1/* This is built as a stand-alone executable by the Makefile, and helps turn
2   modules into frozen modules (like Lib/importlib/_bootstrap.py
3   into Python/importlib.h).
4
5   This is used directly by Tools/scripts/freeze_modules.py, and indirectly by "make regen-frozen".
6
7   See Python/frozen.c for more info.
8
9   Keep this file in sync with Programs/_freeze_module.py.
10*/
11
12#include <Python.h>
13#include <marshal.h>
14#include "pycore_fileutils.h"     // _Py_stat_struct
15#include <pycore_import.h>
16
17#include <stdio.h>
18#include <stdlib.h>               // malloc()
19#include <sys/types.h>
20#include <sys/stat.h>
21#ifndef MS_WINDOWS
22#include <unistd.h>
23#endif
24
25/* Empty initializer for deepfrozen modules */
26int _Py_Deepfreeze_Init(void)
27{
28    return 0;
29}
30/* Empty finalizer for deepfrozen modules */
31void
32_Py_Deepfreeze_Fini(void)
33{
34}
35
36/* To avoid a circular dependency on frozen.o, we create our own structure
37   of frozen modules instead, left deliberately blank so as to avoid
38   unintentional import of a stale version of _frozen_importlib. */
39
40static const struct _frozen no_modules[] = {
41    {0, 0, 0} /* sentinel */
42};
43static const struct _module_alias aliases[] = {
44    {0, 0} /* sentinel */
45};
46
47const struct _frozen *_PyImport_FrozenBootstrap;
48const struct _frozen *_PyImport_FrozenStdlib;
49const struct _frozen *_PyImport_FrozenTest;
50const struct _frozen *PyImport_FrozenModules;
51const struct _module_alias *_PyImport_FrozenAliases;
52
53static const char header[] =
54    "/* Auto-generated by Programs/_freeze_module.c */";
55
56static void
57runtime_init(void)
58{
59    PyConfig config;
60    PyConfig_InitIsolatedConfig(&config);
61
62    config.site_import = 0;
63
64    PyStatus status;
65    status = PyConfig_SetString(&config, &config.program_name,
66                                L"./_freeze_module");
67    if (PyStatus_Exception(status)) {
68        PyConfig_Clear(&config);
69        Py_ExitStatusException(status);
70    }
71
72    /* Don't install importlib, since it could execute outdated bytecode. */
73    config._install_importlib = 0;
74    config._init_main = 0;
75
76    status = Py_InitializeFromConfig(&config);
77    PyConfig_Clear(&config);
78    if (PyStatus_Exception(status)) {
79        Py_ExitStatusException(status);
80    }
81}
82
83static const char *
84read_text(const char *inpath)
85{
86    FILE *infile = fopen(inpath, "rb");
87    if (infile == NULL) {
88        fprintf(stderr, "cannot open '%s' for reading\n", inpath);
89        return NULL;
90    }
91
92    struct _Py_stat_struct stat;
93    if (_Py_fstat_noraise(fileno(infile), &stat)) {
94        fprintf(stderr, "cannot fstat '%s'\n", inpath);
95        fclose(infile);
96        return NULL;
97    }
98    size_t text_size = (size_t)stat.st_size;
99
100    char *text = (char *) malloc(text_size + 1);
101    if (text == NULL) {
102        fprintf(stderr, "could not allocate %ld bytes\n", (long) text_size);
103        fclose(infile);
104        return NULL;
105    }
106    size_t n = fread(text, 1, text_size, infile);
107    fclose(infile);
108
109    if (n < text_size) {
110        fprintf(stderr, "read too short: got %ld instead of %ld bytes\n",
111                (long) n, (long) text_size);
112        free(text);
113        return NULL;
114    }
115
116    text[text_size] = '\0';
117    return (const char *)text;
118}
119
120static PyObject *
121compile_and_marshal(const char *name, const char *text)
122{
123    char *filename = (char *) malloc(strlen(name) + 10);
