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Empty Set Literal Notation for Python 2.7 [BUGFIX] Replaced minus sign with @ symbol. With the minus sign, Python couldn't handle any set notation that started with a negative (e.g. {-3} would fail).
>>> isinstance( {@}, set )
True
>>> len( {@} )
0
# Grammar for Python
# Note: Changing the grammar specified in this file will most likely
# require corresponding changes in the parser module
# (../Modules/parsermodule.c). If you can't make the changes to
# that module yourself, please co-ordinate the required changes
# with someone who can; ask around on python-dev for help. Fred
# Drake <fdrake@acm.org> will probably be listening there.
# NOTE WELL: You should also follow all the steps listed in PEP 306,
# "How to Change Python's Grammar"
# Start symbols for the grammar:
# single_input is a single interactive statement;
# file_input is a module or sequence of commands read from an input file;
# eval_input is the input for the eval() and input() functions.
# NB: compound_stmt in single_input is followed by extra NEWLINE!
single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
file_input: (NEWLINE | stmt)* ENDMARKER
eval_input: testlist NEWLINE* ENDMARKER
decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
decorators: decorator+
decorated: decorators (classdef | funcdef)
funcdef: 'def' NAME parameters ':' suite
parameters: '(' [varargslist] ')'
varargslist: ((fpdef ['=' test] ',')*
('*' NAME [',' '**' NAME] | '**' NAME) |
fpdef ['=' test] (',' fpdef ['=' test])* [','])
fpdef: NAME | '(' fplist ')'
fplist: fpdef (',' fpdef)* [',']
stmt: simple_stmt | compound_stmt
simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
small_stmt: (expr_stmt | print_stmt | del_stmt | pass_stmt | flow_stmt |
import_stmt | global_stmt | exec_stmt | assert_stmt)
expr_stmt: testlist (augassign (yield_expr|testlist) |
('=' (yield_expr|testlist))*)
augassign: ('+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' |
'<<=' | '>>=' | '**=' | '//=')
# For normal assignments, additional restrictions enforced by the interpreter
print_stmt: 'print' ( [ test (',' test)* [','] ] |
'>>' test [ (',' test)+ [','] ] )
del_stmt: 'del' exprlist
pass_stmt: 'pass'
flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
break_stmt: 'break'
continue_stmt: 'continue'
return_stmt: 'return' [testlist]
yield_stmt: yield_expr
raise_stmt: 'raise' [test [',' test [',' test]]]
import_stmt: import_name | import_from
import_name: 'import' dotted_as_names
import_from: ('from' ('.'* dotted_name | '.'+)
'import' ('*' | '(' import_as_names ')' | import_as_names))
import_as_name: NAME ['as' NAME]
dotted_as_name: dotted_name ['as' NAME]
import_as_names: import_as_name (',' import_as_name)* [',']
dotted_as_names: dotted_as_name (',' dotted_as_name)*
dotted_name: NAME ('.' NAME)*
global_stmt: 'global' NAME (',' NAME)*
exec_stmt: 'exec' expr ['in' test [',' test]]
assert_stmt: 'assert' test [',' test]
compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated
if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
while_stmt: 'while' test ':' suite ['else' ':' suite]
for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
try_stmt: ('try' ':' suite
((except_clause ':' suite)+
['else' ':' suite]
['finally' ':' suite] |
'finally' ':' suite))
with_stmt: 'with' with_item (',' with_item)* ':' suite
with_item: test ['as' expr]
# NB compile.c makes sure that the default except clause is last
except_clause: 'except' [test [('as' | ',') test]]
suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
# Backward compatibility cruft to support:
# [ x for x in lambda: True, lambda: False if x() ]
# even while also allowing:
# lambda x: 5 if x else 2
# (But not a mix of the two)
testlist_safe: old_test [(',' old_test)+ [',']]
old_test: or_test | old_lambdef
old_lambdef: 'lambda' [varargslist] ':' old_test
test: or_test ['if' or_test 'else' test] | lambdef
or_test: and_test ('or' and_test)*
and_test: not_test ('and' not_test)*
not_test: 'not' not_test | comparison
comparison: expr (comp_op expr)*
comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
expr: xor_expr ('|' xor_expr)*
xor_expr: and_expr ('^' and_expr)*
and_expr: shift_expr ('&' shift_expr)*
shift_expr: arith_expr (('<<'|'>>') arith_expr)*
arith_expr: term (('+'|'-') term)*
term: factor (('*'|'/'|'%'|'//') factor)*
factor: ('+'|'-'|'~') factor | power
power: atom trailer* ['**' factor]
atom: ('(' [yield_expr|testlist_comp] ')' |
'[' [listmaker] ']' |
'{' [dictorsetmaker] '}' |
'`' testlist1 '`' |
NAME | NUMBER | STRING+)
listmaker: test ( list_for | (',' test)* [','] )
testlist_comp: test ( comp_for | (',' test)* [','] )
lambdef: 'lambda' [varargslist] ':' test
trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
subscriptlist: subscript (',' subscript)* [',']
subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop]
sliceop: ':' [test]
exprlist: expr (',' expr)* [',']
testlist: test (',' test)* [',']
dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
('@') |
(test (comp_for | (',' test)* [','])) )
classdef: 'class' NAME ['(' [testlist] ')'] ':' suite
arglist: (argument ',')* (argument [',']
|'*' test (',' argument)* [',' '**' test]
|'**' test)
# The reason that keywords are test nodes instead of NAME is that using NAME
# results in an ambiguity. ast.c makes sure it's a NAME.
argument: test [comp_for] | test '=' test
list_iter: list_for | list_if
list_for: 'for' exprlist 'in' testlist_safe [list_iter]
list_if: 'if' old_test [list_iter]
comp_iter: comp_for | comp_if
comp_for: 'for' exprlist 'in' or_test [comp_iter]
comp_if: 'if' old_test [comp_iter]
testlist1: test (',' test)*
# not used in grammar, but may appear in "node" passed from Parser to Compiler
encoding_decl: NAME
yield_expr: 'yield' [testlist]
/*
* This file includes functions to transform a concrete syntax tree (CST) to
* an abstract syntax tree (AST). The main function is PyAST_FromNode().
*
*/
#include "Python.h"
#include "Python-ast.h"
#include "grammar.h"
#include "node.h"
#include "pyarena.h"
#include "ast.h"
#include "token.h"
#include "parsetok.h"
#include "graminit.h"
#include <assert.h>
/* Data structure used internally */
struct compiling {
char *c_encoding; /* source encoding */
int c_future_unicode; /* __future__ unicode literals flag */
PyArena *c_arena; /* arena for allocating memeory */
const char *c_filename; /* filename */
};
static asdl_seq *seq_for_testlist(struct compiling *, const node *);
static expr_ty ast_for_expr(struct compiling *, const node *);
static stmt_ty ast_for_stmt(struct compiling *, const node *);
static asdl_seq *ast_for_suite(struct compiling *, const node *);
static asdl_seq *ast_for_exprlist(struct compiling *, const node *,
expr_context_ty);
static expr_ty ast_for_testlist(struct compiling *, const node *);
static stmt_ty ast_for_classdef(struct compiling *, const node *, asdl_seq *);
static expr_ty ast_for_testlist_comp(struct compiling *, const node *);
/* Note different signature for ast_for_call */
static expr_ty ast_for_call(struct compiling *, const node *, expr_ty);
static PyObject *parsenumber(struct compiling *, const char *);
static PyObject *parsestr(struct compiling *, const char *);
static PyObject *parsestrplus(struct compiling *, const node *n);
#ifndef LINENO
#define LINENO(n) ((n)->n_lineno)
#endif
#define COMP_GENEXP 0
#define COMP_SETCOMP 1
static identifier
new_identifier(const char* n, PyArena *arena) {
PyObject* id = PyString_InternFromString(n);
if (id != NULL)
PyArena_AddPyObject(arena, id);
return id;
}
#define NEW_IDENTIFIER(n) new_identifier(STR(n), c->c_arena)
/* This routine provides an invalid object for the syntax error.
The outermost routine must unpack this error and create the
proper object. We do this so that we don't have to pass
the filename to everything function.
XXX Maybe we should just pass the filename...
*/
static int
ast_error(const node *n, const char *errstr)
{
PyObject *u = Py_BuildValue("zi", errstr, LINENO(n));
if (!u)
return 0;
PyErr_SetObject(PyExc_SyntaxError, u);
Py_DECREF(u);
return 0;
}
static void
ast_error_finish(const char *filename)
{
PyObject *type, *value, *tback, *errstr, *loc, *tmp;
long lineno;
assert(PyErr_Occurred());
if (!PyErr_ExceptionMatches(PyExc_SyntaxError))
return;
PyErr_Fetch(&type, &value, &tback);
errstr = PyTuple_GetItem(value, 0);
if (!errstr)
return;
Py_INCREF(errstr);
lineno = PyInt_AsLong(PyTuple_GetItem(value, 1));
if (lineno == -1) {
Py_DECREF(errstr);
return;
}
Py_DECREF(value);
loc = PyErr_ProgramText(filename, lineno);
if (!loc) {
Py_INCREF(Py_None);
loc = Py_None;
}
tmp = Py_BuildValue("(zlOO)", filename, lineno, Py_None, loc);
Py_DECREF(loc);
if (!tmp) {
Py_DECREF(errstr);
return;
}
value = PyTuple_Pack(2, errstr, tmp);
Py_DECREF(errstr);
Py_DECREF(tmp);
if (!value)
return;
PyErr_Restore(type, value, tback);
}
static int
ast_warn(struct compiling *c, const node *n, char *msg)
{
if (PyErr_WarnExplicit(PyExc_SyntaxWarning, msg, c->c_filename, LINENO(n),
NULL, NULL) < 0) {
/* if -Werr, change it to a SyntaxError */
if (PyErr_Occurred() && PyErr_ExceptionMatches(PyExc_SyntaxWarning))
ast_error(n, msg);
return 0;
}
return 1;
}
static int
forbidden_check(struct compiling *c, const node *n, const char *x)
{
if (!strcmp(x, "None"))
return ast_error(n, "cannot assign to None");
if (!strcmp(x, "__debug__"))
return ast_error(n, "cannot assign to __debug__");
if (Py_Py3kWarningFlag) {
if (!(strcmp(x, "True") && strcmp(x, "False")) &&
!ast_warn(c, n, "assignment to True or False is forbidden in 3.x"))
return 0;
if (!strcmp(x, "nonlocal") &&
!ast_warn(c, n, "nonlocal is a keyword in 3.x"))
return 0;
}
return 1;
}
/* num_stmts() returns number of contained statements.
Use this routine to determine how big a sequence is needed for
the statements in a parse tree. Its raison d'etre is this bit of
grammar:
stmt: simple_stmt | compound_stmt
simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
A simple_stmt can contain multiple small_stmt elements joined
by semicolons. If the arg is a simple_stmt, the number of
small_stmt elements is returned.
