Merge pull request #73677 from mikeash/lazy-signposts-6.0

[6.0][Runtime] Don't emit signposts until the system is ready.

Author: mikeash

include/swift/Runtime/TracingCommon.h

@@ -22,7 +22,13 @@
 #include "swift/Runtime/Config.h"
 #include <os/signpost.h>
 
-extern const char *__progname;
+extern "C" const char *__progname;
+
+// This function may not be present when building at desk, and isn't really
+// needed there, so just skip it in that case.
+#if SWIFT_BNI_OS_BUILD
+extern "C" bool _os_trace_lazy_init_completed_4swift(void);
+#endif
 
 namespace swift {
 namespace runtime {
@@ -40,6 +46,15 @@ static inline bool shouldEnableTracing() {
   return true;
 }
 
+static inline bool tracingReady() {
+#if SWIFT_BNI_OS_BUILD
+  if (!_os_trace_lazy_init_completed_4swift())
+    return false;
+#endif
+
+  return true;
+}
+
 } // namespace trace
 } // namespace runtime
 } // namespace swift

stdlib/public/Concurrency/TracingSignpost.cpp

@@ -17,7 +17,6 @@
 #if SWIFT_STDLIB_CONCURRENCY_TRACING
 
 #include "TracingSignpost.h"
-#include "swift/Runtime/TracingCommon.h"
 #include <stdio.h>
 
 #define SWIFT_LOG_CONCURRENCY_SUBSYSTEM "com.apple.swift.concurrency"

stdlib/public/Concurrency/TracingSignpost.h

@@ -23,6 +23,7 @@
 #include "swift/Basic/Lazy.h"
 #include "swift/Runtime/Casting.h"
 #include "swift/Runtime/HeapObject.h"
+#include "swift/Runtime/TracingCommon.h"
 #include <inttypes.h>
 #include <os/log.h>
 #include <os/signpost.h>
@@ -79,6 +80,8 @@ void setupLogs(void *unused);
 // optimized out.
 #define ENSURE_LOGS(...)                                                       \
   do {                                                                         \
+    if (!runtime::trace::tracingReady())                                       \
+      return __VA_ARGS__;                                                      \
     swift::once(LogsToken, setupLogs, nullptr);                                \
     if (!TracingEnabled)                                                       \
       return __VA_ARGS__;                                                      \

stdlib/public/runtime/Tracing.cpp

@@ -15,7 +15,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "Tracing.h"
-#include "swift/Runtime/TracingCommon.h"
 
 #if SWIFT_STDLIB_TRACING
 

stdlib/public/runtime/Tracing.h

@@ -20,6 +20,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "swift/ABI/Metadata.h"
 #include "swift/Demangling/Demangler.h"
+#include "swift/Runtime/TracingCommon.h"
 
 #if SWIFT_STDLIB_TRACING
 #include <os/signpost.h>
@@ -49,6 +50,8 @@ void setupLogs(void *unused);
 // optimized out.
 #define ENSURE_LOG(log)                                                        \
   do {                                                                         \
+    if (!tracingReady())                                                       \
+      return {};                                                               \
     swift::once(LogsToken, setupLogs, nullptr);                                \
     if (!TracingEnabled)                                                       \
       return {};                                                               \