From c3653dcda6657a792b54b7ae7df3014709a615bc Mon Sep 17 00:00:00 2001
From: Nico Weber <nicolasweber@gmx.de>
Date: Mon, 30 Sep 2019 18:13:48 +0000
Subject: [PATCH] Revert "[MC] Emit unused undefined symbol even if its binding
 is not set"

This reverts r373168. It caused PR43511.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@373242 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/MC/ELFObjectWriter.cpp |  3 +++
 test/MC/ELF/undef.s        | 22 ----------------------
 test/MC/ELF/weakref.s      |  9 ---------
 3 files changed, 3 insertions(+), 31 deletions(-)

diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp
index f8e93889344..6f160e491ce 100644
--- a/lib/MC/ELFObjectWriter.cpp
+++ b/lib/MC/ELFObjectWriter.cpp
@@ -615,6 +615,9 @@ bool ELFWriter::isInSymtab(const MCAsmLayout &Layout, const MCSymbolELF &Symbol,
     return false;
   }
 
+  if (Symbol.isUndefined() && !Symbol.isBindingSet())
+    return false;
+
   if (Symbol.isTemporary())
     return false;
 
diff --git a/test/MC/ELF/undef.s b/test/MC/ELF/undef.s
index 9d99b834ffd..f313d71369e 100644
--- a/test/MC/ELF/undef.s
+++ b/test/MC/ELF/undef.s
@@ -18,8 +18,6 @@
         .text
         movsd   .Lsym8(%rip), %xmm1
 
-.hidden hidden
-
 test2_a = undef
 test2_b = undef + 1
 
@@ -43,17 +41,6 @@ test2_b = undef + 1
 // CHECK-NEXT:     Section: .rodata.str1.1
 // CHECK-NEXT:   }
 // CHECK-NEXT:   Symbol {
-// CHECK-NEXT:     Name: hidden
-// CHECK-NEXT:     Value: 0x0
-// CHECK-NEXT:     Size: 0
-// CHECK-NEXT:     Binding: Global
-// CHECK-NEXT:     Type: None
-// CHECK-NEXT:     Other [
-// CHECK-NEXT:       STV_HIDDEN
-// CHECK-NEXT:     ]
-// CHECK-NEXT:     Section: Undefined
-// CHECK-NEXT:   }
-// CHECK-NEXT:   Symbol {
 // CHECK-NEXT:     Name: sym6
 // CHECK-NEXT:     Value: 0x0
 // CHECK-NEXT:     Size: 0
@@ -62,13 +49,4 @@ test2_b = undef + 1
 // CHECK-NEXT:     Other: 0
 // CHECK-NEXT:     Section: Undefined
 // CHECK-NEXT:   }
-// CHECK-NEXT:   Symbol {
-// CHECK-NEXT:     Name: undef
-// CHECK-NEXT:     Value: 0x0
-// CHECK-NEXT:     Size: 0
-// CHECK-NEXT:     Binding: Global
-// CHECK-NEXT:     Type: None
-// CHECK-NEXT:     Other: 0
-// CHECK-NEXT:     Section: Undefined
-// CHECK-NEXT:   }
 // CHECK-NEXT: ]
diff --git a/test/MC/ELF/weakref.s b/test/MC/ELF/weakref.s
index bca8ec4f281..51905d8ad7c 100644
--- a/test/MC/ELF/weakref.s
+++ b/test/MC/ELF/weakref.s
@@ -125,15 +125,6 @@ bar15:
 // CHECK-NEXT:     Section: .text
 // CHECK-NEXT:   }
 // CHECK-NEXT:   Symbol {
-// CHECK-NEXT:     Name: bar1
-// CHECK-NEXT:     Value: 0x0
-// CHECK-NEXT:     Size: 0
-// CHECK-NEXT:     Binding: Global
-// CHECK-NEXT:     Type: None
-// CHECK-NEXT:     Other: 0
-// CHECK-NEXT:     Section: Undefined
-// CHECK-NEXT:   }
-// CHECK-NEXT:   Symbol {
 // CHECK-NEXT:     Name: bar10
 // CHECK-NEXT:     Value: 0x28
 // CHECK-NEXT:     Size: 0