*/
static int
num_stmts(const node *n)
{
int i, l;
node *ch;
switch (TYPE(n)) {
case single_input:
if (TYPE(CHILD(n, 0)) == NEWLINE)
return 0;
else
return num_stmts(CHILD(n, 0));
case file_input:
l = 0;
for (i = 0; i < NCH(n); i++) {
ch = CHILD(n, i);
if (TYPE(ch) == stmt)
l += num_stmts(ch);
}
return l;
case stmt:
return num_stmts(CHILD(n, 0));
case compound_stmt:
return 1;
case simple_stmt:
return NCH(n) / 2; /* Divide by 2 to remove count of semi-colons */
case suite:
if (NCH(n) == 1)
return num_stmts(CHILD(n, 0));
else {
l = 0;
for (i = 2; i < (NCH(n) - 1); i++)
l += num_stmts(CHILD(n, i));
return l;
}
default: {
char buf[128];
sprintf(buf, "Non-statement found: %d %d",
TYPE(n), NCH(n));
Py_FatalError(buf);
}
}
assert(0);
return 0;
}
/* Transform the CST rooted at node * to the appropriate AST
*/
mod_ty
PyAST_FromNode(const node *n, PyCompilerFlags *flags, const char *filename,
PyArena *arena)
{
int i, j, k, num;
asdl_seq *stmts = NULL;
stmt_ty s;
node *ch;
struct compiling c;
if (flags && flags->cf_flags & PyCF_SOURCE_IS_UTF8) {
c.c_encoding = "utf-8";
if (TYPE(n) == encoding_decl) {
ast_error(n, "encoding declaration in Unicode string");
goto error;
}
} else if (TYPE(n) == encoding_decl) {
c.c_encoding = STR(n);
n = CHILD(n, 0);
} else {
c.c_encoding = NULL;
}
c.c_future_unicode = flags && flags->cf_flags & CO_FUTURE_UNICODE_LITERALS;
c.c_arena = arena;
c.c_filename = filename;
k = 0;
switch (TYPE(n)) {
case file_input:
stmts = asdl_seq_new(num_stmts(n), arena);
if (!stmts)
return NULL;
for (i = 0; i < NCH(n) - 1; i++) {
ch = CHILD(n, i);
if (TYPE(ch) == NEWLINE)
continue;
REQ(ch, stmt);
num = num_stmts(ch);
if (num == 1) {
s = ast_for_stmt(&c, ch);
if (!s)
goto error;
asdl_seq_SET(stmts, k++, s);
}
else {
ch = CHILD(ch, 0);
REQ(ch, simple_stmt);
for (j = 0; j < num; j++) {
s = ast_for_stmt(&c, CHILD(ch, j * 2));
if (!s)
goto error;
asdl_seq_SET(stmts, k++, s);
}
}
}
return Module(stmts, arena);
case eval_input: {
expr_ty testlist_ast;
/* XXX Why not comp_for here? */
testlist_ast = ast_for_testlist(&c, CHILD(n, 0));
if (!testlist_ast)
goto error;
return Expression(testlist_ast, arena);
}
case single_input:
if (TYPE(CHILD(n, 0)) == NEWLINE) {
stmts = asdl_seq_new(1, arena);
if (!stmts)
goto error;
asdl_seq_SET(stmts, 0, Pass(n->n_lineno, n->n_col_offset,
arena));
if (!asdl_seq_GET(stmts, 0))
goto error;
return Interactive(stmts, arena);
}
else {
n = CHILD(n, 0);
num = num_stmts(n);
stmts = asdl_seq_new(num, arena);
if (!stmts)
goto error;
if (num == 1) {
s = ast_for_stmt(&c, n);
if (!s)
goto error;
asdl_seq_SET(stmts, 0, s);
}
else {
/* Only a simple_stmt can contain multiple statements. */
REQ(n, simple_stmt);
for (i = 0; i < NCH(n); i += 2) {
if (TYPE(CHILD(n, i)) == NEWLINE)
break;
s = ast_for_stmt(&c, CHILD(n, i));
if (!s)
goto error;
asdl_seq_SET(stmts, i / 2, s);
}
}
return Interactive(stmts, arena);
}
default:
PyErr_Format(PyExc_SystemError,
"invalid node %d for PyAST_FromNode", TYPE(n));
goto error;
}
error:
ast_error_finish(filename);
return NULL;
}
/* Return the AST repr. of the operator represented as syntax (|, ^, etc.)
*/
static operator_ty
get_operator(const node *n)
{
switch (TYPE(n)) {
case VBAR:
return BitOr;
case CIRCUMFLEX:
return BitXor;
case AMPER:
return BitAnd;
case LEFTSHIFT:
return LShift;
case RIGHTSHIFT:
return RShift;
case PLUS:
return Add;
case MINUS:
return Sub;
case STAR:
return Mult;
case SLASH:
return Div;
case DOUBLESLASH:
return FloorDiv;
case PERCENT:
return Mod;
default:
return (operator_ty)0;
}
}
/* Set the context ctx for expr_ty e, recursively traversing e.
Only sets context for expr kinds that "can appear in assignment context"
(according to ../Parser/Python.asdl). For other expr kinds, it sets
an appropriate syntax error and returns false.
*/
static int
set_context(struct compiling *c, expr_ty e, expr_context_ty ctx, const node *n)
{
asdl_seq *s = NULL;
/* If a particular expression type can't be used for assign / delete,
set expr_name to its name and an error message will be generated.
*/
const char* expr_name = NULL;
/* The ast defines augmented store and load contexts, but the
implementation here doesn't actually use them. The code may be
a little more complex than necessary as a result. It also means
that expressions in an augmented assignment have a Store context.
Consider restructuring so that augmented assignment uses
set_context(), too.
*/
assert(ctx != AugStore && ctx != AugLoad);
switch (e->kind) {
case Attribute_kind:
if (ctx == Store && !forbidden_check(c, n,
PyBytes_AS_STRING(e->v.Attribute.attr)))
return 0;
e->v.Attribute.ctx = ctx;
break;
case Subscript_kind:
e->v.Subscript.ctx = ctx;
break;
case Name_kind:
if (ctx == Store && !forbidden_check(c, n,
PyBytes_AS_STRING(e->v.Name.id)))
return 0;
e->v.Name.ctx = ctx;
break;
case List_kind:
e->v.List.ctx = ctx;
s = e->v.List.elts;
break;
case Tuple_kind:
if (asdl_seq_LEN(e->v.Tuple.elts)) {
e->v.Tuple.ctx = ctx;
s = e->v.Tuple.elts;
}
else {
expr_name = "()";
}
break;
case Lambda_kind:
expr_name = "lambda";
break;
case Call_kind:
expr_name = "function call";
break;
case BoolOp_kind:
case BinOp_kind:
case UnaryOp_kind:
expr_name = "operator";
break;
case GeneratorExp_kind:
expr_name = "generator expression";
break;
case Yield_kind:
expr_name = "yield expression";
break;
case ListComp_kind:
expr_name = "list comprehension";
break;
case SetComp_kind:
expr_name = "set comprehension";
break;
case DictComp_kind:
expr_name = "dict comprehension";
break;
case Dict_kind:
case Set_kind:
case Num_kind:
case Str_kind:
expr_name = "literal";
break;
case Compare_kind:
expr_name = "comparison";
break;
case Repr_kind:
expr_name = "repr";
break;
case IfExp_kind:
expr_name = "conditional expression";
break;
default:
PyErr_Format(PyExc_SystemError,
"unexpected expression in assignment %d (line %d)",
e->kind, e->lineno);
return 0;
}
/* Check for error string set by switch */
if (expr_name) {
char buf[300];
PyOS_snprintf(buf, sizeof(buf),
"can't %s %s",
ctx == Store ? "assign to" : "delete",
expr_name);
return ast_error(n, buf);
}
/* If the LHS is a list or tuple, we need to set the assignment
context for all the contained elements.
*/
if (s) {
int i;
for (i = 0; i < asdl_seq_LEN(s); i++) {
if (!set_context(c, (expr_ty)asdl_seq_GET(s, i), ctx, n))
return 0;
}
}
return 1;
}
static operator_ty
ast_for_augassign(struct compiling *c, const node *n)
{
REQ(n, augassign);
n = CHILD(n, 0);
switch (STR(n)[0]) {
case '+':
return Add;
case '-':
return Sub;
case '/':
if (STR(n)[1] == '/')
return FloorDiv;
else
return Div;
case '%':
return Mod;
case '<':
return LShift;
case '>':
return RShift;
case '&':
return BitAnd;
case '^':
return BitXor;
case '|':
return BitOr;
case '*':
if (STR(n)[1] == '*')
return Pow;
else
return Mult;
default:
PyErr_Format(PyExc_SystemError, "invalid augassign: %s", STR(n));
return (operator_ty)0;
}
}
static cmpop_ty
ast_for_comp_op(struct compiling *c, const node *n)
{
/* comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'
|'is' 'not'
*/
REQ(n, comp_op);
if (NCH(n) == 1) {
n = CHILD(n, 0);
switch (TYPE(n)) {
case LESS:
return Lt;
case GREATER:
return Gt;
case EQEQUAL: /* == */
return Eq;
case LESSEQUAL:
return LtE;
case GREATEREQUAL:
return GtE;
case NOTEQUAL:
return NotEq;
case NAME:
if (strcmp(STR(n), "in") == 0)
return In;
if (strcmp(STR(n), "is") == 0)
return Is;
default:
PyErr_Format(PyExc_SystemError, "invalid comp_op: %s",
STR(n));
return (cmpop_ty)0;
}
}
else if (NCH(n) == 2) {
/* handle "not in" and "is not" */
switch (TYPE(CHILD(n, 0))) {
case NAME:
if (strcmp(STR(CHILD(n, 1)), "in") == 0)
return NotIn;
if (strcmp(STR(CHILD(n, 0)), "is") == 0)
return IsNot;
default:
PyErr_Format(PyExc_SystemError, "invalid comp_op: %s %s",
STR(CHILD(n, 0)), STR(CHILD(n, 1)));
return (cmpop_ty)0;
}
}
PyErr_Format(PyExc_SystemError, "invalid comp_op: has %d children",
NCH(n));
return (cmpop_ty)0;
}
static asdl_seq *
seq_for_testlist(struct compiling *c, const node *n)
{
/* testlist: test (',' test)* [','] */
asdl_seq *seq;
expr_ty expression;
int i;
assert(TYPE(n) == testlist ||
TYPE(n) == listmaker ||
TYPE(n) == testlist_comp ||
TYPE(n) == testlist_safe ||
TYPE(n) == testlist1);
seq = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
if (!seq)
return NULL;
for (i = 0; i < NCH(n); i += 2) {
assert(TYPE(CHILD(n, i)) == test || TYPE(CHILD(n, i)) == old_test);
expression = ast_for_expr(c, CHILD(n, i));
if (!expression)
return NULL;
assert(i / 2 < seq->size);
asdl_seq_SET(seq, i / 2, expression);
}
return seq;
}
static expr_ty
compiler_complex_args(struct compiling *c, const node *n)
{
int i, len = (NCH(n) + 1) / 2;
expr_ty result;
asdl_seq *args = asdl_seq_new(len, c->c_arena);
if (!args)
return NULL;
/* fpdef: NAME | '(' fplist ')'
fplist: fpdef (',' fpdef)* [',']
*/
REQ(n, fplist);
for (i = 0; i < len; i++) {
PyObject *arg_id;
const node *fpdef_node = CHILD(n, 2*i);
const node *child;
expr_ty arg;
set_name:
/* fpdef_node is either a NAME or an fplist */
child = CHILD(fpdef_node, 0);
if (TYPE(child) == NAME) {
if (!forbidden_check(c, n, STR(child)))
return NULL;
arg_id = NEW_IDENTIFIER(child);
if (!arg_id)
return NULL;
arg = Name(arg_id, Store, LINENO(child), child->n_col_offset,
c->c_arena);
}
else {
assert(TYPE(fpdef_node) == fpdef);
/* fpdef_node[0] is not a name, so it must be '(', get CHILD[1] */
child = CHILD(fpdef_node, 1);
assert(TYPE(child) == fplist);
/* NCH == 1 means we have (x), we need to elide the extra parens */
if (NCH(child) == 1) {
fpdef_node = CHILD(child, 0);
assert(TYPE(fpdef_node) == fpdef);
goto set_name;
}
arg = compiler_complex_args(c, child);
}
asdl_seq_SET(args, i, arg);
}
result = Tuple(args, Store, LINENO(n), n->n_col_offset, c->c_arena);
if (!set_context(c, result, Store, n))
return NULL;
return result;
}
/* Create AST for argument list. */
static arguments_ty
ast_for_arguments(struct compiling *c, const node *n)
{
/* parameters: '(' [varargslist] ')'
varargslist: (fpdef ['=' test] ',')* ('*' NAME [',' '**' NAME]
| '**' NAME) | fpdef ['=' test] (',' fpdef ['=' test])* [',']
*/
int i, j, k, n_args = 0, n_defaults = 0, found_default = 0;
asdl_seq *args, *defaults;
identifier vararg = NULL, kwarg = NULL;
node *ch;
if (TYPE(n) == parameters) {
if (NCH(n) == 2) /* () as argument list */
return arguments(NULL, NULL, NULL, NULL, c->c_arena);
n = CHILD(n, 1);
}
REQ(n, varargslist);
/* first count the number of normal args & defaults */
for (i = 0; i < NCH(n); i++) {
ch = CHILD(n, i);
if (TYPE(ch) == fpdef)
n_args++;
if (TYPE(ch) == EQUAL)
n_defaults++;
}
args = (n_args ? asdl_seq_new(n_args, c->c_arena) : NULL);
if (!args && n_args)
return NULL;
defaults = (n_defaults ? asdl_seq_new(n_defaults, c->c_arena) : NULL);
if (!defaults && n_defaults)
return NULL;
/* fpdef: NAME | '(' fplist ')'
fplist: fpdef (',' fpdef)* [',']
*/
i = 0;
j = 0; /* index for defaults */
k = 0; /* index for args */
while (i < NCH(n)) {
ch = CHILD(n, i);
switch (TYPE(ch)) {
case fpdef: {
int complex_args = 0, parenthesized = 0;
handle_fpdef:
/* XXX Need to worry about checking if TYPE(CHILD(n, i+1)) is
anything other than EQUAL or a comma? */
/* XXX Should NCH(n) check be made a separate check? */
if (i + 1 < NCH(n) && TYPE(CHILD(n, i + 1)) == EQUAL) {
expr_ty expression = ast_for_expr(c, CHILD(n, i + 2));
if (!expression)
return NULL;
assert(defaults != NULL);
asdl_seq_SET(defaults, j++, expression);
i += 2;
found_default = 1;
}
else if (found_default) {
/* def f((x)=4): pass should raise an error.
