/* Store new value in gtk model. */
+		int2asciihex(new, str, regwin_infos->w);
+		gtk_list_store_set(GTK_LIST_STORE(model), &iter, COL_VAL, str, -1);
+
+		/*
+		 * Make sure to update all windows.
+		 * For example, R0-R7 values depends on internal memory values.
+		 */
+		emugtk_UpdateDisplay();
 	}
-
-	/* Store new value in emulator register. */
-	regwin_write(regwin_infos, new);
-
-	/* Store new value in gtk model. */
-	int2asciihex(new, str, regwin_infos->w);
-        gtk_list_store_set(GTK_LIST_STORE(model), &iter, COL_VAL, str, -1);
-
-	/*
-	 * Make sure to update all windows.
-	 * For example, R0-R7 values depends on internal memory values.
-	 */
-	emugtk_UpdateDisplay();
 };
 
 static void
-- 
2.20.1