1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
|
#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 = _PyUnicode_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) {
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, "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;
static PyObject *future;
if (!future) {
future = PyUnicode_InternFromString("__future__");
if (!future)
return 0;
}
if (!(mod->kind == Module_kind || mod->kind == Interactive_kind))
return 1;
/* A subsequent pass will detect future imports that don't
appear at the beginning of the file. There's one case,
however, that is easier to handle here: A series of imports
joined by semi-colons, where the first import is a future
statement but some subsequent import has the future form
but is preceded by a regular import.
*/
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
still possible to find a future statement. The only things
that can precede a future statement are another future
statement and a doc string.
*/
if (s->kind == ImportFrom_kind) {
if (s->v.ImportFrom.module == 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;
}
|