def f((x, (y))): pass will just incur the tuple unpacking warning. */
if (parenthesized && !complex_args) {
ast_error(n, "parenthesized arg with default");
return NULL;
}
ast_error(n,
"non-default argument follows default argument");
return NULL;
}
if (NCH(ch) == 3) {
ch = CHILD(ch, 1);
/* def foo((x)): is not complex, special case. */
if (NCH(ch) != 1) {
/* We have complex arguments, setup for unpacking. */
if (Py_Py3kWarningFlag && !ast_warn(c, ch,
"tuple parameter unpacking has been removed in 3.x"))
return NULL;
complex_args = 1;
asdl_seq_SET(args, k++, compiler_complex_args(c, ch));
if (!asdl_seq_GET(args, k-1))
return NULL;
} else {
/* def foo((x)): setup for checking NAME below. */
/* Loop because there can be many parens and tuple
unpacking mixed in. */
parenthesized = 1;
ch = CHILD(ch, 0);
assert(TYPE(ch) == fpdef);
goto handle_fpdef;
}
}
if (TYPE(CHILD(ch, 0)) == NAME) {
PyObject *id;
expr_ty name;
if (!forbidden_check(c, n, STR(CHILD(ch, 0))))
return NULL;
id = NEW_IDENTIFIER(CHILD(ch, 0));
if (!id)
return NULL;
name = Name(id, Param, LINENO(ch), ch->n_col_offset,
c->c_arena);
if (!name)
return NULL;
asdl_seq_SET(args, k++, name);
}
i += 2; /* the name and the comma */
if (parenthesized && Py_Py3kWarningFlag &&
!ast_warn(c, ch, "parenthesized argument names "
"are invalid in 3.x"))
return NULL;
break;
}
case STAR:
if (!forbidden_check(c, CHILD(n, i+1), STR(CHILD(n, i+1))))
return NULL;
vararg = NEW_IDENTIFIER(CHILD(n, i+1));
if (!vararg)
return NULL;
i += 3;
break;
case DOUBLESTAR:
if (!forbidden_check(c, CHILD(n, i+1), STR(CHILD(n, i+1))))
return NULL;
kwarg = NEW_IDENTIFIER(CHILD(n, i+1));
if (!kwarg)
return NULL;
i += 3;
break;
default:
PyErr_Format(PyExc_SystemError,
"unexpected node in varargslist: %d @ %d",
TYPE(ch), i);
return NULL;
}
}
return arguments(args, vararg, kwarg, defaults, c->c_arena);
}
static expr_ty
ast_for_dotted_name(struct compiling *c, const node *n)
{
expr_ty e;
identifier id;
int lineno, col_offset;
int i;
REQ(n, dotted_name);
lineno = LINENO(n);
col_offset = n->n_col_offset;
id = NEW_IDENTIFIER(CHILD(n, 0));
if (!id)
return NULL;
e = Name(id, Load, lineno, col_offset, c->c_arena);
if (!e)
return NULL;
for (i = 2; i < NCH(n); i+=2) {
id = NEW_IDENTIFIER(CHILD(n, i));
if (!id)
return NULL;
e = Attribute(e, id, Load, lineno, col_offset, c->c_arena);
if (!e)
return NULL;
}
return e;
}
static expr_ty
ast_for_decorator(struct compiling *c, const node *n)
{
/* decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE */
expr_ty d = NULL;
expr_ty name_expr;
REQ(n, decorator);
REQ(CHILD(n, 0), AT);
REQ(RCHILD(n, -1), NEWLINE);
name_expr = ast_for_dotted_name(c, CHILD(n, 1));
if (!name_expr)
return NULL;
if (NCH(n) == 3) { /* No arguments */
d = name_expr;
name_expr = NULL;
}
else if (NCH(n) == 5) { /* Call with no arguments */
d = Call(name_expr, NULL, NULL, NULL, NULL, LINENO(n),
n->n_col_offset, c->c_arena);
if (!d)
return NULL;
name_expr = NULL;
}
else {
d = ast_for_call(c, CHILD(n, 3), name_expr);
if (!d)
return NULL;
name_expr = NULL;
}
return d;
}
static asdl_seq*
ast_for_decorators(struct compiling *c, const node *n)
{
asdl_seq* decorator_seq;
expr_ty d;
int i;
REQ(n, decorators);
decorator_seq = asdl_seq_new(NCH(n), c->c_arena);
if (!decorator_seq)
return NULL;
for (i = 0; i < NCH(n); i++) {
d = ast_for_decorator(c, CHILD(n, i));
if (!d)
return NULL;
asdl_seq_SET(decorator_seq, i, d);
}
return decorator_seq;
}
static stmt_ty
ast_for_funcdef(struct compiling *c, const node *n, asdl_seq *decorator_seq)
{
/* funcdef: 'def' NAME parameters ':' suite */
identifier name;
arguments_ty args;
asdl_seq *body;
int name_i = 1;
REQ(n, funcdef);
name = NEW_IDENTIFIER(CHILD(n, name_i));
if (!name)
return NULL;
else if (!forbidden_check(c, CHILD(n, name_i), STR(CHILD(n, name_i))))
return NULL;
args = ast_for_arguments(c, CHILD(n, name_i + 1));
if (!args)
return NULL;
body = ast_for_suite(c, CHILD(n, name_i + 3));
if (!body)
return NULL;
return FunctionDef(name, args, body, decorator_seq, LINENO(n),
n->n_col_offset, c->c_arena);
}
static stmt_ty
ast_for_decorated(struct compiling *c, const node *n)
{
/* decorated: decorators (classdef | funcdef) */
stmt_ty thing = NULL;
asdl_seq *decorator_seq = NULL;
REQ(n, decorated);
decorator_seq = ast_for_decorators(c, CHILD(n, 0));
if (!decorator_seq)
return NULL;
assert(TYPE(CHILD(n, 1)) == funcdef ||
TYPE(CHILD(n, 1)) == classdef);
if (TYPE(CHILD(n, 1)) == funcdef) {
thing = ast_for_funcdef(c, CHILD(n, 1), decorator_seq);
} else if (TYPE(CHILD(n, 1)) == classdef) {
thing = ast_for_classdef(c, CHILD(n, 1), decorator_seq);
}
/* we count the decorators in when talking about the class' or
function's line number */
if (thing) {
thing->lineno = LINENO(n);
thing->col_offset = n->n_col_offset;
}
return thing;
}
static expr_ty
ast_for_lambdef(struct compiling *c, const node *n)
{
/* lambdef: 'lambda' [varargslist] ':' test */
arguments_ty args;
expr_ty expression;
if (NCH(n) == 3) {
args = arguments(NULL, NULL, NULL, NULL, c->c_arena);
if (!args)
return NULL;
expression = ast_for_expr(c, CHILD(n, 2));
if (!expression)
return NULL;
}
else {
args = ast_for_arguments(c, CHILD(n, 1));
if (!args)
return NULL;
expression = ast_for_expr(c, CHILD(n, 3));
if (!expression)
return NULL;
}
return Lambda(args, expression, LINENO(n), n->n_col_offset, c->c_arena);
}
static expr_ty
ast_for_ifexpr(struct compiling *c, const node *n)
{
/* test: or_test 'if' or_test 'else' test */
expr_ty expression, body, orelse;
assert(NCH(n) == 5);
body = ast_for_expr(c, CHILD(n, 0));
if (!body)
return NULL;
expression = ast_for_expr(c, CHILD(n, 2));
if (!expression)
return NULL;
orelse = ast_for_expr(c, CHILD(n, 4));
if (!orelse)
return NULL;
return IfExp(expression, body, orelse, LINENO(n), n->n_col_offset,
c->c_arena);
}
/* XXX(nnorwitz): the listcomp and genexpr code should be refactored
so there is only a single version. Possibly for loops can also re-use
the code.
*/
/* Count the number of 'for' loop in a list comprehension.
Helper for ast_for_listcomp().
*/
static int
count_list_fors(struct compiling *c, const node *n)
{
int n_fors = 0;
node *ch = CHILD(n, 1);
count_list_for:
n_fors++;
REQ(ch, list_for);
if (NCH(ch) == 5)
ch = CHILD(ch, 4);
else
return n_fors;
count_list_iter:
REQ(ch, list_iter);
ch = CHILD(ch, 0);
if (TYPE(ch) == list_for)
goto count_list_for;
else if (TYPE(ch) == list_if) {
if (NCH(ch) == 3) {
ch = CHILD(ch, 2);
goto count_list_iter;
}
else
return n_fors;
}
/* Should never be reached */
PyErr_SetString(PyExc_SystemError, "logic error in count_list_fors");
return -1;
}
/* Count the number of 'if' statements in a list comprehension.
Helper for ast_for_listcomp().
*/
static int
count_list_ifs(struct compiling *c, const node *n)
{
int n_ifs = 0;
count_list_iter:
REQ(n, list_iter);
if (TYPE(CHILD(n, 0)) == list_for)
return n_ifs;
n = CHILD(n, 0);
REQ(n, list_if);
n_ifs++;
if (NCH(n) == 2)
return n_ifs;
n = CHILD(n, 2);
goto count_list_iter;
}
static expr_ty
ast_for_listcomp(struct compiling *c, const node *n)
{
/* listmaker: test ( list_for | (',' test)* [','] )
list_for: 'for' exprlist 'in' testlist_safe [list_iter]
list_iter: list_for | list_if
list_if: 'if' test [list_iter]
testlist_safe: test [(',' test)+ [',']]
*/
expr_ty elt, first;
asdl_seq *listcomps;
int i, n_fors;
node *ch;
REQ(n, listmaker);
assert(NCH(n) > 1);
elt = ast_for_expr(c, CHILD(n, 0));
if (!elt)
return NULL;
n_fors = count_list_fors(c, n);
if (n_fors == -1)
return NULL;
listcomps = asdl_seq_new(n_fors, c->c_arena);
if (!listcomps)
return NULL;
ch = CHILD(n, 1);
for (i = 0; i < n_fors; i++) {
comprehension_ty lc;
asdl_seq *t;
expr_ty expression;
node *for_ch;
REQ(ch, list_for);
for_ch = CHILD(ch, 1);
t = ast_for_exprlist(c, for_ch, Store);
if (!t)
return NULL;
expression = ast_for_testlist(c, CHILD(ch, 3));
if (!expression)
return NULL;
/* Check the # of children rather than the length of t, since
[x for x, in ... ] has 1 element in t, but still requires a Tuple.
*/
first = (expr_ty)asdl_seq_GET(t, 0);
if (NCH(for_ch) == 1)
lc = comprehension(first, expression, NULL, c->c_arena);
else
lc = comprehension(Tuple(t, Store, first->lineno, first->col_offset,
c->c_arena),
expression, NULL, c->c_arena);
if (!lc)
return NULL;
if (NCH(ch) == 5) {
int j, n_ifs;
asdl_seq *ifs;
expr_ty list_for_expr;
ch = CHILD(ch, 4);
n_ifs = count_list_ifs(c, ch);
if (n_ifs == -1)
return NULL;
ifs = asdl_seq_new(n_ifs, c->c_arena);
if (!ifs)
return NULL;
for (j = 0; j < n_ifs; j++) {
REQ(ch, list_iter);
ch = CHILD(ch, 0);
REQ(ch, list_if);
list_for_expr = ast_for_expr(c, CHILD(ch, 1));
if (!list_for_expr)
return NULL;
asdl_seq_SET(ifs, j, list_for_expr);
if (NCH(ch) == 3)
ch = CHILD(ch, 2);
}
/* on exit, must guarantee that ch is a list_for */
if (TYPE(ch) == list_iter)
ch = CHILD(ch, 0);
lc->ifs = ifs;
}
asdl_seq_SET(listcomps, i, lc);
}
return ListComp(elt, listcomps, LINENO(n), n->n_col_offset, c->c_arena);
}
/*
Count the number of 'for' loops in a comprehension.
