/src/Python-3.8.3/Python/future.c

Source
#include "Python.h"
#include "Python-ast.h"
#include "node.h"
#include "token.h"
#include "graminit.h"
#include "code.h"
#include "symtable.h"
#include "ast.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, PyObject *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_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_SyntaxLocationObject(filename, s->lineno, s->col_offset + 1);
            return 0;
        } else {
            PyErr_Format(PyExc_SyntaxError,
                         UNDEFINED_FUTURE_FEATURE, feature);
            PyErr_SyntaxLocationObject(filename, s->lineno, s->col_offset + 1);
            return 0;
        }
    }
    return 1;
}

static int
future_parse(PyFutureFeatures *ff, mod_ty mod, PyObject *filename)
{
    int i, done = 0, prev_line = 0;

    if (!(mod->kind == Module_kind || mod->kind == Interactive_kind))
        return 1;

    if (asdl_seq_LEN(mod->v.Module.body) == 0)
        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.
    */

    i = 0;
    if (_PyAST_GetDocString(mod->v.Module.body) != NULL)
        i++;

    for (; 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) {
            identifier modname = s->v.ImportFrom.module;
            if (modname &&
                _PyUnicode_EqualToASCIIString(modname, "__future__")) {
                if (done) {
                    PyErr_SetString(PyExc_SyntaxError,
                                    ERR_LATE_FUTURE);
                    PyErr_SyntaxLocationObject(filename, s->lineno, s->col_offset);
                    return 0;
                }
                if (!future_check_features(ff, s, filename))
                    return 0;
                ff->ff_lineno = s->lineno;
            }
            else {
                done = 1;
            }
        }
        else {
            done = 1;
        }
    }
    return 1;
}


PyFutureFeatures *
PyFuture_FromASTObject(mod_ty mod, PyObject *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;
}


PyFutureFeatures *
PyFuture_FromAST(mod_ty mod, const char *filename_str)
{
    PyFutureFeatures *ff;
    PyObject *filename;

    filename = PyUnicode_DecodeFSDefault(filename_str);
    if (filename == NULL)
        return NULL;
    ff = PyFuture_FromASTObject(mod, filename);
    Py_DECREF(filename);
    return ff;
}

