Oz is allowed to make size optimizations that make the code slower,
where Os isn't. Optimize with Oz, as we care more about having a small
code footprint than having fast code.
Only effective together with --rom, makes two changes:
- abort in case of build warnings
- skip writing statistics
The goal is to make sure we build cleanly in the configuration used for
measuring code size, with all the compilers we use, both because we care about
that configuration and those compilers, and because any warnings would cast a
shadow on the code size measurements.
Currently the build fails with armc5 due to a pre-existing warning in PK, this
will be fixed in the next commit.
The next commit will also add an all.sh component to make sure we have no
regression in the future. (Which is the motivation for --check skipping
statistics: an all.sh component should probably not leave files around.)
While at it, fix two things:
1. The call to gcc --version was redundant with the echo line below
2. WARNING_CFLAGS shouldn't be overriden with armclang, as it would remove the
-Wall -Wextra and any directory-specific warning (such as
-Wdeclaration-after-statement in library). It's meant to be overriden only
with compilers that don't accept the default value (namely armc5 here).
This commit modifies `scripts/baremetal.sh` to print the total code-size
of the SSL, X.509 and Crypto libraries are runs of
- ./scripts/baremetal.sh --rom --gcc
- ./scripts/baremetal.sh --rom --armc5
- ./scripts/baremetal.sh --rom --armc6
This eases quick investigation of the effect of changes on code-size.
So far, `baremetal.sh --ram --stack` ran `callgrind` to extract
a call stack in an example run of ssl_client2 and ssl_server2.
This, however, needs to be complemented with per-function stack
usage to be able to extract the maximum stack usage.
This commit adds `-fstack-usage` to the CFLAGS used when building
the library in `baremetal.sh --ram` runs, which generates *.su
files indicating the stack usage of individual functions.
