LLD/ELF: Fix C4307: '-': integral constant overflow for MSVC15

[ruiu]

This patch effectively reverts r315877, but it contains some formatting, so it is not a complete rollback patch. Can you re-create a patch using svn revert or git revert? Or I can do that for you.

[kzhuravl]

In D38955#898745, @ruiu wrote:

This patch effectively reverts r315877, but it contains some formatting, so it is not a complete rollback patch. Can you re-create a patch using svn revert or git revert? Or I can do that for you.

Ok, I will just revert it.

[kzhuravl]

Just revert.

[ruiu]

Please change the patch subject to Revert r315877: Simplify. and write the reason (it causes MSVC 2015 to emit "C4307: '-': integral constant overflow" warning) as a commit message.

With that, LGTM.

lld/trunk/ELF/SymbolTable.h

private:
 
   llvm::StringMap<std::vector<SymbolBody *>> &getDemangledSyms();
   void handleAnonymousVersion();
   void assignExactVersion(SymbolVersion Ver, uint16_t VersionId,
                           StringRef VersionName);
   void assignWildcardVersion(SymbolVersion Ver, uint16_t VersionId);
 
   struct SymIndex {
-    int32_t Idx : 31;
-    uint32_t Traced : 1;
+    SymIndex(int Idx, bool Traced) : Idx(Idx), Traced(Traced) {}
+    int Idx : 31;
+    unsigned Traced : 1;
   };
 
   // The order the global symbols are in is not defined. We can use an arbitrary
   // order, but it has to be reproducible. That is true even when cross linking.
   // The default hashing of StringRef produces different results on 32 and 64
   // bit systems so we use a map to a vector. That is arbitrary, deterministic
   // but a bit inefficient.
   // FIXME: Experiment with passing in a custom hashing or sorting the symbols

lld/trunk/ELF/SymbolTable.cpp

std::pair<Symbol *, bool> SymbolTable::insert(StringRef Name) {
   // Since this is a hot path, the following string search code is
   // optimized for speed. StringRef::find(char) is much faster than
   // StringRef::find(StringRef).
   size_t Pos = Name.find('@');
   if (Pos != StringRef::npos && Pos + 1 < Name.size() && Name[Pos + 1] == '@')
     Name = Name.take_front(Pos);
 
   auto P = Symtab.insert(
-      {CachedHashStringRef(Name), SymIndex{(int)SymVector.size(), false}});
+      {CachedHashStringRef(Name), SymIndex((int)SymVector.size(), false)});
   SymIndex &V = P.first->second;
   bool IsNew = P.second;
 
   if (V.Idx == -1) {
     IsNew = true;
-    V = SymIndex{(int)SymVector.size(), true};
+    V = SymIndex((int)SymVector.size(), true);
   }
 
   Symbol *Sym;
   if (IsNew) {
     Sym = make<Symbol>();
     Sym->InVersionScript = false;
     Sym->Binding = STB_WEAK;
     Sym->Visibility = STV_DEFAULT;