Initial commit of Open Source release

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

7 files changed, 293 insertions, 0 deletions

diff --git a/ccan/container_of/LICENSE b/ccan/container_of/LICENSE
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--- /dev/null
+++ b/ccan/container_of/LICENSE
@@ -0,0 +1,28 @@
+Statement of Purpose
+
+The laws of most jurisdictions throughout the world automatically confer exclusive Copyright and Related Rights (defined below) upon the creator and subsequent owner(s) (each and all, an "owner") of an original work of authorship and/or a database (each, a "Work").
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+
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+
+1. Copyright and Related Rights. A Work made available under CC0 may be protected by copyright and related or neighboring rights ("Copyright and Related Rights"). Copyright and Related Rights include, but are not limited to, the following:
+
+    the right to reproduce, adapt, distribute, perform, display, communicate, and translate a Work;
+    moral rights retained by the original author(s) and/or performer(s);
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+
+2. Waiver. To the greatest extent permitted by, but not in contravention of, applicable law, Affirmer hereby overtly, fully, permanently, irrevocably and unconditionally waives, abandons, and surrenders all of Affirmer's Copyright and Related Rights and associated claims and causes of action, whether now known or unknown (including existing as well as future claims and causes of action), in the Work (i) in all territories worldwide, (ii) for the maximum duration provided by applicable law or treaty (including future time extensions), (iii) in any current or future medium and for any number of copies, and (iv) for any purpose whatsoever, including without limitation commercial, advertising or promotional purposes (the "Waiver"). Affirmer makes the Waiver for the benefit of each member of the public at large and to the detriment of Affirmer's heirs and successors, fully intending that such Waiver shall not be subject to revocation, rescission, cancellation, termination, or any other legal or equitable action to disrupt the quiet enjoyment of the Work by the public as contemplated by Affirmer's express Statement of Purpose.
+
+3. Public License Fallback. Should any part of the Waiver for any reason be judged legally invalid or ineffective under applicable law, then the Waiver shall be preserved to the maximum extent permitted taking into account Affirmer's express Statement of Purpose. In addition, to the extent the Waiver is so judged Affirmer hereby grants to each affected person a royalty-free, non transferable, non sublicensable, non exclusive, irrevocable and unconditional license to exercise Affirmer's Copyright and Related Rights in the Work (i) in all territories worldwide, (ii) for the maximum duration provided by applicable law or treaty (including future time extensions), (iii) in any current or future medium and for any number of copies, and (iv) for any purpose whatsoever, including without limitation commercial, advertising or promotional purposes (the "License"). The License shall be deemed effective as of the date CC0 was applied by Affirmer to the Work. Should any part of the License for any reason be judged legally invalid or ineffective under applicable law, such partial invalidity or ineffectiveness shall not invalidate the remainder of the License, and in such case Affirmer hereby affirms that he or she will not (i) exercise any of his or her remaining Copyright and Related Rights in the Work or (ii) assert any associated claims and causes of action with respect to the Work, in either case contrary to Affirmer's express Statement of Purpose.
+
+4. Limitations and Disclaimers.
+
+    No trademark or patent rights held by Affirmer are waived, abandoned, surrendered, licensed or otherwise affected by this document.
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+    Affirmer disclaims responsibility for clearing rights of other persons that may apply to the Work or any use thereof, including without limitation any person's Copyright and Related Rights in the Work. Further, Affirmer disclaims responsibility for obtaining any necessary consents, permissions or other rights required for any use of the Work.
+    Affirmer understands and acknowledges that Creative Commons is not a party to this document and has no duty or obligation with respect to this CC0 or use of the Work.
diff --git a/ccan/container_of/_info b/ccan/container_of/_info
new file mode 100644
index 0000000..77b3bd1
--- /dev/null
+++ b/ccan/container_of/_info
@@ -0,0 +1,63 @@
+#include <stdio.h>
+#include <string.h>
+#include "config.h"
+
+/**
+ * container_of - routine for upcasting
+ *
+ * It is often convenient to create code where the caller registers a pointer
+ * to a generic structure and a callback.  The callback might know that the
+ * pointer points to within a larger structure, and container_of gives a
+ * convenient and fairly type-safe way of returning to the enclosing structure.
+ *
+ * This idiom is an alternative to providing a void * pointer for every
+ * callback.
