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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.

llvm-svn: 190888
This commit is contained in:
Reid Kleckner 2013-09-17 21:24:44 +00:00
parent 50689eb917
commit 3ea536fef4
2 changed files with 13 additions and 20 deletions
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22
llvm/lib/MC/WinCOFFObjectWriter.cpp
View File

@ -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,

11
llvm/test/MC/COFF/alias.s
View File

@ -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: }