cpython/Tools/cases_generator/analyzer.py

889 lines
27 KiB
Python

from dataclasses import dataclass, field
import lexer
import parser
import re
from typing import Optional
@dataclass
class Properties:
escapes: bool
error_with_pop: bool
error_without_pop: bool
deopts: bool
oparg: bool
jumps: bool
eval_breaker: bool
ends_with_eval_breaker: bool
needs_this: bool
always_exits: bool
stores_sp: bool
uses_co_consts: bool
uses_co_names: bool
uses_locals: bool
has_free: bool
side_exit: bool
pure: bool
tier: int | None = None
oparg_and_1: bool = False
const_oparg: int = -1
def dump(self, indent: str) -> None:
print(indent, end="")
text = ", ".join([f"{key}: {value}" for (key, value) in self.__dict__.items()])
print(indent, text, sep="")
@staticmethod
def from_list(properties: list["Properties"]) -> "Properties":
return Properties(
escapes=any(p.escapes for p in properties),
error_with_pop=any(p.error_with_pop for p in properties),
error_without_pop=any(p.error_without_pop for p in properties),
deopts=any(p.deopts for p in properties),
oparg=any(p.oparg for p in properties),
jumps=any(p.jumps for p in properties),
eval_breaker=any(p.eval_breaker for p in properties),
ends_with_eval_breaker=any(p.ends_with_eval_breaker for p in properties),
needs_this=any(p.needs_this for p in properties),
always_exits=any(p.always_exits for p in properties),
stores_sp=any(p.stores_sp for p in properties),
uses_co_consts=any(p.uses_co_consts for p in properties),
uses_co_names=any(p.uses_co_names for p in properties),
uses_locals=any(p.uses_locals for p in properties),
has_free=any(p.has_free for p in properties),
side_exit=any(p.side_exit for p in properties),
pure=all(p.pure for p in properties),
)
@property
def infallible(self) -> bool:
return not self.error_with_pop and not self.error_without_pop
SKIP_PROPERTIES = Properties(
escapes=False,
error_with_pop=False,
error_without_pop=False,
deopts=False,
oparg=False,
jumps=False,
eval_breaker=False,
ends_with_eval_breaker=False,
needs_this=False,
always_exits=False,
stores_sp=False,
uses_co_consts=False,
uses_co_names=False,
uses_locals=False,
has_free=False,
side_exit=False,
pure=False,
)
@dataclass
class Skip:
"Unused cache entry"
size: int
@property
def name(self) -> str:
return f"unused/{self.size}"
@property
def properties(self) -> Properties:
return SKIP_PROPERTIES
@dataclass
class StackItem:
name: str
type: str | None
condition: str | None
size: str
peek: bool = False
def __str__(self) -> str:
cond = f" if ({self.condition})" if self.condition else ""
size = f"[{self.size}]" if self.size != "1" else ""
type = "" if self.type is None else f"{self.type} "
return f"{type}{self.name}{size}{cond} {self.peek}"
def is_array(self) -> bool:
return self.type == "PyObject **"
@dataclass
class StackEffect:
inputs: list[StackItem]
outputs: list[StackItem]
def __str__(self) -> str:
return f"({', '.join([str(i) for i in self.inputs])} -- {', '.join([str(i) for i in self.outputs])})"
@dataclass
class CacheEntry:
name: str
size: int
def __str__(self) -> str:
return f"{self.name}/{self.size}"
@dataclass
class Uop:
name: str
context: parser.Context | None
annotations: list[str]
stack: StackEffect
caches: list[CacheEntry]
body: list[lexer.Token]
properties: Properties
_size: int = -1
implicitly_created: bool = False
replicated = 0
replicates : "Uop | None" = None
def dump(self, indent: str) -> None:
print(
indent, self.name, ", ".join(self.annotations) if self.annotations else ""
)
print(indent, self.stack, ", ".join([str(c) for c in self.caches]))
self.properties.dump(" " + indent)
@property
def size(self) -> int:
if self._size < 0:
self._size = sum(c.size for c in self.caches)
return self._size
def why_not_viable(self) -> str | None:
if self.name == "_SAVE_RETURN_OFFSET":
return None # Adjusts next_instr, but only in tier 1 code
if "INSTRUMENTED" in self.name:
return "is instrumented"
if "replaced" in self.annotations:
return "is replaced"
if self.name in ("INTERPRETER_EXIT", "JUMP_BACKWARD"):
return "has tier 1 control flow"
if self.properties.needs_this:
