[CodeGen][ObjC] Fix infinite recursion in getObjCEncodingForTypeImpl.

Check that ExpandStructures is true before visiting the list of ivars.

rdar://problem/27135221

Differential revision: https://reviews.llvm.org/D22929

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@278956 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 49948a5d4186783922f6c645e02268da9733ddb1..425aeac3c046c68bdf04924cdb2533a03df74e49 100644 (file)
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -5906,18 +5906,20 @@ void ASTContext::getObjCEncodingForTypeImpl(QualType T, std::string& S,
     ObjCInterfaceDecl *OI = T->castAs<ObjCObjectType>()->getInterface();
     S += '{';
     S += OI->getObjCRuntimeNameAsString();
-    S += '=';
-    SmallVector<const ObjCIvarDecl*, 32> Ivars;
-    DeepCollectObjCIvars(OI, true, Ivars);
-    for (unsigned i = 0, e = Ivars.size(); i != e; ++i) {
-      const FieldDecl *Field = cast<FieldDecl>(Ivars[i]);
-      if (Field->isBitField())
-        getObjCEncodingForTypeImpl(Field->getType(), S, false, true, Field);
-      else
-        getObjCEncodingForTypeImpl(Field->getType(), S, false, true, FD,
-                                   false, false, false, false, false,
-                                   EncodePointerToObjCTypedef,
-                                   NotEncodedT);
+    if (ExpandStructures) {
+      S += '=';
+      SmallVector<const ObjCIvarDecl*, 32> Ivars;
+      DeepCollectObjCIvars(OI, true, Ivars);
+      for (unsigned i = 0, e = Ivars.size(); i != e; ++i) {
+        const FieldDecl *Field = cast<FieldDecl>(Ivars[i]);
+        if (Field->isBitField())
+          getObjCEncodingForTypeImpl(Field->getType(), S, false, true, Field);
+        else
+          getObjCEncodingForTypeImpl(Field->getType(), S, false, true, FD,
+                                     false, false, false, false, false,
+                                     EncodePointerToObjCTypedef,
+                                     NotEncodedT);
+      }
     }
     S += '}';
     return;

diff --git a/test/CodeGenObjCXX/encode.mm b/test/CodeGenObjCXX/encode.mm
index e0171efbed8a206461b56148ba7754050de035a1..6b7fc70e25429059ccf5ead944706f75db39d655 100644 (file)
--- a/test/CodeGenObjCXX/encode.mm
+++ b/test/CodeGenObjCXX/encode.mm
@@ -224,3 +224,24 @@ namespace PR17142 {
   // CHECK: @_ZN7PR171421xE = constant [14 x i8] c"{E=^^?i^^?ii}\00"
   extern const char x[] = @encode(E);
 }
+
+// This test used to cause infinite recursion.
+template<typename T>
+struct S {
+  typedef T Ty;
+  Ty *t;
+};
+
+@interface N
+{
+  S<N> a;
+}
+@end
+
+@implementation N
+@end
+
+const char *expand_struct() {
+  // CHECK: @{{.*}} = private unnamed_addr constant [16 x i8] c"{N={S<N>=^{N}}}\00"
+  return @encode(N);
+}