tree 9db9f939de0c288b24f8bf30bd0bc4c4ffe2dbc8
parent 0dec9fa5db1d294d7de0d7cfc7e4d66ec4cab634
author Masahiro Yamada <yamada.masahiro@socionext.com> 1482382947 +0900
committer Masahiro Yamada <yamada.masahiro@socionext.com> 1483583956 +0900

Build: generate .d file at the same time as object is created

Currently, .d files are generated before any objects are built.
So, IS_ANYTHING_TO_BUILD flag is needed to avoid such processing for
non-build targets.

There is a cleverer way; just create a .d file simultaneously when
the corresponding object is created.  No need to have separate rules
for .d files.

This commit will also fix a bug; -D$(IMAGE) is defined for $(OBJ),
but not for $(PREREQUISITES).  So, .d files are generated with
different macro sets from those for .o files, then wrong .d files
are generated.

For example, in lib/cpus/aarch64/cpu_helpers.S

  #if IMAGE_BL31
  #include <cpu_data.h>
  #endif

<cpu_data.h> is parsed for the object when built for BL31, but the
.d file does not pick up that dependency.

With this commit, the compiler will generate .o and .d at the same
time, guaranteeing they are generated under the same circumstances.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>