commit b8eaee68b66ee1b56ec03d42a49dddebefc86389
author Yi Kong <yikong@google.com> Tue Oct 31 21:58:42 2023 +0900
committer Yi Kong <yikong@google.com> Tue Oct 31 21:59:45 2023 +0900
tree 8c346fb999f1adff36eb41fac054dcbb5ff95e3d
parent 87e4128270542d78526409a9154fe2eeb40f797c

Add option to emit ThinLTO indexes and imports for MLGO training

Test: presubmit
Bug: 293827654
Change-Id: I8de1287543194d8e47ff5b57d4cabc7416048bbf

cc/lto.go

diff --git a/cc/lto.go b/cc/lto.go
index d48be14..20e4f24 100644
--- a/cc/lto.go
+++ b/cc/lto.go
@@ -147,6 +147,12 @@
 			}
 		}
 
+		// For ML training
+		if ctx.Config().IsEnvTrue("THINLTO_EMIT_INDEXES_AND_IMPORTS") {
+			ltoLdFlags = append(ltoLdFlags, "-Wl,--save-temps=import")
+			ltoLdFlags = append(ltoLdFlags, "-Wl,--thinlto-emit-index-files")
+		}
+
 		flags.Local.CFlags = append(flags.Local.CFlags, ltoCFlags...)
 		flags.Local.AsFlags = append(flags.Local.AsFlags, ltoCFlags...)
 		flags.Local.LdFlags = append(flags.Local.LdFlags, ltoCFlags...)