python, hg: tow outside the environment.

they've served us well, and can ride off into the sunset.

1 files changed, 0 insertions, 3292 deletions

diff --git a/sys/src/cmd/python/Python/ast.c b/sys/src/cmd/python/Python/ast.c
deleted file mode 100644
index 67f45ed06..000000000
--- a/sys/src/cmd/python/Python/ast.c
+++ /dev/null
@@ -1,3292 +0,0 @@
-/*
- * 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>
-
-/* XXX TO DO
-   - re-indent this file (should be done)
-   - internal error checking (freeing memory, etc.)
-   - syntax errors
-*/
-
-/* Data structure used internally */
-struct compiling {
-    char *c_encoding; /* source encoding */
-    PyArena *c_arena; /* arena for allocating memeory */
-};
-
-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 expr_ty ast_for_testlist_gexp(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(const char *);
-static PyObject *parsestr(const char *s, const char *encoding);
-static PyObject *parsestrplus(struct compiling *, const node *n);
-
-#ifndef LINENO
-#define LINENO(n)	((n)->n_lineno)
-#endif
-
-static identifier
-new_identifier(const char* n, PyArena *arena) {
-    PyObject* id = PyString_InternFromString(n);
-    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);
-}
-
-/* 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\n",
-                    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_arena = arena;
-
-    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 gen_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));
-                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:
-            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(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 &&
-		    !strcmp(PyString_AS_STRING(e->v.Attribute.attr), "None")) {
-		    return ast_error(n, "assignment to None");
-	    }
-	    e->v.Attribute.ctx = ctx;
-	    break;
-        case Subscript_kind:
-	    e->v.Subscript.ctx = ctx;
-	    break;
-        case Name_kind:
-	    if (ctx == Store &&
-		!strcmp(PyString_AS_STRING(e->v.Name.id), "None")) {
-		    return ast_error(n, "assignment to None");
-	    }
-	    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) == 0) 
-                return ast_error(n, "can't assign to ()");
-	    e->v.Tuple.ctx = ctx;
-	    s = e->v.Tuple.elts;
-	    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 Dict_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((expr_ty)asdl_seq_GET(s, i), ctx, n))
-		return 0;
-	}
-    }
-    return 1;
-}
-
-static operator_ty
-ast_for_augassign(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(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_gexp
-	   || 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++) {
-        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 (!strcmp(STR(child), "None")) {
-	    		ast_error(child, "assignment to None");
-		    	return NULL;
-		    }   
-            arg = Name(NEW_IDENTIFIER(child), 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 a '(', 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(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; /* Don't need to goto error; no objects allocated */
-    defaults = (n_defaults ? asdl_seq_new(n_defaults, c->c_arena) : NULL);
-    if (!defaults && n_defaults)
-    	return NULL; /* Don't need to goto error; no objects allocated */
-
-    /* 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:
-            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)
-                            goto error;
-                    assert(defaults != NULL);
-                    asdl_seq_SET(defaults, j++, expression);
-                    i += 2;
-		    found_default = 1;
-                }
-		else if (found_default) {
-		    ast_error(n, 
-			     "non-default argument follows default argument");
-		    goto error;
-		}
-                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. */
-			asdl_seq_SET(args, k++, compiler_complex_args(c, ch));
