Index: cfe/trunk/lib/Driver/ToolChains/FreeBSD.h
===================================================================
--- cfe/trunk/lib/Driver/ToolChains/FreeBSD.h
+++ cfe/trunk/lib/Driver/ToolChains/FreeBSD.h
@@ -69,7 +69,7 @@
       const llvm::opt::ArgList &Args) const override;
   bool isPIEDefault() const override;
   SanitizerMask getSupportedSanitizers() const override;
-  unsigned GetDefaultDwarfVersion() const override { return 2; }
+  unsigned GetDefaultDwarfVersion() const override;
   // Until dtrace (via CTF) and LLDB can deal with distributed debug info,
   // FreeBSD defaults to standalone/full debug info.
   bool GetDefaultStandaloneDebug() const override { return true; }
Index: cfe/trunk/lib/Driver/ToolChains/FreeBSD.cpp
===================================================================
--- cfe/trunk/lib/Driver/ToolChains/FreeBSD.cpp
+++ cfe/trunk/lib/Driver/ToolChains/FreeBSD.cpp
@@ -364,6 +364,12 @@
   return ToolChain::CST_Libstdcxx;
 }
 
+unsigned FreeBSD::GetDefaultDwarfVersion() const {
+  if (getTriple().getOSMajorVersion() < 12)
+    return 2;
+  return 4;
+}
+
 void FreeBSD::addLibStdCxxIncludePaths(
     const llvm::opt::ArgList &DriverArgs,
     llvm::opt::ArgStringList &CC1Args) const {
Index: cfe/trunk/test/Driver/debug-options.c
===================================================================
--- cfe/trunk/test/Driver/debug-options.c
+++ cfe/trunk/test/Driver/debug-options.c
@@ -66,8 +66,12 @@
 // RUN:                         -check-prefix=G_DWARF4 %s
 
 // FreeBSD.
-// RUN: %clang -### -c -g %s -target x86_64-pc-freebsd10.0 2>&1 \
-// RUN:             | FileCheck -check-prefix=G_GDB %s
+// RUN: %clang -### -c -g %s -target x86_64-pc-freebsd11.0 2>&1 \
+// RUN:             | FileCheck -check-prefix=G_GDB \
+// RUN:                         -check-prefix=G_DWARF2 %s
+// RUN: %clang -### -c -g %s -target x86_64-pc-freebsd12.0 2>&1 \
+// RUN:             | FileCheck -check-prefix=G_GDB \
+// RUN:                         -check-prefix=G_DWARF4 %s
 
 // Windows.
 // RUN: %clang -### -c -g %s -target x86_64-w64-windows-gnu 2>&1 \