diff options
| -rw-r--r-- | Doc/library/traceback.rst | 4 | ||||
| -rw-r--r-- | Lib/test/test_traceback.py | 82 | ||||
| -rw-r--r-- | Lib/traceback.py | 60 | ||||
| -rw-r--r-- | Python/traceback.c | 266 |
4 files changed, 366 insertions, 46 deletions
diff --git a/Doc/library/traceback.rst b/Doc/library/traceback.rst index 1961b9a..be1f43e 100644 --- a/Doc/library/traceback.rst +++ b/Doc/library/traceback.rst @@ -473,7 +473,7 @@ The output for the example would look similar to this: ['Traceback (most recent call last):\n', ' File "<doctest default[0]>", line 10, in <module>\n lumberjack()\n ^^^^^^^^^^^^\n', ' File "<doctest default[0]>", line 4, in lumberjack\n bright_side_of_death()\n ^^^^^^^^^^^^^^^^^^^^^^\n', - ' File "<doctest default[0]>", line 7, in bright_side_of_death\n return tuple()[0]\n ^^^^^^^^^^\n', + ' File "<doctest default[0]>", line 7, in bright_side_of_death\n return tuple()[0]\n ~~~~~~~^^^\n', 'IndexError: tuple index out of range\n'] *** extract_tb: [<FrameSummary file <doctest...>, line 10 in <module>>, @@ -482,7 +482,7 @@ The output for the example would look similar to this: *** format_tb: [' File "<doctest default[0]>", line 10, in <module>\n lumberjack()\n ^^^^^^^^^^^^\n', ' File "<doctest default[0]>", line 4, in lumberjack\n bright_side_of_death()\n ^^^^^^^^^^^^^^^^^^^^^^\n', - ' File "<doctest default[0]>", line 7, in bright_side_of_death\n return tuple()[0]\n ^^^^^^^^^^\n'] + ' File "<doctest default[0]>", line 7, in bright_side_of_death\n return tuple()[0]\n ~~~~~~~^^^\n'] *** tb_lineno: 10 diff --git a/Lib/test/test_traceback.py b/Lib/test/test_traceback.py index 50ebcce..8baf38c 100644 --- a/Lib/test/test_traceback.py +++ b/Lib/test/test_traceback.py @@ -12,9 +12,11 @@ from test.support import (Error, captured_output, cpython_only, ALWAYS_EQ, requires_debug_ranges, has_no_debug_ranges) from test.support.os_helper import TESTFN, unlink from test.support.script_helper import assert_python_ok, assert_python_failure -import textwrap +import os +import textwrap import traceback +from functools import partial test_code = namedtuple('code', ['co_filename', 'co_name']) @@ -406,6 +408,82 @@ class TracebackErrorLocationCaretTests(unittest.TestCase): result_lines = self.get_exception(f_with_multiline) self.assertEqual(result_lines, expected_f.splitlines()) + def test_caret_for_binary_operators(self): + def f_with_binary_operator(): + divisor = 20 + return 10 + divisor / 0 + 30 + + lineno_f = f_with_binary_operator.__code__.co_firstlineno + expected_error = ( + 'Traceback (most recent call last):\n' + f' File "{__file__}", line {self.callable_line}, in get_exception\n' + ' callable()\n' + ' ^^^^^^^^^^\n' + f' File "{__file__}", line {lineno_f+2}, in f_with_binary_operator\n' + ' return 10 + divisor / 0 + 30\n' + ' ~~~~~~~~^~~\n' + ) + result_lines = self.get_exception(f_with_binary_operator) + self.assertEqual(result_lines, expected_error.splitlines()) + + def test_caret_for_binary_operators_two_char(self): + def f_with_binary_operator(): + divisor = 20 + return 10 + divisor // 0 + 30 + + lineno_f = f_with_binary_operator.__code__.co_firstlineno + expected_error = ( + 'Traceback (most recent call last):\n' + f' File "{__file__}", line {self.callable_line}, in get_exception\n' + ' callable()\n' + ' ^^^^^^^^^^\n' + f' File "{__file__}", line {lineno_f+2}, in f_with_binary_operator\n' + ' return 10 + divisor // 0 + 30\n' + ' ~~~~~~~~^^~~\n' + ) + result_lines = self.get_exception(f_with_binary_operator) + self.assertEqual(result_lines, expected_error.splitlines()) + + def test_caret_for_subscript(self): + def f_with_subscript(): + some_dict = {'x': {'y': None}} + return some_dict['x']['y']['z'] + + lineno_f = f_with_subscript.__code__.co_firstlineno + expected_error = ( + 'Traceback (most recent call last):\n' + f' File "{__file__}", line {self.callable_line}, in get_exception\n' + ' callable()\n' + ' ^^^^^^^^^^\n' + f' File "{__file__}", line {lineno_f+2}, in f_with_subscript\n' + " return some_dict['x']['y']['z']\n" + ' ~~~~~~~~~~~~~~~~~~~^^^^^\n' + ) + result_lines = self.get_exception(f_with_subscript) + self.assertEqual(result_lines, expected_error.splitlines()) + + def test_traceback_specialization_with_syntax_error(self): + bytecode = compile("1 / 0 / 1 / 2\n", TESTFN, "exec") + + with open(TESTFN, "w") as file: + # make the file's contents invalid + file.write("1 $ 0 / 1 / 2\n") + self.addCleanup(unlink, TESTFN) + + func = partial(exec, bytecode) + result_lines = self.get_exception(func) + + lineno_f = bytecode.co_firstlineno + expected_error = ( + 'Traceback (most recent call last):\n' + f' File "{__file__}", line {self.callable_line}, in get_exception\n' + ' callable()\n' + ' ^^^^^^^^^^\n' + f' File "{TESTFN}", line {lineno_f}, in <module>\n' + " 1 $ 0 / 1 / 2\n" + ' ^^^^^\n' + ) + self.assertEqual(result_lines, expected_error.splitlines()) @cpython_only @requires_debug_ranges() @@ -1615,7 +1693,7 @@ class TestTracebackException(unittest.TestCase): self.assertEqual( output.getvalue().split('\n')[-5:], [' x/0', - ' ^^^', + ' ~^~', ' x = 12', 'ZeroDivisionError: division by zero', '']) diff --git a/Lib/traceback.py b/Lib/traceback.py index 7cb1241..ec5e20d 100644 --- a/Lib/traceback.py +++ b/Lib/traceback.py @@ -494,9 +494,23 @@ class StackSummary(list): colno = _byte_offset_to_character_offset(frame._original_line, frame.colno) end_colno = _byte_offset_to_character_offset(frame._original_line, frame.end_colno) + try: + anchors = _extract_caret_anchors_from_line_segment( + frame._original_line[colno - 1:end_colno] + ) + except Exception: + anchors = None + row.append(' ') row.append(' ' * (colno - stripped_characters)) - row.append('^' * (end_colno - colno)) + + if anchors: + row.append(anchors.primary_char * (anchors.left_end_offset)) + row.append(anchors.secondary_char * (anchors.right_start_offset - anchors.left_end_offset)) + row.append(anchors.primary_char * (end_colno - colno - anchors.right_start_offset)) + else: + row.append('^' * (end_colno - colno)) + row.append('\n') if frame.locals: @@ -520,6 +534,50 @@ def _byte_offset_to_character_offset(str, offset): return len(as_utf8[:offset + 1].decode("utf-8")) +_Anchors = collections.namedtuple( + "_Anchors", + [ + "left_end_offset", + "right_start_offset", + "primary_char", + "secondary_char", + ], + defaults=["~", "^"] +) + +def _extract_caret_anchors_from_line_segment(segment): + import ast + + try: + tree = ast.parse(segment) + except SyntaxError: + return None + + if len(tree.body) != 1: + return None + + statement = tree.body[0] + match statement: + case ast.Expr(expr): + match expr: + case ast.BinOp(): + operator_str = segment[expr.left.end_col_offset:expr.right.col_offset] + operator_offset = len(operator_str) - len(operator_str.lstrip()) + + left_anchor = expr.left.end_col_offset + operator_offset + right_anchor = left_anchor + 1 + if ( + operator_offset + 1 < len(operator_str) + and not operator_str[operator_offset + 1].isspace() + ): + right_anchor += 1 + return _Anchors(left_anchor, right_anchor) + case ast.Subscript(): + return _Anchors(expr.value.end_col_offset, expr.slice.end_col_offset + 1) + + return None + + class TracebackException: """An exception ready for rendering. diff --git a/Python/traceback.c b/Python/traceback.c index a60f991..199d3ea 100644 --- a/Python/traceback.c +++ b/Python/traceback.c @@ -7,6 +7,10 @@ #include "pycore_interp.h" // PyInterpreterState.gc #include "frameobject.h" // PyFrame_GetBack() #include "pycore_frame.h" // _PyFrame_GetCode() +#include "pycore_pyarena.h" // _PyArena_Free() +#include "pycore_ast.h" // asdl_seq_* +#include "pycore_compile.h" // _PyAST_Optimize +#include "pycore_parser.h" // _PyParser_ASTFromString #include "../Parser/pegen.h" // _PyPegen_byte_offset_to_character_offset() #include "structmember.h" // PyMemberDef #include "osdefs.h" // SEP @@ -512,8 +516,172 @@ _Py_DisplaySourceLine(PyObject *f, PyObject *filename, int lineno, int indent, i return err; } +/* AST based Traceback Specialization + * + * When displaying a new traceback line, for certain syntactical constructs + * (e.g a subscript, an arithmetic operation) we try to create a representation + * that separates the primary source of error from the rest. + * + * Example specialization of BinOp nodes: + * Traceback (most recent call last): + * File "/home/isidentical/cpython/cpython/t.py", line 10, in <module> + * add_values(1, 2, 'x', 3, 4) + * ^^^^^^^^^^^^^^^^^^^^^^^^^^^ + * File "/home/isidentical/cpython/cpython/t.py", line 2, in add_values + * return a + b + c + d + e + * ~~~~~~^~~ + * TypeError: 'NoneType' object is not subscriptable + */ + +#define IS_WHITESPACE(c) (((c) == ' ') || ((c) == '\t') || ((c) == '\f')) + +static int +extract_anchors_from_expr(const char *segment_str, expr_ty expr, Py_ssize_t *left_anchor, Py_ssize_t *right_anchor, + char** primary_error_char, char** secondary_error_char) +{ + switch (expr->kind) { + case BinOp_kind: { + expr_ty left = expr->v.BinOp.left; + expr_ty right = expr->v.BinOp.right; + for (int i = left->end_col_offset + 1; i < right->col_offset; i++) { + if (IS_WHITESPACE(segment_str[i])) { + continue; + } + + *left_anchor = i; + *right_anchor = i + 1; + + // Check whether if this a two-character operator (e.g //) + if (i + 1 < right->col_offset && !IS_WHITESPACE(segment_str[i + 1])) { + ++*right_anchor; + } + + // Set the error characters + *primary_error_char = "~"; + *secondary_error_char = "^"; + break; + } + return 1; + } + case Subscript_kind: { + *left_anchor = expr->v.Subscript.value->end_col_offset; + *right_anchor = expr->v.Subscript.slice->end_col_offset + 1; + + // Set the error characters + *primary_error_char = "~"; + *secondary_error_char = "^"; + return 1; + } + default: + return 0; + } +} + +static int +extract_anchors_from_stmt(const char *segment_str, stmt_ty statement, Py_ssize_t *left_anchor, Py_ssize_t *right_anchor, + char** primary_error_char, char** secondary_error_char) +{ + switch (statement->kind) { + case Expr_kind: { + return extract_anchors_from_expr(segment_str, statement->v.Expr.value, left_anchor, right_anchor, + primary_error_char, secondary_error_char); + } + default: + return 0; + } +} + +static int +extract_anchors_from_line(PyObject *filename, PyObject *line, + Py_ssize_t start_offset, Py_ssize_t end_offset, + Py_ssize_t *left_anchor, Py_ssize_t *right_anchor, + char** primary_error_char, char** secondary_error_char) +{ + int res = -1; + PyArena *arena = NULL; + PyObject *segment = PyUnicode_Substring(line, start_offset, end_offset); + if (!segment) { + goto done; + } + + const char *segment_str = PyUnicode_AsUTF8(segment); + if (!segment) { + goto done; + } + + arena = _PyArena_New(); + if (!arena) { + goto done; + } + + PyCompilerFlags flags = _PyCompilerFlags_INIT; + + _PyASTOptimizeState state; + state.optimize = _Py_GetConfig()->optimization_level; + state.ff_features = 0; + + mod_ty module = _PyParser_ASTFromString(segment_str, filename, Py_file_input, + &flags, arena); + if (!module) { + goto done; + } + if (!_PyAST_Optimize(module, arena, &state)) { + goto done; + } + + assert(module->kind == Module_kind); + if (asdl_seq_LEN(module->v.Module.body) == 1) { + stmt_ty statement = asdl_seq_GET(module->v.Module.body, 0); + res = extract_anchors_from_stmt(segment_str, statement, left_anchor, right_anchor, + primary_error_char, secondary_error_char); + } else { + res = 0; + } + +done: + if (res > 0) { + *left_anchor += start_offset; + *right_anchor += start_offset; + } + Py_XDECREF(segment); + if (arena) { + _PyArena_Free(arena); + } + return res; +} + #define _TRACEBACK_SOURCE_LINE_INDENT 4 +static inline int +ignore_source_errors(void) { + if (PyErr_Occurred()) { + if (PyErr_ExceptionMatches(PyExc_KeyboardInterrupt)) { + return -1; + } + PyErr_Clear(); + } + return 0; +} + +static inline int +print_error_location_carets(PyObject *f, int offset, Py_ssize_t start_offset, Py_ssize_t end_offset, + Py_ssize_t right_start_offset, Py_ssize_t left_end_offset, + const char *primary, const char *secondary) { + int err = 0; + int special_chars = (left_end_offset != -1 || right_start_offset != -1); + while (++offset <= end_offset) { + if (offset <= start_offset || offset > end_offset) { + err = PyFile_WriteString(" ", f); + } else if (special_chars && left_end_offset < offset && offset <= right_start_offset) { + err = PyFile_WriteString(secondary, f); + } else { + err = PyFile_WriteString(primary, f); + } + } + err = PyFile_WriteString("\n", f); + return err; +} + static int tb_displayline(PyTracebackObject* tb, PyObject *f, PyObject *filename, int lineno, PyFrameObject *frame, PyObject *name) @@ -533,52 +701,68 @@ tb_displayline(PyTracebackObject* tb, PyObject *f, PyObject *filename, int linen return err; int truncation = _TRACEBACK_SOURCE_LINE_INDENT; PyObject* source_line = NULL; - /* ignore errors since we can't report them, can we? */ - if (!