[ORC] Coalesce all of ORC's symbol renaming / linkage-promotion utilities into

one SymbolLinkagePromoter utility.

SymbolLinkagePromoter renames anonymous and private symbols, and bumps all
linkages to at least global/hidden-visibility. Modules whose symbols have been
promoted by this utility can be decomposed into sub-modules without introducing
link errors. This is used by the CompileOnDemandLayer to extract single-function
modules for lazy compilation.

llvm-svn: 343257

2 files changed, 16 insertions, 50 deletions

diff --git a/llvm/lib/ExecutionEngine/Orc/IndirectionUtils.cpp b/llvm/lib/ExecutionEngine/Orc/IndirectionUtils.cpp
index 54baed237b2..c1ece816b75 100644
--- a/llvm/lib/ExecutionEngine/Orc/IndirectionUtils.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/IndirectionUtils.cpp
@@ -246,57 +246,23 @@ void makeStub(Function &F, Value &ImplPointer) {
     Builder.CreateRet(Call);
 }
 
-// Utility class for renaming global values and functions during partitioning.
-class GlobalRenamer {
-public:
-
-  static bool needsRenaming(const Value &New) {
-    return !New.hasName() || New.getName().startswith("\01L");
-  }
-
-  const std::string& getRename(const Value &Orig) {
-    // See if we have a name for this global.
-    {
-      auto I = Names.find(&Orig);
-      if (I != Names.end())
-        return I->second;
+void SymbolLinkagePromoter::operator()(Module &M) {
+  for (auto &GV : M.global_values()) {
+
+    // Rename if necessary.
+    if (!GV.hasName())
+      GV.setName("__orc_anon." + Twine(NextId++));
+    else if (GV.getName().startswith("\01L"))
+      GV.setName("__" + GV.getName().substr(1) + "." + Twine(NextId++));
+    else if (GV.hasLocalLinkage())
+      GV.setName("__orc_lcl." + GV.getName() + "." + Twine(NextId++));
+
+    if (GV.hasLocalLinkage()) {
+      GV.setLinkage(GlobalValue::ExternalLinkage);
+      GV.setVisibility(GlobalValue::HiddenVisibility);
     }
-
-    // Nope. Create a new one.
-    // FIXME: Use a more robust uniquing scheme. (This may blow up if the user
-    //        writes a "__orc_anon[[:digit:]]* method).
-    unsigned ID = Names.size();
-    std::ostringstream NameStream;
-    NameStream << "__orc_anon" << ID++;
-    auto I = Names.insert(std::make_pair(&Orig, NameStream.str()));
-    return I.first->second;
-  }
-private:
-  DenseMap<const Value*, std::string> Names;
-};
-
-static void raiseVisibilityOnValue(GlobalValue &V, GlobalRenamer &R) {
-  if (V.hasLocalLinkage()) {
-    if (R.needsRenaming(V))
-      V.setName(R.getRename(V));
-    V.setLinkage(GlobalValue::ExternalLinkage);
-    V.setVisibility(GlobalValue::HiddenVisibility);
+    GV.setUnnamedAddr(GlobalValue::UnnamedAddr::None);
   }
-  V.setUnnamedAddr(GlobalValue::UnnamedAddr::None);
-  assert(!R.needsRenaming(V) && "Invalid global name.");
-}
-
-void makeAllSymbolsExternallyAccessible(Module &M) {
-  GlobalRenamer Renamer;
-
-  for (auto &F : M)
-    raiseVisibilityOnValue(F, Renamer);
-
-  for (auto &GV : M.globals())
-    raiseVisibilityOnValue(GV, Renamer);
-
-  for (auto &A : M.aliases())
-    raiseVisibilityOnValue(A, Renamer);
 }
 
 Function* cloneFunctionDecl(Module &Dst, const Function &F,
diff --git a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
index fef190ba575..91fa4ec2077 100644
--- a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
@@ -181,7 +181,7 @@ Error LLLazyJIT::addLazyIRModule(JITDylib &JD, ThreadSafeModule TSM) {
   if (auto Err = applyDataLayout(*TSM.getModule()))
     return Err;
 
-  makeAllSymbolsExternallyAccessible(*TSM.getModule());
+  PromoteSymbols(*TSM.getModule());
 
   recordCtorDtors(*TSM.getModule());