"""Utilities for emitting C code.""" from __future__ import annotations import pprint import sys import textwrap from typing import Callable, Final from mypyc.codegen.literals import Literals from mypyc.common import ( ATTR_PREFIX, BITMAP_BITS, FAST_ISINSTANCE_MAX_SUBCLASSES, HAVE_IMMORTAL, NATIVE_PREFIX, REG_PREFIX, STATIC_PREFIX, TYPE_PREFIX, ) from mypyc.ir.class_ir import ClassIR, all_concrete_classes from mypyc.ir.func_ir import FuncDecl from mypyc.ir.ops import BasicBlock, Value from mypyc.ir.rtypes import ( RInstance, RPrimitive, RTuple, RType, RUnion, int_rprimitive, is_bit_rprimitive, is_bool_rprimitive, is_bytes_rprimitive, is_dict_rprimitive, is_fixed_width_rtype, is_float_rprimitive, is_frozenset_rprimitive, is_int16_rprimitive, is_int32_rprimitive, is_int64_rprimitive, is_int_rprimitive, is_list_rprimitive, is_none_rprimitive, is_object_rprimitive, is_optional_type, is_range_rprimitive, is_set_rprimitive, is_short_int_rprimitive, is_str_rprimitive, is_tuple_rprimitive, is_uint8_rprimitive, object_rprimitive, optional_value_type, ) from mypyc.namegen import NameGenerator, exported_name from mypyc.sametype import is_same_type # Whether to insert debug asserts for all error handling, to quickly # catch errors propagating without exceptions set. DEBUG_ERRORS: Final = False class HeaderDeclaration: """A representation of a declaration in C. This is used to generate declarations in header files and (optionally) definitions in source files. Attributes: decl: C source code for the declaration. defn: Optionally, C source code for a definition. dependencies: The names of any objects that must be declared prior. is_type: Whether the declaration is of a C type. (C types will be declared in external header files and not marked 'extern'.) needs_export: Whether the declared object needs to be exported to other modules in the linking table. """ def __init__( self, decl: str | list[str], defn: list[str] | None = None, *, dependencies: set[str] | None = None, is_type: bool = False, needs_export: bool = False, ) -> None: self.decl = [decl] if isinstance(decl, str) else decl self.defn = defn self.dependencies = dependencies or set() self.is_type = is_type self.needs_export = needs_export class EmitterContext: """Shared emitter state for a compilation group.""" def __init__( self, names: NameGenerator, group_name: str | None = None, group_map: dict[str, str | None] | None = None, ) -> None: """Setup shared emitter state. Args: names: The name generator to use group_map: Map from module names to group name group_name: Current group name """ self.temp_counter = 0 self.names = names self.group_name = group_name self.group_map = group_map or {} # Groups that this group depends on self.group_deps: set[str] = set() # The map below is used for generating declarations and # definitions at the top of the C file. The main idea is that they can # be generated at any time during the emit phase. # A map of a C identifier to whatever the C identifier declares. Currently this is # used for declaring structs and the key corresponds to the name of the struct. # The declaration contains the body of the struct. self.declarations: dict[str, HeaderDeclaration] = {} self.literals = Literals() class ErrorHandler: """Describes handling errors in unbox/cast operations.""" class AssignHandler(ErrorHandler): """Assign an error value on error.""" class GotoHandler(ErrorHandler): """Goto label on error.""" def __init__(self, label: str) -> None: self.label = label class TracebackAndGotoHandler(ErrorHandler): """Add traceback item and goto label on error.""" def __init__( self, label: str, source_path: str, module_name: str, traceback_entry: tuple[str, int] ) -> None: self.label = label self.source_path = source_path self.module_name = module_name self.traceback_entry = traceback_entry class ReturnHandler(ErrorHandler): """Return a constant value on error.""" def __init__(self, value: str) -> None: self.value = value class Emitter: """Helper for C code generation.""" def __init__( self, context: EmitterContext, value_names: dict[Value, str] | None = None, capi_version: tuple[int, int] | None = None, ) -> None: self.context = context self.capi_version = capi_version or sys.version_info[:2] self.names = context.names self.value_names = value_names or {} self.fragments: list[str] = [] self._indent = 0 # Low-level operations def indent(self) -> None: self._indent += 4 def dedent(self) -> None: self._indent -= 4 assert self._indent >= 0 def label(self, label: BasicBlock) -> str: return "CPyL%s" % label.label def reg(self, reg: Value) -> str: return REG_PREFIX + self.value_names[reg] def