1 files changed, 15 insertions, 0 deletions
diff --git a/tools/gn/ninja_helper.cc b/tools/gn/ninja_helper.cc
index 6ddacd0..0ea93016 100644
--- a/tools/gn/ninja_helper.cc
+++ b/tools/gn/ninja_helper.cc
@@ -86,6 +86,19 @@ OutputFile NinjaHelper::GetOutputFileForSource(
       name.append("res");
       break;
 
+    // Pass .o/.obj files through unchanged.
+    case SOURCE_O: {
+      // System-absolute file names get preserved (they don't need to be
+      // rebased relative to the build dir).
+      if (source.is_system_absolute())
+        return OutputFile(source.value());
+
+      // Construct the relative location of the file from the build dir.
+      OutputFile ret(build_to_src_no_last_slash());
+      source.SourceAbsoluteWithOneSlash().AppendToString(&ret.value());
+      return ret;
+    }
+
     case SOURCE_H:
     case SOURCE_UNKNOWN:
       NOTREACHED();
@@ -224,5 +237,7 @@ std::string NinjaHelper::GetRuleForSourceType(const Settings* settings,
 
   // TODO(brettw) asm files.
 
+  // .obj files have no rules to make them (they're already built) so we return
+  // the enpty string for SOURCE_O.
   return std::string();
 }