Allow user defined __init_aray_start.

Fixes pr27683.

llvm-svn: 268926

lld/ELF/Writer.cpp

@@ -1104,8 +1104,11 @@ template <class ELFT>
 static Symbol *addOptionalSynthetic(SymbolTable<ELFT> &Table, StringRef Name,
                                     OutputSectionBase<ELFT> *Sec,
                                     typename ELFT::uint Val) {
-  if (!Table.find(Name))
+  SymbolBody *S = Table.find(Name);
+  if (!S)
     return nullptr;
+  if (!S->isUndefined() && !S->isShared())
+    return S->symbol();
   return Table.addSynthetic(Name, Sec, Val);
 }
 

lld/test/ELF/user_def_init_array_start.s

@@ -0,0 +1,10 @@
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+// RUN: ld.lld %t.o -o %t2.so -shared
+// Allow user defined __init_array_start. This is used by musl because of the
+// the bfd linker not handling these properly. We always create them as
+// hidden, musl should not have problems with lld.
+
+        .hidden __init_array_start
+        .globl  __init_array_start
+__init_array_start:
+        .zero   8