[lld] [lld][AArch64][ELF][PAC] Support AUTH relocations and AUTH ELF marking (PR #72714)

[Fangrui Song via llvm-commits]

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+# REQUIRES: aarch64
+
+# RUN: rm -rf %t && split-file %s %t && cd %t
+
+# RUN: llvm-mc -filetype=obj -triple=aarch64-linux-gnu abi-tag1.s -o tag1.o
+# RUN: cp tag1.o tag1a.o
+# RUN: ld.lld -shared tag1.o tag1a.o -o tagok.so
+# RUN: llvm-readelf -n tagok.so | FileCheck --check-prefix OK %s
+
+# OK: AArch64 PAuth ABI tag: platform 0x2a, version 0x1
+
+# RUN: llvm-mc -filetype=obj -triple=aarch64-linux-gnu abi-tag2.s -o tag2.o
+# RUN: not ld.lld tag1.o tag1a.o tag2.o -o /dev/null 2>&1 | FileCheck --check-prefix ERR1 %s
+
+# ERR1: error: incompatible values of AArch64 PAuth compatibility info found
+# ERR1: tag1.o: 0x2A000000000000000{{1|2}}00000000000000
+# ERR1: tag2.o: 0x2A000000000000000{{1|2}}00000000000000
+
+# RUN: llvm-mc -filetype=obj -triple=aarch64-linux-gnu abi-tag-errs.s -o errs.o
+# RUN: not ld.lld errs.o -o /dev/null 2>&1 | FileCheck --check-prefix ERR2 %s
+
+# ERR2:      error: errs.o:(.note.AARCH64-PAUTH-ABI-tag): invalid type field value 42 (1 expected)
+# ERR2-NEXT: error: errs.o:(.note.AARCH64-PAUTH-ABI-tag): invalid name field value XXX (ARM expected)
+# ERR2-NEXT: error: errs.o:(.note.AARCH64-PAUTH-ABI-tag): AArch64 PAuth compatibility info is too short (at least 16 bytes expected)
+
+# RUN: llvm-mc -filetype=obj -triple=aarch64-linux-gnu abi-tag-short.s -o short.o
+# RUN: not ld.lld short.o -o /dev/null 2>&1 | FileCheck --check-prefix ERR3 %s
+
+# ERR3: error: short.o:(.note.AARCH64-PAUTH-ABI-tag): section is too short
+
+# RUN: llvm-mc -filetype=obj -triple=aarch64-linux-gnu no-info.s -o noinfo1.o
+# RUN: cp noinfo1.o noinfo2.o
+# RUN: not ld.lld -z pauth-report=error tag1.o noinfo1.o noinfo2.o -o /dev/null 2>&1 | FileCheck --check-prefix ERR4 %s
+# RUN: ld.lld -z pauth-report=warning tag1.o noinfo1.o noinfo2.o -o /dev/null 2>&1 | FileCheck --check-prefix WARN %s
+# RUN: ld.lld -z pauth-report=none tag1.o noinfo1.o noinfo2.o --fatal-warnings -o /dev/null
+
+# ERR4:      error: noinfo1.o has no AArch64 PAuth compatibility info while tag1.o has one; either all or no input files must have it
+# ERR4-NEXT: error: noinfo2.o has no AArch64 PAuth compatibility info while tag1.o has one; either all or no input files must have it
+# WARN:      warning: noinfo1.o has no AArch64 PAuth compatibility info while tag1.o has one; either all or no input files must have it
+# WARN-NEXT: warning: noinfo2.o has no AArch64 PAuth compatibility info while tag1.o has one; either all or no input files must have it
+
+#--- abi-tag-short.s
+
+.section ".note.AARCH64-PAUTH-ABI-tag", "a"
+.long 4
+.long 8
+
+#--- abi-tag-errs.s
+
+.section ".note.AARCH64-PAUTH-ABI-tag", "a"
+.long 4
+.long 8
+.long 42
+.asciz "XXX"
+
+.quad 42
+
+#--- abi-tag1.s
+
+.section ".note.AARCH64-PAUTH-ABI-tag", "a"
+.long 4
+.long 16
+.long 1
+.asciz "ARM"
+
+.quad 42         // platform
+.quad 1          // version
+
+#--- abi-tag2.s
+
+.section ".note.AARCH64-PAUTH-ABI-tag", "a"
+.long 4
+.long 16
+.long 1
+.asciz "ARM"
+
+.quad 42         // platform
+.quad 2          // version
+
+#--- no-info.s
+
+.globl _start;   // define _start to avoid missing entry warning and use --fatal-warnings to assert no diagnostic
+.weak _start;    // allow multiple definitions of _start for simplicity
+_start:
+
+.section ".test", "a"
----------------
MaskRay wrote:

This seems unused

https://github.com/llvm/llvm-project/pull/72714