[lld] r329367 - Don't ignore addend when a SHF_MERGE section is dead.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Thu Apr  5 18:10:33 2018
New Revision: 329367

URL: http://llvm.org/viewvc/llvm-project?rev=329367&view=rev
Log:
Don't ignore addend when a SHF_MERGE section is dead.

This is similar to r329219, but for the entire section. Like r329219 I
don't expect this to have any real impact, it is just more consistent
and simpler.

Added:
    lld/trunk/test/ELF/merge-gc-piece2.s
Modified:
    lld/trunk/ELF/InputSection.cpp
    lld/trunk/ELF/SyntheticSections.cpp

Modified: lld/trunk/ELF/InputSection.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/InputSection.cpp?rev=329367&r1=329366&r2=329367&view=diff
==============================================================================
--- lld/trunk/ELF/InputSection.cpp (original)
+++ lld/trunk/ELF/InputSection.cpp Thu Apr  5 18:10:33 2018
@@ -970,9 +970,6 @@ SectionPiece *MergeInputSection::getSect
 // Because contents of a mergeable section is not contiguous in output,
 // it is not just an addition to a base output offset.
 uint64_t MergeInputSection::getOffset(uint64_t Offset) const {
-  if (!Live)
-    return 0;
-
   // Find a string starting at a given offset.
   auto It = OffsetMap.find(Offset);
   if (It != OffsetMap.end())

Modified: lld/trunk/ELF/SyntheticSections.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SyntheticSections.cpp?rev=329367&r1=329366&r2=329367&view=diff
==============================================================================
--- lld/trunk/ELF/SyntheticSections.cpp (original)
+++ lld/trunk/ELF/SyntheticSections.cpp Thu Apr  5 18:10:33 2018
@@ -2532,9 +2532,8 @@ void elf::mergeSections() {
   // splitIntoPieces needs to be called on each MergeInputSection
   // before calling finalizeContents(). Do that first.
   parallelForEach(InputSections, [](InputSectionBase *Sec) {
-    if (Sec->Live)
-      if (auto *S = dyn_cast<MergeInputSection>(Sec))
-        S->splitIntoPieces();
+    if (auto *S = dyn_cast<MergeInputSection>(Sec))
+      S->splitIntoPieces();
   });
 
   std::vector<MergeSyntheticSection *> MergeSections;

Added: lld/trunk/test/ELF/merge-gc-piece2.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/merge-gc-piece2.s?rev=329367&view=auto
==============================================================================
--- lld/trunk/test/ELF/merge-gc-piece2.s (added)
+++ lld/trunk/test/ELF/merge-gc-piece2.s Thu Apr  5 18:10:33 2018
@@ -0,0 +1,27 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+# RUN: ld.lld %t.o -o %t.so -shared --gc-sections
+# RUN: llvm-readobj -s -section-data %t.so | FileCheck %s
+
+# CHECK:      Name: .bar
+# CHECK-NEXT: Type: SHT_PROGBITS
+# CHECK-NEXT: Flags [
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address:
+# CHECK-NEXT: Offset:
+# CHECK-NEXT: Size: 16
+# CHECK-NEXT: Link:
+# CHECK-NEXT: Info:
+# CHECK-NEXT: AddressAlignment:
+# CHECK-NEXT: EntrySize:
+# CHECK-NEXT: SectionData (
+# CHECK-NEXT:   0000: 01000000 00000000 02000000 00000000
+# CHECK-NEXT: )
+
+        .section .foo,"aM", at progbits,8
+        .quad 42
+        .quad 43
+
+        .section .bar
+        .quad .foo + 1
+        .quad .foo + 2