-		    } else {
-			/* def foo((x)): setup for checking NAME below. */
-			/* Loop because there can be many parens and tuple
-			   upacking mixed in. */
-			ch = CHILD(ch, 0);
-			assert(TYPE(ch) == fpdef);
-			goto handle_fpdef;
-		    }
-                }
-                if (TYPE(CHILD(ch, 0)) == NAME) {
-		    expr_ty name;
-		    if (!strcmp(STR(CHILD(ch, 0)), "None")) {
-			    ast_error(CHILD(ch, 0), "assignment to None");
-			    goto error;
-		    }
-                    name = Name(NEW_IDENTIFIER(CHILD(ch, 0)),
-                                Param, LINENO(ch), ch->n_col_offset,
-                                c->c_arena);
-                    if (!name)
-                        goto error;
-                    asdl_seq_SET(args, k++, name);
-					 
-		}
-                i += 2; /* the name and the comma */
-                break;
-            case STAR:
-		if (!strcmp(STR(CHILD(n, i+1)), "None")) {
-			ast_error(CHILD(n, i+1), "assignment to None");
-			goto error;
-		}
-                vararg = NEW_IDENTIFIER(CHILD(n, i+1));
-                i += 3;
-                break;
-            case DOUBLESTAR:
-		if (!strcmp(STR(CHILD(n, i+1)), "None")) {
-			ast_error(CHILD(n, i+1), "assignment to None");
-			goto error;
-		}
-                kwarg = NEW_IDENTIFIER(CHILD(n, i+1));
-                i += 3;
-                break;
-            default:
-                PyErr_Format(PyExc_SystemError,
-                             "unexpected node in varargslist: %d @ %d",
-                             TYPE(ch), i);
-                goto error;
-	}
-    }
-
-    return arguments(args, vararg, kwarg, defaults, c->c_arena);
-
- error:
-    Py_XDECREF(vararg);
-    Py_XDECREF(kwarg);
-    return NULL;
-}
-
-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)
-{
-    /* funcdef: 'def' [decorators] NAME parameters ':' suite */
-    identifier name;
-    arguments_ty args;
-    asdl_seq *body;
-    asdl_seq *decorator_seq = NULL;
-    int name_i;
-
-    REQ(n, funcdef);
-
-    if (NCH(n) == 6) { /* decorators are present */
-	decorator_seq = ast_for_decorators(c, CHILD(n, 0));
-	if (!decorator_seq)
-	    return NULL;
-	name_i = 2;
-    }
-    else {
-	name_i = 1;
-    }
-
-    name = NEW_IDENTIFIER(CHILD(n, name_i));
-    if (!name)
-	return NULL;
-    else if (!strcmp(STR(CHILD(n, name_i)), "None")) {
-	ast_error(CHILD(n, name_i), "assignment to None");
-	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 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);
-}
-
-/* Count the number of 'for' loop in a list comprehension.
-
-   Helper for ast_for_listcomp().
-*/
-
-static int
-count_list_fors(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(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;
-    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(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. */
-	if (NCH(for_ch) == 1)
-	    lc = comprehension((expr_ty)asdl_seq_GET(t, 0), expression, NULL,
-                               c->c_arena);
-	else
-	    lc = comprehension(Tuple(t, Store, LINENO(ch), ch->n_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(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 generator expression.
-
-   Helper for ast_for_genexp().
-*/
-
-static int
-count_gen_fors(const node *n)
-{
-	int n_fors = 0;
-	node *ch = CHILD(n, 1);
-
- count_gen_for:
-	n_fors++;
-	REQ(ch, gen_for);
-	if (NCH(ch) == 5)
-		ch = CHILD(ch, 4);
-	else
-		return n_fors;
- count_gen_iter:
-	REQ(ch, gen_iter);
-	ch = CHILD(ch, 0);
-	if (TYPE(ch) == gen_for)
-		goto count_gen_for;
-	else if (TYPE(ch) == gen_if) {
-		if (NCH(ch) == 3) {
-			ch = CHILD(ch, 2);
-			goto count_gen_iter;
-		}
-		else
-		    return n_fors;
-	}
-
-	/* Should never be reached */
-	PyErr_SetString(PyExc_SystemError,
-			"logic error in count_gen_fors");
-	return -1;
-}
-
-/* Count the number of 'if' statements in a generator expression.
-
-   Helper for ast_for_genexp().
