cpython/Programs/_freeze_module.c
2024-04-22 12:17:57 -07:00

240 lines
6.2 KiB
C

/* This is built as a stand-alone executable by the Makefile, and helps turn
modules into frozen modules.
This is used directly by Tools/build/freeze_modules.py, and indirectly by "make regen-frozen".
See Python/frozen.c for more info.
Keep this file in sync with Programs/_freeze_module.py.
*/
#include <Python.h>
#include <marshal.h>
#include "pycore_fileutils.h" // _Py_stat_struct
#include <pycore_import.h>
#include <stdio.h>
#include <stdlib.h> // malloc()
#include <sys/types.h>
#include <sys/stat.h>
#ifndef MS_WINDOWS
# include <unistd.h>
#endif
/* To avoid a circular dependency on frozen.o, we create our own structure
of frozen modules instead, left deliberately blank so as to avoid
unintentional import of a stale version of _frozen_importlib. */
static const struct _frozen no_modules[] = {
{0, 0, 0} /* sentinel */
};
static const struct _module_alias aliases[] = {
{0, 0} /* sentinel */
};
const struct _frozen *_PyImport_FrozenBootstrap;
const struct _frozen *_PyImport_FrozenStdlib;
const struct _frozen *_PyImport_FrozenTest;
const struct _frozen *PyImport_FrozenModules;
const struct _module_alias *_PyImport_FrozenAliases;
static const char header[] =
"/* Auto-generated by Programs/_freeze_module.c */";
static void
runtime_init(void)
{
PyConfig config;
PyConfig_InitIsolatedConfig(&config);
config.site_import = 0;
PyStatus status;
status = PyConfig_SetString(&config, &config.program_name,
L"./_freeze_module");
if (PyStatus_Exception(status)) {
PyConfig_Clear(&config);
Py_ExitStatusException(status);
}
/* Don't install importlib, since it could execute outdated bytecode. */
config._install_importlib = 0;
config._init_main = 0;
status = Py_InitializeFromConfig(&config);
PyConfig_Clear(&config);
if (PyStatus_Exception(status)) {
Py_ExitStatusException(status);
}
}
static const char *
read_text(const char *inpath)
{
FILE *infile = fopen(inpath, "rb");
if (infile == NULL) {
fprintf(stderr, "cannot open '%s' for reading\n", inpath);
return NULL;
}
struct _Py_stat_struct stat;
if (_Py_fstat_noraise(fileno(infile), &stat)) {
fprintf(stderr, "cannot fstat '%s'\n", inpath);
fclose(infile);
return NULL;
}
size_t text_size = (size_t)stat.st_size;
char *text = (char *) malloc(text_size + 1);
if (text == NULL) {
fprintf(stderr, "could not allocate %ld bytes\n", (long) text_size);
fclose(infile);
return NULL;
}
size_t n = fread(text, 1, text_size, infile);
fclose(infile);
if (n < text_size) {
fprintf(stderr, "read too short: got %ld instead of %ld bytes\n",
(long) n, (long) text_size);
free(text);
return NULL;
}
text[text_size] = '\0';
return (const char *)text;
}
static PyObject *
compile_and_marshal(const char *name, const char *text)
{
char *filename = (char *) malloc(strlen(name) + 10);
sprintf(filename, "<frozen %s>", name);
PyObject *code = Py_CompileStringExFlags(text, filename,
Py_file_input, NULL, 0);
free(filename);
if (code == NULL) {
return NULL;
}
PyObject *marshalled = PyMarshal_WriteObjectToString(code, Py_MARSHAL_VERSION);
Py_CLEAR(code);
if (marshalled == NULL) {
return NULL;
}
assert(PyBytes_CheckExact(marshalled));
return marshalled;
}
static char *
get_varname(const char *name, const char *prefix)
{
size_t n = strlen(prefix);
char *varname = (char *) malloc(strlen(name) + n + 1);
(void)strcpy(varname, prefix);
for (size_t i = 0; name[i] != '\0'; i++) {
if (name[i] == '.') {
varname[n++] = '_';
}
else {
varname[n++] = name[i];
}
}
varname[n] = '\0';
return varname;
}
static void
write_code(FILE *outfile, PyObject *marshalled, const char *varname)
{
unsigned char *data = (unsigned char *) PyBytes_AS_STRING(marshalled);
size_t data_size = PyBytes_GET_SIZE(marshalled);
fprintf(outfile, "const unsigned char %s[] = {\n", varname);
for (size_t n = 0; n < data_size; n += 16) {
size_t i, end = Py_MIN(n + 16, data_size);
fprintf(outfile, " ");
for (i = n; i < end; i++) {
fprintf(outfile, "%u,", (unsigned int) data[i]);
}
fprintf(outfile, "\n");
}
fprintf(outfile, "};\n");
}
static int
write_frozen(const char *outpath, const char *inpath, const char *name,
PyObject *marshalled)
{
/* Open the file in text mode. The hg checkout should be using the eol extension,
which in turn should cause the EOL style match the C library's text mode */
FILE *outfile = fopen(outpath, "w");
if (outfile == NULL) {
fprintf(stderr, "cannot open '%s' for writing\n", outpath);
return -1;
}
fprintf(outfile, "%s\n", header);
char *arrayname = get_varname(name, "_Py_M__");
write_code(outfile, marshalled, arrayname);
free(arrayname);
if (ferror(outfile)) {
fprintf(stderr, "error when writing to '%s'\n", outpath);
fclose(outfile);
return -1;
}
fclose(outfile);
return 0;
}
int
main(int argc, char *argv[])
{
const char *name, *inpath, *outpath;
_PyImport_FrozenBootstrap = no_modules;
_PyImport_FrozenStdlib = no_modules;
_PyImport_FrozenTest = no_modules;
PyImport_FrozenModules = NULL;
_PyImport_FrozenAliases = aliases;
if (argc != 4) {
fprintf(stderr, "need to specify the name, input and output paths\n");
return 2;
}
name = argv[1];
inpath = argv[2];
outpath = argv[3];
runtime_init();
const char *text = read_text(inpath);
if (text == NULL) {
goto error;
}
PyObject *marshalled = compile_and_marshal(name, text);
free((char *)text);
if (marshalled == NULL) {
goto error;
}
int res = write_frozen(outpath, inpath, name, marshalled);
Py_DECREF(marshalled);
if (res != 0) {
goto error;
}
Py_Finalize();
return 0;
error:
PyErr_Print();
Py_Finalize();
return 1;
}