attr(self, name: str) -> str: return ATTR_PREFIX + name def object_annotation(self, obj: object, line: str) -> str: """Build a C comment with an object's string representation. If the comment exceeds the line length limit, it's wrapped into a multiline string (with the extra lines indented to be aligned with the first line's comment). If it contains illegal characters, an empty string is returned.""" line_width = self._indent + len(line) formatted = pprint.pformat(obj, compact=True, width=max(90 - line_width, 20)) if any(x in formatted for x in ("/*", "*/", "\0")): return "" if "\n" in formatted: first_line, rest = formatted.split("\n", maxsplit=1) comment_continued = textwrap.indent(rest, (line_width + 3) * " ") return f" /* {first_line}\n{comment_continued} */" else: return f" /* {formatted} */" def emit_line(self, line: str = "", *, ann: object = None) -> None: if line.startswith("}"): self.dedent() comment = self.object_annotation(ann, line) if ann is not None else "" self.fragments.append(self._indent * " " + line + comment + "\n") if line.endswith("{"): self.indent() def emit_lines(self, *lines: str) -> None: for line in lines: self.emit_line(line) def emit_label(self, label: BasicBlock | str) -> None: if isinstance(label, str): text = label else: if label.label == 0 or not label.referenced: return text = self.label(label) # Extra semicolon prevents an error when the next line declares a tempvar self.fragments.append(f"{text}: ;\n") def emit_from_emitter(self, emitter: Emitter) -> None: self.fragments.extend(emitter.fragments) def emit_printf(self, fmt: str, *args: str) -> None: fmt = fmt.replace("\n", "\\n") self.emit_line("printf(%s);" % ", ".join(['"%s"' % fmt] + list(args))) self.emit_line("fflush(stdout);") def temp_name(self) -> str: self.context.temp_counter += 1 return "__tmp%d" % self.context.temp_counter def new_label(self) -> str: self.context.temp_counter += 1 return "__LL%d" % self.context.temp_counter def get_module_group_prefix(self, module_name: str) -> str: """Get the group prefix for a module (relative to the current group). The prefix should be prepended to the object name whenever accessing an object from this module. If the module lives is in the current compilation group, there is no prefix. But if it lives in a different group (and hence a separate extension module), we need to access objects from it indirectly via an export table. For example, for code in group `a` to call a function `bar` in group `b`, it would need to do `exports_b.CPyDef_bar(...)`, while code that is also in group `b` can simply do `CPyDef_bar(...)`. Thus the prefix for a module in group `b` is 'exports_b.' if the current group is *not* b and just '' if it is. """ groups = self.context.group_map target_group_name = groups.get(module_name) if target_group_name and target_group_name != self.context.group_name: self.context.group_deps.add(target_group_name) return f"exports_{exported_name(target_group_name)}." else: return "" def get_group_prefix(self, obj: ClassIR | FuncDecl) -> str: """Get the group prefix for an object.""" # See docs above return self.get_module_group_prefix(obj.module_name) def static_name(self, id: str, module: str | None, prefix: str = STATIC_PREFIX) -> str: """Create name of a C static variable. These are used for literals and imported modules, among other things. The caller should ensure that the (id, module) pair cannot overlap with other calls to this method within a compilation group. """ lib_prefix = "" if not module else self.get_module_group_prefix(module) # If we are accessing static via the export table, we need to dereference # the pointer also. star_maybe = "*" if lib_prefix else "" suffix = self.names.private_name(module or "", id) return f"{star_maybe}{lib_prefix}{prefix}{suffix}" def type_struct_name(self, cl: ClassIR) -> str: return self.static_name(cl.name, cl.module_name, prefix=TYPE_PREFIX) def ctype(self, rtype: RType) -> str: return rtype._ctype def ctype_spaced(self, rtype: RType) -> str: """Adds a space after ctype for non-pointers.""" ctype = self.ctype(rtype) if ctype[-1] == "*": return ctype else: return ctype + " " def c_undefined_value(self, rtype: RType) -> str: if not rtype.is_unboxed: return "NULL" elif isinstance(rtype, RPrimitive): return rtype.c_undefined elif isinstance(rtype, RTuple): return self.tuple_undefined_value(rtype) assert False, rtype def c_error_value(self, rtype: RType) -> str: return self.c_undefined_value(rtype) def native_function_name(self, fn: FuncDecl) -> str: return f"{NATIVE_PREFIX}{fn.cname(self.names)}" def tuple_c_declaration(self, rtuple: RTuple) -> list[str]: result = [ f"#ifndef MYPYC_DECLARED_{rtuple.struct_name}", f"#define MYPYC_DECLARED_{rtuple.struct_name}", f"typedef struct {rtuple.struct_name} {{", ] if len(rtuple.types) == 0: # empty tuple # Empty tuples contain a flag so that they can still indicate # error values. result.append("int empty_struct_error_flag;") else: i = 0 for typ in rtuple.types: result.append(f"{self.ctype_spaced(typ)}f{i};") i += 1 result.append(f"}} {rtuple.struct_name};") result.append("#endif") result.append("") return result def bitmap_field(self, index: int) -> str: """Return C field name used for attribute bitmap.""" n = index // BITMAP_BITS if n == 0: return "bitmap" return f"bitmap{n + 1}" def attr_bitmap_expr(self, obj: str, cl: ClassIR, index: int) -> str: """Return reference to the attribute definedness bitmap.""" cast = f"({cl.struct_name(self.names)} *)" attr = self.bitmap_field(index) return f"({cast}{obj})->{attr}" def emit_attr_bitmap_set( self, value: str, obj: str, rtype: RType, cl: ClassIR, attr: str ) -> None: """Mark an attribute as defined in the attribute bitmap. Assumes that the attribute is tracked in the bitmap (only some attributes use the bitmap). If 'value' is not equal to the error value, do nothing. """ self._emit_attr_bitmap_update(value, obj, rtype, cl, attr, clear=False) def emit_attr_bitmap_clear(self, obj: str, rtype: RType, cl: ClassIR, attr: str) -> None: """Mark an attribute as undefined in the attribute bitmap. Unlike emit_attr_bitmap_set, clear unconditionally. """ self._emit_attr_bitmap_update("", obj, rtype, cl, attr, clear=True) def _emit_attr_bitmap_update( self, value: str, obj: str, rtype: RType, cl: ClassIR, attr: str, clear: bool ) -> None: if value: check = self.error_value_check(rtype, value, "==") self.emit_line(f"if (unlikely({check})) {{") index = cl.bitmap_attrs.index(attr) mask = 1 << (index & (BITMAP_BITS - 1)) bitmap = self.attr_bitmap_expr(obj, cl, index) if clear: self.emit_line(f"{bitmap} &= ~{mask};") else: self.emit_line(f"{bitmap} |= {mask};") if value: self.emit_line("}") def emit_undefined_attr_check( self, rtype: RType, attr_expr: str, compare: str, obj: str, attr: str, cl: ClassIR, *, unlikely: bool = False, ) -> None: check = self.error_value_check(rtype, attr_expr, compare) if unlikely: check = f"unlikely({check})" if rtype.error_overlap: index = cl.bitmap_attrs.index(attr) bit = 1 << (index & (BITMAP_BITS - 1)) attr = self.bitmap_field(index) obj_expr = f"({cl.struct_name(self.names)} *){obj}" check = f"{check} && !(({obj_expr})->{attr} & {bit})" self.emit_line(f"if ({check}) {{") def error_value_check(self, rtype: RType, value: str, compare: str) -> str: if isinstance(rtype, RTuple): return self.tuple_undefined_check_cond( rtype, value, self.c_error_value, compare, check_exception=False ) else: return f"{value} {compare} {self.c_error_value(rtype)}" def tuple_undefined_check_cond( self, rtuple: RTuple, tuple_expr_in_c: str, c_type_compare_val: Callable[[RType], str], compare: str, *, check_exception: bool = True, ) -> str: if len(rtuple.types) == 0: # empty tuple return "{}.empty_struct_error_flag {} {}".format( tuple_expr_in_c, compare, c_type_compare_val(int_rprimitive) ) if rtuple.error_overlap: i = 0 item_type = rtuple.types[0] else: for i, typ in enumerate(rtuple.types): if not typ.error_overlap: item_type = rtuple.types[i] break else: assert False, "not expecting tuple with error overlap" if isinstance(item_type, RTuple): return self.tuple_undefined_check_cond( item_type, tuple_expr_in_c + f".f{i}", c_type_compare_val, compare ) else: check = f"{tuple_expr_in_c}.f{i} {compare} {c_type_compare_val(item_type)}" if rtuple.error_overlap and check_exception: check += " && PyErr_Occurred()" return check def tuple_undefined_value(self, rtuple: RTuple) -> str: """Undefined tuple value suitable in an expression.""" return f"({rtuple.struct_name}) {self.c_initializer_undefined_value(rtuple)}" def c_initializer_undefined_value(self, rtype: RType) -> str: """Undefined value represented in a form suitable for variable initialization.""" if isinstance(rtype, RTuple): if not rtype.types: # Empty tuples contain a flag so that they can still indicate # error values. return f"{{ {int_rprimitive.c_undefined} }}" items = ", ".join([self.c_initializer_undefined_value(t) for t in rtype.types]) return f"{{ {items} }}" else: return self.c_undefined_value(rtype) # Higher-level operations def declare_tuple_struct(self, tuple_type: RTuple) -> None: if tuple_type.struct_name not in self.context.declarations: dependencies = set() for typ in tuple_type.types: # XXX other types might eventually need similar