[PATCH v2] Makefile: Manually forward RELAX_FLAG to the GNU assembler when linking with LLD

Bin Meng bmeng.cn at gmail.com
Sun Jul 11 19:12:53 PDT 2021


When generating code with -mno-relax, GCC puts .option norelax in
the generated assembly, and so doesn’t bother passing on -mno-relax
to the assembler. This has the unfortunate effect that, when using
GCC to assemble hand-written assembly, -mno-relax does nothing,
and we have to pass -Wa,-mno-relax to manually forward it to the
assembler.

This is an old GCC bug that was fixed [1] recently. For the time
being, let's pass "-Wa,-mno-relax" to ASFLAGS for the GCC + LLD
combination to work, e.g.:

  $ make CC=riscv64-unknown-elf-gcc LLVM=1 PLATFORM=generic

[1] https://github.com/gcc-mirror/gcc/commit/3b0a7d624e64eeb81e4d5e8c62c46d86ef521857

Signed-off-by: Bin Meng <bmeng.cn at gmail.com>

---

Changes in v2:
- Use Jessica's suggestion

 Makefile | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Makefile b/Makefile
index 129b8ed..16d9dca 100644
--- a/Makefile
+++ b/Makefile
@@ -272,6 +272,11 @@ ASFLAGS		+=	-mno-save-restore -mstrict-align
 ASFLAGS		+=	-mabi=$(PLATFORM_RISCV_ABI) -march=$(PLATFORM_RISCV_ISA)
 ASFLAGS		+=	-mcmodel=$(PLATFORM_RISCV_CODE_MODEL)
 ASFLAGS		+=	$(RELAX_FLAG)
+ifneq ($(CC_IS_CLANG),y)
+ifneq ($(RELAX_FLAG),)
+ASFLAGS		+=	-Wa,$(RELAX_FLAG)
+endif
+endif
 ASFLAGS		+=	$(GENFLAGS)
 ASFLAGS		+=	$(platform-asflags-y)
 ASFLAGS		+=	$(firmware-asflags-y)
-- 
2.25.1




More information about the opensbi mailing list