| # Copyright 2017 The Chromium Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| """Logic for parsing a C/C++ function signature.""" |
| |
| |
| def _FindParameterListParen(name): |
| """Finds index of the "(" that denotes the start of a paremeter list.""" |
| # This loops from left-to-right, but the only reason (I think) that this |
| # is necessary (rather than reusing _FindLastCharOutsideOfBrackets), is |
| # to capture the outer-most function in the case where classes are nested. |
| start_idx = 0 |
| while True: |
| template_balance_count = 0 |
| paren_balance_count = 0 |
| while True: |
| idx = name.find('(', start_idx) |
| if idx == -1: |
| return -1 |
| template_balance_count += ( |
| name.count('<', start_idx, idx) - name.count('>', start_idx, idx)) |
| # Special: operators with angle brackets. |
| operator_idx = name.find('operator<', start_idx, idx) |
| if operator_idx != -1: |
| if name[operator_idx + 9] == '<': |
| template_balance_count -= 2 |
| else: |
| template_balance_count -= 1 |
| else: |
| operator_idx = name.find('operator>', start_idx, idx) |
| if operator_idx != -1: |
| if name[operator_idx + 9] == '>': |
| template_balance_count += 2 |
| else: |
| template_balance_count += 1 |
| |
| paren_balance_count += ( |
| name.count('(', start_idx, idx) - name.count(')', start_idx, idx)) |
| if template_balance_count == 0 and paren_balance_count == 0: |
| # Special case: skip "(anonymous namespace)". |
| if -1 != name.find('(anonymous namespace)', idx, idx + 21): |
| start_idx = idx + 21 |
| continue |
| # Special case: skip "decltype (...)" |
| if name[idx - 1] != ' ': |
| return idx |
| start_idx = idx + 1 |
| paren_balance_count += 1 |
| |
| |
| def _FindLastCharOutsideOfBrackets(name, target_char, prev_idx=None): |
| """Returns the last index of |target_char| that is not within ()s nor <>s.""" |
| paren_balance_count = 0 |
| template_balance_count = 0 |
| while True: |
| idx = name.rfind(target_char, 0, prev_idx) |
| if idx == -1: |
| return -1 |
| # It is much faster to use.find() and.count() than to loop over each |
| # character. |
| template_balance_count += ( |
| name.count('<', idx, prev_idx) - name.count('>', idx, prev_idx)) |
| paren_balance_count += ( |
| name.count('(', idx, prev_idx) - name.count(')', idx, prev_idx)) |
| if template_balance_count == 0 and paren_balance_count == 0: |
| return idx |
| prev_idx = idx |
| |
| |
| def _FindReturnValueSpace(name, paren_idx): |
| """Returns the index of the space that comes after the return type.""" |
| space_idx = paren_idx |
| # Special case: const cast operators (see tests). |
| if -1 != name.find(' const', paren_idx - 6, paren_idx): |
| space_idx = paren_idx - 6 |
| while True: |
| space_idx = _FindLastCharOutsideOfBrackets(name, ' ', space_idx) |
| # Special case: "operator new", and "operator<< <template>". |
| if -1 == space_idx or ( |
| -1 == name.find('operator', space_idx - 8, space_idx) and |
| -1 == name.find('operator<<', space_idx - 10, space_idx)): |
| break |
| space_idx -= 8 |
| return space_idx |
| |
| |
| def Parse(name): |
| """Extracts a function name from a function signature. |
| |
| See unit tests for example signatures. |
| |
| Returns: |
| A tuple of (name_without_return_type, name_without_return_type_and_params). |
| """ |
| left_paren_idx = _FindParameterListParen(name) |
| |
| if left_paren_idx > 0: |
| right_paren_idx = name.rindex(')') |
| assert right_paren_idx > left_paren_idx |
| space_idx = _FindReturnValueSpace(name, left_paren_idx) |
| return (name[space_idx + 1:], |
| name[space_idx + 1:left_paren_idx] + name[right_paren_idx + 1:]) |
| return name, name |
