toolchain-funcs.eclass: add tc-ld-is-bfd

This matches tc-ld-is-gold and tc-ld-is-lld.

Signed-off-by: Sam James <[email protected]>

eclass/toolchain-funcs.eclass

@@ -447,6 +447,41 @@ econf_build() {
  tc-env_build econf_env "$@"
 }
 
+# @FUNCTION: tc-ld-is-bfd
+# @USAGE: [toolchain prefix]
+# @DESCRIPTION:
+# Return true if the current linker is set to GNU bfd.
+tc-ld-is-bfd() {
+ local out
+
+ # Ensure ld output is in English.
+ local -x LC_ALL=C
+
+ # First check the linker directly.
+ out=$($(tc-getLD "$@") --version 2>&1)
+ if [[ ${out} != "GNU ld"* ]] ; then
+ return 1
+ fi
+
+ # Then see if they're selecting bfd via compiler flags.
+ # Note: We're assuming they're using LDFLAGS to hold the
+ # options and not CFLAGS/CXXFLAGS.
+ local base="${T}/test-tc-bfd"
+ cat <<-EOF > "${base}.c"
+ int main(void) { return 0; }
+ EOF
+ out=$($(tc-getCC "$@") ${CFLAGS} ${CPPFLAGS} ${LDFLAGS} -Wl,--version "${base}.c" -o "${base}" 2>&1)
+ rm -f "${base}"*
+ if [[ ${out} != "GNU ld"* ]] ; then
+ return 1
+ fi
+
+ # It's bfd!
+ # We use positive logic here unlike tc-ld-is-gold and tc-ld-is-mold
+ # because LD might be bfd even if *FLAGS isn't.
+ return 0
+}
+
 # @FUNCTION: tc-ld-is-gold
 # @USAGE: [toolchain prefix]
 # @DESCRIPTION: