From b70617a1604e8bfc39ceb701ed70f69fd4f34a8b Mon Sep 17 00:00:00 2001
From: Vic Yang <victoryang@google.com>
Date: Mon, 14 Jan 2019 11:00:10 -0800
Subject: [PATCH] Add Symbol_ordering_file property

We add an optional Symbol_ordering_file property to linker properties
to allow modules to specify the order of symbols in the binary.

Bug: 112073665
Test: Build libc with a symbol ordering file and check the resulting
      binary.

Change-Id: Ibb24697cfdee4a5750442cb74f1ee6390d8a6430
---
 cc/linker.go | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/cc/linker.go b/cc/linker.go
index 854dfc578..eb7126874 100644
--- a/cc/linker.go
+++ b/cc/linker.go
@@ -150,6 +150,9 @@ type BaseLinkerProperties struct {
 
 	// local file name to pass to the linker as --version_script
 	Version_script *string `android:"arch_variant"`
+
+	// Local file name to pass to the linker as --symbol-ordering-file
+	Symbol_ordering_file *string `android:"arch_variant"`
 }
 
 func NewBaseLinker(sanitize *sanitize) *baseLinker {
@@ -279,6 +282,8 @@ func (linker *baseLinker) linkerDeps(ctx DepsContext, deps Deps) Deps {
 			linker.Properties.Target.Vendor.Version_script)
 	}
 
+	android.ExtractSourceDeps(ctx, linker.Properties.Symbol_ordering_file)
+
 	return deps
 }
 
@@ -435,6 +440,16 @@ func (linker *baseLinker) linkerFlags(ctx ModuleContext, flags Flags) Flags {
 		}
 	}
 
+	if !linker.dynamicProperties.BuildStubs {
+		symbolOrderingFile := ctx.ExpandOptionalSource(
+			linker.Properties.Symbol_ordering_file, "Symbol_ordering_file")
+		if symbolOrderingFile.Valid() {
+			flags.LdFlags = append(flags.LdFlags,
+				"-Wl,--symbol-ordering-file,"+symbolOrderingFile.String())
+			flags.LdFlagsDeps = append(flags.LdFlagsDeps, symbolOrderingFile.Path())
+		}
+	}
+
 	return flags
 }