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f7f438ba3b
- IMPORT_NAME takes an extra argument from the stack: the relativeness of the import. Only passed to __import__ when it's not -1. - __import__() takes an optional 5th argument for the same thing; it __defaults to -1 (old semantics: try relative, then absolute) - 'from . import name' imports name (be it module or regular attribute) from the current module's *package*. Likewise, 'from .module import name' will import name from a sibling to the current module. - Importing from outside a package is not allowed; 'from . import sys' in a toplevel module will not work, nor will 'from .. import sys' in a (single-level) package. - 'from __future__ import absolute_import' will turn on the new semantics for import and from-import: imports will be absolute, except for from-import with dots. Includes tests for regular imports and importhooks, parser changes and a NEWS item, but no compiler-package changes or documentation changes.
132 lines
3.2 KiB
C
132 lines
3.2 KiB
C
#include "Python.h"
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#include "Python-ast.h"
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#include "node.h"
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#include "token.h"
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#include "graminit.h"
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#include "code.h"
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#include "compile.h"
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#include "symtable.h"
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#define UNDEFINED_FUTURE_FEATURE "future feature %.100s is not defined"
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static int
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future_check_features(PyFutureFeatures *ff, stmt_ty s, const char *filename)
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{
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int i;
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asdl_seq *names;
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assert(s->kind == ImportFrom_kind);
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names = s->v.ImportFrom.names;
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for (i = 0; i < asdl_seq_LEN(names); i++) {
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alias_ty name = asdl_seq_GET(names, i);
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const char *feature = PyString_AsString(name->name);
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if (!feature)
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return 0;
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if (strcmp(feature, FUTURE_NESTED_SCOPES) == 0) {
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continue;
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} else if (strcmp(feature, FUTURE_GENERATORS) == 0) {
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continue;
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} else if (strcmp(feature, FUTURE_DIVISION) == 0) {
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ff->ff_features |= CO_FUTURE_DIVISION;
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} else if (strcmp(feature, FUTURE_ABSIMPORT) == 0) {
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ff->ff_features |= CO_FUTURE_ABSIMPORT;
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} else if (strcmp(feature, "braces") == 0) {
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PyErr_SetString(PyExc_SyntaxError,
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"not a chance");
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PyErr_SyntaxLocation(filename, s->lineno);
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return 0;
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} else {
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PyErr_Format(PyExc_SyntaxError,
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UNDEFINED_FUTURE_FEATURE, feature);
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PyErr_SyntaxLocation(filename, s->lineno);
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return 0;
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}
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}
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return 1;
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}
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static int
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future_parse(PyFutureFeatures *ff, mod_ty mod, const char *filename)
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{
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int i, found_docstring = 0, done = 0, prev_line = 0;
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static PyObject *future;
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if (!future) {
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future = PyString_InternFromString("__future__");
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if (!future)
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return 0;
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}
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if (!(mod->kind == Module_kind || mod->kind == Interactive_kind))
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return 1;
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/* A subsequent pass will detect future imports that don't
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appear at the beginning of the file. There's one case,
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however, that is easier to handl here: A series of imports
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joined by semi-colons, where the first import is a future
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statement but some subsequent import has the future form
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but is preceded by a regular import.
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*/
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for (i = 0; i < asdl_seq_LEN(mod->v.Module.body); i++) {
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stmt_ty s = asdl_seq_GET(mod->v.Module.body, i);
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if (done && s->lineno > prev_line)
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return 1;
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prev_line = s->lineno;
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/* The tests below will return from this function unless it is
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still possible to find a future statement. The only things
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that can precede a future statement are another future
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statement and a doc string.
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*/
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if (s->kind == ImportFrom_kind) {
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if (s->v.ImportFrom.module == future) {
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if (done) {
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PyErr_SetString(PyExc_SyntaxError,
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ERR_LATE_FUTURE);
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PyErr_SyntaxLocation(filename,
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s->lineno);
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return 0;
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}
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if (!future_check_features(ff, s, filename))
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return 0;
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ff->ff_lineno = s->lineno;
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}
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else
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done = 1;
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}
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else if (s->kind == Expr_kind && !found_docstring) {
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expr_ty e = s->v.Expr.value;
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if (e->kind != Str_kind)
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done = 1;
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else
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found_docstring = 1;
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}
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else
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done = 1;
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}
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return 1;
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}
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PyFutureFeatures *
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PyFuture_FromAST(mod_ty mod, const char *filename)
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{
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PyFutureFeatures *ff;
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ff = (PyFutureFeatures *)PyMem_Malloc(sizeof(PyFutureFeatures));
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if (ff == NULL)
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return NULL;
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ff->ff_features = 0;
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ff->ff_lineno = -1;
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if (!future_parse(ff, mod, filename)) {
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PyMem_Free((void *)ff);
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return NULL;
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}
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return ff;
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}
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