[PATCH] D43241: [ELF] - Do not crash with --emit-relocs and --icf=all together.

[George Rimar via Phabricator via llvm-commits]

grimar created this revision.
grimar added reviewers: ruiu, espindola.
Herald added subscribers: arichardson, emaste.

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.


https://reviews.llvm.org/D43241

Files:
  ELF/InputSection.cpp
  test/ELF/emit-relocs-icf.s


Index: test/ELF/emit-relocs-icf.s
===================================================================
--- test/ELF/emit-relocs-icf.s
+++ test/ELF/emit-relocs-icf.s
@@ -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
Index: ELF/InputSection.cpp
===================================================================
--- ELF/InputSection.cpp
+++ ELF/InputSection.cpp
@@ -758,6 +758,8 @@
   Alignment = std::max(Alignment, Other->Alignment);
   Other->Repl = Repl;
   Other->Live = false;
+  for (InputSection *IS : Other->DependentSections)
+    IS->Live = false;
 }
 
 template <class ELFT>


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