[ELF] Use the Repl point to avoid the segfault when using ICF

This addresses PR38918.

Differential Revision: https://reviews.llvm.org/D52202

3 files changed, 69 insertions, 1 deletions

diff --git a/lld/ELF/InputSection.cpp b/lld/ELF/InputSection.cpp
index dbc12fef6d4..88c71ccb8c0 100644
--- a/lld/ELF/InputSection.cpp
+++ b/lld/ELF/InputSection.cpp
@@ -402,7 +402,7 @@ void InputSection::copyRelocations(uint8_t *Buf, ArrayRef<RelTy> Rels) {
       }
 
       if (RelTy::IsRela)
-        P->r_addend = Sym.getVA(Addend) - Section->getOutputSection()->Addr;
+        P->r_addend = Sym.getVA(Addend) - Section->Repl->getOutputSection()->Addr;
       else if (Config->Relocatable)
         Sec->Relocations.push_back({R_ABS, Type, Rel.r_offset, Addend, &Sym});
     }
diff --git a/lld/test/ELF/emit-relocs-icf1.s b/lld/test/ELF/emit-relocs-icf1.s
new file mode 100644
index 00000000000..2f7e0cab27f
--- /dev/null
+++ b/lld/test/ELF/emit-relocs-icf1.s
@@ -0,0 +1,32 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
+# RUN: ld.lld --emit-relocs --icf=all %t.o -o %t
+# RUN: llvm-readobj -r %t | FileCheck %s
+
+# CHECK:      Relocations [
+# CHECK-NEXT:   Section (3) .rela.text {
+# CHECK-NEXT:     0x201000 R_X86_64_64 .text 0x11
+# CHECK-NEXT:     0x201008 R_X86_64_64 .text 0x11
+# CHECK-NEXT:     0x201011 R_X86_64_64 .rodata 0x0
+# CHECK-NEXT:   }
+# CHECK-NEXT: ]
+
+.rodata
+quux:
+.quad 0xfe
+
+.section .text.foo,"ax"
+foo:
+.quad quux
+
+.section .text.bar,"ax"
+bar:
+.quad quux
+
+.text
+.quad foo
+.quad bar
+
+.global _start
+_start:
+  nop
diff --git a/lld/test/ELF/emit-relocs-icf2.s b/lld/test/ELF/emit-relocs-icf2.s
new file mode 100644
index 00000000000..7c9ac229b73
--- /dev/null
+++ b/lld/test/ELF/emit-relocs-icf2.s
@@ -0,0 +1,36 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
+# RUN: ld.lld --gc-sections --emit-relocs --icf=all %t.o -o %t
+# RUN: llvm-readobj -r %t | FileCheck %s
+
+# CHECK:      Relocations [
+# CHECK-NEXT:   Section (3) .rela.text {
+# CHECK-NEXT:     0x201000 R_X86_64_64 .text 0x11
+# CHECK-NEXT:     0x201008 R_X86_64_64 .text 0x11
+# CHECK-NEXT:     0x201011 R_X86_64_64 .rodata 0x0
+# CHECK-NEXT:   }
+# CHECK-NEXT: ]
+
+.rodata
+quux:
+.quad 0xfe
+
+.section .text.foo,"ax"
+foo:
+.quad quux
+
+.section .text.bar,"ax"
+bar:
+.quad quux
+
+.section .text.baz,"ax"
+baz:
+.quad quux
+
+.text
+.quad foo
+.quad bar
+
+.global _start
+_start:
+  nop