[lld] r288511 - Removed a wrong assertion about non-colorable sections.

[Rui Ueyama via llvm-commits]

Author: ruiu
Date: Fri Dec  2 11:23:58 2016
New Revision: 288511

URL: http://llvm.org/viewvc/llvm-project?rev=288511&view=rev
Log:
Removed a wrong assertion about non-colorable sections.

The assertion asserted that colorable sections can never have
a reference to non-colorable sections, but that was simply wrong.
They can have references to non-colorable sections. If that's the
case, referenced sections must be the same in terms of pointer
comparison.

Added:
    lld/trunk/test/ELF/Inputs/icf-non-mergeable.s
    lld/trunk/test/ELF/icf-non-mergeable.s
Modified:
    lld/trunk/ELF/ICF.cpp

Modified: lld/trunk/ELF/ICF.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/ICF.cpp?rev=288511&r1=288510&r2=288511&view=diff
==============================================================================
--- lld/trunk/ELF/ICF.cpp (original)
+++ lld/trunk/ELF/ICF.cpp Fri Dec  2 11:23:58 2016
@@ -242,9 +242,10 @@ bool ICF<ELFT>::variableEq(const InputSe
     // same iteration.
     size_t Idx = (Config->Threads ? Cnt : Cnt + 1) % 2;
 
-    // All colorable sections must have some colors.
-    // 0 is a default non-color value.
-    assert(X->Color[Idx] != 0 && Y->Color[Idx] != 0);
+    // Ineligible sections have the special color 0.
+    // They can never be the same in terms of section colors.
+    if (X->Color[Idx] == 0)
+      return false;
 
     return X->Color[Idx] == Y->Color[Idx];
   };

Added: lld/trunk/test/ELF/Inputs/icf-non-mergeable.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/Inputs/icf-non-mergeable.s?rev=288511&view=auto
==============================================================================
--- lld/trunk/test/ELF/Inputs/icf-non-mergeable.s (added)
+++ lld/trunk/test/ELF/Inputs/icf-non-mergeable.s Fri Dec  2 11:23:58 2016
@@ -0,0 +1,8 @@
+.globl d1, d2
+.section .data.d1, "aw"
+d1:
+  .quad 0
+
+.section .data.d2, "aw"
+d2:
+  .quad 0

Added: lld/trunk/test/ELF/icf-non-mergeable.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/icf-non-mergeable.s?rev=288511&view=auto
==============================================================================
--- lld/trunk/test/ELF/icf-non-mergeable.s (added)
+++ lld/trunk/test/ELF/icf-non-mergeable.s Fri Dec  2 11:23:58 2016
@@ -0,0 +1,28 @@
+// REQUIRES: x86
+
+// This file contains two functions. They are themselves identical,
+// but because they have reloactions against different data section,
+// they are not mergeable.
+
+// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t1
+// RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux \
+// RUN:    %p/Inputs/icf-non-mergeable.s -o %t2
+
+// RUN: ld.lld %t1 %t2 -o %t3 --icf=all --verbose | FileCheck %s
+
+// CHECK-NOT: selected .text.f1
+// CHECK-NOT:   removed .text.f2
+
+.globl _start, f1, f2, d1, d2
+_start:
+  ret
+
+.section .text.f1, "ax"
+f1:
+  movl $5, d1
+  ret
+
+.section .text.f2, "ax"
+f2:
+  movl $5, d2
+  ret