Helper for ast_for_comprehension().
*/
static int
count_comp_fors(struct compiling *c, const node *n)
{
int n_fors = 0;
count_comp_for:
n_fors++;
REQ(n, comp_for);
if (NCH(n) == 5)
n = CHILD(n, 4);
else
return n_fors;
count_comp_iter:
REQ(n, comp_iter);
n = CHILD(n, 0);
if (TYPE(n) == comp_for)
goto count_comp_for;
else if (TYPE(n) == comp_if) {
if (NCH(n) == 3) {
n = CHILD(n, 2);
goto count_comp_iter;
}
else
return n_fors;
}
/* Should never be reached */
PyErr_SetString(PyExc_SystemError,
"logic error in count_comp_fors");
return -1;
}
/* Count the number of 'if' statements in a comprehension.
Helper for ast_for_comprehension().
*/
static int
count_comp_ifs(struct compiling *c, const node *n)
{
int n_ifs = 0;
while (1) {
REQ(n, comp_iter);
if (TYPE(CHILD(n, 0)) == comp_for)
return n_ifs;
n = CHILD(n, 0);
REQ(n, comp_if);
n_ifs++;
if (NCH(n) == 2)
return n_ifs;
n = CHILD(n, 2);
}
}
static asdl_seq *
ast_for_comprehension(struct compiling *c, const node *n)
{
int i, n_fors;
asdl_seq *comps;
n_fors = count_comp_fors(c, n);
if (n_fors == -1)
return NULL;
comps = asdl_seq_new(n_fors, c->c_arena);
if (!comps)
return NULL;
for (i = 0; i < n_fors; i++) {
comprehension_ty comp;
asdl_seq *t;
expr_ty expression, first;
node *for_ch;
REQ(n, comp_for);
for_ch = CHILD(n, 1);
t = ast_for_exprlist(c, for_ch, Store);
if (!t)
return NULL;
expression = ast_for_expr(c, CHILD(n, 3));
if (!expression)
return NULL;
/* Check the # of children rather than the length of t, since
(x for x, in ...) has 1 element in t, but still requires a Tuple. */
first = (expr_ty)asdl_seq_GET(t, 0);
if (NCH(for_ch) == 1)
comp = comprehension(first, expression, NULL, c->c_arena);
else
comp = comprehension(Tuple(t, Store, first->lineno, first->col_offset,
c->c_arena),
expression, NULL, c->c_arena);
if (!comp)
return NULL;
if (NCH(n) == 5) {
int j, n_ifs;
asdl_seq *ifs;
n = CHILD(n, 4);
n_ifs = count_comp_ifs(c, n);
if (n_ifs == -1)
return NULL;
ifs = asdl_seq_new(n_ifs, c->c_arena);
if (!ifs)
return NULL;
for (j = 0; j < n_ifs; j++) {
REQ(n, comp_iter);
n = CHILD(n, 0);
REQ(n, comp_if);
expression = ast_for_expr(c, CHILD(n, 1));
if (!expression)
return NULL;
asdl_seq_SET(ifs, j, expression);
if (NCH(n) == 3)
n = CHILD(n, 2);
}
/* on exit, must guarantee that n is a comp_for */
if (TYPE(n) == comp_iter)
n = CHILD(n, 0);
comp->ifs = ifs;
}
asdl_seq_SET(comps, i, comp);
}
return comps;
}
static expr_ty
ast_for_itercomp(struct compiling *c, const node *n, int type)
{
expr_ty elt;
asdl_seq *comps;
assert(NCH(n) > 1);
elt = ast_for_expr(c, CHILD(n, 0));
if (!elt)
return NULL;
comps = ast_for_comprehension(c, CHILD(n, 1));
if (!comps)
return NULL;
if (type == COMP_GENEXP)
return GeneratorExp(elt, comps, LINENO(n), n->n_col_offset, c->c_arena);
else if (type == COMP_SETCOMP)
return SetComp(elt, comps, LINENO(n), n->n_col_offset, c->c_arena);
else
/* Should never happen */
return NULL;
}
static expr_ty
ast_for_dictcomp(struct compiling *c, const node *n)
{
expr_ty key, value;
asdl_seq *comps;
assert(NCH(n) > 3);
REQ(CHILD(n, 1), COLON);
key = ast_for_expr(c, CHILD(n, 0));
if (!key)
return NULL;
value = ast_for_expr(c, CHILD(n, 2));
if (!value)
return NULL;
comps = ast_for_comprehension(c, CHILD(n, 3));
if (!comps)
return NULL;
return DictComp(key, value, comps, LINENO(n), n->n_col_offset, c->c_arena);
}
static expr_ty
ast_for_genexp(struct compiling *c, const node *n)
{
assert(TYPE(n) == (testlist_comp) || TYPE(n) == (argument));
return ast_for_itercomp(c, n, COMP_GENEXP);
}
static expr_ty
ast_for_setcomp(struct compiling *c, const node *n)
{
assert(TYPE(n) == (dictorsetmaker));
return ast_for_itercomp(c, n, COMP_SETCOMP);
}
static expr_ty
ast_for_atom(struct compiling *c, const node *n)
{
/* atom: '(' [yield_expr|testlist_comp] ')' | '[' [listmaker] ']'
| '{' [dictmaker] '}' | '`' testlist '`' | NAME | NUMBER | STRING+
*/
node *ch = CHILD(n, 0);
switch (TYPE(ch)) {
case NAME: {
/* All names start in Load context, but may later be
changed. */
PyObject *name = NEW_IDENTIFIER(ch);
if (!name)
return NULL;
return Name(name, Load, LINENO(n), n->n_col_offset, c->c_arena);
}
case STRING: {
PyObject *str = parsestrplus(c, n);
if (!str) {
#ifdef Py_USING_UNICODE
if (PyErr_ExceptionMatches(PyExc_UnicodeError)){
PyObject *type, *value, *tback, *errstr;
PyErr_Fetch(&type, &value, &tback);
errstr = PyObject_Str(value);
if (errstr) {
char *s = "";
char buf[128];
s = PyString_AsString(errstr);
PyOS_snprintf(buf, sizeof(buf), "(unicode error) %s", s);
ast_error(n, buf);
Py_DECREF(errstr);
} else {
ast_error(n, "(unicode error) unknown error");
}
Py_DECREF(type);
Py_DECREF(value);
Py_XDECREF(tback);
}
#endif
return NULL;
}
PyArena_AddPyObject(c->c_arena, str);
return Str(str, LINENO(n), n->n_col_offset, c->c_arena);
}
case NUMBER: {
PyObject *pynum = parsenumber(c, STR(ch));
if (!pynum)
return NULL;
PyArena_AddPyObject(c->c_arena, pynum);
return Num(pynum, LINENO(n), n->n_col_offset, c->c_arena);
}
case LPAR: /* some parenthesized expressions */
ch = CHILD(n, 1);
if (TYPE(ch) == RPAR)
return Tuple(NULL, Load, LINENO(n), n->n_col_offset, c->c_arena);
if (TYPE(ch) == yield_expr)
return ast_for_expr(c, ch);
return ast_for_testlist_comp(c, ch);
case LSQB: /* list (or list comprehension) */
ch = CHILD(n, 1);
if (TYPE(ch) == RSQB)
return List(NULL, Load, LINENO(n), n->n_col_offset, c->c_arena);
REQ(ch, listmaker);
if (NCH(ch) == 1 || TYPE(CHILD(ch, 1)) == COMMA) {
asdl_seq *elts = seq_for_testlist(c, ch);
if (!elts)
return NULL;
return List(elts, Load, LINENO(n), n->n_col_offset, c->c_arena);
}
else
return ast_for_listcomp(c, ch);
case LBRACE: {
/* dictorsetmaker:
* (test ':' test (comp_for | (',' test ':' test)* [','])) |
* ('@') |
* (test (comp_for | (',' test)* [',']))
*/
int i, size;
asdl_seq *keys, *values;
ch = CHILD(n, 1);
if (TYPE(ch) == RBRACE) {
/* it's an empty dict */
return Dict(NULL, NULL, LINENO(n), n->n_col_offset, c->c_arena);
} else if (NCH(ch) == 1 || TYPE(CHILD(ch, 1)) == COMMA) {
/* is it the empty set {-}? */
if (NCH(ch) == 1 && TYPE(CHILD(ch, 0)) == AT)
return Set(NULL, LINENO(n), n->n_col_offset, c->c_arena);
/* it's a simple set */
asdl_seq *elts;
size = (NCH(ch) + 1) / 2; /* +1 in case no trailing comma */
elts = asdl_seq_new(size, c->c_arena);
if (!elts)
return NULL;
for (i = 0; i < NCH(ch); i += 2) {
expr_ty expression;
expression = ast_for_expr(c, CHILD(ch, i));
if (!expression)
return NULL;
asdl_seq_SET(elts, i / 2, expression);
}
return Set(elts, LINENO(n), n->n_col_offset, c->c_arena);
} else if (TYPE(CHILD(ch, 1)) == comp_for) {
/* it's a set comprehension */
return ast_for_setcomp(c, ch);
} else if (NCH(ch) > 3 && TYPE(CHILD(ch, 3)) == comp_for) {
return ast_for_dictcomp(c, ch);
} else {
/* it's a dict */
size = (NCH(ch) + 1) / 4; /* +1 in case no trailing comma */
keys = asdl_seq_new(size, c->c_arena);
if (!keys)
return NULL;
values = asdl_seq_new(size, c->c_arena);
if (!values)
return NULL;
for (i = 0; i < NCH(ch); i += 4) {
expr_ty expression;
expression = ast_for_expr(c, CHILD(ch, i));
if (!expression)
return NULL;
asdl_seq_SET(keys, i / 4, expression);
expression = ast_for_expr(c, CHILD(ch, i + 2));
if (!expression)
return NULL;
asdl_seq_SET(values, i / 4, expression);
}
return Dict(keys, values, LINENO(n), n->n_col_offset, c->c_arena);
}
}
case BACKQUOTE: { /* repr */
expr_ty expression;
if (Py_Py3kWarningFlag &&
!ast_warn(c, n, "backquote not supported in 3.x; use repr()"))
return NULL;
expression = ast_for_testlist(c, CHILD(n, 1));
if (!expression)
return NULL;
return Repr(expression, LINENO(n), n->n_col_offset, c->c_arena);
}
default:
PyErr_Format(PyExc_SystemError, "unhandled atom %d", TYPE(ch));
return NULL;
}
}
static slice_ty
ast_for_slice(struct compiling *c, const node *n)
{
node *ch;
expr_ty lower = NULL, upper = NULL, step = NULL;
REQ(n, subscript);
/*
subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop]
sliceop: ':' [test]
*/
ch = CHILD(n, 0);
if (TYPE(ch) == DOT)
return Ellipsis(c->c_arena);
if (NCH(n) == 1 && TYPE(ch) == test) {
/* 'step' variable hold no significance in terms of being used over
other vars */
step = ast_for_expr(c, ch);
if (!step)
return NULL;
return Index(step, c->c_arena);
}
if (TYPE(ch) == test) {
lower = ast_for_expr(c, ch);
if (!lower)
return NULL;
}
/* If there's an upper bound it's in the second or third position. */
if (TYPE(ch) == COLON) {
if (NCH(n) > 1) {
node *n2 = CHILD(n, 1);
if (TYPE(n2) == test) {
upper = ast_for_expr(c, n2);
if (!upper)
return NULL;
}
}
} else if (NCH(n) > 2) {
node *n2 = CHILD(n, 2);
if (TYPE(n2) == test) {
upper = ast_for_expr(c, n2);
if (!upper)
return NULL;
}
}
ch = CHILD(n, NCH(n) - 1);
if (TYPE(ch) == sliceop) {
if (NCH(ch) == 1) {
/*
This is an extended slice (ie "x[::]") with no expression in the
step field. We set this literally to "None" in order to
disambiguate it from x[:]. (The interpreter might have to call
__getslice__ for x[:], but it must call __getitem__ for x[::].)
*/
identifier none = new_identifier("None", c->c_arena);
if (!none)
return NULL;
ch = CHILD(ch, 0);
step = Name(none, Load, LINENO(ch), ch->n_col_offset, c->c_arena);
if (!step)
return NULL;
} else {
ch = CHILD(ch, 1);
if (TYPE(ch) == test) {
step = ast_for_expr(c, ch);
if (!step)
return NULL;
}
}
}
return Slice(lower, upper, step, c->c_arena);
}
static expr_ty
ast_for_binop(struct compiling *c, const node *n)
{
/* Must account for a sequence of expressions.
How should A op B op C by represented?
BinOp(BinOp(A, op, B), op, C).
*/
int i, nops;
expr_ty expr1, expr2, result;
operator_ty newoperator;
expr1 = ast_for_expr(c, CHILD(n, 0));
if (!expr1)
return NULL;
expr2 = ast_for_expr(c, CHILD(n, 2));
if (!expr2)
return NULL;
newoperator = get_operator(CHILD(n, 1));
if (!newoperator)
return NULL;
result = BinOp(expr1, newoperator, expr2, LINENO(n), n->n_col_offset,
c->c_arena);
if (!result)
return NULL;
nops = (NCH(n) - 1) / 2;
for (i = 1; i < nops; i++) {
expr_ty tmp_result, tmp;
const node* next_oper = CHILD(n, i * 2 + 1);
newoperator = get_operator(next_oper);
if (!newoperator)
return NULL;
tmp = ast_for_expr(c, CHILD(n, i * 2 + 2));
if (!tmp)
return NULL;
tmp_result = BinOp(result, newoperator, tmp,
LINENO(next_oper), next_oper->n_col_offset,
c->c_arena);
if (!tmp_result)
return NULL;
result = tmp_result;
}
return result;
}
static expr_ty
ast_for_trailer(struct compiling *c, const node *n, expr_ty left_expr)
{
/* trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
subscriptlist: subscript (',' subscript)* [',']
subscript: '.' '.' '.' | test | [test] ':' [test] [sliceop]
*/
REQ(n, trailer);
if (TYPE(CHILD(n, 0)) == LPAR) {
if (NCH(n) == 2)
return Call(left_expr, NULL, NULL, NULL, NULL, LINENO(n),
n->n_col_offset, c->c_arena);
else
return ast_for_call(c, CHILD(n, 1), left_expr);
}
else if (TYPE(CHILD(n, 0)) == DOT ) {
PyObject *attr_id = NEW_IDENTIFIER(CHILD(n, 1));
if (!attr_id)
return NULL;
return Attribute(left_expr, attr_id, Load,
LINENO(n), n->n_col_offset, c->c_arena);
}
else {
REQ(CHILD(n, 0), LSQB);
REQ(CHILD(n, 2), RSQB);
n = CHILD(n, 1);
if (NCH(n) == 1) {
slice_ty slc = ast_for_slice(c, CHILD(n, 0));
if (!slc)
return NULL;
return Subscript(left_expr, slc, Load, LINENO(n), n->n_col_offset,
c->c_arena);
}
else {
/* The grammar is ambiguous here. The ambiguity is resolved
by treating the sequence as a tuple literal if there are
no slice features.
*/
int j;
slice_ty slc;
expr_ty e;
bool simple = true;
asdl_seq *slices, *elts;
slices = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
if (!slices)
return NULL;
for (j = 0; j < NCH(n); j += 2) {
slc = ast_for_slice(c, CHILD(n, j));
if (!slc)
return NULL;
if (slc->kind != Index_kind)
simple = false;
asdl_seq_SET(slices, j / 2, slc);
}
if (!simple) {
return Subscript(left_expr, ExtSlice(slices, c->c_arena),
Load, LINENO(n), n->n_col_offset, c->c_arena);
}
/* extract Index values and put them in a Tuple */
elts = asdl_seq_new(asdl_seq_LEN(slices), c->c_arena);
if (!elts)
return NULL;
for (j = 0; j < asdl_seq_LEN(slices); ++j) {
slc = (slice_ty)asdl_seq_GET(slices, j);
assert(slc->kind == Index_kind && slc->v.Index.value);
asdl_seq_SET(elts, j, slc->v.Index.value);
}
e = Tuple(elts, Load, LINENO(n), n->n_col_offset, c->c_arena);
if (!e)
return NULL;
return Subscript(left_expr, Index(e, c->c_arena),
Load, LINENO(n), n->n_col_offset, c->c_arena);
}
}
}
static expr_ty
ast_for_factor(struct compiling *c, const node *n)
{
node *pfactor, *ppower, *patom, *pnum;
expr_ty expression;
/* If the unary - operator is applied to a constant, don't generate
a UNARY_NEGATIVE opcode. Just store the approriate value as a
constant. The peephole optimizer already does something like
this but it doesn't handle the case where the constant is
(sys.maxint - 1). In that case, we want a PyIntObject, not a
PyLongObject.
*/
if (TYPE(CHILD(n, 0)) == MINUS &&
NCH(n) == 2 &&
TYPE((pfactor = CHILD(n, 1))) == factor &&
NCH(pfactor) == 1 &&
TYPE((ppower = CHILD(pfactor, 0))) == power &&
NCH(ppower) == 1 &&
TYPE((patom = CHILD(ppower, 0))) == atom &&
TYPE((pnum = CHILD(patom, 0))) == NUMBER) {
PyObject *pynum;
char *s = PyObject_MALLOC(strlen(STR(pnum)) + 2);
if (s == NULL)
return NULL;
s[0] = '-';
strcpy(s + 1, STR(pnum));
pynum = parsenumber(c, s);
PyObject_FREE(s);
if (!pynum)
return NULL;
PyArena_AddPyObject(c->c_arena, pynum);
return Num(pynum, LINENO(n), n->n_col_offset, c->c_arena);
}
expression = ast_for_expr(c, CHILD(n, 1));
if (!expression)
return NULL;
switch (TYPE(CHILD(n, 0))) {
case PLUS:
return UnaryOp(UAdd, expression, LINENO(n), n->n_col_offset,
c->c_arena);
case MINUS:
return UnaryOp(USub, expression, LINENO(n), n->n_col_offset,
c->c_arena);
case TILDE:
return UnaryOp(Invert, expression, LINENO(n),
n->n_col_offset, c->c_arena);
}
PyErr_Format(PyExc_SystemError, "unhandled factor: %d",
TYPE(CHILD(n, 0)));
return NULL;
}
static expr_ty
ast_for_power(struct compiling *c, const node *n)
{
/* power: atom trailer* ('**' factor)*
*/
int i;
expr_ty e, tmp;
REQ(n, power);
e = ast_for_atom(c, CHILD(n, 0));
if (!e)
return NULL;
if (NCH(n) == 1)
return e;
for (i = 1; i < NCH(n); i++) {
node *ch = CHILD(n, i);
if (TYPE(ch) != trailer)
break;
tmp = ast_for_trailer(c, ch, e);
if (!tmp)
return NULL;
tmp->lineno = e->lineno;
tmp->col_offset = e->col_offset;
e = tmp;
}
if (TYPE(CHILD(n, NCH(n) - 1)) == factor) {
expr_ty f = ast_for_expr(c, CHILD(n, NCH(n) - 1));
if (!f)
return NULL;
tmp = BinOp(e, Pow, f, LINENO(n), n->n_col_offset, c->c_arena);
if (!tmp)
return NULL;
e = tmp;
}
return e;
}
/* Do not name a variable 'expr'! Will cause a compile error.
*/
static expr_ty
ast_for_expr(struct compiling *c, const node *n)
{
/* handle the full range of simple expressions
test: or_test ['if' or_test 'else' test] | lambdef
or_test: and_test ('or' and_test)*
and_test: not_test ('and' not_test)*
not_test: 'not' not_test | comparison
comparison: expr (comp_op expr)*
expr: xor_expr ('|' xor_expr)*
xor_expr: and_expr ('^' and_expr)*
and_expr: shift_expr ('&' shift_expr)*
shift_expr: arith_expr (('<<'|'>>') arith_expr)*
arith_expr: term (('+'|'-') term)*
term: factor (('*'|'/'|'%'|'//') factor)*
factor: ('+'|'-'|'~') factor | power
power: atom trailer* ('**' factor)*
As well as modified versions that exist for backward compatibility,
to explicitly allow:
[ x for x in lambda: 0, lambda: 1 ]
(which would be ambiguous without these extra rules)
old_test: or_test | old_lambdef
old_lambdef: 'lambda' [vararglist] ':' old_test
*/
asdl_seq *seq;
int i;
loop:
switch (TYPE(n)) {
case test:
case old_test:
if (TYPE(CHILD(n, 0)) == lambdef ||
TYPE(CHILD(n, 0)) == old_lambdef)
return ast_for_lambdef(c, CHILD(n, 0));
else if (NCH(n) > 1)
return ast_for_ifexpr(c, n);
/* Fallthrough */
case or_test:
case and_test:
if (NCH(n) == 1) {
n = CHILD(n, 0);
goto loop;
}
seq = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
if (!seq)
return NULL;
for (i = 0; i < NCH(n); i += 2) {
expr_ty e = ast_for_expr(c, CHILD(n, i));
if (!e)
return NULL;
asdl_seq_SET(seq, i / 2, e);
}
if (!strcmp(STR(CHILD(n, 1)), "and"))
return BoolOp(And, seq, LINENO(n), n->n_col_offset,
c->c_arena);
assert(!strcmp(STR(CHILD(n, 1)), "or"));
return BoolOp(Or, seq, LINENO(n), n->n_col_offset, c->c_arena);
case not_test:
if (NCH(n) == 1) {
n = CHILD(n, 0);
goto loop;
}
else {
expr_ty expression = ast_for_expr(c, CHILD(n, 1));
if (!expression)
return NULL;
return UnaryOp(Not, expression, LINENO(n), n->n_col_offset,
c->c_arena);
}
case comparison:
if (NCH(n) == 1) {
n = CHILD(n, 0);
goto loop;
}
else {
expr_ty expression;
asdl_int_seq *ops;
asdl_seq *cmps;
ops = asdl_int_seq_new(NCH(n) / 2, c->c_arena);
if (!ops)
return NULL;
cmps = asdl_seq_new(NCH(n) / 2, c->c_arena);
if (!cmps) {
return NULL;
}
for (i = 1; i < NCH(n); i += 2) {
cmpop_ty newoperator;
newoperator = ast_for_comp_op(c, CHILD(n, i));
if (!newoperator) {
return NULL;
}
expression = ast_for_expr(c, CHILD(n, i + 1));
if (!expression) {
return NULL;
}
asdl_seq_SET(ops, i / 2, newoperator);
asdl_seq_SET(cmps, i / 2, expression);
}
expression = ast_for_expr(c, CHILD(n, 0));
if (!expression) {
return NULL;
}
return Compare(expression, ops, cmps, LINENO(n),
n->n_col_offset, c->c_arena);
}
break;
/* The next five cases all handle BinOps. The main body of code
is the same in each case, but the switch turned inside out to
reuse the code for each type of operator.
*/
case expr:
case xor_expr:
case and_expr:
case shift_expr:
case arith_expr:
case term:
if (NCH(n) == 1) {
n = CHILD(n, 0);
goto loop;
}
return ast_for_binop(c, n);
case yield_expr: {
expr_ty exp = NULL;
if (NCH(n) == 2) {
exp = ast_for_testlist(c, CHILD(n, 1));
if (!exp)
return NULL;
}
return Yield(exp, LINENO(n), n->n_col_offset, c->c_arena);
}
case factor:
if (NCH(n) == 1) {
n = CHILD(n, 0);
goto loop;
}
return ast_for_factor(c, n);
case power:
return ast_for_power(c, n);
default:
PyErr_Format(PyExc_SystemError, "unhandled expr: %d", TYPE(n));
return NULL;
}
/* should never get here unless if error is set */
return NULL;
}
static expr_ty
ast_for_call(struct compiling *c, const node *n, expr_ty func)
{
/*
arglist: (argument ',')* (argument [',']| '*' test [',' '**' test]
| '**' test)
argument: [test '='] test [comp_for] # Really [keyword '='] test
*/
int i, nargs, nkeywords, ngens;
asdl_seq *args;
asdl_seq *keywords;
expr_ty vararg = NULL, kwarg = NULL;
REQ(n, arglist);
nargs = 0;
nkeywords = 0;
ngens = 0;
for (i = 0; i < NCH(n); i++) {
node *ch = CHILD(n, i);
if (TYPE(ch) == argument) {
if (NCH(ch) == 1)
nargs++;
else if (TYPE(CHILD(ch, 1)) == comp_for)
ngens++;
else
nkeywords++;
}
}
if (ngens > 1 || (ngens && (nargs || nkeywords))) {
ast_error(n, "Generator expression must be parenthesized "
"if not sole argument");
return NULL;
}
if (nargs + nkeywords + ngens > 255) {
ast_error(n, "more than 255 arguments");
return NULL;
}
args = asdl_seq_new(nargs + ngens, c->c_arena);
if (!args)
return NULL;
keywords = asdl_seq_new(nkeywords, c->c_arena);
if (!keywords)
return NULL;
nargs = 0;
nkeywords = 0;
for (i = 0; i < NCH(n); i++) {
node *ch = CHILD(n, i);
if (TYPE(ch) == argument) {
expr_ty e;
if (NCH(ch) == 1) {
if (nkeywords) {
ast_error(CHILD(ch, 0),
"non-keyword arg after keyword arg");
return NULL;
}
if (vararg) {
ast_error(CHILD(ch, 0),
"only named arguments may follow *expression");
return NULL;
}
e = ast_for_expr(c, CHILD(ch, 0));
if (!e)
return NULL;
asdl_seq_SET(args, nargs++, e);
}
else if (TYPE(CHILD(ch, 1)) == comp_for) {
e = ast_for_genexp(c, ch);
if (!e)
return NULL;
asdl_seq_SET(args, nargs++, e);
}
else {
keyword_ty kw;
identifier key;
int k;
char *tmp;
/* CHILD(ch, 0) is test, but must be an identifier? */
e = ast_for_expr(c, CHILD(ch, 0));
if (!e)
return NULL;
/* f(lambda x: x[0] = 3) ends up getting parsed with
* LHS test = lambda x: x[0], and RHS test = 3.
* SF bug 132313 points out that complaining about a keyword
* then is very confusing.
*/
if (e->kind == Lambda_kind) {
ast_error(CHILD(ch, 0),
"lambda cannot contain assignment");
return NULL;
} else if (e->kind != Name_kind) {
ast_error(CHILD(ch, 0), "keyword can't be an expression");
return NULL;
}
key = e->v.Name.id;
if (!forbidden_check(c, CHILD(ch, 0), PyBytes_AS_STRING(key)))
return NULL;
for (k = 0; k < nkeywords; k++) {
tmp = PyString_AS_STRING(
((keyword_ty)asdl_seq_GET(keywords, k))->arg);
if (!strcmp(tmp, PyString_AS_STRING(key))) {
ast_error(CHILD(ch, 0), "keyword argument repeated");
return NULL;
}
}
e = ast_for_expr(c, CHILD(ch, 2));
if (!e)
return NULL;
kw = keyword(key, e, c->c_arena);
if (!kw)
return NULL;
asdl_seq_SET(keywords, nkeywords++, kw);
}
}
else if (TYPE(ch) == STAR) {
vararg = ast_for_expr(c, CHILD(n, i+1));
if (!vararg)
return NULL;
i++;
}
else if (TYPE(ch) == DOUBLESTAR) {
kwarg = ast_for_expr(c, CHILD(n, i+1));
if (!kwarg)
return NULL;
i++;
}
}
return Call(func, args, keywords, vararg, kwarg, func->lineno,
func->col_offset, c->c_arena);
}
static expr_ty
ast_for_testlist(struct compiling *c, const node* n)
{
/* testlist_comp: test (',' test)* [','] */
/* testlist: test (',' test)* [','] */
/* testlist_safe: test (',' test)+ [','] */
/* testlist1: test (',' test)* */
assert(NCH(n) > 0);
if (TYPE(n) == testlist_comp) {
if (NCH(n) > 1)
assert(TYPE(CHILD(n, 1)) != comp_for);
}
else {
assert(TYPE(n) == testlist ||
TYPE(n) == testlist_safe ||
TYPE(n) == testlist1);
}
if (NCH(n) == 1)
return ast_for_expr(c, CHILD(n, 0));
else {
asdl_seq *tmp = seq_for_testlist(c, n);
if (!tmp)
return NULL;
return Tuple(tmp, Load, LINENO(n), n->n_col_offset, c->c_arena);
}
}
static expr_ty
ast_for_testlist_comp(struct compiling *c, const node* n)
{
/* testlist_comp: test ( comp_for | (',' test)* [','] ) */
/* argument: test [ comp_for ] */
assert(TYPE(n) == testlist_comp || TYPE(n) == argument);
if (NCH(n) > 1 && TYPE(CHILD(n, 1)) == comp_for)
return ast_for_genexp(c, n);
return ast_for_testlist(c, n);
}
/* like ast_for_testlist() but returns a sequence */
static asdl_seq*
ast_for_class_bases(struct compiling *c, const node* n)
{
/* testlist: test (',' test)* [','] */
assert(NCH(n) > 0);
REQ(n, testlist);
if (NCH(n) == 1) {
expr_ty base;
asdl_seq *bases = asdl_seq_new(1, c->c_arena);
if (!bases)
return NULL;
base = ast_for_expr(c, CHILD(n, 0));
if (!base)
return NULL;
asdl_seq_SET(bases, 0, base);
return bases;
}
return seq_for_testlist(c, n);
}
static stmt_ty
ast_for_expr_stmt(struct compiling *c, const node *n)
{
REQ(n, expr_stmt);
/* expr_stmt: testlist (augassign (yield_expr|testlist)
| ('=' (yield_expr|testlist))*)
testlist: test (',' test)* [',']
augassign: '+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^='
| '<<=' | '>>=' | '**=' | '//='
test: ... here starts the operator precendence dance
*/
if (NCH(n) == 1) {
expr_ty e = ast_for_testlist(c, CHILD(n, 0));
if (!e)
return NULL;
return Expr(e, LINENO(n), n->n_col_offset, c->c_arena);
}
else if (TYPE(CHILD(n, 1)) == augassign) {
expr_ty expr1, expr2;
operator_ty newoperator;
node *ch = CHILD(n, 0);
expr1 = ast_for_testlist(c, ch);
if (!expr1)
return NULL;
if(!set_context(c, expr1, Store, ch))
return NULL;
/* set_context checks that most expressions are not the left side.
Augmented assignments can only have a name, a subscript, or an
attribute on the left, though, so we have to explicitly check for
those. */
switch (expr1->kind) {
case Name_kind:
case Attribute_kind:
case Subscript_kind:
break;
default:
ast_error(ch, "illegal expression for augmented assignment");
return NULL;
}
ch = CHILD(n, 2);
if (TYPE(ch) == testlist)
expr2 = ast_for_testlist(c, ch);
else
expr2 = ast_for_expr(c, ch);
if (!expr2)
return NULL;
newoperator = ast_for_augassign(c, CHILD(n, 1));
if (!newoperator)
return NULL;
return AugAssign(expr1, newoperator, expr2, LINENO(n), n->n_col_offset,
c->c_arena);
}
else {
int i;
asdl_seq *targets;
node *value;
expr_ty expression;
/* a normal assignment */
REQ(CHILD(n, 1), EQUAL);
targets = asdl_seq_new(NCH(n) / 2, c->c_arena);
if (!targets)
return NULL;
for (i = 0; i < NCH(n) - 2; i += 2) {
expr_ty e;
node *ch = CHILD(n, i);
if (TYPE(ch) == yield_expr) {
ast_error(ch, "assignment to yield expression not possible");
return NULL;
}
e = ast_for_testlist(c, ch);
if (!e)
return NULL;
/* set context to assign */
if (!set_context(c, e, Store, CHILD(n, i)))
return NULL;
asdl_seq_SET(targets, i / 2, e);
}
value = CHILD(n, NCH(n) - 1);
if (TYPE(value) == testlist)
expression = ast_for_testlist(c, value);
else
expression = ast_for_expr(c, value);
if (!expression)
return NULL;
return Assign(targets, expression, LINENO(n), n->n_col_offset,
c->c_arena);
}
}
static stmt_ty
ast_for_print_stmt(struct compiling *c, const node *n)
{
/* print_stmt: 'print' ( [ test (',' test)* [','] ]
| '>>' test [ (',' test)+ [','] ] )
*/
expr_ty dest = NULL, expression;
asdl_seq *seq = NULL;
bool nl;
int i, j, values_count, start = 1;
REQ(n, print_stmt);
if (NCH(n) >= 2 && TYPE(CHILD(n, 1)) == RIGHTSHIFT) {
dest = ast_for_expr(c, CHILD(n, 2));
if (!dest)
return NULL;
start = 4;
}
values_count = (NCH(n) + 1 - start) / 2;
if (values_count) {
seq = asdl_seq_new(values_count, c->c_arena);
if (!seq)
return NULL;
for (i = start, j = 0; i < NCH(n); i += 2, ++j) {
expression = ast_for_expr(c, CHILD(n, i));
if (!expression)
return NULL;
asdl_seq_SET(seq, j, expression);
}
}
nl = (TYPE(CHILD(n, NCH(n) - 1)) == COMMA) ? false : true;
return Print(dest, seq, nl, LINENO(n), n->n_col_offset, c->c_arena);
}
static asdl_seq *
ast_for_exprlist(struct compiling *c, const node *n, expr_context_ty context)
{
asdl_seq *seq;
int i;
expr_ty e;
REQ(n, exprlist);
seq = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
if (!seq)
return NULL;
for (i = 0; i < NCH(n); i += 2) {
e = ast_for_expr(c, CHILD(n, i));
if (!e)
return NULL;
asdl_seq_SET(seq, i / 2, e);
if (context && !set_context(c, e, context, CHILD(n, i)))
return NULL;
}
return seq;
}
static stmt_ty
ast_for_del_stmt(struct compiling *c, const node *n)
{
asdl_seq *expr_list;
/* del_stmt: 'del' exprlist */
REQ(n, del_stmt);
expr_list = ast_for_exprlist(c, CHILD(n, 1), Del);
if (!expr_list)
return NULL;
return Delete(expr_list, LINENO(n), n->n_col_offset, c->c_arena);
}
static stmt_ty
ast_for_flow_stmt(struct compiling *c, const node *n)
{
/*
flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt
| yield_stmt
break_stmt: 'break'
continue_stmt: 'continue'
return_stmt: 'return' [testlist]
yield_stmt: yield_expr
yield_expr: 'yield' testlist
raise_stmt: 'raise' [test [',' test [',' test]]]
*/
node *ch;
REQ(n, flow_stmt);
ch = CHILD(n, 0);
switch (TYPE(ch)) {
case break_stmt:
return Break(LINENO(n), n->n_col_offset, c->c_arena);
case continue_stmt:
return Continue(LINENO(n), n->n_col_offset, c->c_arena);
case yield_stmt: { /* will reduce to yield_expr */
expr_ty exp = ast_for_expr(c, CHILD(ch, 0));
if (!exp)
return NULL;
return Expr(exp, LINENO(n), n->n_col_offset, c->c_arena);
}
case return_stmt:
if (NCH(ch) == 1)
return Return(NULL, LINENO(n), n->n_col_offset, c->c_arena);
else {
expr_ty expression = ast_for_testlist(c, CHILD(ch, 1));
if (!expression)
return NULL;
return Return(expression, LINENO(n), n->n_col_offset,
c->c_arena);
}
