[ELF,test] Add test for R_AARCH64_* implicit addends

[MaskRay]

to support certain static relocations in the REL format. See #87328 for
the armasm need.

Note: R_AARCH64_{ABS64,PREL32,PREL64} have been implemented by https://reviews.llvm.org/D120535

[llvmbot]

@llvm/pr-subscribers-lld

@llvm/pr-subscribers-lld-elf

Author: Fangrui Song (MaskRay)

Changes

See #87328 for the armasm context.

---

Full diff: https://github.com/llvm/llvm-project/pull/87733.diff

1 Files Affected:

• (added) lld/test/ELF/aarch64-reloc-implicit-addend.test (+86)

diff --git a/lld/test/ELF/aarch64-reloc-implicit-addend.test b/lld/test/ELF/aarch64-reloc-implicit-addend.test
new file mode 100644
index 00000000000000..15f42c4d87b577
--- /dev/null
+++ b/lld/test/ELF/aarch64-reloc-implicit-addend.test
@@ -0,0 +1,86 @@
+## Test certain REL relocation types generated by legacy armasm.
+# RUN: yaml2obj %s -o %t.o
+# RUN: not ld.lld %t.o -o /dev/null 2>&1 | FileCheck %s
+
+# CHECK-COUNT-17: internal linker error: cannot read addend
+
+---
+!ELF
+FileHeader:
+  Class: ELFCLASS64
+  Data: ELFDATA2LSB
+  Type: ET_REL
+  Machine: EM_AARCH64
+Sections:
+  - Name:    .abs
+    Type:    SHT_PROGBITS
+    Flags:   [ SHF_ALLOC ]
+    Content: fffffefffffffdfffffffffffffffcffffffffffffff
+  - Name:    .rel.abs
+    Type:    SHT_REL
+    Link:    .symtab
+    Info:    .abs
+    Relocations:
+      - {Offset: 0, Symbol: abs, Type: R_AARCH64_ABS16}
+      - {Offset: 2, Symbol: abs, Type: R_AARCH64_ABS32}
+      - {Offset: 6, Symbol: abs, Type: R_AARCH64_ABS64}
+      - {Offset: 14, Symbol: abs, Type: R_AARCH64_ADD_ABS_LO12_NC}
+
+  - Name:    .uabs
+    Type:    SHT_PROGBITS
+    Flags:   [ SHF_ALLOC ]
+    AddressAlign: 4
+    Content: 00ffffff00ffffff00ffffff00ffffff00ffffff00ffffff
+  - Name:    .rel.uabs
+    Type:    SHT_REL
+    Link:    .symtab
+    Info:    .uabs
+    Relocations:
+      - {Offset:  0, Symbol: abs, Type: R_AARCH64_MOVW_UABS_G0}
+      - {Offset:  4, Symbol: abs, Type: R_AARCH64_MOVW_UABS_G0_NC}
+      - {Offset:  8, Symbol: abs, Type: R_AARCH64_MOVW_UABS_G1}
+      - {Offset: 12, Symbol: abs, Type: R_AARCH64_MOVW_UABS_G1_NC}
+      - {Offset: 16, Symbol: abs, Type: R_AARCH64_MOVW_UABS_G2}
+      - {Offset: 20, Symbol: abs, Type: R_AARCH64_MOVW_UABS_G2_NC}
+
+  - Name:    .prel
+    Type:    SHT_PROGBITS
+    Flags:   [ SHF_ALLOC ]
+    AddressAlign: 4
+    Content: 00ffffff00ffffff00ffffff00ffffff00ffffff00ffffff
+  - Name:    .rel.prel
+    Type:    SHT_REL
+    Link:    .symtab
+    Info:    .prel
+    Relocations:
+      - {Offset:  0, Symbol: .prel, Type: R_AARCH64_PREL64}
+      - {Offset:  4, Symbol: .prel, Type: R_AARCH64_PREL32}
+      - {Offset:  8, Symbol: .prel, Type: R_AARCH64_PREL16}
+      - {Offset: 12, Symbol: .prel, Type: R_AARCH64_LD_PREL_LO19}
+      - {Offset: 16, Symbol: .prel, Type: R_AARCH64_ADR_PREL_PG_HI21}
+      - {Offset: 20, Symbol: .prel, Type: R_AARCH64_ADR_PREL_PG_HI21_NC}
+
+  - Name:    .branch
+    Type:    SHT_PROGBITS
+    Flags:   [ SHF_ALLOC ]
+    AddressAlign: 4
+    Content: f0fffffff0fffffff0fffffff0ffffff
+  - Name:    .rel.branch
+    Type:    SHT_REL
+    Link:    .symtab
+    Info:    .branch
+    Relocations:
+      - {Offset:  0, Symbol: .branch, Type: R_AARCH64_TSTBR14}
+      - {Offset:  4, Symbol: .branch, Type: R_AARCH64_CONDBR19}
+      - {Offset:  8, Symbol: .branch, Type: R_AARCH64_CALL26}
+      - {Offset: 12, Symbol: .branch, Type: R_AARCH64_JUMP26}
+
+Symbols:
+  - Name:    .branch
+    Section: .branch
+  - Name:    .prel
+    Section: .prel
+  - Name:    abs
+    Index:   SHN_ABS
+    Value:   42
+    Binding: STB_GLOBAL

[artagnon]

LGTM, but I have a question: will not suffice, or do we require not --crash? Is REQUIRES: asserts also needed?

[MaskRay]

LGTM, but I have a question: will not suffice, or do we require not --crash? Is REQUIRES: asserts also needed?

getImplicitAddend is used by both static relocations and dynamic relocations. The dynamic relocations are only for config->checkDynamicRelocs checks, where there is a #ifdef NDEBUG difference.

Static relocations don't need REQUIRES: asserts.