tree d5390c0506b5a4bd3c90c7576625f41bae32bb30
parent f4c1c8a6aee2c5b625cf83a283f109e64f956eb6
author Sandrine Bailleux <sandrine.bailleux@arm.com> 1460376077 +0100
committer Sandrine Bailleux <sandrine.bailleux@arm.com> 1460646997 +0100

Give user's compiler flags precedence over default ones

The user can provide additional CFLAGS to use when building TF.
However, these custom CFLAGS are currently prepended to the
standard CFLAGS that are hardcoded in the TF build system. This
is an issue because when providing conflicting compiler flags
(e.g. different optimisations levels like -O1 and -O0), the last
one on the command line usually takes precedence. This means that
the user flags get overriden.

To address this problem, this patch separates the TF CFLAGS from
the user CFLAGS. The former are now stored in the TF_CFLAGS make
variable, whereas the CFLAGS make variable is untouched and reserved
for the user. The order of the 2 sets of flags is enforced when
invoking the compiler.

Fixes ARM-Software/tf-issues#350

Change-Id: Ib189f44555b885f1dffbec6015092f381600e560