3

g�wU�
�@s dd
lm
Z

dd�Zdd�ZdS)�
)
�c_astc
Cs�t|t
j�st�
t|jt
j�s"|St
jg|jj�}
d
}xh|jjD]\}t|t
jt
j	f�rz|
jj
|�

t||
j�
|
jd}q@|d
kr�|
jj
|�

q@|jj
|�

q@W|
|_|S)a� The 'case' statements in a 'switch' come out of parsing with one
        child node, so subsequent statements are just tucked to the parent
        Compound. Additionally, consecutive (fall-through) case statements
        come out messy. This is a peculiarity of the C grammar. The following:

            switch (myvar) {
                case 10:
                    k = 10;
                    p = k + 1;
                    return 10;
                case 20:
                case 30:
                    return 20;
                default:
                    break;
            }

        Creates this tree (pseudo-dump):

            Switch
                ID: myvar
                Compound:
                    Case 10:
                        k = 10
                    p = k + 1
                    return 10
                    Case 20:
                        Case 30:
                            return 20
                    Default:
                        break

        The goal of this transform it to fix this mess, turning it into the
        following:

            Switch
                ID: myvar
                Compound:
                    Case 10:
                        k = 10
                        p = k + 1
                        return 10
                    Case 20:
                    Case 30:
                        return 20
                    Default:
                        break

        A fixed AST node is returned. The argument may be modified.
    Nr
���)
�
isinstancerZSwitch�AssertionErrorZstmtZCompoundZcoordZblock_items�Case�Default�append�_extract_nested_case�stmts)Zswitch_nodeZnew_compoundZ	last_caseZchild�r�$/usr/lib/python3.6/ast_transforms.py�fix_switch_cases
s3






r
cCs:t|j
d
tjtjf�r6|
j|j
j��

t|
d|
�
dS)z� Recursively extract consecutive Case statements that are made nested
        by the parser and add them to the stmts_list.
    �r
Nr)rr
rrrr�popr	)Z	case_nodeZ
stmts_listrrrr	bs

r	N)�rr
r	rrrr�<module>
sU