Treat unnamed symbols as locals.

There is work under way in llvm to avoid creating unnecessary names for
symbols. This makes lld capable of handling that.

llvm-svn: 255357

3 files changed, 17 insertions, 1 deletions

diff --git a/lld/ELF/OutputSections.cpp b/lld/ELF/OutputSections.cpp
index ab7e337deb4..c64610fe80b 100644
--- a/lld/ELF/OutputSections.cpp
+++ b/lld/ELF/OutputSections.cpp
@@ -1181,7 +1181,7 @@ bool lld::elf2::shouldKeepInSymtab(const ObjectFile<ELFT> &File,
   // * --discard-locals is used.
   // * The symbol is in a SHF_MERGE section, which is normally the reason for
   //   the assembler keeping the .L symbol.
-  if (!SymName.startswith(".L"))
+  if (!SymName.startswith(".L") && !SymName.empty())
     return true;
 
   if (Config->DiscardLocals)
diff --git a/lld/test/ELF/Inputs/discard-merge-unnamed.o b/lld/test/ELF/Inputs/discard-merge-unnamed.o
new file mode 100644
index 00000000000..040addf04f4
--- /dev/null
+++ b/lld/test/ELF/Inputs/discard-merge-unnamed.o
diff --git a/lld/test/ELF/discard-merge-unnamed.s b/lld/test/ELF/discard-merge-unnamed.s
new file mode 100644
index 00000000000..bd0058cbd7d
--- /dev/null
+++ b/lld/test/ELF/discard-merge-unnamed.s
@@ -0,0 +1,16 @@
+// RUN: ld.lld %p/Inputs/discard-merge-unnamed.o -o %t2 -shared
+// RUN: llvm-readobj -t %t2 | FileCheck %s
+
+// Test that the unnamed symbol is SHF_MERGE is omitted.
+
+// CHECK:      Symbols [
+// CHECK-NEXT:   Symbol {
+// CHECK-NEXT:     Name:  (0)
+// CHECK-NEXT:     Value: 0x0
+// CHECK-NEXT:     Size: 0
+// CHECK-NEXT:     Binding: Local
+// CHECK-NEXT:     Type: None
+// CHECK-NEXT:     Other: 0
+// CHECK-NEXT:     Section: Undefined
+// CHECK-NEXT:   }
+// CHECK-NEXT: ]