On 08/10/2021 13:18, Tejas Belagod via Gcc-patches wrote:
Hi,
This patch implements target feature macros when PACBTI is
enabled through the -march option or -mbranch-protection.
Tested on arm-none-eabi. OK for trunk?
2021-10-04 Tejas Belagod <tbela...@arm.com>
gcc/ChangeLog:
* config/arm/arm-c.c (arm_cpu_builtins): Define
__ARM_FEATURE_BTI_DEFAULT and __ARM_FEATURE_PAC_DEFAULT.
gcc/testsuite/ChangeLog:
* gcc.target/arm/acle/pacbti-m-predef-2.c: New test.
* gcc.target/arm/acle/pacbti-m-predef-4.c: New test.
* gcc.target/arm/acle/pacbti-m-predef-5.c: New test.
I presume the specification for this is ACLE - please say so rather than
making me guess.
+ cpp_undef (pfile, "__ARM_FEATURE_BTI_DEFAULT");
+ cpp_undef (pfile, "__ARM_FEATURE_PAC_DEFAULT");
+ if (TARGET_HAVE_PACBTI)
+ {
+ builtin_define_with_int_value ("__ARM_FEATURE_BTI_DEFAULT",
+ arm_enable_pacbti & 0x1);
My reading of the ACLE specification would suggest this shouldn't be
defined if it would have a value of 0, but that's not what this code
does. I think it would be better to move this outside the
TARGET_HAVE_PACBTI and use the def_or_undef approach.
+ builtin_define_with_int_value ("__ARM_FEATURE_PAC_DEFAULT",
+ arm_enable_pacbti >> 1);
This one is less clear, could the value ever be zero? I guess exactly
one of a-key and b-key must be defined and each has a separate bit.
+ }
+
+
Not more than one blank line at the end of a block.
diff --git a/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-2.c
b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-2.c
Given what I've said above, I think you need to also test that
__ARM_FEATURE_BTI_DEFAULT is defined before testing the value (and
emitting #error if it isn't).
R.
