[lld] r325877 - [ELF] - Do not crash with --emit-relocs and --icf=all together.

[George Rimar via llvm-commits]

Author: grimar
Date: Fri Feb 23 02:27:13 2018
New Revision: 325877

URL: http://llvm.org/viewvc/llvm-project?rev=325877&view=rev
Log:
[ELF] - Do not crash with --emit-relocs and --icf=all together.

Previously we would crash because did not mark .rel[a] sections
as dead and they tried to access parent which was not live
after ICF and therefore was null.

Differential revision: https://reviews.llvm.org/D43241

Added:
    lld/trunk/test/ELF/emit-relocs-icf.s
Modified:
    lld/trunk/ELF/InputSection.cpp

Modified: lld/trunk/ELF/InputSection.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputSection.cpp?rev=325877&r1=325876&r2=325877&view=diff
==============================================================================
--- lld/trunk/ELF/InputSection.cpp (original)
+++ lld/trunk/ELF/InputSection.cpp Fri Feb 23 02:27:13 2018
@@ -789,6 +789,8 @@ void InputSection::replace(InputSection
   Alignment = std::max(Alignment, Other->Alignment);
   Other->Repl = Repl;
   Other->Live = false;
+  for (InputSection *IS : Other->DependentSections)
+    IS->Live = false;
 }
 
 template <class ELFT>

Added: lld/trunk/test/ELF/emit-relocs-icf.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/emit-relocs-icf.s?rev=325877&view=auto
==============================================================================
--- lld/trunk/test/ELF/emit-relocs-icf.s (added)
+++ lld/trunk/test/ELF/emit-relocs-icf.s Fri Feb 23 02:27:13 2018
@@ -0,0 +1,33 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t1.o
+# RUN: ld.lld --emit-relocs --icf=all %t1.o -o %t
+# RUN: llvm-readobj -r %t | FileCheck %s
+
+# CHECK:      Relocations [
+# CHECK-NEXT:   Section {{.*}} .rela.text {
+# CHECK-NEXT:     R_X86_64_32 .text 0x1
+# CHECK-NEXT:     R_X86_64_PLT32 fn 0xFFFFFFFFFFFFFFFC
+# CHECK-NEXT:   }
+# CHECK-NEXT: ]
+
+.section .text.fn,"ax", at progbits,unique,0
+.globl fn
+.type fn, at function
+fn:
+ nop
+
+bar:
+  movl $bar, %edx
+  callq fn at PLT
+  nop
+
+.section .text.fn2,"ax", at progbits,unique,1
+.globl fn2
+.type fn2, at function
+fn2:
+ nop
+
+foo:
+  movl $foo, %edx
+  callq fn2 at PLT
+  nop