From 3168868bb91ac871dbb83c879e763d39a39e607e Mon Sep 17 00:00:00 2001
From: Reid Kleckner <reid@kleckner.net>
Date: Tue, 17 Sep 2013 21:24:44 +0000
Subject: [PATCH] COFF: Emit all MCSymbols rather than filtering out some of
 them

In particular, this means we emit non-external symbols defined to
variables, such as aliases or absolute addresses.

This is needed to implement /safeseh, and it appears there was some
confusion about what symbols to emit previously.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190888 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/MC/WinCOFFObjectWriter.cpp | 22 +++-------------------
 test/MC/COFF/alias.s           | 11 ++++++++++-
 2 files changed, 13 insertions(+), 20 deletions(-)

diff --git a/lib/MC/WinCOFFObjectWriter.cpp b/lib/MC/WinCOFFObjectWriter.cpp
index e85c33dc9c7..263151c6afa 100644
--- a/lib/MC/WinCOFFObjectWriter.cpp
+++ b/lib/MC/WinCOFFObjectWriter.cpp
@@ -154,8 +154,6 @@ public:
   void MakeSymbolReal(COFFSymbol &S, size_t Index);
   void MakeSectionReal(COFFSection &S, size_t Number);
 
-  bool ExportSymbol(MCSymbolData const &SymbolData, MCAssembler &Asm);
-
   bool IsPhysicalSection(COFFSection *S);
 
   // Entity writing methods.
@@ -496,18 +494,6 @@ void WinCOFFObjectWriter::MakeSymbolReal(COFFSymbol &S, size_t Index) {
   S.Index = Index;
 }
 
-bool WinCOFFObjectWriter::ExportSymbol(MCSymbolData const &SymbolData,
-                                       MCAssembler &Asm) {
-  // This doesn't seem to be right. Strings referred to from the .data section
-  // need symbols so they can be linked to code in the .text section right?
-
-  // return Asm.isSymbolLinkerVisible (&SymbolData);
-
-  // For now, all non-variable symbols are exported,
-  // the linker will sort the rest out for us.
-  return SymbolData.isExternal() || !SymbolData.getSymbol().isVariable();
-}
-
 bool WinCOFFObjectWriter::IsPhysicalSection(COFFSection *S) {
   return (S->Header.Characteristics
          & COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0;
@@ -609,11 +595,9 @@ void WinCOFFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm,
     DefineSection(*i);
 
   for (MCAssembler::const_symbol_iterator i = Asm.symbol_begin(),
-                                          e = Asm.symbol_end(); i != e; i++) {
-    if (ExportSymbol(*i, Asm)) {
-      DefineSymbol(*i, Asm);
-    }
-  }
+                                          e = Asm.symbol_end();
+       i != e; i++)
+    DefineSymbol(*i, Asm);
 }
 
 void WinCOFFObjectWriter::RecordRelocation(const MCAssembler &Asm,
diff --git a/test/MC/COFF/alias.s b/test/MC/COFF/alias.s
index f6f6d46bf6a..98ef7e5f190 100644
--- a/test/MC/COFF/alias.s
+++ b/test/MC/COFF/alias.s
@@ -45,6 +45,15 @@ weak_aliased_to_external = external2
 // CHECK-NEXT:     AuxSymbolCount: 0
 // CHECK-NEXT:   }
 // CHECK-NEXT:   Symbol {
+// CHECK-NEXT:     Name: external_aliased_to_local
+// CHECK-NEXT:     Value: 0
+// CHECK-NEXT:     Section: .text (1)
+// CHECK-NEXT:     BaseType: Null (0x0)
+// CHECK-NEXT:     ComplexType: Null (0x0)
+// CHECK-NEXT:     StorageClass: Static (0x3)
+// CHECK-NEXT:     AuxSymbolCount: 0
+// CHECK-NEXT:   }
+// CHECK-NEXT:   Symbol {
 // CHECK-NEXT:     Name: global_aliased_to_external
 // CHECK-NEXT:     Value: 0
 // CHECK-NEXT:     Section:  (0)
@@ -89,7 +98,7 @@ weak_aliased_to_external = external2
 // CHECK-NEXT:     StorageClass: WeakExternal (0x69)
 // CHECK-NEXT:     AuxSymbolCount: 1
 // CHECK-NEXT:     AuxWeakExternal {
-// CHECK-NEXT:       Linked: external2 (9)
+// CHECK-NEXT:       Linked: external2 (10)
 // CHECK-NEXT:       Search: Library (0x2)
 // CHECK-NEXT:       Unused: (00 00 00 00 00 00 00 00 00 00)
 // CHECK-NEXT:     }
-- 
2.34.1