Update llvm/clang to trunk r126547.

There are several bugfixes in this update, but the most important one is
to ensure __start_ and __stop_ symbols for linker sets and kernel module
metadata are always emitted in object files:

  http://llvm.org/bugs/show_bug.cgi?id=9292

Before this fix, if you compiled kernel modules with clang, they would
not be properly processed by kldxref, and if they had any dependencies,
the kernel would fail to load those.  Another problem occurred when
attempting to mount a tmpfs filesystem, which would result in 'operation
not supported by device'.

1 files changed, 15 insertions, 21 deletions

diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CGBlocks.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CGBlocks.cpp
index a35648d..9587de2 100644
--- a/contrib/llvm/tools/clang/lib/CodeGen/CGBlocks.cpp
+++ b/contrib/llvm/tools/clang/lib/CodeGen/CGBlocks.cpp
@@ -895,12 +895,9 @@ CodeGenFunction::GenerateBlockFunction(GlobalDecl GD,
   QualType selfTy = getContext().VoidPtrTy;
   IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
 
-  // FIXME: this leaks, and we only need it very temporarily.
-  ImplicitParamDecl *selfDecl =
-    ImplicitParamDecl::Create(getContext(),
-                              const_cast<BlockDecl*>(blockDecl),
-                              SourceLocation(), II, selfTy);
-  args.push_back(std::make_pair(selfDecl, selfTy));
+  ImplicitParamDecl selfDecl(const_cast<BlockDecl*>(blockDecl),
+                             SourceLocation(), II, selfTy);
+  args.push_back(std::make_pair(&selfDecl, selfTy));
 
   // Now add the rest of the parameters.
   for (BlockDecl::param_const_iterator i = blockDecl->param_begin(),
@@ -928,12 +925,11 @@ CodeGenFunction::GenerateBlockFunction(GlobalDecl GD,
                 blockInfo.getBlockExpr()->getBody()->getLocEnd());
   CurFuncDecl = outerFnDecl; // StartFunction sets this to blockDecl
 
-  // Okay.  Undo some of what StartFunction did.  We really don't need
-  // an alloca for the block address;  in theory we could remove it,
-  // but that might do unpleasant things to debug info.
-  llvm::AllocaInst *blockAddrAlloca
-    = cast<llvm::AllocaInst>(LocalDeclMap[selfDecl]);
-  llvm::Value *blockAddr = Builder.CreateLoad(blockAddrAlloca);
+  // Okay.  Undo some of what StartFunction did.
+  
+  // Pull the 'self' reference out of the local decl map.
+  llvm::Value *blockAddr = LocalDeclMap[&selfDecl];
+  LocalDeclMap.erase(&selfDecl);
   BlockPointer = Builder.CreateBitCast(blockAddr,
                                        blockInfo.StructureType->getPointerTo(),
                                        "block");
@@ -1010,7 +1006,7 @@ CodeGenFunction::GenerateBlockFunction(GlobalDecl GD,
         continue;
       }
 
-      DI->EmitDeclareOfBlockDeclRefVariable(variable, blockAddrAlloca,
+      DI->EmitDeclareOfBlockDeclRefVariable(variable, BlockPointer,
                                             Builder, blockInfo);
     }
   }
@@ -1376,10 +1372,9 @@ llvm::Constant *CodeGenModule::BuildbyrefCopyHelper(const llvm::Type *T,
                                                     BlockFieldFlags flags,
                                                     unsigned align,
                                                     const VarDecl *var) {
-  // All alignments below that of pointer alignment collapse down to just
-  // pointer alignment, as we always have at least that much alignment to begin
-  // with.
-  align /= unsigned(getTarget().getPointerAlign(0) / 8);
+  // All alignments below pointer alignment are bumped up, as we
+  // always have at least that much alignment to begin with.
+  if (align < PointerAlignInBytes) align = PointerAlignInBytes;
   
   // As an optimization, we only generate a single function of each kind we
   // might need.  We need a different one for each alignment and for each
@@ -1396,10 +1391,9 @@ llvm::Constant *CodeGenModule::BuildbyrefDestroyHelper(const llvm::Type *T,
                                                        BlockFieldFlags flags,
                                                        unsigned align,
                                                        const VarDecl *var) {
-  // All alignments below that of pointer alignment collpase down to just
-  // pointer alignment, as we always have at least that much alignment to begin
-  // with.
-  align /= unsigned(getTarget().getPointerAlign(0) / 8);
+  // All alignments below pointer alignment are bumped up, as we
+  // always have at least that much alignment to begin with.
+  if (align < PointerAlignInBytes) align = PointerAlignInBytes;
   
   // As an optimization, we only generate a single function of each kind we
   // might need.  We need a different one for each alignment and for each