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Merged
merged 4 commits into from
Jan 24, 2025
Merged

Record stack trace for non-object exceptions #805

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9f6d1a9
Record stack trace for non-object exceptions
bnoordhuis Jan 24, 2025
437cce1
Fix line:column reporting for throw statement
bnoordhuis Jan 24, 2025
a3e2704
fixup! special-case JS_BACKTRACE_FLAG_FILTER_FUNC
bnoordhuis Jan 24, 2025
cd27d90
squash! make codegen
bnoordhuis Jan 24, 2025
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11 changes: 6 additions & 5 deletions gen/function_source.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2,9 +2,9 @@

#include "quickjs-libc.h"

const uint32_t qjsc_function_source_size = 320;
const uint32_t qjsc_function_source_size = 324;

const uint8_t qjsc_function_source[320] = {
const uint8_t qjsc_function_source[324] = {
0x13, 0x05, 0x01, 0x30, 0x74, 0x65, 0x73, 0x74,
0x73, 0x2f, 0x66, 0x75, 0x6e, 0x63, 0x74, 0x69,
0x6f, 0x6e, 0x5f, 0x73, 0x6f, 0x75, 0x72, 0x63,
Expand Down Expand Up @@ -42,9 +42,10 @@ const uint8_t qjsc_function_source[320] = {
0x00, 0xb0, 0xeb, 0x0b, 0x39, 0x95, 0x00, 0x00,
0x00, 0x63, 0x02, 0x00, 0xf0, 0x30, 0x69, 0x02,
0x00, 0x69, 0x01, 0x00, 0x06, 0x2f, 0xc0, 0x03,
0x01, 0x01, 0x14, 0x00, 0x1c, 0x0a, 0x2a, 0x26,
0x03, 0x39, 0x28, 0x00, 0x10, 0x08, 0x27, 0x11,
0x12, 0x67, 0x0d, 0x26, 0x03, 0x39, 0x28, 0x00,
0x01, 0x01, 0x18, 0x00, 0x1c, 0x0a, 0x2a, 0x26,
0x03, 0x20, 0x1c, 0x1b, 0x0c, 0x00, 0x10, 0x08,
0x27, 0x11, 0x12, 0x67, 0x0d, 0x26, 0x03, 0x20,
0x1c, 0x1b, 0x0c, 0x00,
};

static JSContext *JS_NewCustomContext(JSRuntime *rt)
Expand Down
8 changes: 5 additions & 3 deletions quickjs-libc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4159,9 +4159,11 @@ static void js_std_dump_error1(JSContext *ctx, JSValue exception_val)
js_dump_obj(ctx, stderr, exception_val);
if (is_error) {
val = JS_GetPropertyStr(ctx, exception_val, "stack");
if (!JS_IsUndefined(val)) {
js_dump_obj(ctx, stderr, val);
}
} else {
js_std_cmd(/*ErrorBackTrace*/2, ctx, &val);
}
if (!JS_IsUndefined(val)) {
js_dump_obj(ctx, stderr, val);
JS_FreeValue(ctx, val);
}
}
Expand Down
87 changes: 53 additions & 34 deletions quickjs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -394,6 +394,7 @@ struct JSContext {
JSValue promise_ctor;
JSValue native_error_proto[JS_NATIVE_ERROR_COUNT];
JSValue error_ctor;
JSValue error_back_trace;
JSValue error_prepare_stack;
int error_stack_trace_limit;
JSValue iterator_ctor;
Expand Down Expand Up @@ -2305,6 +2306,7 @@ JSContext *JS_NewContextRaw(JSRuntime *rt)
ctx->regexp_ctor = JS_NULL;
ctx->promise_ctor = JS_NULL;
ctx->error_ctor = JS_NULL;
ctx->error_back_trace = JS_UNDEFINED;
ctx->error_prepare_stack = JS_UNDEFINED;
ctx->error_stack_trace_limit = 10;
init_list_head(&ctx->loaded_modules);
Expand Down Expand Up @@ -2424,6 +2426,7 @@ static void JS_MarkContext(JSRuntime *rt, JSContext *ctx,
JS_MarkValue(rt, ctx->native_error_proto[i], mark_func);
}
JS_MarkValue(rt, ctx->error_ctor, mark_func);
JS_MarkValue(rt, ctx->error_back_trace, mark_func);
JS_MarkValue(rt, ctx->error_prepare_stack, mark_func);
for(i = 0; i < rt->class_count; i++) {
JS_MarkValue(rt, ctx->class_proto[i], mark_func);
Expand Down Expand Up @@ -2491,6 +2494,7 @@ void JS_FreeContext(JSContext *ctx)
JS_FreeValue(ctx, ctx->native_error_proto[i]);
}
JS_FreeValue(ctx, ctx->error_ctor);
JS_FreeValue(ctx, ctx->error_back_trace);
JS_FreeValue(ctx, ctx->error_prepare_stack);
for(i = 0; i < rt->class_count; i++) {
JS_FreeValue(ctx, ctx->class_proto[i]);
Expand Down Expand Up @@ -6616,14 +6620,28 @@ static const char *get_func_name(JSContext *ctx, JSValue func)
return JS_ToCString(ctx, val);
}

