Only have one path in the CFG for ternaries if the condition is known.

The return type analysis requires that the CFG is simplified when the
truth values of branches are statically known at analysis time.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@215114 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp
index 20438b478779fc364598786d70341a444c8964e5..b9698d550bfba92d9a0c8d5925408054d501d569 100644 (file)
--- a/lib/Analysis/CFG.cpp
+++ b/lib/Analysis/CFG.cpp
@@ -3711,15 +3711,24 @@ CFGBlock *CFGBuilder::VisitConditionalOperatorForTemporaryDtors(
   VisitForTemporaryDtors(E->getCond(), false, Context);
   CFGBlock *ConditionBlock = Block;
   CFGBlock *ConditionSucc = Succ;
+  TryResult ConditionVal = tryEvaluateBool(E->getCond());
 
   TempDtorContext TrueContext(/*IsConditional=*/true);
-  VisitForTemporaryDtors(E->getTrueExpr(), BindToTemporary, TrueContext);
+  if (!ConditionVal.isFalse()) {
+    VisitForTemporaryDtors(E->getTrueExpr(), BindToTemporary, TrueContext);
+    if (ConditionVal.isTrue())
+      return Block;
+  }
   CFGBlock *TrueBlock = Block;
 
   Block = ConditionBlock;
   Succ = ConditionSucc;
   TempDtorContext FalseContext(/*IsConditional=*/true);
-  VisitForTemporaryDtors(E->getFalseExpr(), BindToTemporary, FalseContext);
+  if (!ConditionVal.isTrue()) {
+    VisitForTemporaryDtors(E->getFalseExpr(), BindToTemporary, FalseContext);
+    if (ConditionVal.isFalse())
+      return Block;
+  }
 
   if (TrueContext.TerminatorExpr && FalseContext.TerminatorExpr) {
     InsertTempDtorDecisionBlock(FalseContext, TrueBlock);

diff --git a/test/SemaCXX/return-noreturn.cpp b/test/SemaCXX/return-noreturn.cpp
index bafeafcf1cf0c3ac7b3f8d3f66387035b9bdcae0..8490be9be3829395b4b5ae06e3dae1dbbcb6aea6 100644 (file)
--- a/test/SemaCXX/return-noreturn.cpp
+++ b/test/SemaCXX/return-noreturn.cpp
@@ -159,6 +159,22 @@ int testTernaryUnconditionalNoreturn() {
   true ? NoReturn() : NoReturn();
 }
 
+int testTernaryStaticallyConditionalNoretrunOnTrue() {
+  true ? NoReturn() : Return();
+}
+
+int testTernaryStaticallyConditionalRetrunOnTrue() {
+  true ? Return() : NoReturn();
+} // expected-warning {{control reaches end of non-void function}}
+
+int testTernaryStaticallyConditionalNoretrunOnFalse() {
+  false ? Return() : NoReturn();
+}
+
+int testTernaryStaticallyConditionalRetrunOnFalse() {
+  false ? NoReturn() : Return();
+} // expected-warning {{control reaches end of non-void function}}
+
 int testTernaryConditionalNoreturnTrueBranch(bool value) {
   value ? (NoReturn() || NoReturn()) : Return();
 } // expected-warning {{control may reach end of non-void function}}