#include "Python.h"

#include "Python-ast.h"

#include "node.h"

#include "token.h"

#include "graminit.h"

#include "code.h"

#include "compile.h"

#include "symtable.h"

#define UNDEFINED_FUTURE_FEATURE "future feature %.100s is not defined"

#define ERR_LATE_FUTURE \

"from __future__ imports must occur at the beginning of the file"

static int

future_check_features(PyFutureFeatures *ff, stmt_ty s, const char *filename)

{

int i;

asdl_seq *names;

assert(s->kind == ImportFrom_kind);

names = s->v.ImportFrom.names;

for (i = 0; i < asdl_seq_LEN(names); i++) {

alias_ty name = (alias_ty)asdl_seq_GET(names, i);

const char *feature = PyString_AsString(name->name);

if (!feature)

return 0;

if (strcmp(feature, FUTURE_NESTED_SCOPES) == 0) {

continue;

} else if (strcmp(feature, FUTURE_GENERATORS) == 0) {

continue;

} else if (strcmp(feature, FUTURE_DIVISION) == 0) {

ff->ff_features |= CO_FUTURE_DIVISION;

} else if (strcmp(feature, FUTURE_ABSOLUTE_IMPORT) == 0) {

ff->ff_features |= CO_FUTURE_ABSOLUTE_IMPORT;

} else if (strcmp(feature, FUTURE_WITH_STATEMENT) == 0) {

ff->ff_features |= CO_FUTURE_WITH_STATEMENT;

} else if (strcmp(feature, FUTURE_PRINT_FUNCTION) == 0) {

ff->ff_features |= CO_FUTURE_PRINT_FUNCTION;

} else if (strcmp(feature, FUTURE_UNICODE_LITERALS) == 0) {

ff->ff_features |= CO_FUTURE_UNICODE_LITERALS;

} else if (strcmp(feature, "braces") == 0) {

PyErr_SetString(PyExc_SyntaxError,

"not a chance");

PyErr_SyntaxLocation(filename, s->lineno);

return 0;

} else {

PyErr_Format(PyExc_SyntaxError,

UNDEFINED_FUTURE_FEATURE, feature);

PyErr_SyntaxLocation(filename, s->lineno);

return 0;

}

}

return 1;

}

static int

future_parse(PyFutureFeatures *ff, mod_ty mod, const char *filename)

{

int i, found_docstring = 0, done = 0, prev_line = 0;

if (!(mod->kind == Module_kind || mod->kind == Interactive_kind))

return 1;

/* A subsequent pass will detect future imports that don't

for (i = 0; i < asdl_seq_LEN(mod->v.Module.body); i++) {

stmt_ty s = (stmt_ty)asdl_seq_GET(mod->v.Module.body, i);

if (done && s->lineno > prev_line)

return 1;

prev_line = s->lineno;

/* The tests below will return from this function unless it is

if (s->kind == ImportFrom_kind) {

identifier modname = s->v.ImportFrom.module;

if (modname && PyString_GET_SIZE(modname) == 10 &&

!strcmp(PyString_AS_STRING(modname), "__future__")) {

if (done) {

PyErr_SetString(PyExc_SyntaxError,

ERR_LATE_FUTURE);

PyErr_SyntaxLocation(filename,

s->lineno);

return 0;

}

if (!future_check_features(ff, s, filename))

return 0;

ff->ff_lineno = s->lineno;

}

else

done = 1;

}

else if (s->kind == Expr_kind && !found_docstring) {

expr_ty e = s->v.Expr.value;

if (e->kind != Str_kind)

done = 1;

else

found_docstring = 1;

}

else

done = 1;

}

return 1;

}

PyFutureFeatures *

PyFuture_FromAST(mod_ty mod, const char *filename)

{

PyFutureFeatures *ff;

ff = (PyFutureFeatures *)PyObject_Malloc(sizeof(PyFutureFeatures));

if (ff == NULL) {

PyErr_NoMemory();

return NULL;

}

ff->ff_features = 0;

ff->ff_lineno = -1;

if (!future_parse(ff, mod, filename)) {

PyObject_Free(ff);

return NULL;

}

return ff;

}