Make buck/bazel generated filepaths match source path with extension
diff --git a/demo/BUILD b/demo/BUILD
index 9a46fa2..c1fb429 100644
--- a/demo/BUILD
+++ b/demo/BUILD
@@ -23,7 +23,7 @@
 genrule(
     name = "gen-header",
     srcs = ["src/main.rs"],
-    outs = ["main.rs.h"],
+    outs = ["src/main.rs.h"],
     cmd = "$(location //:codegen) --header $< > $@",
     tools = ["//:codegen"],
 )
@@ -31,7 +31,7 @@
 genrule(
     name = "gen-source",
     srcs = ["src/main.rs"],
-    outs = ["generated.cc"],
+    outs = ["src/main.rs.cc"],
     cmd = "$(location //:codegen) $< > $@",
     tools = ["//:codegen"],
 )
@@ -39,7 +39,6 @@
 cc_library(
     name = "include",
     hdrs = [":gen-header"],
-    include_prefix = "demo/src",
 )
 
 cc_library(