From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Thu, 1 Nov 2012 22:15:34 +0000 (+0000)
Subject: Split emission of -ftrapv checks and -fcatch-undefined-behavior checks into
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=de67068fc1726f7c9c4ae89d3f3f47b2da512d48;p=platform%2Fupstream%2Fllvm.git

Split emission of -ftrapv checks and -fcatch-undefined-behavior checks into
separate functions, since they share essentially no code.

llvm-svn: 167259
---

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index d59a72d..e52a9ab 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -2017,29 +2017,6 @@ void CodeGenFunction::EmitCheck(llvm::Value *Checked, StringRef CheckName,
                                 bool Recoverable) {
   llvm::BasicBlock *Cont = createBasicBlock("cont");
 
-  // If -fcatch-undefined-behavior is not enabled, just emit a trap. This
-  // happens when using -ftrapv.
-  // FIXME: Should -ftrapv require the ubsan runtime library?
-  if (!CatchUndefined) {
-    // If we're optimizing, collapse all calls to trap down to just one per
-    // function to save on code size.
-    if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
-      TrapBB = createBasicBlock("trap");
-      Builder.CreateCondBr(Checked, Cont, TrapBB);
-      EmitBlock(TrapBB);
-      llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap);
-      llvm::CallInst *TrapCall = Builder.CreateCall(F);
-      TrapCall->setDoesNotReturn();
-      TrapCall->setDoesNotThrow();
-      Builder.CreateUnreachable();
-    } else {
-      Builder.CreateCondBr(Checked, Cont, TrapBB);
-    }
-
-    EmitBlock(Cont);
-    return;
-  }
-
   llvm::BasicBlock *Handler = createBasicBlock("handler." + CheckName);
   Builder.CreateCondBr(Checked, Cont, Handler);
   EmitBlock(Handler);
@@ -2089,6 +2066,27 @@ void CodeGenFunction::EmitCheck(llvm::Value *Checked, StringRef CheckName,
   EmitBlock(Cont);
 }
 
+void CodeGenFunction::EmitTrapvCheck(llvm::Value *Checked) {
+  llvm::BasicBlock *Cont = createBasicBlock("cont");
+
+  // If we're optimizing, collapse all calls to trap down to just one per
+  // function to save on code size.
+  if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
+    TrapBB = createBasicBlock("trap");
+    Builder.CreateCondBr(Checked, Cont, TrapBB);
+    EmitBlock(TrapBB);
+    llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap);
+    llvm::CallInst *TrapCall = Builder.CreateCall(F);
+    TrapCall->setDoesNotReturn();
+    TrapCall->setDoesNotThrow();
+    Builder.CreateUnreachable();
+  } else {
+    Builder.CreateCondBr(Checked, Cont, TrapBB);
+  }
+
+  EmitBlock(Cont);
+}
+
 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
 /// array to pointer, return the array subexpression.
 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index 2354f31..31ec7ea 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -2021,6 +2021,12 @@ Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) {
   const std::string *handlerName =
     &CGF.getContext().getLangOpts().OverflowHandler;
   if (handlerName->empty()) {
+    // If -fcatch-undefined-behavior is enabled, emit a call to its
+    // runtime. Otherwise, this is a -ftrapv check, so just emit a trap.
+    if (CGF.CatchUndefined)
+      EmitBinOpCheck(Builder.CreateNot(overflow), Ops);
+    else
+      CGF.EmitTrapvCheck(Builder.CreateNot(overflow));
     EmitBinOpCheck(Builder.CreateNot(overflow), Ops);
     return result;
   }
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index c3f6c8e..1e9fd00 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -2574,13 +2574,18 @@ public:
   /// passing to a runtime sanitizer handler.
   llvm::Constant *EmitCheckSourceLocation(SourceLocation Loc);
 
-  /// \brief Create a basic block that will call the trap intrinsic, and emit a
-  /// conditional branch to it.
+  /// \brief Create a basic block that will call a handler function in a
+  /// sanitizer runtime with the provided arguments, and create a conditional
+  /// branch to it.
   void EmitCheck(llvm::Value *Checked, StringRef CheckName,
                  llvm::ArrayRef<llvm::Constant *> StaticArgs,
                  llvm::ArrayRef<llvm::Value *> DynamicArgs,
                  bool Recoverable = false);
 
+  /// \brief Create a basic block that will call the trap intrinsic, and emit a
+  /// conditional branch to it, for the -ftrapv checks.
+  void EmitTrapvCheck(llvm::Value *Checked);
+
   /// EmitCallArg - Emit a single call argument.
   void EmitCallArg(CallArgList &args, const Expr *E, QualType ArgType);