+ *
+ * Example:
+ *	#include <stdio.h>
+ *	#include <ccan/container_of/container_of.h>
+ *
+ *	struct timer {
+ *		void *members;
+ *	};
+ *
+ *	struct info {
+ *		int my_stuff;
+ *		struct timer timer;
+ *	};
+ *
+ *	static void register_timer(struct timer *timer)
+ *	{
+ *		//...
+ *	}
+ *
+ *	static void my_timer_callback(struct timer *timer)
+ *	{
+ *		struct info *info = container_of(timer, struct info, timer);
+ *		printf("my_stuff is %u\n", info->my_stuff);
+ *	}
+ *
+ *	int main(void)
+ *	{
+ *		struct info info = { .my_stuff = 1 };
+ *
+ *		register_timer(&info.timer);
+ *		// ...
+ *		return 0;
+ *	}
+ *
+ * License: CC0 (Public domain)
+ * Author: Rusty Russell <rusty@rustcorp.com.au>
+ */
+int main(int argc, char *argv[])
+{
+	if (argc != 2)
+		return 1;
+
+	if (strcmp(argv[1], "depends") == 0) {
+		printf("ccan/check_type\n");
+		return 0;
+	}
+
+	return 1;
+}
diff --git a/ccan/container_of/container_of.h b/ccan/container_of/container_of.h
new file mode 100644
index 0000000..2943b8f
--- /dev/null
+++ b/ccan/container_of/container_of.h
@@ -0,0 +1,109 @@
+/* CC0 (Public domain) - see LICENSE file for details */
+#ifndef CCAN_CONTAINER_OF_H
+#define CCAN_CONTAINER_OF_H
+#include <stddef.h>
+
+#include "config.h"
+#include <ccan/check_type/check_type.h>
+
+/**
+ * container_of - get pointer to enclosing structure
+ * @member_ptr: pointer to the structure member
+ * @containing_type: the type this member is within
+ * @member: the name of this member within the structure.
+ *
+ * Given a pointer to a member of a structure, this macro does pointer
+ * subtraction to return the pointer to the enclosing type.
+ *
+ * Example:
+ *	struct foo {
+ *		int fielda, fieldb;
+ *		// ...
+ *	};
+ *	struct info {
+ *		int some_other_field;
+ *		struct foo my_foo;
+ *	};
+ *
+ *	static struct info *foo_to_info(struct foo *foo)
+ *	{
+ *		return container_of(foo, struct info, my_foo);
+ *	}
+ */
+#define container_of(member_ptr, containing_type, member)		\
+	 ((containing_type *)						\
+	  ((char *)(member_ptr)						\
+	   - container_off(containing_type, member))			\
+	  + check_types_match(*(member_ptr), ((containing_type *)0)->member))
+
+/**
+ * container_off - get offset to enclosing structure
+ * @containing_type: the type this member is within
+ * @member: the name of this member within the structure.
+ *
+ * Given a pointer to a member of a structure, this macro does
+ * typechecking and figures out the offset to the enclosing type.
+ *
+ * Example:
+ *	struct foo {
+ *		int fielda, fieldb;
+ *		// ...
+ *	};
+ *	struct info {
+ *		int some_other_field;
+ *		struct foo my_foo;
+ *	};
+ *
+ *	static struct info *foo_to_info(struct foo *foo)
+ *	{
+ *		size_t off = container_off(struct info, my_foo);
+ *		return (void *)((char *)foo - off);
+ *	}
+ */
+#define container_off(containing_type, member)	\
+	offsetof(containing_type, member)
+
+/**
+ * container_of_var - get pointer to enclosing structure using a variable
+ * @member_ptr: pointer to the structure member
+ * @container_var: a pointer of same type as this member's container
+ * @member: the name of this member within the structure.
+ *
+ * Given a pointer to a member of a structure, this macro does pointer
+ * subtraction to return the pointer to the enclosing type.
+ *
+ * Example:
+ *	static struct info *foo_to_i(struct foo *foo)
+ *	{
+ *		struct info *i = container_of_var(foo, i, my_foo);
+ *		return i;
+ *	}
+ */
+#if HAVE_TYPEOF
+#define container_of_var(member_ptr, container_var, member) \
+	container_of(member_ptr, typeof(*container_var), member)
+#else
+#define container_of_var(member_ptr, container_var, member)	\
+	((void *)((char *)(member_ptr)	-			\
+		  container_off_var(container_var, member)))
+#endif
+
+/**
+ * container_off_var - get offset of a field in enclosing structure
+ * @container_var: a pointer to a container structure
+ * @member: the name of a member within the structure.
