[PATCH] D58659: [Sema] Fix assertion when `auto` parameter in lambda has an attribute.

[Volodymyr Sapsai via Phabricator via cfe-commits]

vsapsai created this revision.
vsapsai added reviewers: rsmith, arphaman.
Herald added subscribers: jdoerfert, dexonsmith, jkorous.

Fixes the assertion

> no Attr* for AttributedType*
>  UNREACHABLE executed at llvm-project/clang/lib/Sema/SemaType.cpp:298!

In `TypeProcessingState::getAttributedType` we put into `AttrsForTypes`
types with `auto` but later in
`TypeProcessingState::takeAttrForAttributedType` we use transformed
types and that's why cannot find `Attr` corresponding to
`AttributedType`.

Fix by keeping `AttrsForTypes` up to date after replacing `AutoType`.

rdar://problem/47689465


https://reviews.llvm.org/D58659

Files:
  clang/lib/Sema/SemaType.cpp
  clang/test/SemaCXX/auto-cxx0x.cpp


Index: clang/test/SemaCXX/auto-cxx0x.cpp
===================================================================
--- clang/test/SemaCXX/auto-cxx0x.cpp
+++ clang/test/SemaCXX/auto-cxx0x.cpp
@@ -15,3 +15,11 @@
   // expected-error at -2 {{'auto' not allowed in lambda parameter}}
 #endif
 }
+
+void rdar47689465() {
+  int x = 0;
+  [](auto __attribute__((noderef)) *){}(&x);
+#if __cplusplus == 201103L
+  // expected-error at -2 {{'auto' not allowed in lambda parameter}}
+#endif
+}
Index: clang/lib/Sema/SemaType.cpp
===================================================================
--- clang/lib/Sema/SemaType.cpp
+++ clang/lib/Sema/SemaType.cpp
@@ -255,6 +255,23 @@
       return T;
     }
 
+    /// Completely replace the \c auto in \p TypeWithAuto by
+    /// \p Replacement. Also replace \p TypeWithAuto in \c TypeAttrPair if
+    /// necessary.
+    QualType ReplaceAutoType(QualType TypeWithAuto, QualType Replacement) {
+      QualType T = sema.ReplaceAutoType(TypeWithAuto, Replacement);
+      if (auto *AttrTy = TypeWithAuto->getAs<AttributedType>()) {
+        // Attributed type still should be an attributed type after replacement.
+        auto *NewAttrTy = cast<AttributedType>(T.getTypePtr());
+        for (TypeAttrPair &A : AttrsForTypes) {
+          if (A.first == AttrTy)
+            A.first = NewAttrTy;
+        }
+        AttrsForTypesSorted = false;
+      }
+      return T;
+    }
+
     /// Extract and remove the Attr* for a given attributed type.
     const Attr *takeAttrForAttributedType(const AttributedType *AT) {
       if (!AttrsForTypesSorted) {
@@ -2935,7 +2952,7 @@
         // template type parameter.
         // FIXME: Retain some type sugar to indicate that this was written
         // as 'auto'.
-        T = SemaRef.ReplaceAutoType(
+        T = state.ReplaceAutoType(
             T, QualType(CorrespondingTemplateParam->getTypeForDecl(), 0));
       }
       break;


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D58659.188283.patch
Type: text/x-patch
Size: 1910 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20190226/f4a8c140/attachment-0001.bin>