behavior if isinstance(typ, RTuple): dependencies.add(typ.struct_name) self.context.declarations[tuple_type.struct_name] = HeaderDeclaration( self.tuple_c_declaration(tuple_type), dependencies=dependencies, is_type=True ) def emit_inc_ref(self, dest: str, rtype: RType, *, rare: bool = False) -> None: """Increment reference count of C expression `dest`. For composite unboxed structures (e.g. tuples) recursively increment reference counts for each component. If rare is True, optimize for code size and compilation speed. """ if is_int_rprimitive(rtype): if rare: self.emit_line("CPyTagged_IncRef(%s);" % dest) else: self.emit_line("CPyTagged_INCREF(%s);" % dest) elif isinstance(rtype, RTuple): for i, item_type in enumerate(rtype.types): self.emit_inc_ref(f"{dest}.f{i}", item_type) elif not rtype.is_unboxed: # Always inline, since this is a simple but very hot op if rtype.may_be_immortal or not HAVE_IMMORTAL: self.emit_line("CPy_INCREF(%s);" % dest) else: self.emit_line("CPy_INCREF_NO_IMM(%s);" % dest) # Otherwise assume it's an unboxed, pointerless value and do nothing. def emit_dec_ref( self, dest: str, rtype: RType, *, is_xdec: bool = False, rare: bool = False ) -> None: """Decrement reference count of C expression `dest`. For composite unboxed structures (e.g. tuples) recursively decrement reference counts for each component. If rare is True, optimize for code size and compilation speed. """ x = "X" if is_xdec else "" if is_int_rprimitive(rtype): if rare: self.emit_line(f"CPyTagged_{x}DecRef({dest});") else: # Inlined self.emit_line(f"CPyTagged_{x}DECREF({dest});") elif isinstance(rtype, RTuple): for i, item_type in enumerate(rtype.types): self.emit_dec_ref(f"{dest}.f{i}", item_type, is_xdec=is_xdec, rare=rare) elif not rtype.is_unboxed: if rare: self.emit_line(f"CPy_{x}DecRef({dest});") else: # Inlined if rtype.may_be_immortal or not HAVE_IMMORTAL: self.emit_line(f"CPy_{x}DECREF({dest});") else: self.emit_line(f"CPy_{x}DECREF_NO_IMM({dest});") # Otherwise assume it's an unboxed, pointerless value and do nothing. def pretty_name(self, typ: RType) -> str: value_type = optional_value_type(typ) if value_type is not None: return "%s or None" % self.pretty_name(value_type) return str(typ) def emit_cast( self, src: str, dest: str, typ: RType, *, declare_dest: bool = False, error: ErrorHandler | None = None, raise_exception: bool = True, optional: bool = False, src_type: RType | None = None, likely: bool = True, ) -> None: """Emit code for casting a value of given type. Somewhat strangely, this supports unboxed types but only operates on boxed versions. This is necessary to properly handle types such as Optional[int] in compatibility glue. By default, assign NULL (error value) to dest if the value has an incompatible type and raise TypeError. These can be customized using 'error' and 'raise_exception'. Always copy/steal the reference in 'src'. Args: src: Name of source C variable dest: Name of target C variable typ: Type of value declare_dest: If True, also declare the variable 'dest' error: What happens on error raise_exception: If True, also raise TypeError on failure likely: If the cast is likely to succeed (can be False for unions) """ error = error or AssignHandler() # Special case casting *from* optional if src_type and is_optional_type(src_type) and not is_object_rprimitive(typ): value_type = optional_value_type(src_type) assert value_type is not None if is_same_type(value_type, typ): if declare_dest: self.emit_line(f"PyObject *{dest};") check = "({} != Py_None)" if likely: check = f"(likely{check})" self.emit_arg_check(src, dest, typ, check.format(src), optional) self.emit_lines(f" {dest} = {src};", "else {") self.emit_cast_error_handler(error, src, dest, typ, raise_exception) self.emit_line("}") return # TODO: Verify refcount handling. if ( is_list_rprimitive(typ) or is_dict_rprimitive(typ) or is_set_rprimitive(typ) or is_frozenset_rprimitive(typ) or is_str_rprimitive(typ) or is_range_rprimitive(typ) or is_float_rprimitive(typ) or is_int_rprimitive(typ) or is_bool_rprimitive(typ) or is_bit_rprimitive(typ) or is_fixed_width_rtype(typ) ): if declare_dest: self.emit_line(f"PyObject *{dest};") if is_list_rprimitive(typ): prefix = "PyList" elif is_dict_rprimitive(typ): prefix = "PyDict" elif is_set_rprimitive(typ): prefix = "PySet" elif is_frozenset_rprimitive(typ): prefix = "PyFrozenSet" elif is_str_rprimitive(typ): prefix = "PyUnicode" elif is_range_rprimitive(typ): prefix = "PyRange" elif is_float_rprimitive(typ): prefix = "CPyFloat" elif is_int_rprimitive(typ) or is_fixed_width_rtype(typ): # TODO: Range check for fixed-width types? prefix = "PyLong" elif is_bool_rprimitive(typ) or is_bit_rprimitive(typ): prefix = "PyBool" else: assert False, f"unexpected primitive type: {typ}" check = "({}_Check({}))" if likely: check = f"(likely{check})" self.emit_arg_check(src, dest, typ, check.format(prefix, src), optional) self.emit_lines(f" {dest} = {src};", "else {") self.emit_cast_error_handler(error, src, dest, typ, raise_exception) self.emit_line("}") elif is_bytes_rprimitive(typ): if declare_dest: self.emit_line(f"PyObject *{dest};") check = "(PyBytes_Check({}) || PyByteArray_Check({}))" if likely: check = f"(likely{check})" self.emit_arg_check(src, dest, typ, check.format(src, src), optional) self.emit_lines(f" {dest} = {src};", "else {") self.emit_cast_error_handler(error, src, dest, typ, raise_exception) self.emit_line("}") elif is_tuple_rprimitive(typ): if declare_dest: self.emit_line(f"{self.ctype(typ)} {dest};") check = "(PyTuple_Check({}))" if likely: check = f"(likely{check})" self.emit_arg_check(src, dest, typ, check.format(src), optional) self.emit_lines(f" {dest} = {src};", "else {") self.emit_cast_error_handler(error, src, dest, typ, raise_exception) self.emit_line("}") elif isinstance(typ, RInstance): if declare_dest: self.emit_line(f"PyObject *{dest};") concrete = all_concrete_classes(typ.class_ir) # If there are too many concrete subclasses or we can't find any # (meaning the code ought to be dead or we aren't doing global opts), # fall back to a normal typecheck. # Otherwise check all the subclasses. if not concrete or len(concrete) > FAST_ISINSTANCE_MAX_SUBCLASSES + 1: check = "(PyObject_TypeCheck({}, {}))".format( src, self.type_struct_name(typ.class_ir) ) else: full_str = "(Py_TYPE({src}) == {targets[0]})" for i in range(1, len(concrete)): full_str += " || (Py_TYPE({src}) == {targets[%d]})" % i if len(concrete) > 1: full_str = "(%s)" % full_str check = full_str.format( src=src, targets=[self.type_struct_name(ir) for ir in concrete] ) if likely: check = f"(likely{check})" self.emit_arg_check(src, dest, typ, check, optional) self.emit_lines(f" {dest} = {src};", "else {") self.emit_cast_error_handler(error, src, dest, typ, raise_exception) self.emit_line("}") elif is_none_rprimitive(typ): if declare_dest: self.emit_line(f"PyObject *{dest};") check = "({} == Py_None)" if likely: check = f"(likely{check})" self.emit_arg_check(src, dest, typ, check.format(src), optional) self.emit_lines(f" {dest} = {src};", "else {") self.emit_cast_error_handler(error, src, dest, typ, raise_exception) self.emit_line("}") elif is_object_rprimitive(typ): if declare_dest: self.emit_line(f"PyObject *{dest};") self.emit_arg_check(src, dest, typ, "", optional) self.emit_line(f"{dest} = {src};") if optional: self.emit_line("}") elif isinstance(typ, RUnion): self.emit_union_cast( src, dest, typ, declare_dest, error, optional, src_type, raise_exception ) elif isinstance(typ, RTuple): assert not optional self.emit_tuple_cast(src, dest, typ, declare_dest, error, src_type) else: assert False, "Cast not implemented: %s" % typ def emit_cast_error_handler( self, error: ErrorHandler, src: str, dest: str, typ: RType, raise_exception: bool ) -> None: if raise_exception: if isinstance(error, TracebackAndGotoHandler): # Merge raising and emitting traceback entry into a single call. self.emit_type_error_traceback( error.source_path, error.module_name, error.traceback_entry, typ=typ, src=src ) self.emit_line("goto %s;" % error.label) return self.emit_line(f'CPy_TypeError("{self.pretty_name(typ)}", {src}); ') if isinstance(error, AssignHandler): self.emit_line("%s = NULL;" % dest) elif isinstance(error, GotoHandler): self.emit_line("goto %s;" % error.label) elif isinstance(error, TracebackAndGotoHandler): self.emit_line("%s = NULL;" % dest) self.emit_traceback(error.source_path, error.module_name, error.traceback_entry) self.emit_line("goto %s;" % error.label) else: assert isinstance(error, ReturnHandler) self.emit_line("return %s;" % error.value) def emit_union_cast( self, src: str, dest: str, typ: RUnion, declare_dest: bool, error: ErrorHandler, optional: bool, src_type: RType | None, raise_exception: bool, ) -> None: """Emit cast to a union type. The arguments are similar to emit_cast. """ if declare_dest: self.emit_line(f"PyObject *{dest};") good_label = self.new_label() if optional: self.emit_line(f"if ({src} == NULL) {{") self.emit_line(f"{dest} = {self.c_error_value(typ)};") self.emit_line(f"goto {good_label};") self.emit_line("}") for item in typ.items: self.emit_cast( src, dest, item, declare_dest=False, raise_exception=False, optional=False, likely=False, ) self.emit_line(f"if ({dest} != NULL) goto {good_label};") # Handle cast failure. self.emit_cast_error_handler(error, src, dest, typ, raise_exception) self.emit_label(good_label) def emit_tuple_cast( self, src: str, dest: str, typ: RTuple, declare_dest: bool, error: ErrorHandler, src_type: RType | None, ) -> None: """Emit cast to a tuple type. The arguments are similar to emit_cast. """ if declare_dest: self.emit_line(f"PyObject *{dest};") # This reuse of the variable is super dodgy. We don't even # care about the values except to check whether they are # invalid. out_label = self.new_label() self.emit_lines( "if (unlikely(!