[libc] Implement htonl and htons

[rtenneti]

Summary

Per spec:

• https://pubs.opengroup.org/onlinepubs/9699919799/functions/htonl.html
• https://pubs.opengroup.org/onlinepubs/9699919799/functions/htons.html

Also adds UInt16Type and UInt32Type to spec.td

Co-authored-by: Jeff Bailey <[e-mail]>

[sivachandra]

libc/include/arpa/inet.h.def

13

I think you should include inttypes.h here.

libc/src/network/htons.cpp

17

Can we just do:

return Endian::to_big_endian(hostlong);

[rtenneti]

Fixed comments from Siva.

[sivachandra]

libc/src/network/htons.cpp

16

hostshort?

[rtenneti]

In htons changed variable name from hostlong to hostshort.

libc/config/linux/aarch64/entrypoints.txt

set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.tanhf
     libc.src.math.trunc
     libc.src.math.truncf
     libc.src.math.truncl
 )
 
 if(LLVM_LIBC_FULL_BUILD)
   list(APPEND TARGET_LIBC_ENTRYPOINTS
+    # network.h entrypoints
+    libc.src.network.htonl
+    libc.src.network.htons
+
     # pthread.h entrypoints
     libc.src.pthread.pthread_atfork
     libc.src.pthread.pthread_attr_destroy
     libc.src.pthread.pthread_attr_init
     libc.src.pthread.pthread_attr_getdetachstate
     libc.src.pthread.pthread_attr_getguardsize
     libc.src.pthread.pthread_attr_getstack
     libc.src.pthread.pthread_attr_getstacksize

libc/config/linux/x86_64/entrypoints.txt

list(APPEND TARGET_LIBC_ENTRYPOINTS
     libc.src.assert.__assert_fail
 
     # dirent.h entrypoints
     libc.src.dirent.closedir
     libc.src.dirent.dirfd
     libc.src.dirent.opendir
     libc.src.dirent.readdir
 
+    # network.h entrypoints
+    libc.src.network.htonl
+    libc.src.network.htons
+
     # pthread.h entrypoints
     libc.src.pthread.pthread_atfork
     libc.src.pthread.pthread_attr_destroy
     libc.src.pthread.pthread_attr_init
     libc.src.pthread.pthread_attr_getdetachstate
     libc.src.pthread.pthread_attr_getguardsize
     libc.src.pthread.pthread_attr_getstack
     libc.src.pthread.pthread_attr_getstacksize

libc/config/linux/x86_64/headers.txt

set(TARGET_PUBLIC_HEADERS
     libc.include.stdio
     libc.include.stdlib
     libc.include.string
     libc.include.termios
     libc.include.threads
     libc.include.time
     libc.include.unistd
 
+    libc.include.arpa_inet
+
     libc.include.sys_auxv
     libc.include.sys_ioctl
     libc.include.sys_mman
     libc.include.sys_prctl
     libc.include.sys_random
     libc.include.sys_resource
     libc.include.sys_select
     libc.include.sys_stat
     libc.include.sys_syscall
     libc.include.sys_time
     libc.include.sys_types
     libc.include.sys_utsname
     libc.include.sys_wait
 )

libc/include/CMakeLists.txt

add_gen_header(
   DEF_FILE math.h.def
   GEN_HDR math.h
   DEPENDS
     .llvm_libc_common_h
     .llvm-libc-types.double_t
     .llvm-libc-types.float_t
 )
 
+# TODO: This should be conditional on POSIX networking being included.
+file(MAKE_DIRECTORY "arpa")
+
+add_gen_header(
+  arpa_inet
+  DEF_FILE arpa/inet.h.def
+  GEN_HDR arpa/inet.h
+  DEPENDS
+    .llvm_libc_common_h
+)
+
 add_gen_header(
   assert
   DEF_FILE assert.h.def
   GEN_HDR assert.h
   DEPENDS
     .llvm_libc_common_h
 )
 

libc/include/arpa/inet.h.def

+//===-- C standard library header network.h -------------------------------===//
+//
+// 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_ARPA_INET_H
+#define LLVM_LIBC_ARPA_INET_H
+
+#include <__llvm-libc-common.h>
+
+#include <inttypes.h>
+
+%%public_api()
+
+#endif // LLVM_LIBC_ARPA_INET_H

libc/spec/posix.td

[
         FunctionSpec<
             "uname",
             RetValSpec<IntType>,
             [ArgSpec<StructUtsNamePtr>]
         >,
     ]
   >;
 
+  HeaderSpec ArpaInet = HeaderSpec<
+      "arpa/inet.h",
+      [], // Macros
+      [], // Types
+      [], // Enumerations
+      [
+          FunctionSpec<
+              "htonl",
+              RetValSpec<UInt32Type>,
+              [ArgSpec<UInt32Type>]
+          >,
+          FunctionSpec<
+              "htons",
+              RetValSpec<UInt16Type>,
+              [ArgSpec<UInt16Type>]
+          >,
+      ]
+  >;
+
   HeaderSpec PThread = HeaderSpec<
     "pthread.h",
     [], // Macros
     [
         AtForkCallbackT,
         PThreadAttrTType,
         PThreadKeyT,
         PThreadMutexAttrTType,
HeaderSpec SysTypes = HeaderSpec<
     [BlkCntT, BlkSizeT, ClockIdT, DevT, GidT, InoT, ModeTType, NLinkT, OffTType, PidT,
      PThreadAttrTType, PThreadKeyT, PThreadMutexTType, PThreadMutexAttrTType, PThreadOnceT, PThreadTType,
      SizeTType, SSizeTType, SuSecondsT, TimeTType, UidT],
     [], // Enumerations
     []  // Functions
   >;
 
   let Headers = [
+    ArpaInet,
     CType,
     Dirent,
     Errno,
     FCntl,
     PThread,
     Signal,
     Spawn,
     StdIO,

libc/spec/spec.td

 def SizeTPtr : PtrType<SizeTType>;
 def RestrictedSizeTPtr : RestrictedPtrType<SizeTType>;
 
 def LongDoublePtr : PtrType<LongDoubleType>;
 
 def IntMaxTType : NamedType<"intmax_t">;
 def UIntMaxTType : NamedType<"uintmax_t">;
 
