Implement checking of the tail keyword.

llvm-svn: 104744

2 files changed, 21 insertions, 1 deletions

diff --git a/llvm/lib/Analysis/Lint.cpp b/llvm/lib/Analysis/Lint.cpp
index 25d4f9571da..8b3873362c8 100644
--- a/llvm/lib/Analysis/Lint.cpp
+++ b/llvm/lib/Analysis/Lint.cpp
@@ -219,7 +219,15 @@ void Lint::visitCallSite(CallSite CS) {
     // TODO: Check sret attribute.
   }
 
-  // TODO: Check the "tail" keyword constraints.
+  if (CS.isCall() && cast<CallInst>(CS.getInstruction())->isTailCall())
+    for (CallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end();
+         AI != AE; ++AI) {
+      Value *Obj = (*AI)->getUnderlyingObject();
+      Assert1(!isa<AllocaInst>(Obj) && !isa<VAArgInst>(Obj),
+              "Undefined behavior: Call with \"tail\" keyword references "
+              "alloca or va_arg", &I);
+    }
+
 
   if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I))
     switch (II->getIntrinsicID()) {
diff --git a/llvm/test/Other/lint.ll b/llvm/test/Other/lint.ll
index d0db5e46c66..eb0b7629e43 100644
--- a/llvm/test/Other/lint.ll
+++ b/llvm/test/Other/lint.ll
@@ -77,8 +77,20 @@ define void @not_vararg(i8* %p) nounwind {
   ret void
 }
 
+; CHECK: Undefined behavior: Branch to non-blockaddress
 define void @use_indbr() {
   indirectbr i8* bitcast (i32()* @foo to i8*), [label %block]
 block:
   unreachable
 }
+
+; CHECK: Undefined behavior: Call with "tail" keyword references alloca or va_arg
+; CHECK: Undefined behavior: Call with "tail" keyword references alloca or va_arg
+declare void @tailcallee(i8*)
+define void @use_tail(i8* %valist) {
+  %t = alloca i8
+  tail call void @tailcallee(i8* %t)
+  %s = va_arg i8* %valist, i8*
+  tail call void @tailcallee(i8* %s)
+  ret void
+}