(PyTuple_Check({r}) && PyTuple_GET_SIZE({r}) == {size}))) {{".format( r=src, size=len(typ.types) ), f"{dest} = NULL;", f"goto {out_label};", "}", ) for i, item in enumerate(typ.types): # Since we did the checks above this should never fail self.emit_cast( f"PyTuple_GET_ITEM({src}, {i})", dest, item, declare_dest=False, raise_exception=False, optional=False, ) self.emit_line(f"if ({dest} == NULL) goto {out_label};") self.emit_line(f"{dest} = {src};") self.emit_label(out_label) def emit_arg_check(self, src: str, dest: str, typ: RType, check: str, optional: bool) -> None: if optional: self.emit_line(f"if ({src} == NULL) {{") self.emit_line(f"{dest} = {self.c_error_value(typ)};") if check != "": self.emit_line("{}if {}".format("} else " if optional else "", check)) elif optional: self.emit_line("else {") def emit_unbox( self, src: str, dest: str, typ: RType, *, declare_dest: bool = False, error: ErrorHandler | None = None, raise_exception: bool = True, optional: bool = False, borrow: bool = False, ) -> None: """Emit code for unboxing a value of given type (from PyObject *). By default, assign error value to dest if the value has an incompatible type and raise TypeError. These can be customized using 'error' and 'raise_exception'. Generate a new reference unless 'borrow' is True. Args: src: Name of source C variable dest: Name of target C variable typ: Type of value declare_dest: If True, also declare the variable 'dest' error: What happens on error raise_exception: If True, also raise TypeError on failure borrow: If True, create a borrowed reference """ error = error or AssignHandler() # TODO: Verify refcount handling. if isinstance(error, AssignHandler): failure = f"{dest} = {self.c_error_value(typ)};" elif isinstance(error, GotoHandler): failure = "goto %s;" % error.label else: assert isinstance(error, ReturnHandler) failure = "return %s;" % error.value if raise_exception: raise_exc = f'CPy_TypeError("{self.pretty_name(typ)}", {src}); ' failure = raise_exc + failure if is_int_rprimitive(typ) or is_short_int_rprimitive(typ): if declare_dest: self.emit_line(f"CPyTagged {dest};") self.emit_arg_check(src, dest, typ, f"(likely(PyLong_Check({src})))", optional) if borrow: self.emit_line(f" {dest} = CPyTagged_BorrowFromObject({src});") else: self.emit_line(f" {dest} = CPyTagged_FromObject({src});") self.emit_line("else {") self.emit_line(failure) self.emit_line("}") elif is_bool_rprimitive(typ) or is_bit_rprimitive(typ): # Whether we are borrowing or not makes no difference. if declare_dest: self.emit_line(f"char {dest};") self.emit_arg_check(src, dest, typ, f"(unlikely(!PyBool_Check({src}))) {{", optional) self.emit_line(failure) self.emit_line("} else") conversion = f"{src} == Py_True" self.emit_line(f" {dest} = {conversion};") elif is_none_rprimitive(typ): # Whether we are borrowing or not makes no difference. if declare_dest: self.emit_line(f"char {dest};") self.emit_arg_check(src, dest, typ, f"(unlikely({src} != Py_None)) {{", optional) self.emit_line(failure) self.emit_line("} else") self.emit_line(f" {dest} = 1;") elif is_int64_rprimitive(typ): # Whether we are borrowing or not makes no difference. assert not optional # Not supported for overlapping error values if declare_dest: self.emit_line(f"int64_t {dest};") self.emit_line(f"{dest} = CPyLong_AsInt64({src});") if not isinstance(error, AssignHandler): self.emit_unbox_failure_with_overlapping_error_value(dest, typ, failure) elif is_int32_rprimitive(typ): # Whether we are borrowing or not makes no difference. assert not optional # Not supported for overlapping error values if declare_dest: self.emit_line(f"int32_t {dest};") self.emit_line(f"{dest} = CPyLong_AsInt32({src});") if not isinstance(error, AssignHandler): self.emit_unbox_failure_with_overlapping_error_value(dest, typ, failure) elif is_int16_rprimitive(typ): # Whether we are borrowing or not makes no difference. assert not optional # Not supported for overlapping error values if declare_dest: self.emit_line(f"int16_t {dest};") self.emit_line(f"{dest} = CPyLong_AsInt16({src});") if