Method emit_error_check

mypyc/codegen/emit.py:1273–1289

Emit code for checking a native function return value for uncaught exception.

(self, value: str, rtype: RType, failure: str)

            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 isinstance(rtype, RVec):
            self.emit_line(f"if ({value}.len < 0) {{")
        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.