From c7d209fb2442a63d328a25e1036b4726b0c4a49d Mon Sep 17 00:00:00 2001
From: John McCall <rjmccall@apple.com>
Date: Sat, 3 Jul 2010 09:25:20 +0000
Subject: Provide convenience routines to save and restore the current
 insertion point.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107570 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGBuilder.h | 55 ++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 52 insertions(+), 3 deletions(-)

(limited to 'lib/CodeGen/CGBuilder.h')

diff --git a/lib/CodeGen/CGBuilder.h b/lib/CodeGen/CGBuilder.h
index ed56bd9137..33d868920d 100644
--- a/lib/CodeGen/CGBuilder.h
+++ b/lib/CodeGen/CGBuilder.h
@@ -14,12 +14,61 @@
 
 namespace clang {
 namespace CodeGen {
-  // Don't preserve names on values in an optimized build.
+
+// Don't preserve names on values in an optimized build.
 #ifdef NDEBUG
-  typedef llvm::IRBuilder<false> CGBuilderTy;
+typedef llvm::IRBuilder<false> CGBuilderSuperTy;
 #else
-  typedef llvm::IRBuilder<> CGBuilderTy;
+typedef llvm::IRBuilder<> CGBuilderSuperTy;
 #endif
+
+/// IR generation's wrapper around an LLVM IRBuilder.
+class CGBuilderTy : public CGBuilderSuperTy {
+public:
+  CGBuilderTy(llvm::LLVMContext &Context) : CGBuilderSuperTy(Context) {}
+  CGBuilderTy(llvm::BasicBlock *Block) : CGBuilderSuperTy(Block) {}
+  CGBuilderTy(llvm::BasicBlock *Block, llvm::BasicBlock::iterator Point)
+    : CGBuilderSuperTy(Block, Point) {}
+
+  CGBuilderTy(const CGBuilderTy &Builder)
+    : CGBuilderSuperTy(Builder.getContext()) {
+
+    if (Builder.GetInsertBlock())
+      SetInsertPoint(Builder.GetInsertBlock(), Builder.GetInsertPoint());
+  }
+
+  /// A saved insertion point.
+  class InsertPoint {
+    llvm::BasicBlock *Block;
+    llvm::BasicBlock::iterator Point;
+
+  public:
+    InsertPoint(llvm::BasicBlock *Block, llvm::BasicBlock::iterator Point)
+      : Block(Block), Point(Point) {}
+
+    bool isSet() const { return (Block != 0); }
+    llvm::BasicBlock *getBlock() const { return Block; }
+    llvm::BasicBlock::iterator getPoint() const { return Point; }
+  };
+
+  InsertPoint saveIP() const {
+    return InsertPoint(GetInsertBlock(), GetInsertPoint());
+  }
+
+  InsertPoint saveAndClearIP() {
+    InsertPoint IP(GetInsertBlock(), GetInsertPoint());
+    ClearInsertionPoint();
+    return IP;
+  }
+
+  void restoreIP(InsertPoint IP) {
+    if (IP.isSet())
+      SetInsertPoint(IP.getBlock(), IP.getPoint());
+    else
+      ClearInsertionPoint();
+  }
+};
+
 }  // end namespace CodeGen
 }  // end namespace clang
 
-- 
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