CFI directives are not emitted in the Epilogue for RISC-V

[varunkumare99]

https://godbolt.org/z/bhTzz9Tb6

foo():                             
        .cfi_sections .debug_frame
        .cfi_startproc
        addi    sp, sp, -16
        .cfi_def_cfa_offset 16
        .loc    1 2 1 prologue_end           
        sd      ra, 8(sp)                      
        sd      s0, 0(sp)                       
        .cfi_offset ra, -8
        .cfi_offset s0, -16
        addi    s0, sp, 16
        .cfi_def_cfa s0, 0
        ld      ra, 8(sp)                       
        ld      s0, 0(sp)                      
        .loc    1 2 1 epilogue_begin is_stmt 0 
        addi    sp, sp, 16
        ret

[llvmbot]

@llvm/issue-subscribers-backend-risc-v

[asb]

Hi Varun - thanks for filing this bug report. I know you also recently posted D143248 which is relevant to this issue. In the future, please do include such context in the bug report in order to save us time in digging it up!

Other relevant links:

• gdb: watchpoint for local variable doesn't work on RISC-V #51206 discussed this issue somewhat
• D69723 is the revision that disabled epilog CFI directives in order to avoid broken unwinding

[dlav-sc]

Found this while scrolling through the issues. I think it was fixed a year ago in #110810. @asb, should we close it?