[PATCH] llvm: add binutils-plugin PACKAGECONFIG for LLVMgold.so

[mark.yang@lge.com]

From: "mark.yang" <mark.yang@lge.com>

Add a 'binutils-plugin' PACKAGECONFIG option to selectively build
LLVMgold.so by passing -DLLVM_BINUTILS_INCDIR and adding binutils
to DEPENDS only when enabled.

LLVMgold.so is the LLVM LTO plugin for GNU ld BFD.
When using lld as the linker, this plugin is not needed since lld has
built-in LTO support. However, for toolchains that rely on BFD
this plugin is required to enable LTO.

binutils-plugin is named after Gentoo's USE flag convention for similar
functionality.

Signed-off-by: mark.yang <mark.yang@lge.com>
---
 meta/recipes-devtools/clang/llvm_git.bb | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/meta/recipes-devtools/clang/llvm_git.bb b/meta/recipes-devtools/clang/llvm_git.bb
index 96ea383731..e12ac11853 100644
--- a/meta/recipes-devtools/clang/llvm_git.bb
+++ b/meta/recipes-devtools/clang/llvm_git.bb
@@ -79,6 +79,7 @@ PACKAGECONFIG[opt-viewer] = "-DLLVM_TOOL_OPT_VIEWER_BUILD=ON,-DLLVM_TOOL_OPT_VIE
                              python3-pyyaml python3-pygments,"
 PACKAGECONFIG[lto] = "-DLLVM_ENABLE_LTO=Full -DLLVM_BINUTILS_INCDIR=${STAGING_INCDIR},,binutils,"
 PACKAGECONFIG[thin-lto] = "-DLLVM_ENABLE_LTO=Thin -DLLVM_BINUTILS_INCDIR=${STAGING_INCDIR},,binutils,"
+PACKAGECONFIG[binutils-plugin] = "-DLLVM_BINUTILS_INCDIR=${STAGING_INCDIR},,binutils,"
 
 # LLVM debug symbols are very large (several gigabytes), reduce the debug level
 # so they're just hundreds of megabytes.
@@ -126,6 +127,10 @@ llvm_sysroot_preprocess() {
         install -m 0755 ${S}/llvm/tools/llvm-config/llvm-config ${SYSROOT_DESTDIR}${bindir_crossscripts}/
 }
 
+PACKAGES =+ "llvm-linker-tools"
+
+FILES:llvm-linker-tools = "${libdir}/LLVMgold* ${libdir}/libLTO.so.*"
+
 FILES:${PN}-dev += "${libdir}/llvm-config"
 
 BBCLASSEXTEND = "native nativesdk"