-*/
-
-static int
-count_gen_ifs(const node *n)
-{
-	int n_ifs = 0;
-
-	while (1) {
-		REQ(n, gen_iter);
-		if (TYPE(CHILD(n, 0)) == gen_for)
-			return n_ifs;
-		n = CHILD(n, 0);
-		REQ(n, gen_if);
-		n_ifs++;
-		if (NCH(n) == 2)
-			return n_ifs;
-		n = CHILD(n, 2);
-	}
-}
-
-/* TODO(jhylton): Combine with list comprehension code? */
-static expr_ty
-ast_for_genexp(struct compiling *c, const node *n)
-{
-    /* testlist_gexp: test ( gen_for | (',' test)* [','] )
-       argument: [test '='] test [gen_for]	 # Really [keyword '='] test */
-    expr_ty elt;
-    asdl_seq *genexps;
-    int i, n_fors;
-    node *ch;
-    
-    assert(TYPE(n) == (testlist_gexp) || TYPE(n) == (argument));
-    assert(NCH(n) > 1);
-    
-    elt = ast_for_expr(c, CHILD(n, 0));
-    if (!elt)
-        return NULL;
-    
-    n_fors = count_gen_fors(n);
-    if (n_fors == -1)
-        return NULL;
-
-    genexps = asdl_seq_new(n_fors, c->c_arena);
-    if (!genexps)
-        return NULL;
-
-    ch = CHILD(n, 1);
-    for (i = 0; i < n_fors; i++) {
-        comprehension_ty ge;
-        asdl_seq *t;
-        expr_ty expression;
-        node *for_ch;
-        
-        REQ(ch, gen_for);
-        
-        for_ch = CHILD(ch, 1);
-        t = ast_for_exprlist(c, for_ch, Store);
-        if (!t)
-            return NULL;
-        expression = ast_for_expr(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. */
-        if (NCH(for_ch) == 1)
-            ge = comprehension((expr_ty)asdl_seq_GET(t, 0), expression,
-                               NULL, c->c_arena);
-        else
-            ge = comprehension(Tuple(t, Store, LINENO(ch), ch->n_col_offset,
-                                     c->c_arena),
-                               expression, NULL, c->c_arena);
-
-        if (!ge)
-            return NULL;
-
-        if (NCH(ch) == 5) {
-            int j, n_ifs;
-            asdl_seq *ifs;
-            
-            ch = CHILD(ch, 4);
-            n_ifs = count_gen_ifs(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, gen_iter);
-                ch = CHILD(ch, 0);
-                REQ(ch, gen_if);
-                
-                expression = ast_for_expr(c, CHILD(ch, 1));
-                if (!expression)
-                    return NULL;
-                asdl_seq_SET(ifs, j, expression);
-                if (NCH(ch) == 3)
-                    ch = CHILD(ch, 2);
-            }
-            /* on exit, must guarantee that ch is a gen_for */
-            if (TYPE(ch) == gen_iter)
-                ch = CHILD(ch, 0);
-            ge->ifs = ifs;
-        }
-        asdl_seq_SET(genexps, i, ge);
-    }
-    
-    return GeneratorExp(elt, genexps, LINENO(n), n->n_col_offset, c->c_arena);
-}
-
-static expr_ty
-ast_for_atom(struct compiling *c, const node *n)
-{
-    /* atom: '(' [yield_expr|testlist_gexp] ')' | '[' [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. */
-	return Name(NEW_IDENTIFIER(ch), Load, LINENO(n), n->n_col_offset, c->c_arena);
-    case STRING: {
-	PyObject *str = parsestrplus(c, n);
-	if (!str)
-	    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(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);
-	
-	if ((NCH(ch) > 1) && (TYPE(CHILD(ch, 1)) == gen_for))
-	    return ast_for_genexp(c, ch);
-	
-	return ast_for_testlist_gexp(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: {
-	/* dictmaker: test ':' test (',' test ':' test)* [','] */
-	int i, size;
-	asdl_seq *keys, *values;
-	
-	ch = CHILD(n, 1);
-	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 = 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) {
-            /* No expression, so step is None */
-            ch = CHILD(ch, 0);
-            step = Name(new_identifier("None", c->c_arena), 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) 
-			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 ) {
-        return Attribute(left_expr, NEW_IDENTIFIER(CHILD(n, 1)), 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) {
-        char *s = PyObject_MALLOC(strlen(STR(pnum)) + 2);
-        if (s == NULL)
-            return NULL;
-        s[0] = '-';
-        strcpy(s + 1, STR(pnum));
-        PyObject_FREE(STR(pnum));
-        STR(pnum) = s;
