When internalizing global ctor/dtor list, also mark it constant. This is gross, but

until DSA is working all of the time and is totally reliable, we do this.

llvm-svn: 6917

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/IPO/Internalize.cpp b/llvm/lib/Transforms/IPO/Internalize.cpp
index ec28ecf81d0..0ed76aba628 100644
--- a/llvm/lib/Transforms/IPO/Internalize.cpp
+++ b/llvm/lib/Transforms/IPO/Internalize.cpp
@@ -87,6 +87,14 @@ namespace {
       for (Module::giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
         if (!I->isExternal() && !I->hasInternalLinkage() &&
             !ExternalNames.count(I->getName())) {
+          // Special case handling of the global ctor and dtor list.  When we
+          // internalize it, we mark it constant, which allows elimination of
+          // the list if it's empty.
+          //
+          if (I->hasAppendingLinkage() && (I->getName() == "llvm.global_ctors"||
+                                           I->getName() == "llvm.global_dtors"))
+            I->setConstant(true);
+
           I->setLinkage(GlobalValue::InternalLinkage);
           Changed = true;
           ++NumGlobals;