[PATCH] reproducible builds: strip embedded file paths

[Xiang W]

在 2021-11-21星期日的 11:20 -0800，Vagrant Cascadian写道：
> of the directories below, I built using the same toolchain from
> the same git commit...
> 
> $ cd /home/vagrant/src/opensbi/opensbi1
> $ CROSS_COMPILE=riscv64-linux-gnu- make V=1 FW_PAYLOAD=n
> PLATFORM=generic
> ...
> $ strings build/platform/generic/firmware/fw_dynamic.bin | grep
> /home/vagrant
> /home/vagrant/src/opensbi/opensbi1/lib/sbi/riscv_asm.c
> 
> $ cd /home/vagrant/src/opensbi/opensbi2
> $ CROSS_COMPILE=riscv64-linux-gnu- make V=1 FW_PAYLOAD=n
> PLATFORM=generic
> ...
> $ strings build/platform/generic/firmware/fw_dynamic.bin | grep
> /home/vagrant
> /home/vagrant/src/opensbi/opensbi2/lib/sbi/riscv_asm.c
> 
> 
> With the patch applied:
> 
> $ cd /home/vagrant/src/opensbi/opensbi3
This is because the source file uses the absolute path when compiling,
you can use the relative path by modifying the Makefile

diff --git a/Makefile b/Makefile
index 8623c1c..d017534 100644
--- a/Makefile
+++ b/Makefile
@@ -361,7 +361,7 @@ compile_cc_dep = $(CMD_PREFIX)mkdir -p `dirname
$(1)`; \
 	       -MM $(2) >> $(1) || rm -f $(1)
 compile_cc = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
 	     echo " CC        $(subst $(build_dir)/,,$(1))"; \
-	     $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c $(2) -
o $(1)
+	     $(CC) $(CFLAGS) $(call dynamic_flags,$(1),$(2)) -c
$(subst $(src_dir)/,,$(2)) -o $(1)
 compile_as_dep = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
 	     echo " AS-DEP    $(subst $(build_dir)/,,$(1))"; \
 	     printf %s `dirname $(1)`/ > $(1) && \

Regards,
Xiang W