-        return ast_for_atom(c, patom);
-    }
-
-    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(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 [gen_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)) == gen_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;
-		}
-		e = ast_for_expr(c, CHILD(ch, 0));
-                if (!e)
-                    return NULL;
-		asdl_seq_SET(args, nargs++, e);
-	    }  
-	    else if (TYPE(CHILD(ch, 1)) == gen_for) {
-        	e = ast_for_genexp(c, ch);
-                if (!e)
-                    return NULL;
-		asdl_seq_SET(args, nargs++, e);
-            }
-	    else {
-		keyword_ty kw;
-		identifier key;
-
-		/* 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;
-		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));
-	    i++;
-	}
-	else if (TYPE(ch) == DOUBLESTAR) {
-	    kwarg = ast_for_expr(c, CHILD(n, i+1));
-	    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_gexp: test (',' test)* [','] */
-    /* testlist: test (',' test)* [','] */
-    /* testlist_safe: test (',' test)+ [','] */
-    /* testlist1: test (',' test)* */
-    assert(NCH(n) > 0);
-    if (TYPE(n) == testlist_gexp) {
-        if (NCH(n) > 1)
-            assert(TYPE(CHILD(n, 1)) != gen_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_gexp(struct compiling *c, const node* n)
-{
-    /* testlist_gexp: test ( gen_for | (',' test)* [','] ) */
-    /* argument: test [ gen_for ] */
-    assert(TYPE(n) == testlist_gexp || TYPE(n) == argument);
-    if (NCH(n) > 1 && TYPE(CHILD(n, 1)) == gen_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;
-        /* TODO(nas): Remove duplicated error checks (set_context does it) */
-        switch (expr1->kind) {
-            case GeneratorExp_kind:
-                ast_error(ch, "augmented assignment to generator "
-                          "expression not possible");
-                return NULL;
-            case Yield_kind:
-                ast_error(ch, "augmented assignment to yield "
-                          "expression not possible");
-                return NULL;
-            case Name_kind: {
-                const char *var_name = PyString_AS_STRING(expr1->v.Name.id);
-                if (var_name[0] == 'N' && !strcmp(var_name, "None")) {
-                    ast_error(ch, "assignment to None");
-                    return NULL;
-                }
-                break;
-            }
-            case Attribute_kind:
-            case Subscript_kind:
-                break;
-            default:
-                ast_error(ch, "illegal expression for augmented "
-                          "assignment");
-                return NULL;
-        }
-	if (!set_context(expr1, Store, ch))
-		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(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);
-
-	    /* set context to assign */
-	    if (!e) 
-	      return NULL;
-
-	    if (!set_context(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;
-    bool nl;
-    int i, j, 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;
-    }
-    seq = asdl_seq_new((NCH(n) + 1 - start) / 2, 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(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)
-{
-    /*
-      import_as_name: NAME ['as' NAME]
-      dotted_as_name: dotted_name ['as' NAME]
-      dotted_name: NAME ('.' NAME)*
-    */
-    PyObject *str;
-
- loop:
-    switch (TYPE(n)) {
-        case import_as_name:
-            str = NULL;
-            if (NCH(n) == 3) {
-                if (strcmp(STR(CHILD(n, 1)), "as") != 0) {
-                    ast_error(n, "must use 'as' in import");
-                    return NULL;
-                }
-                str = NEW_IDENTIFIER(CHILD(n, 2));
-            }
-            return alias(NEW_IDENTIFIER(CHILD(n, 0)), str, c->c_arena);
-        case dotted_as_name:
-            if (NCH(n) == 1) {
-                n = CHILD(n, 0);
-                goto loop;
-            }
-            else {
-                alias_ty a = alias_for_import_name(c, CHILD(n, 0));
-                if (!a)
-                    return NULL;
-                if (strcmp(STR(CHILD(n, 1)), "as") != 0) {
