Issue #14928: Fix importlib bootstrap issues by using a custom executable (Modules/_freeze_importlib) to build Python/importlib.h.

Modules/_freeze_importlib.c

@@ -0,0 +1,131 @@
+/* This is built as a stand-alone executable by the Makefile, and helps turn
+   Lib/importlib/_bootstrap.py into a frozen module in Python/importlib.h
+*/
+
+#include <Python.h>
+#include <marshal.h>
+
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+
+/* 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 struct _frozen _PyImport_FrozenModules[] = {
+    {0, 0, 0} /* sentinel */
+};
+
+struct _frozen *PyImport_FrozenModules = _PyImport_FrozenModules;
+
+
+const char header[] = "/* Auto-generated by Modules/_freeze_importlib.c */";
+
+int
+main(int argc, char *argv[])
+{
+    char *inpath, *outpath;
+    FILE *infile, *outfile = NULL;
+    struct stat st;
+    size_t text_size, data_size, n;
+    char *text, *data;
+    PyObject *code, *marshalled;
+
+    if (argc != 3) {
+        fprintf(stderr, "need to specify input and output paths\n");
+        return 2;
+    }
+    inpath = argv[1];
+    outpath = argv[2];
+    infile = fopen(inpath, "rb");
+    if (infile == NULL) {
+        fprintf(stderr, "cannot open '%s' for reading\n", inpath);
+        return 1;
+    }
+    if (fstat(fileno(infile), &st)) {
+        fclose(infile);
+        fprintf(stderr, "cannot fstat '%s'\n", inpath);
+        return 1;
+    }
+    text_size = st.st_size;
+    text = (char *) malloc(text_size + 1);
+    if (text == NULL) {
+        fclose(infile);
+        fprintf(stderr, "could not allocate %ld bytes\n", (long) text_size);
+        return 1;
+    }
+    n = fread(text, 1, text_size, infile);
+    fclose(infile);
+    infile = NULL;
+    if (n < text_size) {
+        fprintf(stderr, "read too short: got %ld instead of %ld bytes\n",
+                (long) n, (long) text_size);
+        return 1;
+    }
+    text[text_size] = '\0';
+
+    Py_NoUserSiteDirectory++;
+    Py_NoSiteFlag++;
+    Py_IgnoreEnvironmentFlag++;
+
+    Py_SetProgramName(L"./_freeze_importlib");
+    /* Don't install importlib, since it could execute outdated bytecode. */
+    _Py_InitializeEx_Private(1, 0);
+
+    code = Py_CompileStringExFlags(text, "<frozen importlib._bootstrap>",
+                                   Py_file_input, NULL, 0);
+    if (code == NULL)
+        goto error;
+    marshalled = PyMarshal_WriteObjectToString(code, Py_MARSHAL_VERSION);
+    Py_DECREF(code);
+    if (marshalled == NULL)
+        goto error;
+
+    assert(PyBytes_CheckExact(marshalled));
+    data = PyBytes_AS_STRING(marshalled);
+    data_size = PyBytes_GET_SIZE(marshalled);
+
+    outfile = fopen(outpath, "wb");
+    if (outfile == NULL) {
+        fprintf(stderr, "cannot open '%s' for writing\n", outpath);
+        return 1;
+    }
+    fprintf(outfile, "%s\n", header);
+    fprintf(outfile, "unsigned char _Py_M__importlib[] = {\n");
+    for (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, "%d,", (int) data[i]);
+        }
+        fprintf(outfile, "\n");
+    }
+    fprintf(outfile, "};\n");
+
+    Py_DECREF(marshalled);
+
+    Py_Finalize();
+    if (infile)
+        fclose(infile);
+    if (outfile) {
+        if (ferror(outfile)) {
+            fprintf(stderr, "error when writing to '%s'\n", outpath);
+            fclose(outfile);
+            return 1;
+        }
+        fclose(outfile);
+    }
+    return 0;
+
+error:
+    PyErr_Print();
+    Py_Finalize();
+    if (infile)
+        fclose(infile);
+    if (outfile)
+        fclose(outfile);
+    return 1;
+}