From 9331379cd49a15a05949a7753b8e781b62aee2ff Mon Sep 17 00:00:00 2001
From: Markus Stange <mstange.moz@gmail.com>
Date: Tue, 11 Apr 2023 17:35:48 +0000
Subject: [PATCH] Bug 1827214 - Make PerfSpewer.cpp compile on macOS, and allow
 --enable-perf on macOS. r=dpalmeiro

Emitting Jitdump files on macOS will be useful once the samply profiler
supports Jitdump on macOS.

Differential Revision: https://phabricator.services.mozilla.com/D175045
---
 js/moz.configure          |  6 ++++--
 js/src/jit/PerfSpewer.cpp | 32 +++++++++++++++++++++++++++++++-
 2 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/js/moz.configure b/js/moz.configure
index 8f22982882bc..37e08a7ea46b 100644
--- a/js/moz.configure
+++ b/js/moz.configure
@@ -431,8 +431,10 @@ option("--enable-perf", env="JS_ION_PERF", help="Enable Linux perf integration")
 
 @depends("--enable-perf", target)
 def ion_perf(value, target):
-    ok_kernel = target.kernel == "Linux" and target.os == "GNU"
-    if value and ok_kernel:
+    is_linux = target.kernel == "Linux" and target.os == "GNU"
+    is_mac = target.kernel == "Darwin" and target.os == "OSX"
+
+    if value and (is_linux or is_mac):
         return True
 
 
diff --git a/js/src/jit/PerfSpewer.cpp b/js/src/jit/PerfSpewer.cpp
index 92d568b5c7aa..a7804f9efc2b 100644
--- a/js/src/jit/PerfSpewer.cpp
+++ b/js/src/jit/PerfSpewer.cpp
@@ -22,6 +22,34 @@
 #  include <unistd.h>
 #  define gettid() static_cast<pid_t>(syscall(__NR_gettid))
 #endif
+
+#if defined(JS_ION_PERF) && defined(XP_MACOSX)
+#  include <pthread.h>
+#  include <unistd.h>
+
+pid_t gettid_pthread() {
+  uint64_t tid;
+  if (pthread_threadid_np(nullptr, &tid) != 0) {
+    return 0;
+  }
+  // Truncate the tid to 32 bits. macOS thread IDs are usually small enough.
+  // And even if we do end up truncating, it doesn't matter much for Jitdump
+  // as long as the process ID is correct.
+  return pid_t(tid);
+}
+#  define gettid() gettid_pthread()
+
+const char* get_current_dir_name_cwd() {
+  constexpr size_t CWD_MAX = 256;
+  char* buffer = (char*)malloc(CWD_MAX);
+  if (getcwd(buffer, CWD_MAX) == nullptr) {
+    buffer[0] = 0;
+  }
+  return buffer;
+}
+#  define get_current_dir_name() get_current_dir_name_cwd()
+#endif
+
 #include "jit/PerfSpewer.h"
 
 #include <atomic>
@@ -171,7 +199,9 @@ static bool openJitDump() {
     if (env_dir[0] == '/') {
       spew_dir = JS_smprintf("%s", env_dir);
     } else {
-      spew_dir = JS_smprintf("%s/%s", get_current_dir_name(), env_dir);
+      const char* dir = get_current_dir_name();
+      spew_dir = JS_smprintf("%s/%s", dir, env_dir);
+      free((void*)dir);
     }
   } else {
     fprintf(stderr, "Please define PERF_SPEW_DIR as an output directory.\n");