Showing the changes to sys/src/cmd/python/Python/future.c (1 of 3706 files). Show all
Unified · Split
| @@ -0,0 +1,136 @@ | |||
| 1 | #include "Python.h" | ||
| 2 | #include "Python-ast.h" | ||
| 3 | #include "node.h" | ||
| 4 | #include "token.h" | ||
| 5 | #include "graminit.h" | ||
| 6 | #include "code.h" | ||
| 7 | #include "compile.h" | ||
| 8 | #include "symtable.h" | ||
| 9 | |||
| 10 | #define UNDEFINED_FUTURE_FEATURE "future feature %.100s is not defined" | ||
| 11 | |||
| 12 | static int | ||
| 13 | future_check_features(PyFutureFeatures *ff, stmt_ty s, const char *filename) | ||
| 14 | { | ||
| 15 | int i; | ||
| 16 | asdl_seq *names; | ||
| 17 | |||
| 18 | assert(s->kind == ImportFrom_kind); | ||
| 19 | |||
| 20 | names = s->v.ImportFrom.names; | ||
| 21 | for (i = 0; i < asdl_seq_LEN(names); i++) { | ||
| 22 | alias_ty name = (alias_ty)asdl_seq_GET(names, i); | ||
| 23 | const char *feature = PyString_AsString(name->name); | ||
| 24 | if (!feature) | ||
| 25 | return 0; | ||
| 26 | if (strcmp(feature, FUTURE_NESTED_SCOPES) == 0) { | ||
| 27 | continue; | ||
| 28 | } else if (strcmp(feature, FUTURE_GENERATORS) == 0) { | ||
| 29 | continue; | ||
| 30 | } else if (strcmp(feature, FUTURE_DIVISION) == 0) { | ||
| 31 | ff->ff_features |= CO_FUTURE_DIVISION; | ||
| 32 | } else if (strcmp(feature, FUTURE_ABSOLUTE_IMPORT) == 0) { | ||
| 33 | ff->ff_features |= CO_FUTURE_ABSOLUTE_IMPORT; | ||
| 34 | } else if (strcmp(feature, FUTURE_WITH_STATEMENT) == 0) { | ||
| 35 | ff->ff_features |= CO_FUTURE_WITH_STATEMENT; | ||
| 36 | } else if (strcmp(feature, "braces") == 0) { | ||
| 37 | PyErr_SetString(PyExc_SyntaxError, | ||
| 38 | "not a chance"); | ||
| 39 | PyErr_SyntaxLocation(filename, s->lineno); | ||
| 40 | return 0; | ||
| 41 | } else { | ||
| 42 | PyErr_Format(PyExc_SyntaxError, | ||
| 43 | UNDEFINED_FUTURE_FEATURE, feature); | ||
| 44 | PyErr_SyntaxLocation(filename, s->lineno); | ||
| 45 | return 0; | ||
| 46 | } | ||
| 47 | } | ||
| 48 | return 1; | ||
| 49 | } | ||
| 50 | |||
| 51 | static int | ||
| 52 | future_parse(PyFutureFeatures *ff, mod_ty mod, const char *filename) | ||
| 53 | { | ||
| 54 | int i, found_docstring = 0, done = 0, prev_line = 0; | ||
| 55 | |||
| 56 | static PyObject *future; | ||
| 57 | if (!future) { | ||
| 58 | future = PyString_InternFromString("__future__"); | ||
| 59 | if (!future) | ||
| 60 | return 0; | ||
| 61 | } | ||
| 62 | |||
| 63 | if (!(mod->kind == Module_kind || mod->kind == Interactive_kind)) | ||
| 64 | return 1; | ||
| 65 | |||
| 66 | /* A subsequent pass will detect future imports that don't | ||
| 67 | appear at the beginning of the file. There's one case, | ||
| 68 | however, that is easier to handl here: A series of imports | ||
| 69 | joined by semi-colons, where the first import is a future | ||
| 70 | statement but some subsequent import has the future form | ||
| 71 | but is preceded by a regular import. | ||
| 72 | */ | ||
| 73 | |||
| 74 | |||
| 75 | for (i = 0; i < asdl_seq_LEN(mod->v.Module.body); i++) { | ||
| 76 | stmt_ty s = (stmt_ty)asdl_seq_GET(mod->v.Module.body, i); | ||
| 77 | |||
| 78 | if (done && s->lineno > prev_line) | ||
| 79 | return 1; | ||
| 80 | prev_line = s->lineno; | ||
| 81 | |||
| 82 | /* The tests below will return from this function unless it is | ||
| 83 | still possible to find a future statement. The only things | ||
| 84 | that can precede a future statement are another future | ||
| 85 | statement and a doc string. | ||
| 86 | */ | ||
| 87 | |||
| 88 | if (s->kind == ImportFrom_kind) { | ||
| 89 | if (s->v.ImportFrom.module == future) { | ||
| 90 | if (done) { | ||
| 91 | PyErr_SetString(PyExc_SyntaxError, | ||
| 92 | ERR_LATE_FUTURE); | ||
| 93 | PyErr_SyntaxLocation(filename, | ||
| 94 | s->lineno); | ||
| 95 | return 0; | ||
| 96 | } | ||
| 97 | if (!future_check_features(ff, s, filename)) | ||
| 98 | return 0; | ||
| 99 | ff->ff_lineno = s->lineno; | ||
| 100 | } | ||
| 101 | else | ||
| 102 | done = 1; | ||
| 103 | } | ||
| 104 | else if (s->kind == Expr_kind && !found_docstring) { | ||
| 105 | expr_ty e = s->v.Expr.value; | ||
| 106 | if (e->kind != Str_kind) | ||
| 107 | done = 1; | ||
| 108 | else | ||
| 109 | found_docstring = 1; | ||
| 110 | } | ||
| 111 | else | ||
| 112 | done = 1; | ||
| 113 | } | ||
| 114 | return 1; | ||
| 115 | } | ||
| 116 | |||
| 117 | |||
| 118 | PyFutureFeatures * | ||
| 119 | PyFuture_FromAST(mod_ty mod, const char *filename) | ||
| 120 | { | ||
| 121 | PyFutureFeatures *ff; | ||
| 122 | |||
| 123 | ff = (PyFutureFeatures *)PyObject_Malloc(sizeof(PyFutureFeatures)); | ||
| 124 | if (ff == NULL) { | ||
| 125 | PyErr_NoMemory(); | ||
| 126 | return NULL; | ||
| 127 | } | ||
| 128 | ff->ff_features = 0; | ||
| 129 | ff->ff_lineno = -1; | ||
| 130 | |||
| 131 | if (!future_parse(ff, mod, filename)) { | ||
| 132 | PyObject_Free(ff); | ||
| 133 | return NULL; | ||
| 134 | } | ||
| 135 | return ff; | ||
| 136 | } | ||