commit 2b4fa5348ee157b6b1a1af44d0137ca8c7a71573
author Richard Smith <richard-llvm@metafoo.co.uk> Sun Sep 29 05:08:46 2019 +0000
committer Richard Smith <richard-llvm@metafoo.co.uk> Sun Sep 29 05:08:46 2019 +0000
tree b3ac8e6a34f562040ad1ac1e7876eceac4f40a52
parent ac5969933ab7e43d26209ae6c15669842bc86104

For P0784R7: compute whether a variable has constant destruction if it
has a constexpr destructor.

For constexpr variables, reject if the variable does not have constant
destruction. In all cases, do not emit runtime calls to the destructor
for variables with constant destruction.

llvm-svn: 373159

clang/lib/CodeGen/CGDecl.cpp

diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index a9e0161..5c0d52a 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -305,14 +305,6 @@
   return Addr;
 }
 
-/// hasNontrivialDestruction - Determine whether a type's destruction is
-/// non-trivial. If so, and the variable uses static initialization, we must
-/// register its destructor to run on exit.
-static bool hasNontrivialDestruction(QualType T) {
-  CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
-  return RD && !RD->hasTrivialDestructor();
-}
-
 /// AddInitializerToStaticVarDecl - Add the initializer for 'D' to the
 /// global variable that has already been created for it.  If the initializer
 /// has a different type than GV does, this may free GV and return a different
@@ -372,7 +364,7 @@
 
   emitter.finalize(GV);
 
-  if (hasNontrivialDestruction(D.getType()) && HaveInsertPoint()) {
+  if (D.needsDestruction(getContext()) && HaveInsertPoint()) {
     // We have a constant initializer, but a nontrivial destructor. We still
     // need to perform a guarded "initialization" in order to register the
     // destructor.
@@ -1994,7 +1986,7 @@
   const VarDecl &D = *emission.Variable;
 
   // Check the type for a cleanup.
-  if (QualType::DestructionKind dtorKind = D.getType().isDestructedType())
+  if (QualType::DestructionKind dtorKind = D.needsDestruction(getContext()))
     emitAutoVarTypeCleanup(emission, dtorKind);
 
   // In GC mode, honor objc_precise_lifetime.
@@ -2404,7 +2396,8 @@
     // cleanup.
     if (hasAggregateEvaluationKind(Ty) && !CurFuncIsThunk &&
         Ty->getAs<RecordType>()->getDecl()->isParamDestroyedInCallee()) {
-      if (QualType::DestructionKind DtorKind = Ty.isDestructedType()) {
+      if (QualType::DestructionKind DtorKind =
+              D.needsDestruction(getContext())) {
         assert((DtorKind == QualType::DK_cxx_destructor ||
                 DtorKind == QualType::DK_nontrivial_c_struct) &&
                "unexpected destructor type");