[-gmodules] Let LLDB log a warning if the Clang module hash mismatches.

This feature is mostly there to aid debugging of Clang module issues,
since the only useful actual the end-user can to is to recompile their
program.

Differential Revision: https://reviews.llvm.org/D70272

1 files changed, 15 insertions, 4 deletions

diff --git a/lldb/source/Host/common/Host.cpp b/lldb/source/Host/common/Host.cpp
index 8e210c7e5fa..5fbb655fc79 100644
--- a/lldb/source/Host/common/Host.cpp
+++ b/lldb/source/Host/common/Host.cpp
@@ -293,10 +293,21 @@ void Host::SystemLog(SystemLogType type, const char *format, va_list args) {
 #endif
 
 void Host::SystemLog(SystemLogType type, const char *format, ...) {
-  va_list args;
-  va_start(args, format);
-  SystemLog(type, format, args);
-  va_end(args);
+  {
+    va_list args;
+    va_start(args, format);
+    SystemLog(type, format, args);
+    va_end(args);
+  }
+
+  Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST));
+  if (log && log->GetVerbose()) {
+    // Log to log channel. This allows testcases to grep for log output.
+    va_list args;
+    va_start(args, format);
+    log->VAPrintf(format, args);
+    va_end(args);
+  }
 }
 
 lldb::pid_t Host::GetCurrentProcessID() { return ::getpid(); }