Add enum-to-string functions for syntax tree and opcodes.

jscompile.h

@@ -113,7 +113,7 @@ struct js_Function
 };
 
 js_Function *jsC_compile(js_State *J, js_Ast *prog);
-
+const char *jsC_opcodestring(int opcode);
 void jsC_dumpfunction(js_State *J, js_Function *fun);
 
 #endif

jsdump.c

@@ -5,6 +5,8 @@
 
 #include <assert.h>
 
+#define nelem(a) (sizeof (a) / sizeof (a)[0])
+
 static const char *astname[] = {
 	"list", "fundec", "ident", "number", "string", "regexp", "undef",
 	"null", "true", "false", "this", "fun", "array", "object", "prop_val",
@@ -25,6 +27,20 @@ static const char *opname[] = {
 #include "opnames.h"
 };
 
+const char *jsP_aststring(js_AstType type)
+{
+	if (type < 0 || type > nelem(astname))
+		return "<unknown>";
+	return astname[type];
+}
+
+const char *jsC_opcodestring(int type)
+{
+	if (type < 0 || type > nelem(opname))
+		return "<unknown>";
+	return opname[type];
+}
+
 static inline void pc(int c)
 {
 	putchar(c);

jsparse.h

@@ -128,6 +128,7 @@ js_Ast *jsP_parse(js_State *J, const char *filename, const char *source);
 void jsP_optimize(js_State *J, js_Ast *prog);
 void jsP_freeparse(js_State *J);
 
+const char *jsP_aststring(js_AstType type);
 void jsP_dumpsyntax(js_State *J, js_Ast *prog);
 void jsP_dumplist(js_State *J, js_Ast *prog);
 

jsrun.c

@@ -808,7 +808,7 @@ static void jsR_run(js_State *J, js_Function *F)
 			return;
 
 		default:
-			js_error(J, "illegal instruction: %d (pc=%d)", opcode, (int)(pc - F->code - 1));
+			js_error(J, "illegal instruction: %s (pc=%d)", jsC_opcodestring(opcode), (int)(pc - F->code - 1));
 		}
 	}
 }