-                    ast_error(n, "must use 'as' in import");
-                    return NULL;
-                }
-                assert(!a->asname);
-                a->asname = NEW_IDENTIFIER(CHILD(n, 2));
-                return a;
-            }
-            break;
-        case dotted_name:
-            if (NCH(n) == 1)
-                return alias(NEW_IDENTIFIER(CHILD(n, 0)), 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));
-            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;
-	
-       /* 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));
-	    	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;
-	    if (ndots) {
-	        ast_error(n, "'import *' not allowed with 'from .'");
-	        return NULL;
-	    }
-	    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);
-            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));
-                if (!import_alias)
-                    return NULL;
-	            asdl_seq_SET(aliases, i / 2, import_alias);
-            }
-        }
-        if (mod != NULL)
-            modname = mod->name;
-        else
-            modname = new_identifier("", c->c_arena);
-        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;
-    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. */
-    if (NCH(node_target) == 1)
-	target = (expr_ty)asdl_seq_GET(_target, 0);
-    else
-	target = Tuple(_target, Store, LINENO(n), n->n_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 [',' 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(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);
-}
-
-static expr_ty
-ast_for_with_var(struct compiling *c, const node *n)
-{
-    REQ(n, with_var);
-    if (strcmp(STR(CHILD(n, 0)), "as") != 0) {
-        ast_error(n, "expected \"with [expr] as [var]\"");
-        return NULL;
-    }
-    return ast_for_expr(c, CHILD(n, 1));
-}
-
-/* with_stmt: 'with' test [ with_var ] ':' suite */
-static stmt_ty
-ast_for_with_stmt(struct compiling *c, const node *n)
-{
-    expr_ty context_expr, optional_vars = NULL;
-    int suite_index = 3;    /* skip 'with', test, and ':' */
-    asdl_seq *suite_seq;
-
-    assert(TYPE(n) == with_stmt);
-    context_expr = ast_for_expr(c, CHILD(n, 1));
-    if (!context_expr)
-        return NULL;
-    if (TYPE(CHILD(n, 2)) == with_var) {
-        optional_vars = ast_for_with_var(c, CHILD(n, 2));
-
-        if (!optional_vars) {
-            return NULL;
-        }
-	if (!set_context(optional_vars, Store, n)) {
-	    return NULL;
-	}
-        suite_index = 4;
-    }
-
-    suite_seq = ast_for_suite(c, CHILD(n, suite_index));
-    if (!suite_seq) {
-        return NULL;
-    }
-    return With(context_expr, optional_vars, suite_seq, LINENO(n), 
-		n->n_col_offset, c->c_arena);
-}
-
-static stmt_ty
-ast_for_classdef(struct compiling *c, const node *n)
-{
-    /* classdef: 'class' NAME ['(' testlist ')'] ':' suite */
-    asdl_seq *bases, *s;
-    
-    REQ(n, classdef);
-
-    if (!strcmp(STR(CHILD(n, 1)), "None")) {
-	    ast_error(n, "assignment to None");
-	    return NULL;
-    }
-
-    if (NCH(n) == 4) {
-        s = ast_for_suite(c, CHILD(n, 3));
-        if (!s)
-            return NULL;
-	return ClassDef(NEW_IDENTIFIER(CHILD(n, 1)), NULL, s, 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;
-	return ClassDef(NEW_IDENTIFIER(CHILD(n, 1)), NULL, s, 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;
-    return ClassDef(NEW_IDENTIFIER(CHILD(n, 1)), bases, s, 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) {
-	REQ(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);
-            case flow_stmt:
-                return ast_for_flow_stmt(c, n);
-            case import_stmt:
-                return ast_for_import_stmt(c, n);
-            case global_stmt:
-                return ast_for_global_stmt(c, n);
-            case exec_stmt:
-                return ast_for_exec_stmt(c, n);
-            case assert_stmt:
-                return ast_for_assert_stmt(c, n);
-            default:
-                PyErr_Format(PyExc_SystemError,
-                             "unhandled small_stmt: TYPE=%d NCH=%d\n",
-                             TYPE(n), NCH(n));
-                return NULL;