124    sprintf(filename, "<frozen %s>", name);
125    PyObject *code = Py_CompileStringExFlags(text, filename,
126                                             Py_file_input, NULL, 0);
127    free(filename);
128    if (code == NULL) {
129        return NULL;
130    }
131
132    PyObject *marshalled = PyMarshal_WriteObjectToString(code, Py_MARSHAL_VERSION);
133    Py_CLEAR(code);
134    if (marshalled == NULL) {
135        return NULL;
136    }
137    assert(PyBytes_CheckExact(marshalled));
138
139    return marshalled;
140}
141
142static char *
143get_varname(const char *name, const char *prefix)
144{
145    size_t n = strlen(prefix);
146    char *varname = (char *) malloc(strlen(name) + n + 1);
147    (void)strcpy(varname, prefix);
148    for (size_t i = 0; name[i] != '\0'; i++) {
149        if (name[i] == '.') {
150            varname[n++] = '_';
151        }
152        else {
153            varname[n++] = name[i];
154        }
155    }
156    varname[n] = '\0';
157    return varname;
158}
159
160static void
161write_code(FILE *outfile, PyObject *marshalled, const char *varname)
162{
163    unsigned char *data = (unsigned char *) PyBytes_AS_STRING(marshalled);
164    size_t data_size = PyBytes_GET_SIZE(marshalled);
165
166    fprintf(outfile, "const unsigned char %s[] = {\n", varname);
167    for (size_t n = 0; n < data_size; n += 16) {
168        size_t i, end = Py_MIN(n + 16, data_size);
169        fprintf(outfile, "    ");
170        for (i = n; i < end; i++) {
171            fprintf(outfile, "%u,", (unsigned int) data[i]);
172        }
173        fprintf(outfile, "\n");
174    }
175    fprintf(outfile, "};\n");
176}
177
178static int
179write_frozen(const char *outpath, const char *inpath, const char *name,
180             PyObject *marshalled)
181{
182    /* Open the file in text mode. The hg checkout should be using the eol extension,
183       which in turn should cause the EOL style match the C library's text mode */
184    FILE *outfile = fopen(outpath, "w");
185    if (outfile == NULL) {
186        fprintf(stderr, "cannot open '%s' for writing\n", outpath);
187        return -1;
188    }
189
190    fprintf(outfile, "%s\n", header);
191    char *arrayname = get_varname(name, "_Py_M__");
192    write_code(outfile, marshalled, arrayname);
193    free(arrayname);
194
195    if (ferror(outfile)) {
196        fprintf(stderr, "error when writing to '%s'\n", outpath);
197        fclose(outfile);
198        return -1;
199    }
200    fclose(outfile);
201    return 0;
202}
203
204int
205main(int argc, char *argv[])
206{
207    const char *name, *inpath, *outpath;
208
209    _PyImport_FrozenBootstrap = no_modules;
210    _PyImport_FrozenStdlib = no_modules;
211    _PyImport_FrozenTest = no_modules;
212    PyImport_FrozenModules = NULL;
213    _PyImport_FrozenAliases = aliases;
214
215    if (argc != 4) {
216        fprintf(stderr, "need to specify the name, input and output paths\n");
217        return 2;
218    }
219    name = argv[1];
220    inpath = argv[2];
221    outpath = argv[3];
222
223    runtime_init();
224
225    const char *text = read_text(inpath);
226    if (text == NULL) {
227        goto error;
228    }
229
230    PyObject *marshalled = compile_and_marshal(name, text);
231    free((char *)text);
232    if (marshalled == NULL) {
233        goto error;
234    }
235
236    int res = write_frozen(outpath, inpath, name, marshalled);
237    Py_DECREF(marshalled);
238    if (res != 0) {
239        goto error;
240    }
241
242    Py_Finalize();
243    return 0;
244
245error:
246    PyErr_Print();
247    Py_Finalize();
248    return 1;
249}
250
251