Add noreturn support for blocks.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@77377 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index d3fe31e..7c0f849 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -1124,8 +1124,8 @@
/// CheckFallThroughForFunctionDef - Check that we don't fall off the end of a
/// function that should return a value. Check that we don't fall off the end
-/// of a noreturn function. We assume that functions not marked noreturn will
-/// return.
+/// of a noreturn function. We assume that functions and blocks not marked
+/// noreturn will return.
void Sema::CheckFallThroughForFunctionDef(Decl *D, Stmt *Body) {
// FIXME: Would be nice if we had a better way to control cascading errors,
// but for now, avoid them. The problem is that when Parse sees:
@@ -1175,6 +1175,51 @@
}
}
+/// CheckFallThroughForBlock - Check that we don't fall off the end of a block
+/// that should return a value. Check that we don't fall off the end of a
+/// noreturn block. We assume that functions and blocks not marked noreturn
+/// will return.
+void Sema::CheckFallThroughForBlock(QualType BlockTy, Stmt *Body) {
+ // FIXME: Would be nice if we had a better way to control cascading errors,
+ // but for now, avoid them. The problem is that when Parse sees:
+ // int foo() { return a; }
+ // The return is eaten and the Sema code sees just:
+ // int foo() { }
+ // which this code would then warn about.
+ if (getDiagnostics().hasErrorOccurred())
+ return;
+ bool ReturnsVoid = false;
+ bool HasNoReturn = false;
+ if (const FunctionType *FT = BlockTy->getPointeeType()->getAsFunctionType()) {
+ if (FT->getResultType()->isVoidType())
+ ReturnsVoid = true;
+ if (FT->getNoReturnAttr())
+ HasNoReturn = true;
+ }
+
+ if (ReturnsVoid && !HasNoReturn)
+ return;
+ // FIXME: Funtion try block
+ if (CompoundStmt *Compound = dyn_cast<CompoundStmt>(Body)) {
+ switch (CheckFallThrough(Body)) {
+ case MaybeFallThrough:
+ if (HasNoReturn)
+ Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr);
+ else if (!ReturnsVoid)
+ Diag(Compound->getRBracLoc(), diag::err_maybe_falloff_nonvoid_block);
+ break;
+ case AlwaysFallThrough:
+ if (HasNoReturn)
+ Diag(Compound->getRBracLoc(), diag::err_noreturn_block_has_return_expr);
+ else if (!ReturnsVoid)
+ Diag(Compound->getRBracLoc(), diag::err_falloff_nonvoid_block);
+ break;
+ case NeverFallThrough:
+ break;
+ }
+ }
+}
+
/// CheckParmsForFunctionDef - Check that the parameters of the given
/// function are appropriate for the definition of a function. This
/// takes care of any checks that cannot be performed on the