[libc] Provide sys/queue.h (llvm#78081)

This header first appeared in 4.4BSD and is provided by a number of C
libraries including Newlib. Several of our embedded projects use this
header and so to make LLVM libc a drop-in replacement, we need to
provide it as well.

For the initial commit, we only implement singly linked variants (SLIST
and STAILQ). The doubly linked variants (LIST, TAILQ and CIRCLEQ) can be
implemented in the future as needed.

libc/config/baremetal/arm/headers.txt

@@ -8,4 +8,5 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.stdlib
     libc.include.string
     libc.include.strings
+    libc.include.sys_queue
 )

libc/config/baremetal/riscv/headers.txt

@@ -8,4 +8,5 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.stdlib
     libc.include.string
     libc.include.strings
+    libc.include.sys_queue
 )

libc/config/linux/riscv/headers.txt

@@ -31,6 +31,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.sys_mman
     libc.include.sys_prctl
     libc.include.sys_random
+    libc.include.sys_queue
     libc.include.sys_resource
     libc.include.sys_select
     libc.include.sys_socket

libc/config/linux/x86_64/headers.txt

@@ -30,6 +30,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.sys_ioctl
     libc.include.sys_mman
     libc.include.sys_prctl
+    libc.include.sys_queue
     libc.include.sys_random
     libc.include.sys_resource
     libc.include.sys_select

libc/include/CMakeLists.txt

@@ -345,6 +345,14 @@ add_gen_header(
     .llvm_libc_common_h
 )
 
+add_header(
+  sys_queue
+  HDR
+    sys/queue.h
+  DEPENDS
+    .llvm-libc-macros.sys_queue_macros
+)
+
 add_gen_header(
   sys_random
   DEF_FILE sys/random.h.def

libc/include/llvm-libc-macros/CMakeLists.txt

@@ -4,7 +4,7 @@ function(add_macro_header name)
     "MACRO_HEADER"
     "" # Optional arguments
     "HDR" # Single value arguments
-    "" # Multi-value arguments
+    "DEPENDS" # Multi-value arguments
     ${ARGN}
   )
   if(TARGET libc.include.llvm-libc-macros.${LIBC_TARGET_OS}.${name})
@@ -14,12 +14,15 @@ function(add_macro_header name)
         ${MACRO_HEADER_HDR}
       DEPENDS
         .${LIBC_TARGET_OS}.${name}
+        ${MACRO_HEADER_DEPENDS}
     )
   else()
     add_header(
       ${name}
       HDR
         ${MACRO_HEADER_HDR}
+      DEPENDS
+        ${MACRO_HEADER_DEPENDS}
     )
   endif()
 endfunction(add_macro_header)
@@ -70,6 +73,20 @@ add_macro_header(
     math-macros.h
 )
 
+add_macro_header(
+  offsetof_macro
+  HDR
+    offsetof-macro.h
+)
+
+add_macro_header(
+  containerof_macro
+  HDR
+    containerof-macro.h
+  DEPENDS
+    .offsetof_macro
+)
+
 add_macro_header(
   sched_macros
   HDR
@@ -118,6 +135,15 @@ add_macro_header(
     sys-mman-macros.h
 )
 
+add_macro_header(
+  sys_queue_macros
+  HDR
+    sys-queue-macros.h
+  DEPENDS
+    .null_macro
+    .containerof_macro
+)
+
 add_macro_header(
   sys_random_macros
   HDR

libc/include/llvm-libc-macros/containerof-macro.h

@@ -0,0 +1,20 @@
+//===-- Definition of the containerof macro -------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __LLVM_LIBC_MACROS_CONTAINEROF_MACRO_H
+#define __LLVM_LIBC_MACROS_CONTAINEROF_MACRO_H
+
+#include <llvm-libc-macros/offsetof-macro.h>
+
+#define __containerof(ptr, type, member)                                       \
+  ({                                                                           \
+    const __typeof(((type *)0)->member) *__ptr = (ptr);                        \
+    (type *)(void *)((const char *)__ptr - offsetof(type, member));            \
+  })
+
+#endif // __LLVM_LIBC_MACROS_CONTAINEROF_MACRO_H

libc/include/llvm-libc-macros/offsetof-macro.h

@@ -0,0 +1,15 @@
+//===-- Definition of the offsetof macro ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef __LLVM_LIBC_MACROS_OFFSETOF_MACRO_H
+#define __LLVM_LIBC_MACROS_OFFSETOF_MACRO_H
+
+#define __need_offsetof
+#include <stddef.h>
+
+#endif // __LLVM_LIBC_MACROS_OFFSETOF_MACRO_H