[PATCH v2 01/18] kbuild: add ld-name macro and support for GNU gold

Sami Tolvanen
2017-11-15T21:34:45Z

GNU gold may require different flags than GNU ld. Add a macro for
detecting the linker and conditionally add gold specific flags from
LDFLAGS_GOLD.

Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
Makefile | 5 +++++
scripts/Kbuild.include | 4 ++++
2 files changed, 9 insertions(+)

diff --git a/Makefile b/Makefile
index 763ab35df12a..f976af9525bf 100644
--- a/Makefile
+++ b/Makefile
@@ -827,6 +827,11 @@ include scripts/Makefile.kasan
include scripts/Makefile.extrawarn
include scripts/Makefile.ubsan

+# Add any flags specific to ld.gold
+ifeq ($(ld-name),gold)
+LDFLAGS += $(LDFLAGS_GOLD)
+endif
+
# Add any arch overrides and user supplied CPPFLAGS, AFLAGS and CFLAGS as the
# last assignments
KBUILD_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 9ffd3dda3889..584d6cecd7c0 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -172,6 +172,10 @@ ld-option = $(call try-run,\
# Important: no spaces around options
ar-option = $(call try-run, $(AR) rc$(1) "$$TMP",$(1),$(2))

+# ld-name
+# Expands to either bfd or gold
+ld-name = $(shell $(LD) -v 2>&1 | grep -q "GNU gold" && echo gold || echo bfd)
+
# ld-version
# Note this is mainly for HJ Lu's 3 number binutil versions
ld-version = $(shell $(LD) --version | $(srctree)/scripts/ld-version.sh)
--
2.15.0.448.gf294e3d99a-goog