-        }
-    }
-    else {
-        /* compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt
-	                | funcdef | classdef
-	*/
-	node *ch = CHILD(n, 0);
-	REQ(n, compound_stmt);
-	switch (TYPE(ch)) {
-            case if_stmt:
-                return ast_for_if_stmt(c, ch);
-            case while_stmt:
-                return ast_for_while_stmt(c, ch);
-            case for_stmt:
-                return ast_for_for_stmt(c, ch);
-            case try_stmt:
-                return ast_for_try_stmt(c, ch);
-            case with_stmt:
-                return ast_for_with_stmt(c, ch);
-            case funcdef:
-                return ast_for_funcdef(c, ch);
-            case classdef:
-                return ast_for_classdef(c, ch);
-            default:
-                PyErr_Format(PyExc_SystemError,
-                             "unhandled small_stmt: TYPE=%d NCH=%d\n",
-                             TYPE(n), NCH(n));
-                return NULL;
-	}
-    }
-}
-
-static PyObject *
-parsenumber(const char *s)
-{
-	const char *end;
-	long x;
-	double dx;
-#ifndef WITHOUT_COMPLEX
-	Py_complex c;
-	int imflag;
-#endif
-
-	errno = 0;
-	end = s + strlen(s) - 1;
-#ifndef WITHOUT_COMPLEX
-	imflag = *end == 'j' || *end == 'J';
-#endif
-	if (*end == 'l' || *end == 'L')
-		return PyLong_FromString((char *)s, (char **)0, 0);
-	if (s[0] == '0') {
-		x = (long) PyOS_strtoul((char *)s, (char **)&end, 0);
- 		if (x < 0 && errno == 0) {
-	 			return PyLong_FromString((char *)s,
-							 (char **)0,
-							 0);
-		}
-	}
-	else
-		x = PyOS_strtol((char *)s, (char **)&end, 0);
-	if (*end == '\0') {
-		if (errno != 0)
-			return PyLong_FromString((char *)s, (char **)0, 0);
-		return PyInt_FromLong(x);
-	}
-	/* XXX Huge floats may silently fail */
-#ifndef WITHOUT_COMPLEX
-	if (imflag) {
-		c.real = 0.;
-		PyFPE_START_PROTECT("atof", return 0)
-		c.imag = PyOS_ascii_atof(s);
-		PyFPE_END_PROTECT(c)
-		return PyComplex_FromCComplex(c);
-	}
-	else
-#endif
-	{
-		PyFPE_START_PROTECT("atof", return 0)
-		dx = PyOS_ascii_atof(s);
-		PyFPE_END_PROTECT(dx)
-		return PyFloat_FromDouble(dx);
-	}
-}
-
-static PyObject *
-decode_utf8(const char **sPtr, const char *end, char* encoding)
-{
-#ifndef Py_USING_UNICODE
-	Py_FatalError("decode_utf8 should not be called in this build.");
-        return NULL;
-#else
-	PyObject *u, *v;
-	char *s, *t;
-	t = s = (char *)*sPtr;
-	/* while (s < end && *s != '\\') s++; */ /* inefficient for u".." */
-	while (s < end && (*s & 0x80)) s++;
-	*sPtr = s;
-	u = PyUnicode_DecodeUTF8(t, s - t, NULL);
-	if (u == NULL)
-		return NULL;
-	v = PyUnicode_AsEncodedString(u, encoding, NULL);
-	Py_DECREF(u);
-	return v;
-#endif
-}
-
-static PyObject *
-decode_unicode(const char *s, size_t len, int rawmode, const char *encoding)
-{
-	PyObject *v, *u;
-	char *buf;
-	char *p;
-	const char *end;
-	if (encoding == NULL) {
-	     	buf = (char *)s;
-		u = NULL;
-	} else if (strcmp(encoding, "iso-8859-1") == 0) {
-	     	buf = (char *)s;
-		u = NULL;
-	} else {
-		/* "\XX" may become "\u005c\uHHLL" (12 bytes) */
-		u = PyString_FromStringAndSize((char *)NULL, len * 4);
-		if (u == NULL)
-			return NULL;
-		p = buf = PyString_AsString(u);
-		end = s + len;
-		while (s < end) {
-			if (*s == '\\') {
-				*p++ = *s++;
-				if (*s & 0x80) {
-					strcpy(p, "u005c");
-					p += 5;
-				}
-			}
-			if (*s & 0x80) { /* XXX inefficient */
-				PyObject *w;
-				char *r;
-				Py_ssize_t rn, i;
-				w = decode_utf8(&s, end, "utf-16-be");
-				if (w == NULL) {
-					Py_DECREF(u);
-					return NULL;
-				}
-				r = PyString_AsString(w);
-				rn = PyString_Size(w);
-				assert(rn % 2 == 0);
-				for (i = 0; i < rn; i += 2) {
-					sprintf(p, "\\u%02x%02x",
-						r[i + 0] & 0xFF,
-						r[i + 1] & 0xFF);
-					p += 6;
-				}
-				Py_DECREF(w);
-			} else {
-				*p++ = *s++;
-			}
-		}
-		len = p - buf;
-		s = buf;
-	}
-	if (rawmode)
-		v = PyUnicode_DecodeRawUnicodeEscape(s, len, NULL);
-	else
-		v = PyUnicode_DecodeUnicodeEscape(s, len, NULL);
-	Py_XDECREF(u);
-	return v;
-}
-
-/* s is a Python string literal, including the bracketing quote characters,
- * and r &/or u prefixes (if any), and embedded escape sequences (if any).
