COFF: Implement Safe SEH support for x86.

An object file compatible with Safe SEH contains a .sxdata section.
The section contains a list of symbol table indices, each of which
is an exception handler function. A safe SEH-enabled executable
contains a list of exception handler RVAs. So, what the linker has
to do to support Safe SEH is basically to read the .sxdata section,
interpret the contents as a list of symbol indices, unique-fy and
sort their RVAs, and then emit that list to .rdata. This patch
implements that feature.

llvm-svn: 243182

1 files changed, 10 insertions, 2 deletions

diff --git a/lld/COFF/SymbolTable.cpp b/lld/COFF/SymbolTable.cpp
index 14fb72480d9..d3f8b038460 100644
--- a/lld/COFF/SymbolTable.cpp
+++ b/lld/COFF/SymbolTable.cpp
@@ -317,8 +317,16 @@ Undefined *SymbolTable::addUndefined(StringRef Name) {
   return New;
 }
 
-void SymbolTable::addRelative(StringRef Name, uint64_t VA) {
-  addSymbol(new (Alloc) DefinedRelative(Name, VA));
+DefinedRelative *SymbolTable::addRelative(StringRef Name, uint64_t VA) {
+  auto *New = new (Alloc) DefinedRelative(Name, VA);
+  addSymbol(New);
+  return New;
+}
+
+DefinedAbsolute *SymbolTable::addAbsolute(StringRef Name, uint64_t VA) {
+  auto *New = new (Alloc) DefinedAbsolute(Name, VA);
+  addSymbol(New);
+  return New;
 }
 
 void SymbolTable::printMap(llvm::raw_ostream &OS) {