Code heap debugging in FEP

vm/code_gc.c

@@ -126,7 +126,7 @@ void free_unmarked(HEAP *heap)
 		if(scan->status == B_ALLOCATED)
 		{
 			/* merge blocks? */
-			if(next_block(heap,prev) == scan)
+			if(prev && next_block(heap,prev) == scan)
 				prev->size += scan->size;
 			else
 			{
@@ -241,3 +241,32 @@ void primitive_code_gc(void)
 {
 	garbage_collection(TENURED,true);
 }
+
+void dump_heap(HEAP *heap)
+{
+	F_BLOCK *scan = (F_BLOCK *)heap->base;
+
+	while(scan)
+	{
+		char *status;
+		switch(scan->status)
+		{
+		case B_FREE:
+			status = "free";
+			break;
+		case B_ALLOCATED:
+			status = "allocated";
+			break;
+		case B_MARKED:
+			status = "marked";
+			break;
+		default:
+			status = "invalid";
+			break;
+		}
+
+		fprintf(stderr,"%lx %s\n",(CELL)scan,status);
+
+		scan = next_block(heap,scan);
+	}
+}

vm/code_gc.h

@@ -77,3 +77,4 @@ void collect_literals(void);
 void recursive_mark(CELL xt);
 void primitive_code_room(void);
 void primitive_code_gc(void);
+void dump_heap(HEAP *heap);

vm/debug.c

@@ -165,7 +165,7 @@ void factorbug(void)
 	fprintf(stderr,"g                -- dump generations\n");
 	fprintf(stderr,"card <addr>      -- print card containing address\n");
 	fprintf(stderr,"addr <card>      -- print address containing card\n");
-	fprintf(stderr,"c <gen>          -- force garbage collection\n");
+	fprintf(stderr,"code             -- code heap dump\n");
 	
 	for(;;)
 	{
@@ -243,6 +243,8 @@ void factorbug(void)
 			exit(1);
 		else if(strcmp(cmd,"im") == 0)
 			save_image("fep.image");
+		else if(strcmp(cmd,"code") == 0)
+			dump_heap(&compiling);
 		else
 			fprintf(stderr,"unknown command\n");
 	}