[lld] r316928 - Skip abs symbols when handling copy reloc aliases.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Mon Oct 30 10:26:12 2017
New Revision: 316928

URL: http://llvm.org/viewvc/llvm-project?rev=316928&view=rev
Log:
Skip abs symbols when handling copy reloc aliases.

Since we now only check st_value, we have to consider the case where
the section index is special.

Added:
    lld/trunk/test/ELF/Inputs/copy-rel-abs.s
    lld/trunk/test/ELF/copy-rel-abs.s
Modified:
    lld/trunk/ELF/Relocations.cpp

Modified: lld/trunk/ELF/Relocations.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Relocations.cpp?rev=316928&r1=316927&r2=316928&view=diff
==============================================================================
--- lld/trunk/ELF/Relocations.cpp (original)
+++ lld/trunk/ELF/Relocations.cpp Mon Oct 30 10:26:12 2017
@@ -469,7 +469,8 @@ static std::vector<SharedSymbol *> getSy
 
   std::vector<SharedSymbol *> Ret;
   for (const Elf_Sym &S : File->getGlobalELFSyms()) {
-    if (S.st_shndx == 0 || S.st_value != SS->Value)
+    if (S.st_shndx == SHN_UNDEF || S.st_shndx == SHN_ABS ||
+        S.st_value != SS->Value)
       continue;
     StringRef Name = check(S.getName(File->getStringTable()));
     SymbolBody *Sym = Symtab->find(Name);

Added: lld/trunk/test/ELF/Inputs/copy-rel-abs.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/Inputs/copy-rel-abs.s?rev=316928&view=auto
==============================================================================
--- lld/trunk/test/ELF/Inputs/copy-rel-abs.s (added)
+++ lld/trunk/test/ELF/Inputs/copy-rel-abs.s Mon Oct 30 10:26:12 2017
@@ -0,0 +1,13 @@
+        .global foo
+        .type foo, @object
+        .size foo, 4
+foo:
+        .weak bar
+        .type bar, @object
+        .size bar, 4
+bar:
+        .long 42
+
+        .weak zed
+        .type zed, @object
+        zed = 0x1000

Added: lld/trunk/test/ELF/copy-rel-abs.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/copy-rel-abs.s?rev=316928&view=auto
==============================================================================
--- lld/trunk/test/ELF/copy-rel-abs.s (added)
+++ lld/trunk/test/ELF/copy-rel-abs.s Mon Oct 30 10:26:12 2017
@@ -0,0 +1,47 @@
+// REQUIRES: x86
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/copy-rel-abs.s -o %t1.o
+// RUN: ld.lld --hash-style=gnu -shared %t1.o -o %t1.so
+// RUN: llvm-readelf --dyn-symbols %t1.so | FileCheck --check-prefix=SYMS %s
+
+// The symbols have the same st_value, but one is ABS.
+// SYMS: 0000000000001000 {{.*}}   4 bar
+// SYMS: 0000000000001000 {{.*}}   4 foo
+// SYMS: 0000000000001000 {{.*}} ABS zed
+
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t2.o
+// RUN: ld.lld %t2.o %t1.so -o %t2
+// RUN: llvm-readobj --dyn-symbols %t2 | FileCheck %s
+
+// CHECK:      DynamicSymbols [
+// CHECK-NEXT:   Symbol {
+// CHECK-NEXT:     Name:
+// CHECK-NEXT:     Value:
+// CHECK-NEXT:     Size:
+// CHECK-NEXT:     Binding:
+// CHECK-NEXT:     Type:
+// CHECK-NEXT:     Other:
+// CHECK-NEXT:     Section:
+// CHECK-NEXT:   }
+// CHECK-NEXT:   Symbol {
+// CHECK-NEXT:     Name: foo
+// CHECK-NEXT:     Value:
+// CHECK-NEXT:     Size:
+// CHECK-NEXT:     Binding:
+// CHECK-NEXT:     Type:
+// CHECK-NEXT:     Other:
+// CHECK-NEXT:     Section: .bss.rel.ro
+// CHECK-NEXT:   }
+// CHECK-NEXT:   Symbol {
+// CHECK-NEXT:     Name: bar
+// CHECK-NEXT:     Value:
+// CHECK-NEXT:     Size:
+// CHECK-NEXT:     Binding:
+// CHECK-NEXT:     Type:
+// CHECK-NEXT:     Other:
+// CHECK-NEXT:     Section: .bss.rel.ro
+// CHECK-NEXT:   }
+// CHECK-NEXT: ]
+
+.global _start
+_start:
+.quad foo