toolchain-funcs: Add tc-ld-is-lld helper.

LLD is a new linker for LLVM project.
Add tc-ld-is-lld helper to be able to detect it.

Signed-off-by: Manoj Gupta <manojgupta@google.com>
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>

diff --git a/eclass/toolchain-funcs.eclass b/eclass/toolchain-funcs.eclass
index 7bd90bb4e4a06dc5046de3525ac15efe0d17236e..e358d484417ab0ddad812ce54feb9141618cc2e8 100644 (file)
--- a/eclass/toolchain-funcs.eclass
+++ b/eclass/toolchain-funcs.eclass
@@ -453,6 +453,36 @@ tc-ld-is-gold() {
        return 1
 }
 
+# @FUNCTION: tc-ld-is-lld
+# @USAGE: [toolchain prefix]
+# @DESCRIPTION:
+# Return true if the current linker is set to lld.
+tc-ld-is-lld() {
+       local out
+
+       # First check the linker directly.
+       out=$($(tc-getLD "$@") --version 2>&1)
+       if [[ ${out} == *"LLD"* ]] ; then
+               return 0
+       fi
+
+       # Then see if they're selecting lld via compiler flags.
+       # Note: We're assuming they're using LDFLAGS to hold the
+       # options and not CFLAGS/CXXFLAGS.
+       local base="${T}/test-tc-lld"
+       cat <<-EOF > "${base}.c"
+       int main() { return 0; }
+       EOF
+       out=$($(tc-getCC "$@") ${CFLAGS} ${CPPFLAGS} ${LDFLAGS} -Wl,--version "${base}.c" -o "${base}" 2>&1)
+       rm -f "${base}"*
+       if [[ ${out} == *"LLD"* ]] ; then
+               return 0
+       fi
+
+       # No lld here!
+       return 1
+}
+
 # @FUNCTION: tc-ld-disable-gold
 # @USAGE: [toolchain prefix]
 # @DESCRIPTION: