At present it is possible to call the CMSE functions for checking
addresses (such as cmse_check_address_range) and forget to check/use
the return value. This patch makes the interfaces more robust against
programmer error by marking these functions with the warn_unused_result
attribute. With this set, any use of these functions that does not use
the result will produce a warning.
This produces a warning on default warn levels when the result of the
cmse functions is not used.
For the following function:
void foo()
{
int *data;
cmse_check_address_range((int*)data, 0, 0);
}
The following warning is emitted:
warning: ignoring return value of 'cmse_check_address_range' declared
with attribute 'warn_unused_result' [-Wunused-result]
6 | cmse_check_address_range((int*)data, 0, 0);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
gcc/ChangeLog:
2019-07-31 Joel Hutton <Joel.Hutton@arm.com>
* config/arm/arm_cmse.h (cmse_nonsecure_caller): Add
warn_unused_result attribute.
(cmse_check_address_range): Add warn_unused_result attribute.
libgcc/ChangeLog:
2019-07-31 Joel Hutton <Joel.Hutton@arm.com>
* config/arm/cmse.c (cmse_check_address_range): Add
warn_unused_result attribute.
2019-07-31 Joel Hutton <Joel.Hutton@arm.com>
* gcc.target/arm/cmse/cmse-17.c: New test.
From-SVN: r273924
