[lld] [LLD][ARM] Allow R_ARM_SBREL32 relocations in debug info (PR #116956)

[Peter Smith via llvm-commits]

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@@ -0,0 +1,57 @@
+// REQUIRES: arm
+// RUN: rm -rf %t && split-file %s %t && cd %t
+
+// RUN: llvm-mc -filetype=obj -triple=armv7a asm.s -o obj.o
+// RUN: ld.lld -T lds.ld obj.o -o exe.elf -e main 2>&1 | FileCheck %s --implicit-check-not=warning: --allow-empty
+// RUN: llvm-objdump -D exe.elf | FileCheck --check-prefix=DISASM %s
+
+// DISASM:      Disassembly of section data1:
+// DISASM:      00001000 <rw>:
+// DISASM-NEXT:     1000: 0000002a
+
+// DISASM:      Disassembly of section data2:
+// DISASM:      00002000 <rw2>:
+// DISASM-NEXT:     2000: 000004d2
+
+// DISASM:      Disassembly of section .debug_something:
+// DISASM:      00000000 <.debug_something>:
+// DISASM-NEXT:        0: 00001000
+// DISASM-NEXT:      ...
+// DISASM-NEXT:      104: 00002000
+
+// Test that R_ARM_SBREL32 relocations in debug info are relocated as if the
+// static base register (r9) is zero. Real DWARF info will use an expression to
+// add this to the real value of the static base at runtime.
+
+//--- lds.ld
+SECTIONS {
+  data1 0x1000 : { *(data1) }
+  data2 0x2000 : { *(data2) }
+}
+
+//--- asm.s
+  .text
+	.type	main,%function
+	.globl	main
+main:
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smithp35 wrote:

Not a huge saving, but could simplify by using _start here instead of main and remove the -e main in the ld.lld run command.

https://github.com/llvm/llvm-project/pull/116956