PR37450: Fix bug that disabled some type checks for variables with deduced types.

Also improve diagnostic for the case where a type is non-literal because it's a lambda.

llvm-svn: 332286

2 files changed, 21 insertions, 7 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 377bb106325..9a1ab4a3c58 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -7293,8 +7293,7 @@ void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
   if (NewVD->isInvalidDecl())
     return;
 
-  TypeSourceInfo *TInfo = NewVD->getTypeSourceInfo();
-  QualType T = TInfo->getType();
+  QualType T = NewVD->getType();
 
   // Defer checking an 'auto' type until its initializer is attached.
   if (T->isUndeducedType())
@@ -7438,10 +7437,18 @@ void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
       (T->isVariableArrayType() && NewVD->hasGlobalStorage())) {
     bool SizeIsNegative;
     llvm::APSInt Oversized;
-    TypeSourceInfo *FixedTInfo =
-      TryToFixInvalidVariablyModifiedTypeSourceInfo(TInfo, Context,
-                                                    SizeIsNegative, Oversized);
-    if (!FixedTInfo && T->isVariableArrayType()) {
+    TypeSourceInfo *FixedTInfo = TryToFixInvalidVariablyModifiedTypeSourceInfo(
+        NewVD->getTypeSourceInfo(), Context, SizeIsNegative, Oversized);
+    QualType FixedT;
+    if (FixedTInfo &&  T == NewVD->getTypeSourceInfo()->getType())
+      FixedT = FixedTInfo->getType();
+    else if (FixedTInfo) {
+      // Type and type-as-written are canonically different. We need to fix up
+      // both types separately.
+      FixedT = TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative,
+                                                   Oversized);
+    }
+    if ((!FixedTInfo || FixedT.isNull()) && T->isVariableArrayType()) {
       const VariableArrayType *VAT = Context.getAsVariableArrayType(T);
       // FIXME: This won't give the correct result for
       // int a[10][n];
@@ -7470,7 +7477,7 @@ void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
     }
 
     Diag(NewVD->getLocation(), diag::warn_illegal_constant_array_size);
-    NewVD->setType(FixedTInfo->getType());
+    NewVD->setType(FixedT);
     NewVD->setTypeSourceInfo(FixedTInfo);
   }
 
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 439031065f8..b13570f97bf 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -7809,6 +7809,13 @@ bool Sema::RequireLiteralType(SourceLocation Loc, QualType T,
   if (RequireCompleteType(Loc, ElemType, diag::note_non_literal_incomplete, T))
     return true;
 
+  // [expr.prim.lambda]p3:
+  //   This class type is [not] a literal type.
+  if (RD->isLambda() && !getLangOpts().CPlusPlus17) {
+    Diag(RD->getLocation(), diag::note_non_literal_lambda);
+    return true;
+  }
+
   // If the class has virtual base classes, then it's not an aggregate, and
   // cannot have any constexpr constructors or a trivial default constructor,
   // so is non-literal. This is better to diagnose than the resulting absence