case raise_stmt:
if (NCH(ch) == 1)
return Raise(NULL, NULL, NULL, LINENO(n), n->n_col_offset,
c->c_arena);
else if (NCH(ch) == 2) {
expr_ty expression = ast_for_expr(c, CHILD(ch, 1));
if (!expression)
return NULL;
return Raise(expression, NULL, NULL, LINENO(n),
n->n_col_offset, c->c_arena);
}
else if (NCH(ch) == 4) {
expr_ty expr1, expr2;
expr1 = ast_for_expr(c, CHILD(ch, 1));
if (!expr1)
return NULL;
expr2 = ast_for_expr(c, CHILD(ch, 3));
if (!expr2)
return NULL;
return Raise(expr1, expr2, NULL, LINENO(n), n->n_col_offset,
c->c_arena);
}
else if (NCH(ch) == 6) {
expr_ty expr1, expr2, expr3;
expr1 = ast_for_expr(c, CHILD(ch, 1));
if (!expr1)
return NULL;
expr2 = ast_for_expr(c, CHILD(ch, 3));
if (!expr2)
return NULL;
expr3 = ast_for_expr(c, CHILD(ch, 5));
if (!expr3)
return NULL;
return Raise(expr1, expr2, expr3, LINENO(n), n->n_col_offset,
c->c_arena);
}
default:
PyErr_Format(PyExc_SystemError,
"unexpected flow_stmt: %d", TYPE(ch));
return NULL;
}
PyErr_SetString(PyExc_SystemError, "unhandled flow statement");
return NULL;
}
static alias_ty
alias_for_import_name(struct compiling *c, const node *n, int store)
{
/*
import_as_name: NAME ['as' NAME]
dotted_as_name: dotted_name ['as' NAME]
dotted_name: NAME ('.' NAME)*
*/
PyObject *str, *name;
loop:
switch (TYPE(n)) {
case import_as_name: {
node *name_node = CHILD(n, 0);
str = NULL;
if (NCH(n) == 3) {
node *str_node = CHILD(n, 2);
if (store && !forbidden_check(c, str_node, STR(str_node)))
return NULL;
str = NEW_IDENTIFIER(str_node);
if (!str)
return NULL;
}
else {
if (!forbidden_check(c, name_node, STR(name_node)))
return NULL;
}
name = NEW_IDENTIFIER(name_node);
if (!name)
return NULL;
return alias(name, str, c->c_arena);
}
case dotted_as_name:
if (NCH(n) == 1) {
n = CHILD(n, 0);
goto loop;
}
else {
node *asname_node = CHILD(n, 2);
alias_ty a = alias_for_import_name(c, CHILD(n, 0), 0);
if (!a)
return NULL;
assert(!a->asname);
if (!forbidden_check(c, asname_node, STR(asname_node)))
return NULL;
a->asname = NEW_IDENTIFIER(asname_node);
if (!a->asname)
return NULL;
return a;
}
break;
case dotted_name:
if (NCH(n) == 1) {
node *name_node = CHILD(n, 0);
if (store && !forbidden_check(c, name_node, STR(name_node)))
return NULL;
name = NEW_IDENTIFIER(name_node);
if (!name)
return NULL;
return alias(name, NULL, c->c_arena);
}
else {
/* Create a string of the form "a.b.c" */
int i;
size_t len;
char *s;
len = 0;
for (i = 0; i < NCH(n); i += 2)
/* length of string plus one for the dot */
len += strlen(STR(CHILD(n, i))) + 1;
len--; /* the last name doesn't have a dot */
str = PyString_FromStringAndSize(NULL, len);
if (!str)
return NULL;
s = PyString_AS_STRING(str);
if (!s)
return NULL;
for (i = 0; i < NCH(n); i += 2) {
char *sch = STR(CHILD(n, i));
strcpy(s, STR(CHILD(n, i)));
s += strlen(sch);
*s++ = '.';
}
--s;
*s = '\0';
PyString_InternInPlace(&str);
PyArena_AddPyObject(c->c_arena, str);
return alias(str, NULL, c->c_arena);
}
break;
case STAR:
str = PyString_InternFromString("*");
PyArena_AddPyObject(c->c_arena, str);
return alias(str, NULL, c->c_arena);
default:
PyErr_Format(PyExc_SystemError,
"unexpected import name: %d", TYPE(n));
return NULL;
}
PyErr_SetString(PyExc_SystemError, "unhandled import name condition");
return NULL;
}
static stmt_ty
ast_for_import_stmt(struct compiling *c, const node *n)
{
/*
import_stmt: import_name | import_from
import_name: 'import' dotted_as_names
import_from: 'from' ('.'* dotted_name | '.') 'import'
('*' | '(' import_as_names ')' | import_as_names)
*/
int lineno;
int col_offset;
int i;
asdl_seq *aliases;
REQ(n, import_stmt);
lineno = LINENO(n);
col_offset = n->n_col_offset;
n = CHILD(n, 0);
if (TYPE(n) == import_name) {
n = CHILD(n, 1);
REQ(n, dotted_as_names);
aliases = asdl_seq_new((NCH(n) + 1) / 2, c->c_arena);
if (!aliases)
return NULL;
for (i = 0; i < NCH(n); i += 2) {
alias_ty import_alias = alias_for_import_name(c, CHILD(n, i), 1);
if (!import_alias)
return NULL;
asdl_seq_SET(aliases, i / 2, import_alias);
}
return Import(aliases, lineno, col_offset, c->c_arena);
}
else if (TYPE(n) == import_from) {
int n_children;
int idx, ndots = 0;
alias_ty mod = NULL;
identifier modname = NULL;
/* Count the number of dots (for relative imports) and check for the
optional module name */
for (idx = 1; idx < NCH(n); idx++) {
if (TYPE(CHILD(n, idx)) == dotted_name) {
mod = alias_for_import_name(c, CHILD(n, idx), 0);
if (!mod)
return NULL;
idx++;
break;
} else if (TYPE(CHILD(n, idx)) != DOT) {
break;
}
ndots++;
}
idx++; /* skip over the 'import' keyword */
switch (TYPE(CHILD(n, idx))) {
case STAR:
/* from ... import * */
n = CHILD(n, idx);
n_children = 1;
break;
case LPAR:
/* from ... import (x, y, z) */
n = CHILD(n, idx + 1);
n_children = NCH(n);
break;
case import_as_names:
/* from ... import x, y, z */
n = CHILD(n, idx);
n_children = NCH(n);
if (n_children % 2 == 0) {
ast_error(n, "trailing comma not allowed without"
" surrounding parentheses");
return NULL;
}
break;
default:
ast_error(n, "Unexpected node-type in from-import");
return NULL;
}
aliases = asdl_seq_new((n_children + 1) / 2, c->c_arena);
if (!aliases)
return NULL;
/* handle "from ... import *" special b/c there's no children */
if (TYPE(n) == STAR) {
alias_ty import_alias = alias_for_import_name(c, n, 1);
if (!import_alias)
return NULL;
asdl_seq_SET(aliases, 0, import_alias);
}
else {
for (i = 0; i < NCH(n); i += 2) {
alias_ty import_alias = alias_for_import_name(c, CHILD(n, i), 1);
if (!import_alias)
return NULL;
asdl_seq_SET(aliases, i / 2, import_alias);
}
}
if (mod != NULL)
modname = mod->name;
return ImportFrom(modname, aliases, ndots, lineno, col_offset,
c->c_arena);
}
PyErr_Format(PyExc_SystemError,
"unknown import statement: starts with command '%s'",
STR(CHILD(n, 0)));
return NULL;
}
static stmt_ty
ast_for_global_stmt(struct compiling *c, const node *n)
{
/* global_stmt: 'global' NAME (',' NAME)* */
identifier name;
asdl_seq *s;
int i;
REQ(n, global_stmt);
s = asdl_seq_new(NCH(n) / 2, c->c_arena);
if (!s)
return NULL;
for (i = 1; i < NCH(n); i += 2) {
name = NEW_IDENTIFIER(CHILD(n, i));
if (!name)
return NULL;
asdl_seq_SET(s, i / 2, name);
}
return Global(s, LINENO(n), n->n_col_offset, c->c_arena);
}
static stmt_ty
ast_for_exec_stmt(struct compiling *c, const node *n)
{
expr_ty expr1, globals = NULL, locals = NULL;
int n_children = NCH(n);
if (n_children != 2 && n_children != 4 && n_children != 6) {
PyErr_Format(PyExc_SystemError,
"poorly formed 'exec' statement: %d parts to statement",
n_children);
return NULL;
}
/* exec_stmt: 'exec' expr ['in' test [',' test]] */
REQ(n, exec_stmt);
expr1 = ast_for_expr(c, CHILD(n, 1));
if (!expr1)
return NULL;
if (n_children >= 4) {
globals = ast_for_expr(c, CHILD(n, 3));
if (!globals)
return NULL;
}
if (n_children == 6) {
locals = ast_for_expr(c, CHILD(n, 5));
if (!locals)
return NULL;
}
return Exec(expr1, globals, locals, LINENO(n), n->n_col_offset,
c->c_arena);
}
static stmt_ty
ast_for_assert_stmt(struct compiling *c, const node *n)
{
/* assert_stmt: 'assert' test [',' test] */
REQ(n, assert_stmt);
if (NCH(n) == 2) {
expr_ty expression = ast_for_expr(c, CHILD(n, 1));
if (!expression)
return NULL;
return Assert(expression, NULL, LINENO(n), n->n_col_offset,
c->c_arena);
}
else if (NCH(n) == 4) {
expr_ty expr1, expr2;
expr1 = ast_for_expr(c, CHILD(n, 1));
if (!expr1)
return NULL;
expr2 = ast_for_expr(c, CHILD(n, 3));
if (!expr2)
return NULL;
return Assert(expr1, expr2, LINENO(n), n->n_col_offset, c->c_arena);
}
PyErr_Format(PyExc_SystemError,
"improper number of parts to 'assert' statement: %d",
NCH(n));
return NULL;
}
static asdl_seq *
ast_for_suite(struct compiling *c, const node *n)
{
/* suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT */
asdl_seq *seq;
stmt_ty s;
int i, total, num, end, pos = 0;
node *ch;
REQ(n, suite);
total = num_stmts(n);
seq = asdl_seq_new(total, c->c_arena);
if (!seq)
return NULL;
if (TYPE(CHILD(n, 0)) == simple_stmt) {
n = CHILD(n, 0);
/* simple_stmt always ends with a NEWLINE,
and may have a trailing SEMI
*/
end = NCH(n) - 1;
if (TYPE(CHILD(n, end - 1)) == SEMI)
end--;
/* loop by 2 to skip semi-colons */
for (i = 0; i < end; i += 2) {
ch = CHILD(n, i);
s = ast_for_stmt(c, ch);
if (!s)
return NULL;
asdl_seq_SET(seq, pos++, s);
}
}
else {
for (i = 2; i < (NCH(n) - 1); i++) {
ch = CHILD(n, i);
REQ(ch, stmt);
num = num_stmts(ch);
if (num == 1) {
/* small_stmt or compound_stmt with only one child */
s = ast_for_stmt(c, ch);
if (!s)
return NULL;
asdl_seq_SET(seq, pos++, s);
}
else {
int j;
ch = CHILD(ch, 0);
REQ(ch, simple_stmt);
for (j = 0; j < NCH(ch); j += 2) {
/* statement terminates with a semi-colon ';' */
if (NCH(CHILD(ch, j)) == 0) {
assert((j + 1) == NCH(ch));
break;
}
s = ast_for_stmt(c, CHILD(ch, j));
if (!s)
return NULL;
asdl_seq_SET(seq, pos++, s);
}
}
}
}
assert(pos == seq->size);
return seq;
}
static stmt_ty
ast_for_if_stmt(struct compiling *c, const node *n)
{
/* if_stmt: 'if' test ':' suite ('elif' test ':' suite)*
['else' ':' suite]
*/
char *s;
REQ(n, if_stmt);
if (NCH(n) == 4) {
expr_ty expression;
asdl_seq *suite_seq;
expression = ast_for_expr(c, CHILD(n, 1));
if (!expression)
return NULL;
suite_seq = ast_for_suite(c, CHILD(n, 3));
if (!suite_seq)
return NULL;
return If(expression, suite_seq, NULL, LINENO(n), n->n_col_offset,
c->c_arena);
}
s = STR(CHILD(n, 4));
/* s[2], the third character in the string, will be
's' for el_s_e, or
'i' for el_i_f
*/
if (s[2] == 's') {
expr_ty expression;
asdl_seq *seq1, *seq2;
expression = ast_for_expr(c, CHILD(n, 1));
if (!expression)
return NULL;
seq1 = ast_for_suite(c, CHILD(n, 3));
if (!seq1)
return NULL;
seq2 = ast_for_suite(c, CHILD(n, 6));
if (!seq2)
return NULL;
return If(expression, seq1, seq2, LINENO(n), n->n_col_offset,
