There's an issue with LLVM metadata support; it triggers an assert when trying

to generate asm for code with metadata globals.
This new pass is used as a workaround: it strips metadata from the module before
it reaches the code generator.
Obviously, this is disabled if LLVM doesn't support metadata.

gen/passes/StripMetaData.cpp

@@ -0,0 +1,85 @@
+//===- StripMetaData - Strips D-specific metadata -------------------------===//
+//
+//                             The LLVM D Compiler
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// There's an issue with the new LLVM metadata support; an assertion fires when
+// trying to generate asm for metadata globals.
+//
+// This pass is a workaround; it deletes the metadata LDC generates so the code
+// generator doesn't see it.
+// Obviously, this should only run after all passes that make use of that
+// metadata or they won't work.
+//
+//===----------------------------------------------------------------------===//
+
+#include "gen/metadata.h"
+
+// This pass isn't needed without metadata, so #ifdef it out entirely if the
+// LLVM version in use doesn't support it.
+#ifdef USE_METADATA
+
+
+#define DEBUG_TYPE "strip-metadata"
+
+#include "Passes.h"
+
+#include "llvm/Pass.h"
+#include "llvm/Module.h"
+#include "llvm/Constants.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+using namespace llvm;
+
+STATISTIC(NumDeleted, "Number of metadata globals deleted");
+
+//===----------------------------------------------------------------------===//
+// StripMetaData Pass Implementation
+//===----------------------------------------------------------------------===//
+
+namespace {
+    /// This pass optimizes library functions from the D runtime as used by LDC.
+    ///
+    class VISIBILITY_HIDDEN StripMetaData : public ModulePass {
+        public:
+        static char ID; // Pass identification
+        StripMetaData() : ModulePass(&ID) {}
+        
+        bool runOnModule(Module &M);
+    };
+    char StripMetaData::ID = 0;
+} // end anonymous namespace.
+
+static RegisterPass<StripMetaData>
+X("strip-metadata", "Delete D-specific metadata");
+
+// Public interface to the pass.
+ModulePass *createStripMetaData() {
+  return new StripMetaData(); 
+}
+
+/// runOnFunction - Top level algorithm.
+///
+bool StripMetaData::runOnModule(Module &M) {
+    bool Changed = false;
+    for (Module::global_iterator I = M.global_begin(), E = M.global_end(); I != E;) {
+        GlobalVariable* G = I++;
+        if (G->getNameLen() >= 9 && !strncmp(G->getNameStart(), "llvm.ldc.", 9)) {
+            assert(G->hasInitializer() && isa<MDNode>(G->getInitializer())
+                && "Not a metadata global?");
+            Changed = true;
+            NumDeleted++;
+            DEBUG(DOUT << "Deleting " << *G << '\n');
+            G->eraseFromParent();
+        }
+    }
+    return Changed;
+}
+
+
+#endif //USE_METADATA