diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
--- a/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp
@@ -1230,6 +1230,17 @@
       IncludeDir =
           IncludeDirectories[Entry.DirIdx - 1].getAsCString().getValue();
   }
+
+  // An include directory may be relative to the compilation directory, or may
+  // be an absolute path itself, similar to the compilation directory. Handle an
+  // absolute-path include direcctory the same as an absolute-path compilation
+  // directory.
+  if (Kind == FileLineInfoKind::RelativeFilePath && !IncludeDir.empty() &&
+      isPathAbsoluteOnWindowsOrPosix(IncludeDir)) {
+    Result = std::string(llvm::sys::path::filename(FileName));
+    return true;
+  }
+
   // For absolute paths only, include the compilation directory of compile unit.
   // We know that FileName is not absolute, the only way to have an absolute
   // path at this point would be if IncludeDir is absolute.
diff --git a/llvm/test/tools/llvm-symbolizer/relativenames.s b/llvm/test/tools/llvm-symbolizer/relativenames.s
--- a/llvm/test/tools/llvm-symbolizer/relativenames.s
+++ b/llvm/test/tools/llvm-symbolizer/relativenames.s
@@ -8,11 +8,16 @@
 # RUN: llvm-symbolizer 0 --relativenames --obj=%t.o \
 # RUN:    | FileCheck %s -DDIR=%p --check-prefix=RELATIVENAMES
 
+## Sanity check for default.
+# RUN: llvm-symbolizer 0 --obj=%t.o \
+# RUN:    | FileCheck %s -DDIR=%p --check-prefix=ABSOLUTENAMES
+
 ## Ensure last option wins.
 # RUN: llvm-symbolizer 0 --basenames --relativenames --obj=%t.o \
 # RUN:    | FileCheck %s -DDIR=%p --check-prefix=RELATIVENAMES
 # RUN: llvm-symbolizer 0 --relativenames --basenames --obj=%t.o \
 # RUN:    | FileCheck %s --check-prefix=BASENAMES
 
-# RELATIVENAMES: [[DIR]]{{\\|/}}relativenames.s:4
+# ABSOLUTENAMES: [[DIR]]{{\\|/}}relativenames.s:4
+# RELATIVENAMES: {{^}}relativenames.s:4
 # BASENAMES: {{^}}relativenames.s:4