Line	Count	Source
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 "symtable.h"
8		#include "ast.h"
9
10	0	#define UNDEFINED_FUTURE_FEATURE "future feature %.100s is not defined"
11	0	#define ERR_LATE_FUTURE \
12	0	"from __future__ imports must occur at the beginning of the file"
13
14		static int
15		future_check_features(PyFutureFeatures ff, stmt_ty s, PyObject filename)
16	0	{
17	0	int i;
18	0	asdl_seq *names;
19
20	0	assert(s->kind == ImportFrom_kind);
21
22	0	names = s->v.ImportFrom.names;
23	0	for (i = 0; i < asdl_seq_LEN(names); i++) {
24	0	alias_ty name = (alias_ty)asdl_seq_GET(names, i);
25	0	const char *feature = PyUnicode_AsUTF8(name->name);
26	0	if (!feature)
27	0	return 0;
28	0	if (strcmp(feature, FUTURE_NESTED_SCOPES) == 0) {
29	0	continue;
30	0	} else if (strcmp(feature, FUTURE_GENERATORS) == 0) {
31	0	continue;
32	0	} else if (strcmp(feature, FUTURE_DIVISION) == 0) {
33	0	continue;
34	0	} else if (strcmp(feature, FUTURE_ABSOLUTE_IMPORT) == 0) {
35	0	continue;
36	0	} else if (strcmp(feature, FUTURE_WITH_STATEMENT) == 0) {
37	0	continue;
38	0	} else if (strcmp(feature, FUTURE_PRINT_FUNCTION) == 0) {
39	0	continue;
40	0	} else if (strcmp(feature, FUTURE_UNICODE_LITERALS) == 0) {
41	0	continue;
42	0	} else if (strcmp(feature, FUTURE_BARRY_AS_BDFL) == 0) {
43	0	ff->ff_features \|= CO_FUTURE_BARRY_AS_BDFL;
44	0	} else if (strcmp(feature, FUTURE_GENERATOR_STOP) == 0) {
45	0	continue;
46	0	} else if (strcmp(feature, FUTURE_ANNOTATIONS) == 0) {
47	0	ff->ff_features \|= CO_FUTURE_ANNOTATIONS;
48	0	} else if (strcmp(feature, "braces") == 0) {
49	0	PyErr_SetString(PyExc_SyntaxError,
50	0	"not a chance");
51	0	PyErr_SyntaxLocationObject(filename, s->lineno, s->col_offset + 1);
52	0	return 0;
53	0	} else {
54	0	PyErr_Format(PyExc_SyntaxError,
55	0	UNDEFINED_FUTURE_FEATURE, feature);
56	0	PyErr_SyntaxLocationObject(filename, s->lineno, s->col_offset + 1);
57	0	return 0;
58	0	}
59	0	}
60	0	return 1;
61	0	}
62
63		static int
64		future_parse(PyFutureFeatures ff, mod_ty mod, PyObject filename)
65	16	{
66	16	int i, done = 0, prev_line = 0;
67
68	16	if (!(mod->kind == Module_kind \|\| mod->kind == Interactive_kind))
69	0	return 1;
70
71	16	if (asdl_seq_LEN(mod->v.Module.body) == 0)
72	0	return 1;
73
74		/* A subsequent pass will detect future imports that don't
75		appear at the beginning of the file. There's one case,
76		however, that is easier to handle here: A series of imports
77		joined by semi-colons, where the first import is a future
78		statement but some subsequent import has the future form
79		but is preceded by a regular import.
80		*/
81
82	16	i = 0;
83	16	if (_PyAST_GetDocString(mod->v.Module.body) != NULL)
84	0	i++;
85
86	32	for (; i < asdl_seq_LEN(mod->v.Module.body); i++) {
87	18	stmt_ty s = (stmt_ty)asdl_seq_GET(mod->v.Module.body, i);
88
89	18	if (done && s->lineno > prev_line)
90	2	return 1;
91	16	prev_line = s->lineno;
92
93		/* The tests below will return from this function unless it is
94		still possible to find a future statement. The only things
95		that can precede a future statement are another future
96		statement and a doc string.
97		*/
98
99	16	if (s->kind == ImportFrom_kind) {
100	0	identifier modname = s->v.ImportFrom.module;
101	0	if (modname &&
102	0	_PyUnicode_EqualToASCIIString(modname, "__future__")) {
103	0	if (done) {
104	0	PyErr_SetString(PyExc_SyntaxError,
105	0	ERR_LATE_FUTURE);
106	0	PyErr_SyntaxLocationObject(filename, s->lineno, s->col_offset);
107	0	return 0;
108	0	}
109	0	if (!future_check_features(ff, s, filename))
110	0	return 0;
111	0	ff->ff_lineno = s->lineno;
112	0	}
113	0	else {
114	0	done = 1;
115	0	}
116	0	}
117	16	else {
118	16	done = 1;
119	16	}
120	16	}
121	14	return 1;
122	16	}
123
124
125		PyFutureFeatures *
126		PyFuture_FromASTObject(mod_ty mod, PyObject *filename)
127	16	{
128	16	PyFutureFeatures *ff;
129
130	16	ff = (PyFutureFeatures *)PyObject_Malloc(sizeof(PyFutureFeatures));
131	16	if (ff == NULL) {
132	0	PyErr_NoMemory();
133	0	return NULL;
134	0	}
135	16	ff->ff_features = 0;
136	16	ff->ff_lineno = -1;
137
138	16	if (!future_parse(ff, mod, filename)) {
139	0	PyObject_Free(ff);
140	0	return NULL;
141	0	}
142	16	return ff;
143	16	}
144
145
146		PyFutureFeatures *
147		PyFuture_FromAST(mod_ty mod, const char *filename_str)
148	0	{
149	0	PyFutureFeatures *ff;
150	0	PyObject *filename;
151
152	0	filename = PyUnicode_DecodeFSDefault(filename_str);
153	0	if (filename == NULL)
154	0	return NULL;
155	0	ff = PyFuture_FromASTObject(mod, filename);
156	0	Py_DECREF(filename);
157	0	return ff;
158	0	}

Coverage Report

Created: 2025-10-27 06:40