Function rewrite_traceback_stack

src/jinja2/debug.py:14–73

Rewrite the current exception to replace any tracebacks from within compiled template code with tracebacks that look like they came from the template source. This must be called within an ``except`` block. :param source: For ``TemplateSyntaxError``, the original source if k

(source: t.Optional[str] = None)

def rewrite_traceback_stack(source: t.Optional[str] = None) -> BaseException:
    class="st">"""Rewrite the current exception to replace any tracebacks from
    within compiled template code with tracebacks that look like they
    came from the template source.

    This must be called within an ``except`` block.

    :param source: For ``TemplateSyntaxError``, the original source if
        known.
    :return: The original exception with the rewritten traceback.
    class="st">"""
    _, exc_value, tb = sys.exc_info()
    exc_value = t.cast(BaseException, exc_value)
    tb = t.cast(TracebackType, tb)

    if isinstance(exc_value, TemplateSyntaxError) and not exc_value.translated:
        exc_value.translated = True
        exc_value.source = source
        class="cm"># Remove the old traceback, otherwise the frames from the
        class="cm"># compiler still show up.
        exc_value.with_traceback(None)
        class="cm"># Outside of runtime, so the frame isn't executing template
        class="cm"># code, but it still needs to point at the template.
        tb = fake_traceback(
            exc_value, None, exc_value.filename or class="st">"<unknown>", exc_value.lineno
        )
    else:
        class="cm"># Skip the frame for the render function.
        tb = tb.tb_next

    stack = []

    class="cm"># Build the stack of traceback object, replacing any in template
    class="cm"># code with the source file and line information.
    while tb is not None:
        class="cm"># Skip frames decorated with @internalcode. These are internal
        class="cm"># calls that aren't useful in template debugging output.
        if tb.tb_frame.f_code in internal_code:
            tb = tb.tb_next
            continue

        template = tb.tb_frame.f_globals.get(class="st">"__jinja_template__")

        if template is not None:
            lineno = template.get_corresponding_lineno(tb.tb_lineno)
            fake_tb = fake_traceback(exc_value, tb, template.filename, lineno)
            stack.append(fake_tb)
        else:
            stack.append(tb)

        tb = tb.tb_next

    tb_next = None

    class="cm"># Assign tb_next in reverse to avoid circular references.
    for tb in reversed(stack):
        tb.tb_next = tb_next
        tb_next = tb