return "uses the 'this_instr' variable"
if len([c for c in self.caches if c.name != "unused"]) > 1:
return "has unused cache entries"
if self.properties.error_with_pop and self.properties.error_without_pop:
return "has both popping and not-popping errors"
if self.properties.eval_breaker:
if self.properties.error_with_pop or self.properties.error_without_pop:
return "has error handling and eval-breaker check"
if self.properties.side_exit:
return "exits and eval-breaker check"
if self.properties.deopts:
return "deopts and eval-breaker check"
return None
def is_viable(self) -> bool:
return self.why_not_viable() is None
def is_super(self) -> bool:
for tkn in self.body:
if tkn.kind == "IDENTIFIER" and tkn.text == "oparg1":
return True
return False
Part = Uop | Skip
@dataclass
class Instruction:
name: str
parts: list[Part]
_properties: Properties | None
is_target: bool = False
family: Optional["Family"] = None
opcode: int = -1
@property
def properties(self) -> Properties:
if self._properties is None:
self._properties = self._compute_properties()
return self._properties
def _compute_properties(self) -> Properties:
return Properties.from_list([part.properties for part in self.parts])
def dump(self, indent: str) -> None:
print(indent, self.name, "=", ", ".join([part.name for part in self.parts]))
self.properties.dump(" " + indent)
@property
def size(self) -> int:
return 1 + sum(part.size for part in self.parts)
def is_super(self) -> bool:
if len(self.parts) != 1:
return False
uop = self.parts[0]
if isinstance(uop, Uop):
return uop.is_super()
else:
return False
@dataclass
class PseudoInstruction:
name: str
stack: StackEffect
targets: list[Instruction]
flags: list[str]
opcode: int = -1
def dump(self, indent: str) -> None:
print(indent, self.name, "->", " or ".join([t.name for t in self.targets]))
@property
def properties(self) -> Properties:
return Properties.from_list([i.properties for i in self.targets])
@dataclass
class Family:
name: str
size: str
members: list[Instruction]
def dump(self, indent: str) -> None:
print(indent, self.name, "= ", ", ".join([m.name for m in self.members]))
@dataclass
class Analysis:
instructions: dict[str, Instruction]
uops: dict[str, Uop]
families: dict[str, Family]
pseudos: dict[str, PseudoInstruction]
opmap: dict[str, int]
have_arg: int
min_instrumented: int
def analysis_error(message: str, tkn: lexer.Token) -> SyntaxError:
# To do -- support file and line output
# Construct a SyntaxError instance from message and token
return lexer.make_syntax_error(message, tkn.filename, tkn.line, tkn.column, "")
def override_error(
name: str,
context: parser.Context | None,
prev_context: parser.Context | None,
token: lexer.Token,
) -> SyntaxError:
return analysis_error(
f"Duplicate definition of '{name}' @ {context} "
f"previous definition @ {prev_context}",
token,
)
def convert_stack_item(item: parser.StackEffect, replace_op_arg_1: str | None) -> StackItem:
cond = item.cond
if replace_op_arg_1 and OPARG_AND_1.match(item.cond):
cond = replace_op_arg_1
return StackItem(
item.name, item.type, cond, (item.size or "1")
)
def analyze_stack(op: parser.InstDef | parser.Pseudo, replace_op_arg_1: str | None = None) -> StackEffect:
inputs: list[StackItem] = [
convert_stack_item(i, replace_op_arg_1) for i in op.inputs if isinstance(i, parser.StackEffect)
]
outputs: list[StackItem] = [convert_stack_item(i, replace_op_arg_1) for i in op.outputs]
for input, output in zip(inputs, outputs):
if input.name == output.name:
input.peek = output.peek = True
return StackEffect(inputs, outputs)
def analyze_caches(inputs: list[parser.InputEffect]) -> list[CacheEntry]:
caches: list[parser.CacheEffect] = [
i for i in inputs if isinstance(i, parser.CacheEffect)
]
for cache in caches:
if cache.name == "unused":
raise analysis_error(
"Unused cache entry in op. Move to enclosing macro.", cache.tokens[0]
)
return [CacheEntry(i.name, int(i.size)) for i in caches]
def variable_used(node: parser.InstDef, name: str) -> bool:
"""Determine whether a variable with a given name is used in a node."""
