Makefile: Dereference symlinks on install

Adds the `-L` flag (follow symlinks) to the `cp` commands used to
install `libsbi.a` and `include/sbi/*`.

This should make no difference in regular compilation. However,
it does make a difference when compiling with bazel.  Namely,
bazel's sandboxing will turn all the source files into symlinks.
After installation with `cp` the destination files will be
symlinks pointing to the sandbox symlinks. As the sandbox files
are removed when compilation ends, the just-copied symlinks
become dangling symlinks.

The resulting include files will be
unusable due to the dangling symlink issues. Adding `-L` when
copying ensures that the files obtained by executing the `install`
targets are always dereferenced to files, rather than symlinks,
eliminating this issue.

Signed-off-by: Filip Filmar <fmil@google.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

diff --git a/Makefile b/Makefile
index a26a39baf12db81749f5e2de69958e7fba53b197..730dbd910e5122733391ec71f3e83e5d549fc9d5 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -401,10 +401,10 @@ merge_deps = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
             cat $(2) > $(1)
 copy_file =  $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
             echo " COPY      $(subst $(build_dir)/,,$(1))"; \
-            cp -f $(2) $(1)
+            cp -L -f $(2) $(1)
 inst_file =  $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
             echo " INSTALL   $(subst $(install_root_dir)/,,$(1))"; \
-            cp -f $(2) $(1)
+            cp -L -f $(2) $(1)
 inst_file_list = $(CMD_PREFIX)if [ ! -z "$(4)" ]; then \
             mkdir -p $(1)/$(3); \
             for file in $(4) ; do \
@@ -413,12 +413,12 @@ inst_file_list = $(CMD_PREFIX)if [ ! -z "$(4)" ]; then \
             dest_dir=`dirname $$dest_file`; \
             echo " INSTALL   "$(3)"/"`echo $$rel_file`; \
             mkdir -p $$dest_dir; \
-            cp -f $$file $$dest_file; \
+            cp -L -f $$file $$dest_file; \
             done \
             fi
 inst_header_dir =  $(CMD_PREFIX)mkdir -p $(1); \
             echo " INSTALL   $(subst $(install_root_dir)/,,$(1))"; \
-            cp -rf $(2) $(1)
+            cp -L -rf $(2) $(1)
 compile_cpp_dep = $(CMD_PREFIX)mkdir -p `dirname $(1)`; \
             echo " CPP-DEP   $(subst $(build_dir)/,,$(1))"; \
             printf %s `dirname $(1)`/  > $(1) && \