c->c_arena);
}
else if (s[2] == 'i') {
int i, n_elif, has_else = 0;
expr_ty expression;
asdl_seq *suite_seq;
asdl_seq *orelse = NULL;
n_elif = NCH(n) - 4;
/* must reference the child n_elif+1 since 'else' token is third,
not fourth, child from the end. */
if (TYPE(CHILD(n, (n_elif + 1))) == NAME
&& STR(CHILD(n, (n_elif + 1)))[2] == 's') {
has_else = 1;
n_elif -= 3;
}
n_elif /= 4;
if (has_else) {
asdl_seq *suite_seq2;
orelse = asdl_seq_new(1, c->c_arena);
if (!orelse)
return NULL;
expression = ast_for_expr(c, CHILD(n, NCH(n) - 6));
if (!expression)
return NULL;
suite_seq = ast_for_suite(c, CHILD(n, NCH(n) - 4));
if (!suite_seq)
return NULL;
suite_seq2 = ast_for_suite(c, CHILD(n, NCH(n) - 1));
if (!suite_seq2)
return NULL;
asdl_seq_SET(orelse, 0,
If(expression, suite_seq, suite_seq2,
LINENO(CHILD(n, NCH(n) - 6)),
CHILD(n, NCH(n) - 6)->n_col_offset,
c->c_arena));
/* the just-created orelse handled the last elif */
n_elif--;
}
for (i = 0; i < n_elif; i++) {
int off = 5 + (n_elif - i - 1) * 4;
asdl_seq *newobj = asdl_seq_new(1, c->c_arena);
if (!newobj)
return NULL;
expression = ast_for_expr(c, CHILD(n, off));
if (!expression)
return NULL;
suite_seq = ast_for_suite(c, CHILD(n, off + 2));
if (!suite_seq)
return NULL;
asdl_seq_SET(newobj, 0,
If(expression, suite_seq, orelse,
LINENO(CHILD(n, off)),
CHILD(n, off)->n_col_offset, c->c_arena));
orelse = newobj;
}
expression = ast_for_expr(c, CHILD(n, 1));
if (!expression)
return NULL;
suite_seq = ast_for_suite(c, CHILD(n, 3));
if (!suite_seq)
return NULL;
return If(expression, suite_seq, orelse,
LINENO(n), n->n_col_offset, c->c_arena);
}
PyErr_Format(PyExc_SystemError,
"unexpected token in 'if' statement: %s", s);
return NULL;
}
static stmt_ty
ast_for_while_stmt(struct compiling *c, const node *n)
{
/* while_stmt: 'while' test ':' suite ['else' ':' suite] */
REQ(n, while_stmt);
if (NCH(n) == 4) {
expr_ty expression;
asdl_seq *suite_seq;
expression = ast_for_expr(c, CHILD(n, 1));
if (!expression)
return NULL;
suite_seq = ast_for_suite(c, CHILD(n, 3));
if (!suite_seq)
return NULL;
return While(expression, suite_seq, NULL, LINENO(n), n->n_col_offset,
c->c_arena);
}
else if (NCH(n) == 7) {
expr_ty expression;
asdl_seq *seq1, *seq2;
expression = ast_for_expr(c, CHILD(n, 1));
if (!expression)
return NULL;
seq1 = ast_for_suite(c, CHILD(n, 3));
if (!seq1)
return NULL;
seq2 = ast_for_suite(c, CHILD(n, 6));
if (!seq2)
return NULL;
return While(expression, seq1, seq2, LINENO(n), n->n_col_offset,
c->c_arena);
}
PyErr_Format(PyExc_SystemError,
"wrong number of tokens for 'while' statement: %d",
NCH(n));
return NULL;
}
static stmt_ty
ast_for_for_stmt(struct compiling *c, const node *n)
{
asdl_seq *_target, *seq = NULL, *suite_seq;
expr_ty expression;
expr_ty target, first;
const node *node_target;
/* for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite] */
REQ(n, for_stmt);
if (NCH(n) == 9) {
seq = ast_for_suite(c, CHILD(n, 8));
if (!seq)
return NULL;
}
node_target = CHILD(n, 1);
_target = ast_for_exprlist(c, node_target, Store);
if (!_target)
return NULL;
/* Check the # of children rather than the length of _target, since
for x, in ... has 1 element in _target, but still requires a Tuple. */
first = (expr_ty)asdl_seq_GET(_target, 0);
if (NCH(node_target) == 1)
target = first;
else
target = Tuple(_target, Store, first->lineno, first->col_offset, c->c_arena);
expression = ast_for_testlist(c, CHILD(n, 3));
if (!expression)
return NULL;
suite_seq = ast_for_suite(c, CHILD(n, 5));
if (!suite_seq)
return NULL;
return For(target, expression, suite_seq, seq, LINENO(n), n->n_col_offset,
c->c_arena);
}
static excepthandler_ty
ast_for_except_clause(struct compiling *c, const node *exc, node *body)
{
/* except_clause: 'except' [test [(',' | 'as') test]] */
REQ(exc, except_clause);
REQ(body, suite);
if (NCH(exc) == 1) {
asdl_seq *suite_seq = ast_for_suite(c, body);
if (!suite_seq)
return NULL;
return ExceptHandler(NULL, NULL, suite_seq, LINENO(exc),
exc->n_col_offset, c->c_arena);
}
else if (NCH(exc) == 2) {
expr_ty expression;
asdl_seq *suite_seq;
expression = ast_for_expr(c, CHILD(exc, 1));
if (!expression)
return NULL;
suite_seq = ast_for_suite(c, body);
if (!suite_seq)
return NULL;
return ExceptHandler(expression, NULL, suite_seq, LINENO(exc),
exc->n_col_offset, c->c_arena);
}
else if (NCH(exc) == 4) {
asdl_seq *suite_seq;
expr_ty expression;
expr_ty e = ast_for_expr(c, CHILD(exc, 3));
if (!e)
return NULL;
if (!set_context(c, e, Store, CHILD(exc, 3)))
return NULL;
expression = ast_for_expr(c, CHILD(exc, 1));
if (!expression)
return NULL;
suite_seq = ast_for_suite(c, body);
if (!suite_seq)
return NULL;
return ExceptHandler(expression, e, suite_seq, LINENO(exc),
exc->n_col_offset, c->c_arena);
}
PyErr_Format(PyExc_SystemError,
"wrong number of children for 'except' clause: %d",
NCH(exc));
return NULL;
}
static stmt_ty
ast_for_try_stmt(struct compiling *c, const node *n)
{
const int nch = NCH(n);
int n_except = (nch - 3)/3;
asdl_seq *body, *orelse = NULL, *finally = NULL;
REQ(n, try_stmt);
body = ast_for_suite(c, CHILD(n, 2));
if (body == NULL)
return NULL;
if (TYPE(CHILD(n, nch - 3)) == NAME) {
if (strcmp(STR(CHILD(n, nch - 3)), "finally") == 0) {
if (nch >= 9 && TYPE(CHILD(n, nch - 6)) == NAME) {
/* we can assume it's an "else",
because nch >= 9 for try-else-finally and
it would otherwise have a type of except_clause */
orelse = ast_for_suite(c, CHILD(n, nch - 4));
if (orelse == NULL)
return NULL;
n_except--;
}
finally = ast_for_suite(c, CHILD(n, nch - 1));
if (finally == NULL)
return NULL;
n_except--;
}
else {
/* we can assume it's an "else",
otherwise it would have a type of except_clause */
orelse = ast_for_suite(c, CHILD(n, nch - 1));
if (orelse == NULL)
return NULL;
n_except--;
}
}
else if (TYPE(CHILD(n, nch - 3)) != except_clause) {
ast_error(n, "malformed 'try' statement");
return NULL;
}
if (n_except > 0) {
int i;
stmt_ty except_st;
/* process except statements to create a try ... except */
asdl_seq *handlers = asdl_seq_new(n_except, c->c_arena);
if (handlers == NULL)
return NULL;
for (i = 0; i < n_except; i++) {
excepthandler_ty e = ast_for_except_clause(c, CHILD(n, 3 + i * 3),
CHILD(n, 5 + i * 3));
if (!e)
return NULL;
asdl_seq_SET(handlers, i, e);
}
except_st = TryExcept(body, handlers, orelse, LINENO(n),
n->n_col_offset, c->c_arena);
if (!finally)
return except_st;
/* if a 'finally' is present too, we nest the TryExcept within a
TryFinally to emulate try ... except ... finally */
body = asdl_seq_new(1, c->c_arena);
if (body == NULL)
return NULL;
asdl_seq_SET(body, 0, except_st);
}
/* must be a try ... finally (except clauses are in body, if any exist) */
assert(finally != NULL);
return TryFinally(body, finally, LINENO(n), n->n_col_offset, c->c_arena);
}
/* with_item: test ['as' expr] */
static stmt_ty
ast_for_with_item(struct compiling *c, const node *n, asdl_seq *content)
{
expr_ty context_expr, optional_vars = NULL;
REQ(n, with_item);
context_expr = ast_for_expr(c, CHILD(n, 0));
if (!context_expr)
return NULL;
if (NCH(n) == 3) {
optional_vars = ast_for_expr(c, CHILD(n, 2));
if (!optional_vars) {
return NULL;
}
if (!set_context(c, optional_vars, Store, n)) {
return NULL;
}
}
return With(context_expr, optional_vars, content, LINENO(n),
n->n_col_offset, c->c_arena);
}
/* with_stmt: 'with' with_item (',' with_item)* ':' suite */
static stmt_ty
ast_for_with_stmt(struct compiling *c, const node *n)
{
int i;
stmt_ty ret;
asdl_seq *inner;
REQ(n, with_stmt);
/* process the with items inside-out */
i = NCH(n) - 1;
/* the suite of the innermost with item is the suite of the with stmt */
inner = ast_for_suite(c, CHILD(n, i));
if (!inner)
return NULL;
for (;;) {
i -= 2;
ret = ast_for_with_item(c, CHILD(n, i), inner);
if (!ret)
return NULL;
/* was this the last item? */
if (i == 1)
break;
/* if not, wrap the result so far in a new sequence */
inner = asdl_seq_new(1, c->c_arena);
if (!inner)
return NULL;
asdl_seq_SET(inner, 0, ret);
}
return ret;
}
static stmt_ty
ast_for_classdef(struct compiling *c, const node *n, asdl_seq *decorator_seq)
{
/* classdef: 'class' NAME ['(' testlist ')'] ':' suite */
PyObject *classname;
asdl_seq *bases, *s;
REQ(n, classdef);
if (!forbidden_check(c, n, STR(CHILD(n, 1))))
return NULL;
if (NCH(n) == 4) {
s = ast_for_suite(c, CHILD(n, 3));
if (!s)
return NULL;
classname = NEW_IDENTIFIER(CHILD(n, 1));
if (!classname)
return NULL;
return ClassDef(classname, NULL, s, decorator_seq, LINENO(n),
n->n_col_offset, c->c_arena);
}
/* check for empty base list */
if (TYPE(CHILD(n,3)) == RPAR) {
s = ast_for_suite(c, CHILD(n,5));
if (!s)
return NULL;
classname = NEW_IDENTIFIER(CHILD(n, 1));
if (!classname)
return NULL;
return ClassDef(classname, NULL, s, decorator_seq, LINENO(n),
n->n_col_offset, c->c_arena);
}
/* else handle the base class list */
bases = ast_for_class_bases(c, CHILD(n, 3));
if (!bases)
return NULL;
s = ast_for_suite(c, CHILD(n, 6));
if (!s)
return NULL;
classname = NEW_IDENTIFIER(CHILD(n, 1));
if (!classname)
return NULL;
return ClassDef(classname, bases, s, decorator_seq,
LINENO(n), n->n_col_offset, c->c_arena);
}
static stmt_ty
ast_for_stmt(struct compiling *c, const node *n)
{
if (TYPE(n) == stmt) {
assert(NCH(n) == 1);
n = CHILD(n, 0);
}
if (TYPE(n) == simple_stmt) {
assert(num_stmts(n) == 1);
n = CHILD(n, 0);
}
if (TYPE(n) == small_stmt) {
n = CHILD(n, 0);
/* small_stmt: expr_stmt | print_stmt | del_stmt | pass_stmt
| flow_stmt | import_stmt | global_stmt | exec_stmt
| assert_stmt
*/
switch (TYPE(n)) {
case expr_stmt:
return ast_for_expr_stmt(c, n);
case print_stmt:
return ast_for_print_stmt(c, n);
case del_stmt:
return ast_for_del_stmt(c, n);
case pass_stmt:
return Pass(LINENO(n), n->n_col_offset, c->c_arena);