_Py_DisplaySourceLine(f, filename, lineno, _TRACEBACK_SOURCE_LINE_INDENT, - &truncation, &source_line)) { - int code_offset = tb->tb_lasti; - PyCodeObject* code = _PyFrame_GetCode(frame); - - int start_line; - int end_line; - int start_col_byte_offset; - int end_col_byte_offset; - if (!PyCode_Addr2Location(code, code_offset, &start_line, &start_col_byte_offset, - &end_line, &end_col_byte_offset)) { - goto done; - } - if (start_line != end_line) { - goto done; - } - if (start_col_byte_offset < 0 || end_col_byte_offset < 0) { - goto done; - } - // Convert the utf-8 byte offset to the actual character offset so we - // print the right number of carets. - Py_ssize_t start_offset = _PyPegen_byte_offset_to_character_offset(source_line, start_col_byte_offset); - Py_ssize_t end_offset = _PyPegen_byte_offset_to_character_offset(source_line, end_col_byte_offset); + if (_Py_DisplaySourceLine(f, filename, lineno, _TRACEBACK_SOURCE_LINE_INDENT, + &truncation, &source_line) != 0) { + /* ignore errors since we can't report them, can we? */ + err = ignore_source_errors(); + goto done; + } - char offset = truncation; - while (++offset <= start_offset) { - err = PyFile_WriteString(" ", f); - if (err < 0) { - goto done; - } - } - while (++offset <= end_offset + 1) { - err = PyFile_WriteString("^", f); - if (err < 0) { - goto done; - } - } - err = PyFile_WriteString("\n", f); + int code_offset = tb->tb_lasti; + PyCodeObject* code = _PyFrame_GetCode(frame); + + int start_line; + int end_line; + int start_col_byte_offset; + int end_col_byte_offset; + if (!PyCode_Addr2Location(code, code_offset, &start_line, &start_col_byte_offset, + &end_line, &end_col_byte_offset)) { + goto done; + } + if (start_line != end_line) { + goto done; } - else { - PyErr_Clear(); + if (start_col_byte_offset < 0 || end_col_byte_offset < 0) { + goto done; } - + + // When displaying errors, we will use the following generic structure: + // + // ERROR LINE ERROR LINE ERROR LINE ERROR LINE ERROR LINE ERROR LINE ERROR LINE + // ~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^~~~~~~~~~~~~~~~~~~~ + // | |-> left_end_offset | |-> left_offset + // |-> start_offset |-> right_start_offset + // + // In general we will only have (start_offset, end_offset) but we can gather more information + // by analyzing the AST of the text between *start_offset* and *end_offset*. If this succeeds + // we could get *left_end_offset* and *right_start_offset* and some selection of characters for + // the different ranges (primary_error_char and secondary_error_char). If we cannot obtain the + // AST information or we cannot identify special ranges within it, then left_end_offset and + // right_end_offset will be set to -1. + + // Convert the utf-8 byte offset to the actual character offset so we print the right number of carets. + assert(source_line); + Py_ssize_t start_offset = _PyPegen_byte_offset_to_character_offset(source_line, start_col_byte_offset); + Py_ssize_t end_offset = _PyPegen_byte_offset_to_character_offset(source_line, end_col_byte_offset); + Py_ssize_t left_end_offset = -1; + Py_ssize_t right_start_offset = -1; + + char *primary_error_char = "^"; + char *secondary_error_char = primary_error_char; + + int res = extract_anchors_from_line(filename, source_line, start_offset, end_offset, + &left_end_offset, &right_start_offset, + &primary_error_char, &secondary_error_char); + if (res < 0 && ignore_source_errors() < 0) { + goto done; + } + + err = print_error_location_carets(f, truncation, start_offset, end_offset, + right_start_offset, left_end_offset, + primary_error_char, secondary_error_char); + done: Py_XDECREF(source_line); return err; |