Implement an indirect-goto optimization for goto *&&lbl and respect this

in the scope checker.  With that done, turn an indirect goto into a
protected scope into a hard error;  otherwise IR generation has to start
worrying about declarations not dominating their scopes, as exemplified
in PR8473.

If this really affects anyone, I can probably adjust this to only hard-error
on possible indirect gotos into VLA scopes rather than arbitrary scopes.
But we'll see how people cope with the aggressive change on the marginal
feature.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@117539 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 0 deletions

diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index 008c07514e..4de505abdf 100644
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -297,6 +297,11 @@ void CodeGenFunction::EmitGotoStmt(const GotoStmt &S) {
 
 
 void CodeGenFunction::EmitIndirectGotoStmt(const IndirectGotoStmt &S) {
+  if (const LabelStmt *Target = S.getConstantTarget()) {
+    EmitBranchThroughCleanup(getJumpDestForLabel(Target));
+    return;
+  }
+
   // Ensure that we have an i8* for our PHI node.
   llvm::Value *V = Builder.CreateBitCast(EmitScalarExpr(S.getTarget()),
                                          llvm::Type::getInt8PtrTy(VMContext),