/* Note: it is important that no exception is returned by this function */
static bool can_add_backtrace(JSValue obj)
{
JSObject *p;
if (JS_VALUE_GET_TAG(obj) != JS_TAG_OBJECT)
return false;
p = JS_VALUE_GET_OBJ(obj);
if (p->class_id != JS_CLASS_ERROR)
return false;
if (find_own_property1(p, JS_ATOM_stack))
return false;
return true;
}

#define JS_BACKTRACE_FLAG_SKIP_FIRST_LEVEL (1 << 0)
/* only taken into account if filename is provided */
#define JS_BACKTRACE_FLAG_SINGLE_LEVEL (1 << 1)
#define JS_BACKTRACE_FLAG_FILTER_FUNC (1 << 2)

/* if filename != NULL, an additional level is added with the filename
and line number information (used for parse error). */
static void build_backtrace(JSContext *ctx, JSValue error_obj, JSValue filter_func,
static void build_backtrace(JSContext *ctx, JSValue error_val, JSValue filter_func,
const char *filename, int line_num, int col_num,
int backtrace_flags)
{
Expand All @@ -6634,7 +6652,7 @@ static void build_backtrace(JSContext *ctx, JSValue error_obj, JSValue filter_fu
const char *str1;
JSObject *p;
JSFunctionBytecode *b;
bool backtrace_barrier, has_prepare;
bool backtrace_barrier, has_prepare, has_filter_func;
JSRuntime *rt;
JSCallSiteData csd[64];
uint32_t i;
Expand All @@ -6646,6 +6664,7 @@ static void build_backtrace(JSContext *ctx, JSValue error_obj, JSValue filter_fu
stack_trace_limit = max_int(stack_trace_limit, 0);
rt = ctx->rt;
has_prepare = false;
has_filter_func = backtrace_flags & JS_BACKTRACE_FLAG_FILTER_FUNC;
i = 0;

if (!rt->in_prepare_stack_trace && !JS_IsNull(ctx->error_ctor)) {
Expand Down Expand Up @@ -6681,7 +6700,7 @@ static void build_backtrace(JSContext *ctx, JSValue error_obj, JSValue filter_fu

/* Find the frame we want to start from. Note that when a filter is used the filter
function will be the first, but we also specify we want to skip the first one. */
if (backtrace_flags & JS_BACKTRACE_FLAG_FILTER_FUNC) {
if (has_filter_func) {
for (sf = sf_start; sf != NULL && i < stack_trace_limit; sf = sf->prev_frame) {
if (js_same_value(ctx, sf->cur_func, filter_func)) {
sf_start = sf;
Expand Down Expand Up @@ -6717,23 +6736,24 @@ static void build_backtrace(JSContext *ctx, JSValue error_obj, JSValue filter_fu
dbuf_printf(&dbuf, " at %s", str1);
JS_FreeCString(ctx, func_name_str);

if (b) {
if (b && sf->cur_pc) {
const char *atom_str;
int line_num1, col_num1;
uint32_t pc;

/* Bytecode functions must have cur_pc set in the stack frame. */
if (sf->cur_pc == NULL)
abort();