- * parsestr parses it, and returns the decoded Python string object.
- */
-static PyObject *
-parsestr(const char *s, const char *encoding)
-{
-	size_t len;
-	int quote = Py_CHARMASK(*s);
-	int rawmode = 0;
-	int need_encoding;
-	int unicode = 0;
-
-	if (isalpha(quote) || quote == '_') {
-		if (quote == 'u' || quote == 'U') {
-			quote = *++s;
-			unicode = 1;
-		}
-		if (quote == 'r' || quote == 'R') {
-			quote = *++s;
-			rawmode = 1;
-		}
-	}
-	if (quote != '\'' && quote != '\"') {
-		PyErr_BadInternalCall();
-		return NULL;
-	}
-	s++;
-	len = strlen(s);
-	if (len > INT_MAX) {
-		PyErr_SetString(PyExc_OverflowError, 
-				"string to parse is too long");
-		return NULL;
-	}
-	if (s[--len] != quote) {
-		PyErr_BadInternalCall();
-		return NULL;
-	}
-	if (len >= 4 && s[0] == quote && s[1] == quote) {
-		s += 2;
-		len -= 2;
-		if (s[--len] != quote || s[--len] != quote) {
-			PyErr_BadInternalCall();
-			return NULL;
-		}
-	}
-#ifdef Py_USING_UNICODE
-	if (unicode || Py_UnicodeFlag) {
-		return decode_unicode(s, len, rawmode, encoding);
-	}
-#endif
-	need_encoding = (encoding != NULL &&
-			 strcmp(encoding, "utf-8") != 0 &&
-			 strcmp(encoding, "iso-8859-1") != 0);
-	if (rawmode || strchr(s, '\\') == NULL) {
-		if (need_encoding) {
-#ifndef Py_USING_UNICODE
-			/* This should not happen - we never see any other
-			   encoding. */
-			Py_FatalError(
-                            "cannot deal with encodings in this build.");
-#else
-			PyObject *v, *u = PyUnicode_DecodeUTF8(s, len, NULL);
-			if (u == NULL)
-				return NULL;
-			v = PyUnicode_AsEncodedString(u, encoding, NULL);
-			Py_DECREF(u);
-			return v;
-#endif
-		} else {
-			return PyString_FromStringAndSize(s, len);
-		}
-	}
-
-	return PyString_DecodeEscape(s, len, NULL, unicode,
-				     need_encoding ? encoding : NULL);
-}
-
-/* Build a Python string object out of a STRING atom.  This takes care of
- * compile-time literal catenation, calling parsestr() on each piece, and
- * pasting the intermediate results together.
- */
-static PyObject *
-parsestrplus(struct compiling *c, const node *n)
-{
-	PyObject *v;
-	int i;
-	REQ(CHILD(n, 0), STRING);
-	if ((v = parsestr(STR(CHILD(n, 0)), c->c_encoding)) != NULL) {
-		/* String literal concatenation */
-		for (i = 1; i < NCH(n); i++) {
-			PyObject *s;
-			s = parsestr(STR(CHILD(n, i)), c->c_encoding);
-			if (s == NULL)
-				goto onError;
-			if (PyString_Check(v) && PyString_Check(s)) {
-				PyString_ConcatAndDel(&v, s);
-				if (v == NULL)
-				    goto onError;
-			}
-#ifdef Py_USING_UNICODE
-			else {
-				PyObject *temp = PyUnicode_Concat(v, s);
-				Py_DECREF(s);
-				Py_DECREF(v);
-				v = temp;
-				if (v == NULL)
-				    goto onError;
-			}
-#endif
-		}
-	}
-	return v;
-
- onError:
-	Py_XDECREF(v);
-	return NULL;
-}