On 18/01/2023 17:18, Srinath Parvathaneni via Gcc-patches wrote:
Hello, This patch teaches the DWARF support in gcc about RA_AUTH_CODE pseudo hard-register and also updates the ".save", ".cfi_register", ".cfi_offset", ".cfi_restore" directives accordingly. This patch also adds support to emit ".pacspval" directive when "pac ip, lr, sp" instruction in generated in the assembly. RA_AUTH_CODE register number is 107 and it's dwarf register number is 143. Applying this patch on top of PACBTI series posted here https://gcc.gnu.org/pipermail/gcc-patches/2022-August/599658.html and when compiling the following test.c with "-march=armv8.1-m.main+mve+pacbti -mbranch-protection=pac-ret -mthumb -mfloat-abi=hard fasynchronous-unwind-tables -g -O0 -S" command line options, the assembly output after this patch looks like below: $cat test.c void fun1(int a); void fun(int a,...) { fun1(a); } int main() { fun (10); return 0; } $ arm-none-eabi-gcc -march=armv8.1-m.main+mve+pacbti -mbranch-protection=pac-ret -mthumb -mfloat-abi=hard -fasynchronous-unwind-tables -g -O0 -S test.s Assembly output: ... fun: ... .pacspval pac ip, lr, sp .cfi_register 143, 12 push {r3, r7, ip, lr} .save {r3, r7, ra_auth_code, lr} ... .cfi_offset 143, -24 ... .cfi_restore 143 ... aut ip, lr, sp bx lr ... main: ... .pacspval pac ip, lr, sp .cfi_register 143, 12 push {r3, r7, ip, lr} .save {r3, r7, ra_auth_code, lr} ... .cfi_offset 143, -8 ... .cfi_restore 143 ... aut ip, lr, sp bx lr ... Regression tested on arm-none-eabi target and found no regressions. Ok for master? Regards, Srinath. 2023-01-18 Srinath Parvathaneni <srinath.parvathan...@arm.com> * config/arm/aout.h (ra_auth_code): Add entry in enum. (emit_multi_reg_push): Add RA_AUTH_CODE register to dwarf frame expression. (arm_emit_multi_reg_pop): Restore RA_AUTH_CODE register. (arm_expand_prologue): Update frame related information and reg notes for pac/pacbit insn. (arm_regno_class): Check for pac pseudo reigster. (arm_dbx_register_number): Assign ra_auth_code register number in dwarf. (arm_init_machine_status): Set pacspval_needed to zero. (arm_debugger_regno): Check for PAC register. (arm_unwind_emit_sequence): Print .save directive with ra_auth_code register. (arm_unwind_emit_set): Add entry for IP_REGNUM in switch case. (arm_unwind_emit): Update REG_CFA_REGISTER case._ * config/arm/arm.h (FIRST_PSEUDO_REGISTER): Modify. (DWARF_PAC_REGNUM): Define. (IS_PAC_REGNUM): Likewise. (enum reg_class): Add PAC_REG entry. (machine_function): Add pacbti_needed state to structure. * config/arm/arm.md (RA_AUTH_CODE): Define. gcc/testsuite/ChangeLog: 2023-01-18 Srinath Parvathaneni <srinath.parvathan...@arm.com> * g++.target/arm/pac-1.C: New test. * gcc.target/arm/pac-15.c: Likewise.
OK. R.