[llvm] [llvm][Support] Add support for thread naming under DragonFly BSD and Solaris/illumos (PR #106944)

[Brad Smith via llvm-commits]

https://github.com/brad0 updated https://github.com/llvm/llvm-project/pull/106944

>From df24d78299232812c8ad3e9861517672419f4bd4 Mon Sep 17 00:00:00 2001
From: Brad Smith <brad at comstyle.com>
Date: Mon, 2 Sep 2024 00:51:10 -0400
Subject: [PATCH] [llvm][Support] Add support for thread naming under DragonFly
 BSD and Solaris/illumos

---
 llvm/cmake/config-ix.cmake              |  2 ++
 llvm/include/llvm/Config/config.h.cmake |  6 +++++
 llvm/lib/Support/Unix/Threading.inc     | 36 ++++++++++++++-----------
 3 files changed, 29 insertions(+), 15 deletions(-)

diff --git a/llvm/cmake/config-ix.cmake b/llvm/cmake/config-ix.cmake
index f76eacb9d51366..3707ca824f6e9c 100644
--- a/llvm/cmake/config-ix.cmake
+++ b/llvm/cmake/config-ix.cmake
@@ -356,6 +356,8 @@ if (NOT PURE_WINDOWS)
   endif()
   check_symbol_exists(pthread_getname_np pthread.h HAVE_PTHREAD_GETNAME_NP)
   check_symbol_exists(pthread_setname_np pthread.h HAVE_PTHREAD_SETNAME_NP)
+  check_symbol_exists(pthread_get_name_np "pthread.h;pthread_np.h" HAVE_PTHREAD_GET_NAME_NP)
+  check_symbol_exists(pthread_set_name_np "pthread.h;pthread_np.h" HAVE_PTHREAD_SET_NAME_NP)
   if (LLVM_PTHREAD_LIB)
     list(REMOVE_ITEM CMAKE_REQUIRED_LIBRARIES ${LLVM_PTHREAD_LIB})
   endif()
diff --git a/llvm/include/llvm/Config/config.h.cmake b/llvm/include/llvm/Config/config.h.cmake
index f39d2d56d61e89..d71ff40144c097 100644
--- a/llvm/include/llvm/Config/config.h.cmake
+++ b/llvm/include/llvm/Config/config.h.cmake
@@ -125,6 +125,12 @@
 /* Define to 1 if you have the `pthread_setname_np' function. */
 #cmakedefine HAVE_PTHREAD_SETNAME_NP ${HAVE_PTHREAD_SETNAME_NP}
 
+/* Define to 1 if you have the `pthread_get_name_np' function. */
+#cmakedefine HAVE_PTHREAD_GET_NAME_NP ${HAVE_PTHREAD_GET_NAME_NP}
+
+/* Define to 1 if you have the `pthread_set_name_np' function. */
+#cmakedefine HAVE_PTHREAD_SET_NAME_NP ${HAVE_PTHREAD_SET_NAME_NP}
+
 /* Define to 1 if you have the <mach/mach.h> header file. */
 #cmakedefine HAVE_MACH_MACH_H ${HAVE_MACH_MACH_H}
 
diff --git a/llvm/lib/Support/Unix/Threading.inc b/llvm/lib/Support/Unix/Threading.inc
index 1812d990f21ac1..285cc220dca0f4 100644
--- a/llvm/lib/Support/Unix/Threading.inc
+++ b/llvm/lib/Support/Unix/Threading.inc
@@ -137,13 +137,16 @@ uint64_t llvm::get_threadid() {
 }
 
 static constexpr uint32_t get_max_thread_name_length_impl() {
-#if defined(__NetBSD__)
+#if defined(PTHREAD_MAX_NAMELEN_NP)
   return PTHREAD_MAX_NAMELEN_NP;
 #elif defined(__APPLE__)
   return 64;
+#elif defined(__sun__) && defined(__svr4__)
+  return 31;
 #elif defined(__linux__) && HAVE_PTHREAD_SETNAME_NP
   return 16;
-#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__) ||                   \
+    defined(__DragonFly__)
   return 16;
 #elif defined(__OpenBSD__)
   return 32;
@@ -170,15 +173,17 @@ void llvm::set_thread_name(const Twine &Name) {
   if (get_max_thread_name_length() > 0)
     NameStr = NameStr.take_back(get_max_thread_name_length() - 1);
   (void)NameStr;
-#if defined(__linux__) && HAVE_PTHREAD_SETNAME_NP
-  ::pthread_setname_np(::pthread_self(), NameStr.data());
-#elif defined(__FreeBSD__) || defined(__OpenBSD__)
+#if defined(HAVE_PTHREAD_SET_NAME_NP)
   ::pthread_set_name_np(::pthread_self(), NameStr.data());
-#elif defined(__NetBSD__)
+#elif defined(HAVE_PTHREAD_SETNAME_NP)
+#if defined(__NetBSD__)
   ::pthread_setname_np(::pthread_self(), "%s",
                        const_cast<char *>(NameStr.data()));
 #elif defined(__APPLE__)
   ::pthread_setname_np(NameStr.data());
+#else
+  ::pthread_setname_np(::pthread_self(), NameStr.data());
+#endif
 #endif
 }
 
@@ -221,23 +226,24 @@ void llvm::get_thread_name(SmallVectorImpl<char> &Name) {
   }
   free(kp);
   return;
-#elif defined(__NetBSD__)
+#elif defined(__linux__) && HAVE_PTHREAD_GETNAME_NP
+  constexpr uint32_t len = get_max_thread_name_length_impl();
+  char Buffer[len] = {'\0'}; // FIXME: working around MSan false positive.
+  if (0 == ::pthread_getname_np(::pthread_self(), Buffer, len))
+    Name.append(Buffer, Buffer + strlen(Buffer));
+#elif defined(HAVE_PTHREAD_GET_NAME_NP)
   constexpr uint32_t len = get_max_thread_name_length_impl();
   char buf[len];
-  ::pthread_getname_np(::pthread_self(), buf, len);
+  ::pthread_get_name_np(::pthread_self(), buf, len);
 
   Name.append(buf, buf + strlen(buf));
-#elif defined(__OpenBSD__)
+
+#elif defined(HAVE_PTHREAD_GETNAME_NP)
   constexpr uint32_t len = get_max_thread_name_length_impl();
   char buf[len];
-  ::pthread_get_name_np(::pthread_self(), buf, len);
+  ::pthread_getname_np(::pthread_self(), buf, len);
 
   Name.append(buf, buf + strlen(buf));
-#elif defined(__linux__) && HAVE_PTHREAD_GETNAME_NP
-  constexpr uint32_t len = get_max_thread_name_length_impl();
-  char Buffer[len] = {'\0'}; // FIXME: working around MSan false positive.
-  if (0 == ::pthread_getname_np(::pthread_self(), Buffer, len))
-    Name.append(Buffer, Buffer + strlen(Buffer));
 #endif
 }