not isinstance(error, AssignHandler): self.emit_unbox_failure_with_overlapping_error_value(dest, typ, failure) elif is_uint8_rprimitive(typ): # Whether we are borrowing or not makes no difference. assert not optional # Not supported for overlapping error values if declare_dest: self.emit_line(f"uint8_t {dest};") self.emit_line(f"{dest} = CPyLong_AsUInt8({src});") if not isinstance(error, AssignHandler): self.emit_unbox_failure_with_overlapping_error_value(dest, typ, failure) elif is_float_rprimitive(typ): assert not optional # Not supported for overlapping error values if declare_dest: self.emit_line(f"double {dest};") # TODO: Don't use __float__ and __index__ self.emit_line(f"{dest} = PyFloat_AsDouble({src});") self.emit_lines(f"if ({dest} == -1.0 && PyErr_Occurred()) {{", failure, "}") elif isinstance(typ, RTuple): self.declare_tuple_struct(typ) if declare_dest: self.emit_line(f"{self.ctype(typ)} {dest};") # HACK: The error handling for unboxing tuples is busted # and instead of fixing it I am just wrapping it in the # cast code which I think is right. This is not good. if optional: self.emit_line(f"if ({src} == NULL) {{") self.emit_line(f"{dest} = {self.c_error_value(typ)};") self.emit_line("} else {") cast_temp = self.temp_name() self.emit_tuple_cast( src, cast_temp, typ, declare_dest=True, error=error, src_type=None ) self.emit_line(f"if (unlikely({cast_temp} == NULL)) {{") # self.emit_arg_check(src, dest, typ, # '(!PyTuple_Check({}) || PyTuple_Size({}) != {}) {{'.format( # src, src, len(typ.types)), optional) self.emit_line(failure) # TODO: Decrease refcount? self.emit_line("} else {") if not typ.types: self.emit_line(f"{dest}.empty_struct_error_flag = 0;") for i, item_type in enumerate(typ.types): temp = self.temp_name() # emit_tuple_cast above checks the size, so this should not fail self.emit_line(f"PyObject *{temp} = PyTuple_GET_ITEM({src}, {i});") temp2 = self.temp_name() # Unbox or check the item. if item_type.is_unboxed: self.emit_unbox( temp, temp2, item_type, raise_exception=raise_exception, error=error, declare_dest=True, borrow=borrow, ) else: if not borrow: self.emit_inc_ref(temp, object_rprimitive) self.emit_cast(temp, temp2, item_type, declare_dest=True) self.emit_line(f"{dest}.f{i} = {temp2};") self.emit_line("}") if optional: self.emit_line("}") else: assert False, "Unboxing not implemented: %s" % typ def emit_box( self, src: str, dest: str, typ: RType, declare_dest: bool = False, can_borrow: bool = False ) -> None: """Emit code for boxing a value of given type. Generate a simple assignment if no boxing is needed. The source reference count is stolen for the result (no need to decref afterwards). """ # TODO: Always generate a new reference (if a reference type) if declare_dest: declaration = "PyObject *" else: declaration = "" if is_int_rprimitive(typ) or is_short_int_rprimitive(typ): # Steal the existing reference if it exists. self.emit_line(f"{declaration}{dest} = CPyTagged_StealAsObject({src});") elif is_bool_rprimitive(typ) or is_bit_rprimitive(typ): # N.B: bool is special cased to produce a borrowed value # after boxing, so we don't need to increment the refcount # when this comes directly from a Box op. self.emit_lines(f"{declaration}{dest} = {src} ? Py_True : Py_False;") if not can_borrow: self.emit_inc_ref(dest, object_rprimitive) elif is_none_rprimitive(typ): # N.B: None is special cased to produce a borrowed value # after boxing, so we don't need to increment the refcount # when this comes directly from a Box op. self.emit_lines(f"{declaration}{dest} = Py_None;") if not can_borrow: self.emit_inc_ref(dest, object_rprimitive) elif is_int32_rprimitive(typ) or is_int16_rprimitive(typ) or is_uint8_rprimitive(typ): self.emit_line(f"{declaration}{dest} = PyLong_FromLong({src});") elif is_int64_rprimitive(typ): self.emit_line(f"{declaration}{dest} = PyLong_FromLongLong({src});") elif is_float_rprimitive(typ): self.emit_line(f"{declaration}{dest} = PyFloat_FromDouble({src});") elif isinstance(typ, RTuple): self.declare_tuple_struct(typ) self.emit_line(f"{declaration}{dest} = PyTuple_New({len(typ.types)});") self.emit_line(f"if (unlikely({dest} == NULL))") self.emit_line(" CPyError_OutOfMemory();") # TODO: Fail if dest is None for i in range(len(typ.types)): if not typ.is_unboxed: self.emit_line(f"PyTuple_SET_ITEM({dest}, {i}, {src}.f{i}") else: inner_name = self.temp_name() self.emit_box(f"{src}.f{i}", inner_name, typ.types[i], declare_dest=True) self.emit_line(f"PyTuple_SET_ITEM({dest}, {i}, {inner_name});") else: assert not typ.is_unboxed # Type is boxed -- trivially just