[lldb] Add a log level to Host::SystemLog (#90904)

Add the ability to specify a log level to Host::SystemLog.

Author: JDevlieghere

lldb/include/lldb/Host/Host.h

@@ -87,8 +87,15 @@ class Host {
   StartMonitoringChildProcess(const MonitorChildProcessCallback &callback,
                               lldb::pid_t pid);
 
+  /// System log level.
+  enum SystemLogLevel {
+    eSystemLogInfo,
+    eSystemLogWarning,
+    eSystemLogError,
+  };
+
   /// Emit the given message to the operating system log.
-  static void SystemLog(llvm::StringRef message);
+  static void SystemLog(SystemLogLevel log_level, llvm::StringRef message);
 
   /// Get the process ID for the calling process.
   ///

lldb/source/Host/common/Host.cpp

@@ -91,15 +91,37 @@ using namespace lldb_private;
 #if !defined(__APPLE__)
 #if !defined(_WIN32)
 #include <syslog.h>
-void Host::SystemLog(llvm::StringRef message) {
+void Host::SystemLog(SystemLogLevel log_level, llvm::StringRef message) {
   static llvm::once_flag g_openlog_once;
   llvm::call_once(g_openlog_once, [] {
     openlog("lldb", LOG_CONS | LOG_PID | LOG_NDELAY, LOG_USER);
   });
-  syslog(LOG_INFO, "%s", message.data());
+  int level = LOG_DEBUG;
+  switch (log_level) {
+  case eSystemLogInfo:
+    level = LOG_INFO;
+    break;
+  case eSystemLogWarning:
+    level = LOG_WARNING;
+    break;
+  case eSystemLogError:
+    level = LOG_ERR;
+    break;
+  }
+  syslog(level, "%s", message.data());
 }
 #else
-void Host::SystemLog(llvm::StringRef message) { llvm::errs() << message; }
+void Host::SystemLog(SystemLogLevel log_level, llvm::StringRef message) {
+  switch (log_level) {
+  case eSystemLogInfo:
+  case eSystemLogWarning:
+    llvm::outs() << message;
+    break;
+  case eSystemLogError:
+    llvm::errs() << message;
+    break;
+  }
+}
 #endif
 #endif
 
@@ -629,5 +651,5 @@ char SystemLogHandler::ID;
 SystemLogHandler::SystemLogHandler() {}
 
 void SystemLogHandler::Emit(llvm::StringRef message) {
-  Host::SystemLog(message);
+  Host::SystemLog(Host::eSystemLogInfo, message);
 }

lldb/source/Host/macosx/objcxx/Host.mm

@@ -102,12 +102,20 @@
 static os_log_t g_os_log;
 static std::once_flag g_os_log_once;
 
-void Host::SystemLog(llvm::StringRef message) {
+void Host::SystemLog(SystemLogLevel log_level, llvm::StringRef message) {
   if (__builtin_available(macos 10.12, iOS 10, tvOS 10, watchOS 3, *)) {
     std::call_once(g_os_log_once, []() {
       g_os_log = os_log_create("com.apple.dt.lldb", "lldb");
     });
-    os_log(g_os_log, "%{public}s", message.str().c_str());
+    switch (log_level) {
+    case eSystemLogInfo:
+    case eSystemLogWarning:
+      os_log(g_os_log, "%{public}s", message.str().c_str());
+      break;
+    case eSystemLogError:
+      os_log_error(g_os_log, "%{public}s", message.str().c_str());
+      break;
+    }
   } else {
     llvm::errs() << message;
   }