line_num1 = find_line_num(ctx, b,
sf->cur_pc - b->byte_code_buf - 1,
&col_num1);
pc = sf->cur_pc - b->byte_code_buf - 1;
line_num1 = find_line_num(ctx, b, pc, &col_num1);
atom_str = b->filename ? JS_AtomToCString(ctx, b->filename) : NULL;
dbuf_printf(&dbuf, " (%s", atom_str ? atom_str : "<null>");
JS_FreeCString(ctx, atom_str);
if (line_num1 != -1)
dbuf_printf(&dbuf, ":%d:%d", line_num1, col_num1);
dbuf_putc(&dbuf, ')');
} else if (b) {
// FIXME(bnoordhuis) Missing `sf->cur_pc = pc` in bytecode
// handler in JS_CallInternal. Almost never user observable
// except with intercepting JS proxies that throw exceptions.
dbuf_printf(&dbuf, " (missing)");
} else {
dbuf_printf(&dbuf, " (native)");
}
Expand Down Expand Up @@ -6769,7 +6789,7 @@ static void build_backtrace(JSContext *ctx, JSValue error_obj, JSValue filter_fu
JS_FreeValue(ctx, csd[k].func_name);
}
JSValue args[] = {
error_obj,
error_val,
stack,
};
JSValue stack2 = JS_Call(ctx, prepare, ctx->error_ctor, countof(args), args);
Expand All @@ -6790,21 +6810,14 @@ static void build_backtrace(JSContext *ctx, JSValue error_obj, JSValue filter_fu
}

rt->in_prepare_stack_trace = false;
JS_DefinePropertyValue(ctx, error_obj, JS_ATOM_stack, stack, JS_PROP_WRITABLE | JS_PROP_CONFIGURABLE);
}

/* Note: it is important that no exception is returned by this function */
static bool is_backtrace_needed(JSContext *ctx, JSValue obj)
{
JSObject *p;
if (JS_VALUE_GET_TAG(obj) != JS_TAG_OBJECT)
return false;
p = JS_VALUE_GET_OBJ(obj);
if (p->class_id != JS_CLASS_ERROR)
return false;
if (find_own_property1(p, JS_ATOM_stack))
return false;
return true;
if (JS_IsUndefined(ctx->error_back_trace))
ctx->error_back_trace = js_dup(stack);
if (has_filter_func || can_add_backtrace(error_val)) {
JS_DefinePropertyValue(ctx, error_val, JS_ATOM_stack, stack,
JS_PROP_WRITABLE | JS_PROP_CONFIGURABLE);
} else {
JS_FreeValue(ctx, stack);
}
}

JSValue JS_NewError(JSContext *ctx)
Expand Down Expand Up @@ -17432,13 +17445,8 @@ static JSValue JS_CallInternal(JSContext *caller_ctx, JSValue func_obj,
}
}
exception:
if (is_backtrace_needed(ctx, rt->current_exception)) {
/* add the backtrace information now (it is not done
before if the exception happens in a bytecode
operation */
sf->cur_pc = pc;
build_backtrace(ctx, rt->current_exception, JS_UNDEFINED, NULL, 0, 0, 0);
}
sf->cur_pc = pc;
build_backtrace(ctx, rt->current_exception, JS_UNDEFINED, NULL, 0, 0, 0);
if (!JS_IsUncatchableError(ctx, rt->current_exception)) {
while (sp > stack_buf) {
JSValue val = *--sp;
Expand All @@ -17453,6 +17461,8 @@ static JSValue JS_CallInternal(JSContext *caller_ctx, JSValue func_obj,
} else {
*sp++ = rt->current_exception;
rt->current_exception = JS_UNINITIALIZED;
JS_FreeValueRT(rt, ctx->error_back_trace);
ctx->error_back_trace = JS_UNDEFINED;
pc = b->byte_code_buf + pos;
goto restart;
}
Expand Down Expand Up @@ -25570,6 +25580,7 @@ static __exception int js_parse_statement_or_decl(JSParseState *s,
js_parse_error(s, "line terminator not allowed after throw");
goto fail;
}
emit_source_loc(s);
if (js_parse_expr(s))
goto fail;
emit_op(s, OP_throw);
Expand Down Expand Up @@ -56168,7 +56179,9 @@ bool JS_DetectModule(const char *input, size_t input_len)
}

uintptr_t js_std_cmd(int cmd, ...) {
JSContext *ctx;
JSRuntime *rt;
JSValue *pv;
uintptr_t rv;
va_list ap;

Expand All @@ -56183,6 +56196,12 @@ uintptr_t js_std_cmd(int cmd, ...) {
rt = va_arg(ap, JSRuntime *);
rt->libc_opaque = va_arg(ap, void *);
break;
case 2: // ErrorBackTrace
ctx = va_arg(ap, JSContext *);
pv = va_arg(ap, JSValue *);
*pv = ctx->error_back_trace;
ctx->error_back_trace = JS_UNDEFINED;
break;
default:
rv = -1;
}
Expand Down
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