+ *
+ * Given (any) pointer to a structure and a its member name, this
+ * macro does pointer subtraction to return offset of member in a
+ * structure memory layout.
+ *
+ */
+#if HAVE_TYPEOF
+#define container_off_var(var, member)		\
+	container_off(typeof(*var), member)
+#else
+#define container_off_var(var, member)			\
+	((char *)&(var)->member - (char *)(var))
+#endif
+
+#endif /* CCAN_CONTAINER_OF_H */
diff --git a/ccan/container_of/test/compile_fail-bad-type.c b/ccan/container_of/test/compile_fail-bad-type.c
new file mode 100644
index 0000000..b7a1459
--- /dev/null
+++ b/ccan/container_of/test/compile_fail-bad-type.c
@@ -0,0 +1,22 @@
+#include <ccan/container_of/container_of.h>
+#include <stdlib.h>
+
+struct foo {
+	int a;
+	char b;
+};
+
+int main(int argc, char *argv[])
+{
+	struct foo foo = { .a = 1, .b = 2 };
+	int *intp = &foo.a;
+	char *p;
+
+#ifdef FAIL
+	/* p is a char *, but this gives a struct foo * */
+	p = container_of(intp, struct foo, a);
+#else
+	p = (char *)intp;
+#endif
+	return p == NULL;
+}
diff --git a/ccan/container_of/test/compile_fail-types.c b/ccan/container_of/test/compile_fail-types.c
new file mode 100644
index 0000000..cae1c7a
--- /dev/null
+++ b/ccan/container_of/test/compile_fail-types.c
@@ -0,0 +1,22 @@
+#include <ccan/container_of/container_of.h>
+#include <stdlib.h>
+
+struct foo {
+	int a;
+	char b;
+};
+
+int main(int argc, char *argv[])
+{
+	struct foo foo = { .a = 1, .b = 2 }, *foop;
+	int *intp = &foo.a;
+
+#ifdef FAIL
+	/* b is a char, but intp is an int * */
+	foop = container_of(intp, struct foo, b);
+#else
+	foop = NULL;
+#endif
+	(void) foop; /* Suppress unused-but-set-variable warning. */
+	return intp == NULL;
+}
diff --git a/ccan/container_of/test/compile_fail-var-types.c b/ccan/container_of/test/compile_fail-var-types.c
new file mode 100644
index 0000000..f254d92
--- /dev/null
+++ b/ccan/container_of/test/compile_fail-var-types.c
@@ -0,0 +1,25 @@
+#include <ccan/container_of/container_of.h>
+#include <stdlib.h>
+
+struct foo {
+	int a;
+	char b;
+};
+
+int main(int argc, char *argv[])
+{
+	struct foo foo = { .a = 1, .b = 2 }, *foop;
+	int *intp = &foo.a;
+
+#ifdef FAIL
+	/* b is a char, but intp is an int * */
+	foop = container_of_var(intp, foop, b);
+#if !HAVE_TYPEOF
+#error "Unfortunately we don't fail if we don't have typeof."
+#endif
+#else
+	foop = NULL;
+#endif
+	(void) foop; /* Suppress unused-but-set-variable warning. */
+	return intp == NULL;
+}
diff --git a/ccan/container_of/test/run.c b/ccan/container_of/test/run.c
new file mode 100644
index 0000000..96ef483
--- /dev/null
+++ b/ccan/container_of/test/run.c
@@ -0,0 +1,24 @@
+#include <ccan/container_of/container_of.h>
+#include <ccan/tap/tap.h>
+
+struct foo {
+	int a;
+	char b;
+};
+
+int main(int argc, char *argv[])
+{
+	struct foo foo = { .a = 1, .b = 2 };
+	int *intp = &foo.a;
+	char *charp = &foo.b;
+
+	plan_tests(6);
+	ok1(container_of(intp, struct foo, a) == &foo);
+	ok1(container_of(charp, struct foo, b) == &foo);
+	ok1(container_of_var(intp, &foo, a) == &foo);
+	ok1(container_of_var(charp, &foo, b) == &foo);
+
+	ok1(container_off(struct foo, a) == 0);
+	ok1(container_off(struct foo, b) == offsetof(struct foo, b));
+	return exit_status();
+}