[SEH] Implement filter capturing in CodeGen

While capturing filters aren't very common, we'd like to outline
__finally blocks in the frontend to simplify -O0 EH preparation and
reduce code size. Finally blocks are usually have captures, and this is
the first step towards that.

Currently we don't support capturing 'this' or VLAs.

Reviewers: majnemer

Differential Revision: http://reviews.llvm.org/D8825

llvm-svn: 234261

1 files changed, 10 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 8d3408a..6183b49 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -877,6 +877,10 @@ private:
   typedef llvm::DenseMap<const Decl*, llvm::Value*> DeclMapTy;
   DeclMapTy LocalDeclMap;
 
+  /// Track escaped local variables with auto storage. Used during SEH
+  /// outlining to produce a call to llvm.frameescape.
+  llvm::DenseMap<llvm::AllocaInst *, int> EscapedLocals;
+
   /// LabelMap - This keeps track of the LLVM basic block for each C label.
   llvm::DenseMap<const LabelDecl*, JumpDest> LabelMap;
 
@@ -2007,6 +2011,12 @@ public:
   llvm::Value *EmitSEHExceptionInfo();
   llvm::Value *EmitSEHAbnormalTermination();
 
+  /// Scan the outlined statement for captures from the parent function. For
+  /// each capture, mark the capture as escaped and emit a call to
+  /// llvm.framerecover. Insert the framerecover result into the LocalDeclMap.
+  void EmitCapturedLocals(CodeGenFunction &ParentCGF, const Stmt *OutlinedStmt,
+                          llvm::Value *ParentFP);
+
   void EmitCXXForRangeStmt(const CXXForRangeStmt &S,
                            ArrayRef<const Attr *> Attrs = None);