This iterator makes it easier to deal with modules.builtin.objs files,
taking away the parsing burden and letting the caller treat them like C
arrays:
{
struct modules_builtin_iter *i;
char *module_name = NULL;
char **module_paths;
i = modules_builtin_iter_new(modules_builtin);
if (i == NULL) {
fprintf(stderr, "Cannot iterate over builtin modules.\n");
exit(1);
}
while ((module_paths = modules_builtin_iter_next(i, &module_name))) {
char **walk = module_paths;
while (*walk) {
/* do stuff */
walk++;
}
free(module_paths);
}
free(module_name);
modules_builtin_iter_free(i);
}
Will be tied into the build system later, as needed by callers
(initially, the kallmodsyms machinery, which wants to know which builtin
modules particular symbols are part of).
Signed-off-by: Nick Alcock <nick.alcock@xxxxxxxxxx>
---
Notes:
v10: split out of modules_thick.builtin code. Adjust to use
modules.builtin.objs. Armour against lines with no colons.
scripts/modules_builtin.c | 200 ++++++++++++++++++++++++++++++++++++++
scripts/modules_builtin.h | 48 +++++++++
2 files changed, 248 insertions(+)
create mode 100644 scripts/modules_builtin.c
create mode 100644 scripts/modules_builtin.h
diff --git a/scripts/modules_builtin.c b/scripts/modules_builtin.c
new file mode 100644
index 000000000000..df52932a4417
--- /dev/null
+++ b/scripts/modules_builtin.c
@@ -0,0 +1,200 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * A simple modules_builtin reader.
+ *
+ * (C) 2014, 2022 Oracle, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "modules_builtin.h"
+
+/*
+ * Read a modules.builtin.objs file and translate it into a stream of
+ * name / module-name pairs.
+ */
+
+/*
+ * Construct a modules.builtin.objs iterator.
+ */
+struct modules_builtin_iter *
+modules_builtin_iter_new(const char *modules_builtin_file)
+{
+ struct modules_builtin_iter *i;
+
+ i = calloc(1, sizeof(struct modules_builtin_iter));
+ if (i == NULL)
+ return NULL;
+
+ i->f = fopen(modules_builtin_file, "r");
+
+ if (i->f == NULL) {
+ fprintf(stderr, "Cannot open builtin module file %s: %s\n",
+ modules_builtin_file, strerror(errno));
+ return NULL;
+ }
+
+ return i;
+}
+
+/*
+ * Iterate, returning a new null-terminated array of object file names, and a
+ * new dynamically-allocated module name. (The module name passed in is freed.)
+ *
+ * The array of object file names should be freed by the caller: the strings it
+ * points to are owned by the iterator, and should not be freed.
+ */
+
+char ** __attribute__((__nonnull__))
+modules_builtin_iter_next(struct modules_builtin_iter *i, char **module_name)
+{
+ size_t npaths = 1;
+ char **module_paths;
+ char *last_slash;
+ char *last_dot;
+ char *trailing_linefeed;
+ char *object_name = i->line;
+ char *dash;
+ int composite = 0;
+
+ /*
+ * Read in all module entries, computing the suffixless, pathless name
+ * of the module and building the next arrayful of object file names for
+ * return.
+ *
+ * Modules can consist of multiple files: in this case, the portion
+ * before the colon is the path to the module (as before): the portion
+ * after the colon is a space-separated list of files that should be
+ * considered part of this module. In this case, the portion before the
+ * name is an "object file" that does not actually exist: it is merged
+ * into built-in.a without ever being written out.
+ *
+ * All module names have - translated to _, to match what is done to the
+ * names of the same things when built as modules.
+ */
+
+ /*
+ * Reinvocation of exhausted iterator. Return NULL, once.
+ */
+retry:
+ if (getline(&i->line, &i->line_size, i->f) < 0) {
+ if (ferror(i->f)) {
+ fprintf(stderr, "Error reading from modules_builtin file:"
+ " %s\n", strerror(errno));
+ exit(1);
+ }
+ rewind(i->f);
+ return NULL;
+ }
+
+ if (i->line[0] == '\0')
+ goto retry;
+
+ trailing_linefeed = strchr(i->line, '\n');
+ if (trailing_linefeed != NULL)
+ *trailing_linefeed = '\0';
+
+ /*
+ * Slice the line in two at the colon, if any. If there is anything
+ * past the ': ', this is a composite module. (We allow for no colon
+ * for robustness, even though one should always be present.)
