#include "Python.h"

#include "pycore_ast.h" // _PyAST_GetDocString()

#include "pycore_pyerrors.h" // _Py_CalculateSuggestions()

#include "pycore_symtable.h" // _PyFutureFeatures

#include "pycore_unicodeobject.h" // _PyUnicode_EqualToASCIIString()

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

static int

future_check_features(_PyFutureFeatures *ff, stmt_ty s, PyObject *filename)

{

Py_ssize_t i;

assert(s->kind == ImportFrom_kind);

asdl_alias_seq *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 = PyUnicode_AsUTF8(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) {

continue;

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

continue;

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

continue;

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

continue;

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

continue;

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

ff->ff_features |= CO_FUTURE_BARRY_AS_BDFL;

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

continue;

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

ff->ff_features |= CO_FUTURE_ANNOTATIONS;

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

PyErr_SetString(PyExc_SyntaxError,

"not a chance");

PyErr_RangedSyntaxLocationObject(filename,

name->lineno,

name->col_offset + 1,

name->end_lineno,

name->end_col_offset + 1);

return 0;

} else {

// Keep this list in sync with the feature checks above.

PyObject *future_features = Py_BuildValue("[ssssssssss]",

FUTURE_NESTED_SCOPES,

FUTURE_GENERATORS,

FUTURE_DIVISION,

FUTURE_ABSOLUTE_IMPORT,

FUTURE_WITH_STATEMENT,

FUTURE_PRINT_FUNCTION,

FUTURE_UNICODE_LITERALS,

FUTURE_BARRY_AS_BDFL,

FUTURE_GENERATOR_STOP,

FUTURE_ANNOTATIONS);

PyObject *suggestion = NULL;

if (future_features != NULL) {

suggestion = _Py_CalculateSuggestions(future_features,

name->name);

}

if (suggestion != NULL) {

PyErr_Format(PyExc_SyntaxError,

UNDEFINED_FUTURE_FEATURE ". Did you mean: %R?",

feature, suggestion);

Py_DECREF(suggestion);

}

else {

// Do not fail on missing suggestion,

// just show the default message.

PyErr_Format(PyExc_SyntaxError,

UNDEFINED_FUTURE_FEATURE,

feature);

}

Py_XDECREF(future_features);

PyErr_RangedSyntaxLocationObject(filename,

name->lineno,

name->col_offset + 1,

name->end_lineno,

name->end_col_offset + 1);

return 0;

}

}

return 1;

}

static int

future_parse(_PyFutureFeatures *ff, mod_ty mod, PyObject *filename)

{

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

return 1;

}

Py_ssize_t n = asdl_seq_LEN(mod->v.Module.body);

if (n == 0) {

return 1;

}

Py_ssize_t i = 0;

if (_PyAST_GetDocString(mod->v.Module.body) != NULL) {

i++;

}

for (; i < n; i++) {

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

/* The only things that can precede a future statement

if (s->kind == ImportFrom_kind && s->v.ImportFrom.level == 0) {

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

if (modname &&

_PyUnicode_EqualToASCIIString(modname, "__future__")) {

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

return 0;

}

ff->ff_location = SRC_LOCATION_FROM_AST(s);

}

else {

return 1;

}

}

else {

return 1;

}

}

return 1;

}

_PyFuture_FromAST(mod_ty mod, PyObject *filename, _PyFutureFeatures *ff)

{

ff->ff_features = 0;

ff->ff_location = (_Py_SourceLocation){-1, -1, -1, -1};

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

return 0;

}

return 1;

}