From b34d0ef2caa6beb1a1005e55f8855c8d8080f4c4 Mon Sep 17 00:00:00 2001
From: Tim Shen <timshen91@gmail.com>
Date: Tue, 14 Feb 2017 23:46:37 +0000
Subject: [PATCH] [VLA] Handle VLA size expression in a full-expression
 context.

Summary: Previously the cleanups (e.g. dtor calls) are inserted into the
outer scope (e.g. function body scope), instead of it's own scope. After
the fix, the cleanups are inserted right after getting the size value.

This fixes pr30306.

Reviewers: rsmith

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D24333

llvm-svn: 295123
---
 clang/lib/Sema/SemaTemplateInstantiateDecl.cpp |  2 ++
 clang/lib/Sema/TreeTransform.h                 | 11 +++++++++--
 clang/test/Sema/pr30306.cpp                    | 15 +++++++++++++++
 3 files changed, 26 insertions(+), 2 deletions(-)
 create mode 100644 clang/test/Sema/pr30306.cpp

diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index a0e4d2999d9f..f7db189de849 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -3864,6 +3864,8 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
     if (Body.isInvalid())
       Function->setInvalidDecl();
 
+    // FIXME: finishing the function body while in an expression evaluation
+    // context seems wrong. Investigate more.
     ActOnFinishFunctionBody(Function, Body.get(),
                             /*IsInstantiation=*/true);
 
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index ef349c395f8a..8a63d3547464 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -4603,8 +4603,15 @@ TreeTransform<Derived>::TransformVariableArrayType(TypeLocBuilder &TLB,
   if (ElementType.isNull())
     return QualType();
 
-  ExprResult SizeResult
-    = getDerived().TransformExpr(T->getSizeExpr());
+  ExprResult SizeResult;
+  {
+    EnterExpressionEvaluationContext Context(SemaRef,
+                                             Sema::PotentiallyEvaluated);
+    SizeResult = getDerived().TransformExpr(T->getSizeExpr());
+  }
+  if (SizeResult.isInvalid())
+    return QualType();
+  SizeResult = SemaRef.ActOnFinishFullExpr(SizeResult.get());
   if (SizeResult.isInvalid())
     return QualType();
 
diff --git a/clang/test/Sema/pr30306.cpp b/clang/test/Sema/pr30306.cpp
new file mode 100644
index 000000000000..7442377dc51a
--- /dev/null
+++ b/clang/test/Sema/pr30306.cpp
@@ -0,0 +1,15 @@
+// RUN: %clang_cc1 -x c++ -emit-llvm < %s | FileCheck %s
+
+struct A { A(int); ~A(); };
+int f(const A &);
+// CHECK: call void @_ZN1AC1Ei
+// CHECK-NEXT: call i32 @_Z1fRK1A
+// CHECK-NEXT: call void @_ZN1AD1Ev
+// CHECK: call void @_ZN1AC1Ei
+// CHECK-NEXT: call i32 @_Z1fRK1A
+// CHECK-NEXT: call void @_ZN1AD1Ev
+template<typename T> void g() {
+  int a[f(3)];
+  int b[f(3)];
+}
+int main() { g<int>(); }