feat(port): implement current thread ID on FreeBSD

Make all tests pass on FreeBSD by implementing a missing portability
function.

Author: strager

docs/CHANGELOG.md

@@ -33,7 +33,7 @@ Semantic Versioning.
   the language standard.
 * `((x)) => {}` no longer crashes the parser with an assertion failure.
 * Tests now pass if the user's locale is Italian (`it_IT.utf8` on Linux).
-* The FreeBSD build now succeeds.
+* The FreeBSD build now succeeds and tests pass.
 
 ## 2.5.0 (2022-05-23)
 

src/quick-lint-js/have.h

@@ -403,6 +403,19 @@
 #define QLJS_HAVE_SETJMP 0
 #endif
 
+#if !defined(QLJS_HAVE_SYS_THR_H) && defined(__has_include)
+#if __has_include(<sys/thr.h>)
+#define QLJS_HAVE_SYS_THR_H 1
+#endif
+#endif
+#if !defined(QLJS_HAVE_SYS_THR_H)
+#if defined(__FreeBSD__)
+#define QLJS_HAVE_SYS_THR_H 1
+#else
+#define QLJS_HAVE_SYS_THR_H 0
+#endif
+#endif
+
 #if !defined(QLJS_HAVE_INOTIFY)
 #if defined(__linux__)
 #define QLJS_HAVE_INOTIFY 1

src/thread.cpp

@@ -27,6 +27,10 @@
 #include <mach/thread_act.h>
 #endif
 
+#if QLJS_HAVE_SYS_THR_H
+#include <sys/thr.h>
+#endif
+
 #if QLJS_HAVE_GETTID
 #include <sys/types.h>
 #endif
@@ -204,6 +208,11 @@ std::uint64_t get_current_thread_id() noexcept {
   QLJS_ALWAYS_ASSERT(rc == KERN_SUCCESS);
   QLJS_ALWAYS_ASSERT(info_count == THREAD_IDENTIFIER_INFO_COUNT);
   return info.thread_id;
+#elif QLJS_HAVE_SYS_THR_H
+  long thread_id;
+  int rc = ::thr_self(&thread_id);
+  QLJS_ALWAYS_ASSERT(rc == 0);
+  return narrow_cast<std::uint64_t>(thread_id);
 #else
 #warning "Unsupported platform"
   return 0;