llvm-project
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1# REQUIRES: x86
2# RUN: rm -rf %t; split-file %s %t
3
4## Test that we correctly handle the sdata4 DWARF pointer encoding. llvm-mc's
5## CFI directives always generate EH frames using the absptr (i.e. system
6## pointer size) encoding, but it is possible to hand-roll your own EH frames
7## that use the sdata4 encoding. For instance, libffi does this.
8
9# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-macos10.15 %t/sdata4.s -o %t/sdata4.o
10# RUN: %lld -lSystem %t/sdata4.o -o %t/sdata4
11# RUN: llvm-objdump --macho --syms --dwarf=frames %t/sdata4 | FileCheck %s
12
13# CHECK: SYMBOL TABLE:
14# CHECK: [[#%.16x,MAIN:]] g F __TEXT,__text _main
15
16# CHECK: .eh_frame contents:
17# CHECK: 00000000 00000010 00000000 CIE
18# CHECK: Format: DWARF32
19# CHECK: Version: 1
20# CHECK: Augmentation: "zR"
21# CHECK: Code alignment factor: 1
22# CHECK: Data alignment factor: 1
23# CHECK: Return address column: 1
24# CHECK: Augmentation data: 1B
25# CHECK: DW_CFA_def_cfa: reg7 +8
26# CHECK: CFA=reg7+8
27
28# CHECK: 00000014 00000010 00000018 FDE cie=00000000 pc=[[#%x,MAIN]]...[[#%x,MAIN+1]]
29# CHECK: Format: DWARF32
30# CHECK: DW_CFA_GNU_args_size: +16
31# CHECK: DW_CFA_nop:
32# CHECK: 0x[[#%x,MAIN]]: CFA=reg7+8
33
34#--- sdata4.s
35.globl _main
36_main:
37retq
38LmainEnd:
39
40.balign 4
41.section __TEXT,__eh_frame
42# Although we don't reference this EhFrame symbol directly, we must have at
43# least one non-local symbol in this section, otherwise llvm-mc generates bogus
44# subtractor relocations.
45EhFrame:
46LCieHdr:
47.long LCieEnd - LCieStart
48LCieStart:
49.long 0 # CIE ID
50.byte 1 # CIE version
51.ascii "zR\0"
52.byte 1 # Code alignment
53.byte 1 # Data alignment
54.byte 1 # RA column
55.byte 1 # Augmentation size
56.byte 0x1b # FDE pointer encoding (pcrel | sdata4)
57.byte 0xc, 7, 8 # DW_CFA_def_cfa reg7 +8
58.balign 4
59LCieEnd:
60
61LFdeHdr:
62.long LFdeEnd - LFdeStart
63LFdeStart:
64.long LFdeStart - LCieHdr
65# The next two fields are longs instead of quads because of the sdata4
66# encoding.
67.long _main - . # Function address
68.long LmainEnd - _main # Function length
69.byte 0
70## Insert DW_CFA_GNU_args_size to prevent ld64 from creating a compact unwind
71## entry to replace this FDE. Makes it easier for us to cross-check behavior
72## across the two linkers (LLD never bothers trying to synthesize compact
73## unwind if it is not already present).
74.byte 0x2e, 0x10 # DW_CFA_GNU_args_size
75.balign 4
76LFdeEnd:
77
78.long 0 # terminator
79
80.subsections_via_symbols
81