# REQUIRES: x86 # RUN: rm -rf %t; split-file %s %t ## Test that we correctly handle the sdata4 DWARF pointer encoding. llvm-mc's ## CFI directives always generate EH frames using the absptr (i.e. system ## pointer size) encoding, but it is possible to hand-roll your own EH frames ## that use the sdata4 encoding. For instance, libffi does this. # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-macos10.15 %t/sdata4.s -o %t/sdata4.o # RUN: %lld -lSystem %t/sdata4.o -o %t/sdata4 # RUN: llvm-objdump --macho --syms --dwarf=frames %t/sdata4 | FileCheck %s # CHECK: SYMBOL TABLE: # CHECK: [[#%.16x,MAIN:]] g F __TEXT,__text _main # CHECK: .eh_frame contents: # CHECK: 00000000 00000010 00000000 CIE # CHECK: Format: DWARF32 # CHECK: Version: 1 # CHECK: Augmentation: "zR" # CHECK: Code alignment factor: 1 # CHECK: Data alignment factor: 1 # CHECK: Return address column: 1 # CHECK: Augmentation data: 1B # CHECK: DW_CFA_def_cfa: reg7 +8 # CHECK: CFA=reg7+8 # CHECK: 00000014 00000010 00000018 FDE cie=00000000 pc=[[#%x,MAIN]]...[[#%x,MAIN+1]] # CHECK: Format: DWARF32 # CHECK: DW_CFA_GNU_args_size: +16 # CHECK: DW_CFA_nop: # CHECK: 0x[[#%x,MAIN]]: CFA=reg7+8 #--- sdata4.s .globl _main _main: retq LmainEnd: .balign 4 .section __TEXT,__eh_frame # Although we don't reference this EhFrame symbol directly, we must have at # least one non-local symbol in this section, otherwise llvm-mc generates bogus # subtractor relocations. EhFrame: LCieHdr: .long LCieEnd - LCieStart LCieStart: .long 0 # CIE ID .byte 1 # CIE version .ascii "zR\0" .byte 1 # Code alignment .byte 1 # Data alignment .byte 1 # RA column .byte 1 # Augmentation size .byte 0x1b # FDE pointer encoding (pcrel | sdata4) .byte 0xc, 7, 8 # DW_CFA_def_cfa reg7 +8 .balign 4 LCieEnd: LFdeHdr: .long LFdeEnd - LFdeStart LFdeStart: .long LFdeStart - LCieHdr # The next two fields are longs instead of quads because of the sdata4 # encoding. .long _main - . # Function address .long LmainEnd - _main # Function length .byte 0 ## Insert DW_CFA_GNU_args_size to prevent ld64 from creating a compact unwind ## entry to replace this FDE. Makes it easier for us to cross-check behavior ## across the two linkers (LLD never bothers trying to synthesize compact ## unwind if it is not already present). .byte 0x2e, 0x10 # DW_CFA_GNU_args_size .balign 4 LFdeEnd: .long 0 # terminator .subsections_via_symbols