[llvm] [BOLT][AArch64] Fix error message for failed ADR relaxation (PR #142533)

[Paschalis Mpeis via llvm-commits]

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@@ -0,0 +1,35 @@
+## Check that llvm-bolt generates a proper error message when ADR instruction
+## cannot be relaxed.
+
+# RUN: llvm-mc -filetype=obj -triple aarch64-unknown-unknown %s -o %t.o
+# RUN: %clang %cflags %t.o -o %t.exe -Wl,-q -static
+# RUN: not llvm-bolt %t.exe -o %t.bolt 2>&1 | FileCheck %s
+
+# CHECK: BOLT-ERROR: cannot relax ADR in non-simple function _start
+
+## The function contains unknown control flow and llvm-bolt fails to recover
+## CFG. As BOLT has to preserve the function layout, the ADR instruction cannot
+## be relaxed into ADRP+ADD.
+  .text
+  .globl _start
+  .type _start, %function
+_start:
+  .cfi_startproc
+  adr x1, foo
+  br x0
+  ret  x0
+  .cfi_endproc
+  .size _start, .-_start
+
+  .globl foo
+  .type foo, %function
+foo:
+  .cfi_startproc
+  cmp  x1, x11
+  b.hi  .L2
+  mov  x0, #0x0
+.L2:
+  adr x1, foo
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paschalis-mpeis wrote:

Do we need anything in `foo` to trigger this test case, or should the body be just a return?

https://github.com/llvm/llvm-project/pull/142533