+ */
+ if (strchr(i->line, ':') != NULL) {
+ char *name_start;
+
+ object_name = strchr(i->line, ':');
+ *object_name = '\0';
+ object_name++;
+ name_start = object_name + strspn(object_name, " \n");
+ if (*name_start != '\0') {
+ composite = 1;
+ object_name = name_start;
+ }
+ }
+
+ /*
+ * Figure out the module name.
+ */
+ last_slash = strrchr(i->line, '/');
+ last_slash = (!last_slash) ? i->line :
+ last_slash + 1;
+ free(*module_name);
+ *module_name = strdup(last_slash);
+ dash = *module_name;
+
+ while (dash != NULL) {
+ dash = strchr(dash, '-');
+ if (dash != NULL)
+ *dash = '_';
+ }
+
+ last_dot = strrchr(*module_name, '.');
+ if (last_dot != NULL)
+ *last_dot = '\0';
+
+ /*
+ * Multifile separator? Object file names explicitly stated:
+ * slice them up and shuffle them in.
+ *
+ * The array size may be an overestimate if any object file
+ * names start or end with spaces (very unlikely) but cannot be
+ * an underestimate. (Check for it anyway.)
+ */
+ if (composite) {
+ char *one_object;
+
+ for (npaths = 0, one_object = object_name;
+ one_object != NULL;
+ npaths++, one_object = strchr(one_object + 1, ' '));
+ }
+
+ module_paths = malloc((npaths + 1) * sizeof(char *));
+ if (!module_paths) {
+ fprintf(stderr, "%s: out of memory on module %s\n", __func__,
+ *module_name);
+ exit(1);
+ }
+
+ if (composite) {
+ char *one_object;
+ size_t i = 0;
+
+ while ((one_object = strsep(&object_name, " ")) != NULL) {
+ if (i >= npaths) {
+ fprintf(stderr, "%s: num_objs overflow on module "
+ "%s: this is a bug.\n", __func__,
+ *module_name);
+ exit(1);
+ }
+
+ module_paths[i++] = one_object;
+ }
+ } else
+ module_paths[0] = i->line; /* untransformed module name */
+
+ module_paths[npaths] = NULL;
+
+ return module_paths;
+}
+
+/*
+ * Free an iterator. Can be called while iteration is underway, so even
+ * state that is freed at the end of iteration must be freed here too.
+ */
+void
+modules_builtin_iter_free(struct modules_builtin_iter *i)
+{
+ if (i == NULL)
+ return;
+ fclose(i->f);
+ free(i->line);
+ free(i);
+}
diff --git a/scripts/modules_builtin.h b/scripts/modules_builtin.h
new file mode 100644
index 000000000000..5138792b42ef
--- /dev/null
+++ b/scripts/modules_builtin.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * A simple modules.builtin.objs reader.
+ *
+ * (C) 2014, 2022 Oracle, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef _LINUX_MODULES_BUILTIN_H
+#define _LINUX_MODULES_BUILTIN_H
+
+#include <stdio.h>
+#include <stddef.h>
+
+/*
+ * modules.builtin.objs iteration state.
+ */
+struct modules_builtin_iter {
+ FILE *f;
+ char *line;
+ size_t line_size;
+};
+
+/*
+ * Construct a modules_builtin.objs iterator.
+ */
+struct modules_builtin_iter *
+modules_builtin_iter_new(const char *modules_builtin_file);
+
+/*
+ * Iterate, returning a new null-terminated array of object file names, and a
+ * new dynamically-allocated module name. (The module name passed in is freed.)
+ *
+ * The array of object file names should be freed by the caller: the strings it
+ * points to are owned by the iterator, and should not be freed.
+ */
+
+char ** __attribute__((__nonnull__))
+modules_builtin_iter_next(struct modules_builtin_iter *i, char **module_name);
+
+void
+modules_builtin_iter_free(struct modules_builtin_iter *i);
+
+#endif
--
2.38.0.266.g481848f278
