Revert "[ORC][JITLink] Treat common symbols as weak definitions."

This reverts commit 785d376 while I
investigate some bot failures (e.g.
https://lab.llvm.org/buildbot/#/builders/3/builds/1983).

Author: lhames

llvm/lib/ExecutionEngine/JITLink/COFFLinkGraphBuilder.cpp

@@ -467,7 +467,7 @@ Expected<Symbol *> COFFLinkGraphBuilder::createDefinedSymbol(
     return &G->addDefinedSymbol(
         G->createZeroFillBlock(getCommonSection(), Symbol.getValue(),
                                orc::ExecutorAddr(), Symbol.getValue(), 0),
-        0, SymbolName, Symbol.getValue(), Linkage::Weak, Scope::Default,
+        0, SymbolName, Symbol.getValue(), Linkage::Strong, Scope::Default,
         false, false);
   }
   if (Symbol.isAbsolute())

llvm/lib/ExecutionEngine/JITLink/ELFLinkGraphBuilder.h

@@ -472,7 +472,7 @@ template <typename ELFT> Error ELFLinkGraphBuilder<ELFT>::graphifySymbols() {
       Symbol &GSym = G->addDefinedSymbol(
           G->createZeroFillBlock(getCommonSection(), Sym.st_size,
                                  orc::ExecutorAddr(), Sym.getValue(), 0),
-          0, *Name, Sym.st_size, Linkage::Weak, Scope::Default, false, false);
+          0, *Name, Sym.st_size, Linkage::Strong, Scope::Default, false, false);
       setGraphSymbol(SymIndex, GSym);
       continue;
     }

llvm/lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.cpp

@@ -366,7 +366,7 @@ Error MachOLinkGraphBuilder::graphifyRegularSymbols() {
                                    orc::ExecutorAddrDiff(NSym.Value),
                                    orc::ExecutorAddr(),
                                    1ull << MachO::GET_COMM_ALIGN(NSym.Desc), 0),
-            0, *NSym.Name, orc::ExecutorAddrDiff(NSym.Value), Linkage::Weak,
+            0, *NSym.Name, orc::ExecutorAddrDiff(NSym.Value), Linkage::Strong,
             NSym.S, false, NSym.Desc & MachO::N_NO_DEAD_STRIP);
       } else {
         if (!NSym.Name)

llvm/lib/ExecutionEngine/Orc/Core.cpp

@@ -932,17 +932,13 @@ Error JITDylib::resolve(MaterializationResponsibility &MR,
           if (SymI->second.getFlags().hasError())
             SymbolsInErrorState.insert(KV.first);
           else {
-            auto ExpectedFlags = SymI->second.getFlags();
-            if (ExpectedFlags & JITSymbolFlags::Common) {
-              ExpectedFlags &= ~JITSymbolFlags::Common;
-              ExpectedFlags |= JITSymbolFlags::Weak;
-            }
-
-            assert(KV.second.getFlags() == ExpectedFlags &&
+            auto Flags = KV.second.getFlags();
+            Flags &= ~JITSymbolFlags::Common;
+            assert(Flags ==
+                       (SymI->second.getFlags() & ~JITSymbolFlags::Common) &&
                    "Resolved flags should match the declared flags");
 
-            Worklist.push_back(
-                {SymI, {KV.second.getAddress(), SymI->second.getFlags()}});
+            Worklist.push_back({SymI, {KV.second.getAddress(), Flags}});
           }
         }
 
@@ -2903,12 +2899,8 @@ Error ExecutionSession::OL_notifyResolved(MaterializationResponsibility &MR,
            "Resolving symbol outside this responsibility set");
     assert(!I->second.hasMaterializationSideEffectsOnly() &&
            "Can't resolve materialization-side-effects-only symbol");
-    auto ExpectedFlags = I->second;
-    if (ExpectedFlags & JITSymbolFlags::Common) {
-      ExpectedFlags &= ~JITSymbolFlags::Common;
-      ExpectedFlags |= JITSymbolFlags::Weak;
-    }
-    assert(KV.second.getFlags() == ExpectedFlags &&
+    assert((KV.second.getFlags() & ~JITSymbolFlags::Common) ==
+               (I->second & ~JITSymbolFlags::Common) &&
            "Resolving symbol with incorrect flags");
   }
 #endif

llvm/test/ExecutionEngine/JITLink/AArch64/Inputs/MachO_common_x_and_addr_getter.s

@@ -6,7 +6,7 @@
 #
 # CHECK: Creating graph symbols...
 # CHECK:      7: Creating defined graph symbol for COFF symbol "var" in (common) (index: 0)
-# CHECK-NEXT:   0x0 (block + 0x00000000): size: 0x00000004, linkage: weak, scope: default, dead  -   var
+# CHECK-NEXT:   0x0 (block + 0x00000000): size: 0x00000004, linkage: strong, scope: default, dead  -   var
 
 	.text