[clang] Ensure that statements, expressions and types are trivially destructible

Since statements, expressions and types are allocated with the BumpPtrAllocator
from ASTContext their destructor is not executed. Two classes are currently
exempted from the check : InitListExpr due to its ASTVector and
ConstantArrayType due to its APInt.

No functional changes.

Differential Revision: https://reviews.llvm.org/D66646

Reviewed By: lebedev.ri, gribozavr

llvm-svn: 370044

clang/lib/AST/Stmt.cpp

@@ -41,6 +41,7 @@
 #include <cstring>
 #include <string>
 #include <utility>
+#include <type_traits>
 
 using namespace clang;
 
@@ -83,6 +84,16 @@ const char *Stmt::getStmtClassName() const {
                 #CLASS " should not be polymorphic!");
 #include "clang/AST/StmtNodes.inc"
 
+// Check that no statement / expression class has a non-trival destructor.
+// Statements and expressions are allocated with the BumpPtrAllocator from
+// ASTContext and therefore their destructor is not executed.
+#define STMT(CLASS, PARENT)                                                    \
+  static_assert(std::is_trivially_destructible<CLASS>::value,                  \
+                #CLASS " should be trivially destructible!");
+// FIXME: InitListExpr is not trivially destructible due to its ASTVector.
+#define INITLISTEXPR(CLASS, PARENT)
+#include "clang/AST/StmtNodes.inc"
+
 void Stmt::PrintStats() {
   // Ensure the table is primed.
   getStmtInfoTableEntry(Stmt::NullStmtClass);

clang/lib/AST/Type.cpp

@@ -50,6 +50,7 @@
 #include <cassert>
 #include <cstdint>
 #include <cstring>
+#include <type_traits>
 
 using namespace clang;
 
@@ -299,6 +300,18 @@ QualType QualType::getSingleStepDesugaredTypeImpl(QualType type,
                 #CLASS "Type should not be polymorphic!");
 #include "clang/AST/TypeNodes.def"
 
+// Check that no type class has a non-trival destructor. Types are
+// allocated with the BumpPtrAllocator from ASTContext and therefore
+// their destructor is not executed.
+//
+// FIXME: ConstantArrayType is not trivially destructible because of its
+// APInt member. It should be replaced in favor of ASTContext allocation.
+#define TYPE(CLASS, BASE)                                                      \
+  static_assert(std::is_trivially_destructible<CLASS##Type>::value ||          \
+                    std::is_same<CLASS##Type, ConstantArrayType>::value,       \
+                #CLASS "Type should be trivially destructible!");
+#include "clang/AST/TypeNodes.def"
+
 QualType Type::getLocallyUnqualifiedSingleStepDesugaredType() const {
   switch (getTypeClass()) {
 #define ABSTRACT_TYPE(Class, Parent)