return any(
token.kind == "IDENTIFIER" and token.text == name for token in node.tokens
)
def tier_variable(node: parser.InstDef) -> int | None:
"""Determine whether a tier variable is used in a node."""
for token in node.tokens:
if token.kind == "ANNOTATION":
if token.text == "specializing":
return 1
if re.fullmatch(r"tier\d", token.text):
return int(token.text[-1])
return None
def has_error_with_pop(op: parser.InstDef) -> bool:
return (
variable_used(op, "ERROR_IF")
or variable_used(op, "pop_1_error")
or variable_used(op, "exception_unwind")
or variable_used(op, "resume_with_error")
)
def has_error_without_pop(op: parser.InstDef) -> bool:
return (
variable_used(op, "ERROR_NO_POP")
or variable_used(op, "pop_1_error")
or variable_used(op, "exception_unwind")
or variable_used(op, "resume_with_error")
)
NON_ESCAPING_FUNCTIONS = (
"Py_INCREF",
"_PyManagedDictPointer_IsValues",
"_PyObject_GetManagedDict",
"_PyObject_ManagedDictPointer",
"_PyObject_InlineValues",
"_PyDictValues_AddToInsertionOrder",
"Py_DECREF",
"Py_XDECREF",
"_Py_DECREF_SPECIALIZED",
"DECREF_INPUTS_AND_REUSE_FLOAT",
"PyUnicode_Append",
"_PyLong_IsZero",
"Py_SIZE",
"Py_TYPE",
"PyList_GET_ITEM",
"PyList_SET_ITEM",
"PyTuple_GET_ITEM",
"PyList_GET_SIZE",
"PyTuple_GET_SIZE",
"Py_ARRAY_LENGTH",
"Py_Unicode_GET_LENGTH",
"PyUnicode_READ_CHAR",
"_Py_SINGLETON",
"PyUnicode_GET_LENGTH",
"_PyLong_IsCompact",
"_PyLong_IsNonNegativeCompact",
"_PyLong_CompactValue",
"_PyLong_DigitCount",
"_Py_NewRef",
"_Py_IsImmortal",
"PyLong_FromLong",
"_Py_STR",
"_PyLong_Add",
"_PyLong_Multiply",
"_PyLong_Subtract",
"Py_NewRef",
"_PyList_ITEMS",
"_PyTuple_ITEMS",
"_PyList_AppendTakeRef",
"_Py_atomic_load_uintptr_relaxed",
"_PyFrame_GetCode",
"_PyThreadState_HasStackSpace",
"_PyUnicode_Equal",
"_PyFrame_SetStackPointer",
"_PyType_HasFeature",
"PyUnicode_Concat",
"_PyList_FromArraySteal",
"_PyTuple_FromArraySteal",
"PySlice_New",
"_Py_LeaveRecursiveCallPy",
"CALL_STAT_INC",
"STAT_INC",
"maybe_lltrace_resume_frame",
"_PyUnicode_JoinArray",
"_PyEval_FrameClearAndPop",
"_PyFrame_StackPush",
"PyCell_New",
"PyFloat_AS_DOUBLE",
"_PyFrame_PushUnchecked",
"Py_FatalError",
)
ESCAPING_FUNCTIONS = (
"import_name",
"import_from",
)
def makes_escaping_api_call(instr: parser.InstDef) -> bool:
if "CALL_INTRINSIC" in instr.name:
return True
if instr.name == "_BINARY_OP":
return True
tkns = iter(instr.tokens)
for tkn in tkns:
if tkn.kind != lexer.IDENTIFIER:
continue
try:
next_tkn = next(tkns)
except StopIteration:
return False
if next_tkn.kind != lexer.LPAREN:
continue
if tkn.text in ESCAPING_FUNCTIONS:
return True
if tkn.text == "tp_vectorcall":
return True
if not tkn.text.startswith("Py") and not tkn.text.startswith("_Py"):
continue
if tkn.text.endswith("Check"):
continue
if tkn.text.startswith("Py_Is"):
continue
if tkn.text.endswith("CheckExact"):
continue
if tkn.text in NON_ESCAPING_FUNCTIONS:
continue
return True
return False
EXITS = {
"DISPATCH",
"GO_TO_INSTRUCTION",
"Py_UNREACHABLE",
"DISPATCH_INLINED",
"DISPATCH_GOTO",
}
def eval_breaker_at_end(op: parser.InstDef) -> bool:
return op.tokens[-5].text == "CHECK_EVAL_BREAKER"
def always_exits(op: parser.InstDef) -> bool:
depth = 0
tkn_iter = iter(op.tokens)
for tkn in tkn_iter:
if tkn.kind == "LBRACE":
