add a prototype implementation for a stack traceback getter (implemented as an actual function for now)

src/duk_builtin_error.c

@@ -105,3 +105,97 @@ int duk_builtin_error_prototype_to_string(duk_context *ctx) {
 	return DUK_RET_TYPE_ERROR;
 }
 
+/* FIXME: This needs to actually be a getter/setter pair, this is
+ * for prototyping traceback formatting.  The resulting code is
+ * also way too large, so needs rework.
+ */
+int duk_builtin_error_prototype_stack(duk_context *ctx) {
+	int idx_td;
+	int i;
+	const char *str_tailcalled = " tailcalled";
+	const char *str_strict = " strict";
+	const char *str_construct = " construct";
+	const char *str_empty = "";
+
+	duk_push_this(ctx);
+	duk_get_prop_stridx(ctx, -1, DUK_STRIDX_TRACEDATA);
+	idx_td = duk_get_top_index(ctx);
+
+	duk_push_hstring_stridx(ctx, DUK_STRIDX_NEWLINE_TAB);
+	duk_push_this(ctx);
+	duk_to_string(ctx, -1);
+
+	/* [ ... this tracedata sep ToString(this) ] */
+
+	/* FIXME: filename missing */
+	/* FIXME: native / C function */
+	/* FIXME: indicate truncated traceback */
+
+	if (duk_check_type(ctx, idx_td, DUK_TYPE_OBJECT)) {
+		int t;
+		for (i = 0; ; i += 2) {
+			int pc;
+			int line;
+			int flags;
+			double d;
+			duk_hobject *h;
+			duk_hbuffer_fixed *pc2line;
+
+			duk_require_stack(ctx, 5);
+			duk_get_prop_index(ctx, idx_td, i);
+			duk_get_prop_index(ctx, idx_td, i + 1);
+			d = duk_to_number(ctx, -1);
+			t = duk_get_type(ctx, -2);
+			if (t == DUK_TYPE_OBJECT) {
+				h = duk_get_hobject(ctx, -2);
+				DUK_ASSERT(h != NULL);
+
+				pc = (int) fmod(d, DUK_DOUBLE_2TO32);
+				flags = (int) floor(d / DUK_DOUBLE_2TO32);
+				duk_get_prop_stridx(ctx, -2, DUK_STRIDX_NAME);
+				duk_get_prop_stridx(ctx, -3, DUK_STRIDX_INT_FILENAME);
+
+				duk_get_prop_stridx(ctx, -4, DUK_STRIDX_INT_PC2LINE);
+				if (duk_is_buffer(ctx, -1)) {
+					pc2line = (duk_hbuffer_fixed *) duk_get_hbuffer(ctx, -1);
+					DUK_ASSERT(!DUK_HBUFFER_HAS_DYNAMIC(pc2line));
+					line = duk_hobject_pc2line_query(pc2line, pc);
+				} else {
+					line = 0;
+				}
+				duk_pop(ctx);
+
+				if (DUK_HOBJECT_HAS_NATIVEFUNCTION(h)) {
+					duk_push_sprintf(ctx, "%s %s native%s%s%s",
+					                 duk_get_string(ctx, -2), duk_get_string(ctx, -1),
+					                 (flags & DUK_ACT_FLAG_STRICT) ? str_strict : str_empty,
+					                 (flags & DUK_ACT_FLAG_TAILCALLED) ? str_tailcalled : str_empty,
+					                 (flags & DUK_ACT_FLAG_CONSTRUCT) ? str_construct : str_empty);
+
+				} else {
+					duk_push_sprintf(ctx, "%s %s:%d%s%s%s",
+					                 duk_get_string(ctx, -2), duk_get_string(ctx, -1), line,
+					                 (flags & DUK_ACT_FLAG_STRICT) ? str_strict : str_empty,
+					                 (flags & DUK_ACT_FLAG_TAILCALLED) ? str_tailcalled : str_empty,
+					                 (flags & DUK_ACT_FLAG_CONSTRUCT) ? str_construct : str_empty);
+				}
+				duk_replace(ctx, -5);   /* [ ... v1 v2 name filename str ] -> [ ... str v2 name filename ] */
+				duk_pop_n(ctx, 3);      /* -> [ ... str ] */
+			} else if (t == DUK_TYPE_STRING) {
+				duk_push_sprintf(ctx, "%s:%d",
+				                      duk_get_string(ctx, -2), (int) d);
+				duk_replace(ctx, -3);  /* [ ... v1 v2 str ] -> [ ... str v2 ] */
+				duk_pop(ctx);          /* -> [ ... str ] */
+			} else {
+				duk_pop_2(ctx);
+				break;
+			}
+		}
+	}
+
+	/* [ ... this tracedata sep ToString(this) str1 ... strN ] */
+
+	duk_join(ctx, duk_get_top(ctx) - (idx_td + 2) /*count, not including sep*/);
+	return 1;
+}
+

src/duk_builtin_protos.h

@@ -101,6 +101,7 @@ int duk_builtin_duk_object_sleep(duk_context *ctx);
 
 int duk_builtin_error_constructor(duk_context *ctx);
 int duk_builtin_error_prototype_to_string(duk_context *ctx);
+int duk_builtin_error_prototype_stack(duk_context *ctx);  /* FIXME: placeholder */
 int duk_builtin_eval_error_constructor(duk_context *ctx);
 int duk_builtin_range_error_constructor(duk_context *ctx);
 int duk_builtin_reference_error_constructor(duk_context *ctx);

src/genbuiltins.py

@@ -770,12 +770,13 @@ bi_error_prototype = {
 
 		# Custom properties
 
-		{ 'name': 'stack',			'value': '' },
 		# FIXME: custom properties
-
+		# FIXME: stack getter/setter
 	],
 	'functions': [
 		{ 'name': 'toString',			'native': 'duk_builtin_error_prototype_to_string',		'length': 0 },
+		# FIXME: placeholder
+		{ 'name': 'stack',			'native': 'duk_builtin_error_prototype_stack',			'length': 0 },
 	],
 }
 

src/genstrings.py

@@ -451,6 +451,7 @@ standard_other_string_list = [
 	mkstr("", class_name=True),	# used as a class name for unused/invalid class
 	mkstr(","),			# for array joining
 	mkstr(" "),			# for print()
+	mkstr("\n\t"),			# for tracebacks
 	mkstr("Invalid Date"),		# for invalid Date instances
 	# arguments object (E5 Section 10.6)
 	mkstr("arguments"),
@@ -710,6 +711,7 @@ special_define_names = {
 	'': 'EMPTY_STRING',
 	',': 'COMMA',
 	' ': 'SPACE',
+	'\n\t': 'NEWLINE_TAB',
 
 	'{"_undefined":true}': 'JSON_EXT_UNDEFINED',
 	'{"_nan":true}': 'JSON_EXT_NAN',