assign. self.emit_line(f"{declaration}{dest} = {src};") def emit_error_check(self, value: str, rtype: RType, failure: str) -> None: """Emit code for checking a native function return value for uncaught exception.""" if isinstance(rtype, RTuple): if len(rtype.types) == 0: return # empty tuples can't fail. else: cond = self.tuple_undefined_check_cond(rtype, value, self.c_error_value, "==") self.emit_line(f"if ({cond}) {{") elif rtype.error_overlap: # The error value is also valid as a normal value, so we need to also check # for a raised exception. self.emit_line(f"if ({value} == {self.c_error_value(rtype)} && PyErr_Occurred()) {{") else: self.emit_line(f"if ({value} == {self.c_error_value(rtype)}) {{") self.emit_lines(failure, "}") def emit_gc_visit(self, target: str, rtype: RType) -> None: """Emit code for GC visiting a C variable reference. Assume that 'target' represents a C expression that refers to a struct member, such as 'self->x'. """ if not rtype.is_refcounted: # Not refcounted -> no pointers -> no GC interaction. return elif isinstance(rtype, RPrimitive) and rtype.name == "builtins.int": self.emit_line(f"if (CPyTagged_CheckLong({target})) {{") self.emit_line(f"Py_VISIT(CPyTagged_LongAsObject({target}));") self.emit_line("}") elif isinstance(rtype, RTuple): for i, item_type in enumerate(rtype.types): self.emit_gc_visit(f"{target}.f{i}", item_type) elif self.ctype(rtype) == "PyObject *": # The simplest case. self.emit_line(f"Py_VISIT({target});") else: assert False, "emit_gc_visit() not implemented for %s" % repr(rtype) def emit_gc_clear(self, target: str, rtype: RType) -> None: """Emit code for clearing a C attribute reference for GC. Assume that 'target' represents a C expression that refers to a struct member, such as 'self->x'. """ if not rtype.is_refcounted: # Not refcounted -> no pointers -> no GC interaction. return elif isinstance(rtype, RPrimitive) and rtype.name == "builtins.int": self.emit_line(f"if (CPyTagged_CheckLong({target})) {{") self.emit_line(f"CPyTagged __tmp = {target};") self.emit_line(f"{target} = {self.c_undefined_value(rtype)};") self.emit_line("Py_XDECREF(CPyTagged_LongAsObject(__tmp));") self.emit_line("}") elif isinstance(rtype, RTuple): for i, item_type in enumerate(rtype.types): self.emit_gc_clear(f"{target}.f{i}", item_type) elif self.ctype(rtype) == "PyObject *" and self.c_undefined_value(rtype) == "NULL": # The simplest case. self.emit_line(f"Py_CLEAR({target});") else: assert False, "emit_gc_clear() not implemented for %s" % repr(rtype) def emit_traceback( self, source_path: str, module_name: str, traceback_entry: tuple[str, int] ) -> None: return self._emit_traceback("CPy_AddTraceback", source_path, module_name, traceback_entry) def emit_type_error_traceback( self, source_path: str, module_name: str, traceback_entry: tuple[str, int], *, typ: RType, src: str, ) -> None: func = "CPy_TypeErrorTraceback" type_str = f'"{self.pretty_name(typ)}"' return self._emit_traceback( func, source_path, module_name, traceback_entry, type_str=type_str, src=src ) def _emit_traceback( self, func: str, source_path: str, module_name: str, traceback_entry: tuple[str, int], type_str: str = "", src: str = "", ) -> None: globals_static = self.static_name("globals", module_name) line = '%s("%s", "%s", %d, %s' % ( func, source_path.replace("\\", "\\\\"), traceback_entry[0], traceback_entry[1], globals_static, ) if type_str: assert src line += f", {type_str}, {src}" line += ");" self.emit_line(line) if DEBUG_ERRORS: self.emit_line('assert(PyErr_Occurred() != NULL && "failure w/o err!");') def emit_unbox_failure_with_overlapping_error_value( self, dest: str, typ: RType, failure: str ) -> None: self.emit_line(f"if ({dest} == {self.c_error_value(typ)} && PyErr_Occurred()) {{") self.emit_line(failure) self.emit_line("}") def c_array_initializer(components: list[str], *, indented: bool = False) -> str: """Construct an initializer for a C array variable. Components are C expressions valid in an initializer. For example, if components are ["1", "2"], the result would be "{1, 2}", which can be used like this: int a[] = {1, 2}; If the result is long, split it into multiple lines. """ indent = " " * 4 if indented else "" res = [] current: list[str] = [] cur_len = 0 for c in components: if not current or cur_len + 2 + len(indent) + len(c) < 70: current.append(c) cur_len += len(c) + 2 else: res.append(indent + ", ".join(current)) current = [c] cur_len = len(c) if not res: # Result fits on a single line return "{%s}" % ", ".join(current) # Multi-line result res.append(indent + ", ".join(current)) return "{\n " + ",\n ".join(res) + "\n" + indent + "}"