[PATCH] Makefile: Add flag for reprodubility compiler flags

[Khem Raj]

Provides mechanism to remove absolute paths from binaries using
-ffile-prefix-map

It will help distros (e.g. yocto based ones ) which want to ship
the .elf files but need to scrub absolute paths in objects

Signed-off-by: Khem Raj <raj.khem at gmail.com>
---
 Makefile | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Makefile b/Makefile
index e90836c7..22d4ecff 100644
--- a/Makefile
+++ b/Makefile
@@ -174,6 +174,11 @@ else
 USE_LD_FLAG	=	-fuse-ld=bfd
 endif
 
+REPRODUCIBLE ?= n
+ifeq ($(REPRODUCIBLE),y)
+REPRODUCIBLE_FLAGS		+=	-ffile-prefix-map=$(src_dir)=
+endif
+
 # Check whether the linker supports creating PIEs
 OPENSBI_LD_PIE := $(shell $(CC) $(CLANG_TARGET) $(RELAX_FLAG) $(USE_LD_FLAG) -fPIE -nostdlib -Wl,-pie -x c /dev/null -o /dev/null >/dev/null 2>&1 && echo y || echo n)
 
@@ -362,6 +367,7 @@ GENFLAGS	+=	$(firmware-genflags-y)
 
 CFLAGS		=	-g -Wall -Werror -ffreestanding -nostdlib -fno-stack-protector -fno-strict-aliasing -ffunction-sections -fdata-sections
 CFLAGS		+=	-fno-omit-frame-pointer -fno-optimize-sibling-calls
+CFLAGS		+=	$(REPRODUCIBLE_FLAGS)
 # Optionally supported flags
 ifeq ($(CC_SUPPORT_VECTOR),y)
 CFLAGS		+=	-DOPENSBI_CC_SUPPORT_VECTOR
@@ -387,6 +393,7 @@ CPPFLAGS	+=	$(firmware-cppflags-y)
 ASFLAGS		=	-g -Wall -nostdlib
 ASFLAGS		+=	-fno-omit-frame-pointer -fno-optimize-sibling-calls
 ASFLAGS		+=	-fPIE
+ASFLAGS		+=	$(REPRODUCIBLE_FLAGS)
 # Optionally supported flags
 ifeq ($(CC_SUPPORT_SAVE_RESTORE),y)
 ASFLAGS		+=	-mno-save-restore