| 1 | """
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| 2 | util.py
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| 3 | """
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| 4 | from __future__ import print_function
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| 5 | 
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| 6 | import sys
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| 7 | from mypy.nodes import CallExpr, IfStmt, Block, Expression, MypyFile
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| 8 | from mypy.types import Instance, Type
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| 9 | 
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| 10 | from typing import Any, Sequence, Optional
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| 11 | 
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| 12 | # Used by cppgen_pass and const_pass
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| 13 | 
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| 14 | # mycpp/examples/small_str.py sorta works with this!
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| 15 | #SMALL_STR = True
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| 16 | 
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| 17 | SMALL_STR = False
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| 18 | 
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| 19 | SymbolPath = Sequence[str]
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| 20 | 
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| 21 | 
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| 22 | def log(msg: str, *args: Any) -> None:
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| 23 |     if args:
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| 24 |         msg = msg % args
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| 25 |     print(msg, file=sys.stderr)
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| 26 | 
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| 27 | 
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| 28 | def join_name(parts: SymbolPath,
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| 29 |               strip_package: bool = False,
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| 30 |               delim: str = '::') -> str:
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| 31 |     """
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| 32 |     Join the given name path into a string with the given delimiter.
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| 33 |     Use strip_package to remove the top-level directory (e.g. `core`, `ysh`)
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| 34 |     when dealing with C++ namespaces.
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| 35 |     """
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| 36 |     if not strip_package:
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| 37 |         return delim.join(parts)
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| 38 | 
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| 39 |     if len(parts) > 1:
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| 40 |         return delim.join(('', ) + parts[1:])
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| 41 | 
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| 42 |     return parts[0]
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| 43 | 
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| 44 | 
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| 45 | def split_py_name(name: str) -> SymbolPath:
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| 46 |     ret = tuple(name.split('.'))
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| 47 |     if len(ret) and ret[0] == 'mycpp':
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| 48 |         # Drop the prefix 'mycpp.' if present. This makes names compatible with
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| 49 |         # the examples that use testpkg.
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| 50 |         return ret[1:]
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| 51 | 
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| 52 |     return ret
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| 53 | 
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| 54 | 
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| 55 | def _collect_cases(module_path: str,
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| 56 |                    if_node: IfStmt,
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| 57 |                    out: list[tuple[Expression, Block]],
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| 58 |                    errors=None) -> Optional[Block] | bool:
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| 59 |     """
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| 60 |     The MyPy AST has a recursive structure for if-elif-elif rather than a
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| 61 |     flat one.  It's a bit confusing.
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| 62 | 
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| 63 |     Appends (expr, block) cases to out param, and returns the default
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| 64 |     block, which has no expression.
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| 65 | 
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| 66 |     default block may be None.
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| 67 | 
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| 68 |     Returns False if there is no default block.
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| 69 |     """
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| 70 |     assert isinstance(if_node, IfStmt), if_node
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| 71 |     assert len(if_node.expr) == 1, if_node.expr
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| 72 |     assert len(if_node.body) == 1, if_node.body
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| 73 | 
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| 74 |     expr = if_node.expr[0]
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| 75 |     body = if_node.body[0]
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| 76 | 
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| 77 |     if not isinstance(expr, CallExpr):
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| 78 |         if errors is not None:
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| 79 |             errors.append((module_path, expr.line,
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| 80 |                            'Expected call like case(x), got %s' % expr))
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| 81 |         return
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| 82 | 
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| 83 |     out.append((expr, body))
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| 84 | 
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| 85 |     if if_node.else_body:
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| 86 |         first_of_block = if_node.else_body.body[0]
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| 87 |         # BUG: this is meant for 'elif' only.  But it also triggers for
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| 88 |         #
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| 89 |         # else:
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| 90 |         #   if 0:
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| 91 | 
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| 92 |         if isinstance(first_of_block, IfStmt):
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| 93 |             return _collect_cases(module_path, first_of_block, out, errors)
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| 94 |         else:
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| 95 |             # default case - no expression
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| 96 |             return if_node.else_body
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| 97 | 
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| 98 |     return False  # NO DEFAULT BLOCK - Different than None
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| 99 | 
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| 100 | 
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| 101 | def ShouldSkipPyFile(node: MypyFile) -> bool:
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| 102 |     # Skip some stdlib stuff.  A lot of it is brought in by 'import
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| 103 |     # typing'. These module are special; their contents are currently all
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| 104 |     # built-in primitives.
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| 105 |     return node.fullname in ('__future__', 'sys', 'types', 'typing', 'abc',
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| 106 |                              '_ast', 'ast', '_weakrefset', 'collections',
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| 107 |                              'cStringIO', 're', 'builtins')
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| 108 | 
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| 109 | 
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| 110 | def IsStr(t: Type):
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| 111 |     """Helper to check if a type is a string."""
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| 112 |     return isinstance(t, Instance) and t.type.fullname == 'builtins.str'
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