+def UInt16Type : NamedType<"uint16_t">;
+def UInt32Type : NamedType<"uint32_t">;
+
 def OffTType : NamedType<"off_t">;
 def OffTPtr : PtrType<OffTType>;
 def SSizeTType : NamedType<"ssize_t">;
 
 // _Noreturn is really not a type, but it is convenient to treat it as a type.
 def NoReturn : NamedType<"_Noreturn void">;
 
 //types moved from stdc.td

libc/src/CMakeLists.txt

if(${LIBC_TARGET_OS} STREQUAL "linux")
   add_subdirectory(unistd)
 endif()
 
 if(NOT LLVM_LIBC_FULL_BUILD)
   return()
 endif()
 
 add_subdirectory(assert)
+add_subdirectory(network)
 add_subdirectory(setjmp)
 add_subdirectory(signal)
 add_subdirectory(spawn)
 add_subdirectory(threads)
 add_subdirectory(time)

libc/src/network/CMakeLists.txt

+add_entrypoint_object(
+  htonl
+  SRCS
+    htonl.cpp
+  HDRS
+    htonl.h
+  DEPENDS
+    libc.include.arpa_inet
+    libc.src.__support.common
+)
+
+add_entrypoint_object(
+  htons
+  SRCS
+    htons.cpp
+  HDRS
+    htons.h
+  DEPENDS
+    libc.include.arpa_inet
+    libc.src.__support.common
+)

libc/src/network/htonl.h

+//===-- Implementation header of htonl --------------------------*- C++ -*-===//
+//
+// 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_SRC_NETWORK_HTONL_H
+#define LLVM_LIBC_SRC_NETWORK_HTONL_H
+
+#include <stdint.h>
+
+namespace __llvm_libc {
+
+uint32_t htonl(uint32_t hostlong);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_NETWORK_HTONL_H

libc/src/network/htonl.cpp

+//===-- Implementation of htonl function ----------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/network/htonl.h"
+#include "src/__support/common.h"
+#include "src/__support/endian.h"
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(uint32_t, htonl, (uint32_t hostlong)) {
+  return Endian::to_big_endian(hostlong);
+}
+
+} // namespace __llvm_libc

libc/src/network/htons.h

+//===-- Implementation header of htons --------------------------*- C++ -*-===//
+//
+// 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_SRC_NETWORK_HTONS_H
+#define LLVM_LIBC_SRC_NETWORK_HTONS_H
+
+#include <stdint.h>
+
+namespace __llvm_libc {
+
+uint16_t htons(uint16_t hostlong);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_NETWORK_HTONS_H

libc/src/network/htons.cpp

+//===-- Implementation of htons function ----------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/network/htons.h"
+#include "src/__support/common.h"
+#include "src/__support/endian.h"
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(uint16_t, htons, (uint16_t hostshort)) {
+  return Endian::to_big_endian(hostshort);
+}
+
+} // namespace __llvm_libc

libc/test/src/CMakeLists.txt

 endif()
 
 if(NOT LLVM_LIBC_FULL_BUILD)
   return()
 endif()
 
 add_subdirectory(dirent)
 add_subdirectory(assert)
+add_subdirectory(network)
 add_subdirectory(setjmp)
 add_subdirectory(signal)
 add_subdirectory(spawn)
 add_subdirectory(time)
 
 if(${LIBC_TARGET_OS} STREQUAL "linux")
   add_subdirectory(pthread)
 endif()

libc/test/src/network/CMakeLists.txt

+add_libc_testsuite(libc_network_unittests)
+
+add_libc_unittest(
+  htonl
+  SUITE
+    libc_network_unittests
+  SRCS
+    htonl_test.cpp
+  CXX_STANDARD
+    20
+  DEPENDS
+    libc.src.network.htonl
+)
+
+add_libc_unittest(
+  htons
+  SUITE
+    libc_network_unittests
+  SRCS
+    htons_test.cpp
+  CXX_STANDARD
+    20
+  DEPENDS
+    libc.src.network.htons
+)

libc/test/src/network/htonl_test.cpp

+//===-- Unittests for htonl -----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/endian.h"
+#include "src/network/htonl.h"
+#include "test/UnitTest/Test.h"
+
+TEST(LlvmLibcHtonl, SmokeTest) {
+  uint32_t original = 0x67452301;
+  uint32_t swapped = 0x01234567;
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+  EXPECT_EQ(__llvm_libc::htonl(original), swapped);
+#endif
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+  EXPECT_EQ(__llvm_libc::htonl(original), original);
+#endif
+}

libc/test/src/network/htons_test.cpp

+//===-- Unittests for htons -----------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/__support/endian.h"
+#include "src/network/htons.h"
+#include "test/UnitTest/Test.h"
+
+TEST(LlvmLibcHtons, SmokeTest) {
+  uint16_t original = 0x2301;
+  uint16_t swapped = 0x0123;
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+  EXPECT_EQ(__llvm_libc::htons(original), swapped);
+#endif
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+  EXPECT_EQ(__llvm_libc::htons(original), original);
+#endif
+}