[llvm] r190888 - COFF: Emit all MCSymbols rather than filtering out some of them

[Reid Kleckner]

Author: rnk
Date: Tue Sep 17 16:24:44 2013
New Revision: 190888

URL: http://llvm.org/viewvc/llvm-project?rev=190888&view=rev
Log:
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.

Modified:
    llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp
    llvm/trunk/test/MC/COFF/alias.s

Modified: llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp?rev=190888&r1=190887&r2=190888&view=diff
==============================================================================
--- llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp (original)
+++ llvm/trunk/lib/MC/WinCOFFObjectWriter.cpp Tue Sep 17 16:24:44 2013
@@ -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
   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::ExecutePostLay
     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,

Modified: llvm/trunk/test/MC/COFF/alias.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/COFF/alias.s?rev=190888&r1=190887&r2=190888&view=diff
==============================================================================
--- llvm/trunk/test/MC/COFF/alias.s (original)
+++ llvm/trunk/test/MC/COFF/alias.s Tue Sep 17 16:24:44 2013
@@ -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:     }