depth += 1
elif tkn.kind == "RBRACE":
depth -= 1
elif depth > 1:
continue
elif tkn.kind == "GOTO" or tkn.kind == "RETURN":
return True
elif tkn.kind == "KEYWORD":
if tkn.text in EXITS:
return True
elif tkn.kind == "IDENTIFIER":
if tkn.text in EXITS:
return True
if tkn.text == "DEOPT_IF" or tkn.text == "ERROR_IF":
next(tkn_iter) # '('
t = next(tkn_iter)
if t.text == "true":
return True
return False
def stack_effect_only_peeks(instr: parser.InstDef) -> bool:
stack_inputs = [s for s in instr.inputs if not isinstance(s, parser.CacheEffect)]
if len(stack_inputs) != len(instr.outputs):
return False
if len(stack_inputs) == 0:
return False
if any(s.cond for s in stack_inputs) or any(s.cond for s in instr.outputs):
return False
return all(
(s.name == other.name and s.type == other.type and s.size == other.size)
for s, other in zip(stack_inputs, instr.outputs)
)
OPARG_AND_1 = re.compile("\\(*oparg *& *1")
def effect_depends_on_oparg_1(op: parser.InstDef) -> bool:
for effect in op.inputs:
if isinstance(effect, parser.CacheEffect):
continue
if not effect.cond:
continue
if OPARG_AND_1.match(effect.cond):
return True
for effect in op.outputs:
if not effect.cond:
continue
if OPARG_AND_1.match(effect.cond):
return True
return False
def compute_properties(op: parser.InstDef) -> Properties:
has_free = (
variable_used(op, "PyCell_New")
or variable_used(op, "PyCell_GetRef")
or variable_used(op, "PyCell_SetTakeRef")
or variable_used(op, "PyCell_SwapTakeRef")
)
deopts_if = variable_used(op, "DEOPT_IF")
exits_if = variable_used(op, "EXIT_IF")
if deopts_if and exits_if:
tkn = op.tokens[0]
raise lexer.make_syntax_error(
"Op cannot contain both EXIT_IF and DEOPT_IF",
tkn.filename,
tkn.line,
tkn.column,
op.name,
)
error_with_pop = has_error_with_pop(op)
error_without_pop = has_error_without_pop(op)
return Properties(
escapes=makes_escaping_api_call(op),
error_with_pop=error_with_pop,
error_without_pop=error_without_pop,
deopts=deopts_if,
side_exit=exits_if,
oparg=variable_used(op, "oparg"),
jumps=variable_used(op, "JUMPBY"),
eval_breaker=variable_used(op, "CHECK_EVAL_BREAKER"),
ends_with_eval_breaker=eval_breaker_at_end(op),
needs_this=variable_used(op, "this_instr"),
always_exits=always_exits(op),
stores_sp=variable_used(op, "SYNC_SP"),
uses_co_consts=variable_used(op, "FRAME_CO_CONSTS"),
uses_co_names=variable_used(op, "FRAME_CO_NAMES"),
uses_locals=(variable_used(op, "GETLOCAL") or variable_used(op, "SETLOCAL"))
and not has_free,
has_free=has_free,
pure="pure" in op.annotations,
tier=tier_variable(op),
)
def make_uop(name: str, op: parser.InstDef, inputs: list[parser.InputEffect], uops: dict[str, Uop]) -> Uop:
result = Uop(
name=name,
context=op.context,
annotations=op.annotations,
stack=analyze_stack(op),
caches=analyze_caches(inputs),
body=op.block.tokens,
properties=compute_properties(op),
)
if effect_depends_on_oparg_1(op) and "split" in op.annotations:
result.properties.oparg_and_1 = True
for bit in ("0", "1"):
name_x = name + "_" + bit
properties = compute_properties(op)
if properties.oparg:
# May not need oparg anymore
properties.oparg = any(token.text == "oparg" for token in op.block.tokens)
rep = Uop(
name=name_x,
context=op.context,
annotations=op.annotations,
stack=analyze_stack(op, bit),
caches=analyze_caches(inputs),
body=op.block.tokens,
properties=properties,
)
rep.replicates = result
uops[name_x] = rep
for anno in op.annotations:
if anno.startswith("replicate"):
result.replicated = int(anno[10:-1])
break
else:
return result
for oparg in range(result.replicated):
name_x = name + "_" + str(oparg)
properties = compute_properties(op)
properties.oparg = False
properties.const_oparg = oparg
rep = Uop(
name=name_x,
context=op.context,
annotations=op.annotations,
stack=analyze_stack(op),
caches=analyze_caches(inputs),
body=op.block.tokens,
properties=properties,
)
rep.replicates = result
uops[name_x] = rep
return result
def add_op(op: parser.InstDef, uops: dict[str, Uop]) -> None:
assert op.kind == "op"
if op.name in uops:
if "override" not in op.annotations:
raise override_error(
op.name, op.context, uops[op.name].context, op.tokens[0]
)
uops[op.name] = make_uop(op.name, op, op.inputs, uops)
def add_instruction(
name: str, parts: list[Part], instructions: dict[str, Instruction]
) -> None:
instructions[name] = Instruction(name, parts, None)
def desugar_inst(
inst: parser.InstDef, instructions: dict[str, Instruction], uops: dict[str, Uop]
) -> None:
assert inst.kind == "inst"
name = inst.name
op_inputs: list[parser.InputEffect] = []
parts: list[Part] = []
uop_index = -1
# Move unused cache entries to the Instruction, removing them from the Uop.
for input in inst.inputs:
if isinstance(input, parser.CacheEffect) and input.name == "unused":
parts.append(Skip(input.size))
else:
op_inputs.append(input)
if uop_index < 0:
uop_index = len(parts)
# Place holder for the uop.
parts.append(Skip(0))
uop = make_uop("_" + inst.name, inst, op_inputs, uops)
uop.implicitly_created = True
uops[inst.name] = uop
if uop_index < 0:
parts.append(uop)
else:
parts[uop_index] = uop
add_instruction(name, parts, instructions)
def add_macro(
macro: parser.Macro, instructions: dict[str, Instruction], uops: dict[str, Uop]
) -> None:
parts: list[Uop | Skip] = []
for part in macro.uops:
match part:
case parser.OpName():
if part.name not in uops:
analysis_error(f"No Uop named {part.name}", macro.tokens[0])
parts.append(uops[part.name])
case parser.CacheEffect():
parts.append(Skip(part.size))
case _:
assert False
assert parts
add_instruction(macro.name, parts, instructions)
def add_family(
pfamily: parser.Family,
instructions: dict[str, Instruction],
families: dict[str, Family],
) -> None:
family = Family(
pfamily.name,
pfamily.size,
[instructions[member_name] for member_name in pfamily.members],
)
for member in family.members:
member.family = family
# The head of the family is an implicit jump target for DEOPTs
instructions[family.name].is_target = True
families[family.name] = family
def add_pseudo(
pseudo: parser.Pseudo,
instructions: dict[str, Instruction],
pseudos: dict[str, PseudoInstruction],
) -> None:
pseudos[pseudo.name] = PseudoInstruction(
pseudo.name,
analyze_stack(pseudo),
[instructions[target] for target in pseudo.targets],
pseudo.flags,
)
def assign_opcodes(
instructions: dict[str, Instruction],
families: dict[str, Family],
pseudos: dict[str, PseudoInstruction],
) -> tuple[dict[str, int], int, int]:
"""Assigns opcodes, then returns the opmap,
have_arg and min_instrumented values"""
instmap: dict[str, int] = {}
# 0 is reserved for cache entries. This helps debugging.
instmap["CACHE"] = 0
# 17 is reserved as it is the initial value for the specializing counter.
# This helps catch cases where we attempt to execute a cache.
instmap["RESERVED"] = 17
# 149 is RESUME - it is hard coded as such in Tools/build/deepfreeze.py
instmap["RESUME"] = 149
# This is an historical oddity.
instmap["BINARY_OP_INPLACE_ADD_UNICODE"] = 3
instmap["INSTRUMENTED_LINE"] = 254
instrumented = [name for name in instructions if name.startswith("INSTRUMENTED")]
# Special case: this instruction is implemented in ceval.c
# rather than bytecodes.c, so we need to add it explicitly
# here (at least until we add something to bytecodes.c to
# declare external instructions).
instrumented.append("INSTRUMENTED_LINE")
specialized: set[str] = set()
no_arg: list[str] = []
has_arg: list[str] = []
for family in families.values():
specialized.update(inst.name for inst in family.members)
for inst in instructions.values():
name = inst.name
if name in specialized:
continue
if name in instrumented:
continue
if inst.properties.oparg:
has_arg.append(name)
else:
no_arg.append(name)
# Specialized ops appear in their own section
# Instrumented opcodes are at the end of the valid range
min_internal = 150
min_instrumented = 254 - (len(instrumented) - 1)
assert min_internal + len(specialized) < min_instrumented
next_opcode = 1
def add_instruction(name: str) -> None:
nonlocal next_opcode
if name in instmap:
return # Pre-defined name
while next_opcode in instmap.values():
next_opcode += 1
instmap[name] = next_opcode
next_opcode += 1
for name in sorted(no_arg):
add_instruction(name)
for name in sorted(has_arg):
add_instruction(name)
# For compatibility
next_opcode = min_internal
for name in sorted(specialized):
add_instruction(name)
next_opcode = min_instrumented
for name in instrumented:
add_instruction(name)
for name in instructions:
instructions[name].opcode = instmap[name]
for op, name in enumerate(sorted(pseudos), 256):
instmap[name] = op
pseudos[name].opcode = op
return instmap, len(no_arg), min_instrumented
def analyze_forest(forest: list[parser.AstNode]) -> Analysis:
instructions: dict[str, Instruction] = {}
uops: dict[str, Uop] = {}
families: dict[str, Family] = {}
pseudos: dict[str, PseudoInstruction] = {}
for node in forest:
match node:
case parser.InstDef(name):
if node.kind == "inst":
desugar_inst(node, instructions, uops)
else:
assert node.kind == "op"
add_op(node, uops)
case parser.Macro():
pass
case parser.Family():
pass
case parser.Pseudo():
pass
case _:
assert False
for node in forest:
if isinstance(node, parser.Macro):
add_macro(node, instructions, uops)
for node in forest:
match node:
case parser.Family():
add_family(node, instructions, families)
case parser.Pseudo():
add_pseudo(node, instructions, pseudos)
case _:
pass
for uop in uops.values():
tkn_iter = iter(uop.body)
for tkn in tkn_iter:
if tkn.kind == "IDENTIFIER" and tkn.text == "GO_TO_INSTRUCTION":
if next(tkn_iter).kind != "LPAREN":
continue
target = next(tkn_iter)
if target.kind != "IDENTIFIER":
continue
if target.text in instructions:
instructions[target.text].is_target = True
# Special case BINARY_OP_INPLACE_ADD_UNICODE
# BINARY_OP_INPLACE_ADD_UNICODE is not a normal family member,
# as it is the wrong size, but we need it to maintain an
# historical optimization.
if "BINARY_OP_INPLACE_ADD_UNICODE" in instructions:
inst = instructions["BINARY_OP_INPLACE_ADD_UNICODE"]
inst.family = families["BINARY_OP"]
families["BINARY_OP"].members.append(inst)
opmap, first_arg, min_instrumented = assign_opcodes(instructions, families, pseudos)
return Analysis(
instructions, uops, families, pseudos, opmap, first_arg, min_instrumented
)
def analyze_files(filenames: list[str]) -> Analysis:
return analyze_forest(parser.parse_files(filenames))
def dump_analysis(analysis: Analysis) -> None:
print("Uops:")
for u in analysis.uops.values():
u.dump(" ")
print("Instructions:")
for i in analysis.instructions.values():
i.dump(" ")
print("Families:")
for f in analysis.families.values():
f.dump(" ")
print("Pseudos:")
for p in analysis.pseudos.values():
p.dump(" ")
if __name__ == "__main__":
import sys
if len(sys.argv) < 2:
print("No input")
else:
filenames = sys.argv[1:]
dump_analysis(analyze_files(filenames))