From: Erich Keane <erich.keane@intel.com>
Date: Fri, 14 Dec 2018 22:41:18 +0000 (+0000)
Subject: Revert "Add extension to always default-initialize nullptr_t."
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=1e78a7db56c2946ae84d57cdf43051ce96cc06aa;p=clang

Revert "Add extension to always default-initialize nullptr_t."

This reverts commit 46efdf2ccc2a80aefebf8433dbf9c7c959f6e629.

Richard Smith commented just after I submitted this that this is the
wrong solution.  Reverting so that I can fix differently.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@349206 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 57277f6e82..c2f14229d8 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -4881,13 +4881,6 @@ static void TryDefaultInitialization(Sema &S,
     return;
   }
 
-  // As an extension, and to fix Core issue 1013, zero initialize nullptr_t.
-  // Since there is only 1 valid value of nullptr_t, we can just use that.
-  if (DestType->isNullPtrType()) {
-    Sequence.AddZeroInitializationStep(Entity.getType());
-    return;
-  }
-
   //     - otherwise, no initialization is performed.
 
   //   If a program calls for the default initialization of an object of
diff --git a/test/Analysis/nullptr.cpp b/test/Analysis/nullptr.cpp
index 1d913c11d3..38e099b7fb 100644
--- a/test/Analysis/nullptr.cpp
+++ b/test/Analysis/nullptr.cpp
@@ -125,16 +125,21 @@ struct Type {
 };
 
 void shouldNotCrash() {
-  decltype(nullptr) p; // expected-note{{'p' initialized to a null pointer value}}
+  decltype(nullptr) p; // expected-note{{'p' declared without an initial value}}
   if (getSymbol()) // expected-note   {{Assuming the condition is false}}
                    // expected-note@-1{{Taking false branch}}
-                   // expected-note@-2{{Assuming the condition is true}}
-                   // expected-note@-3{{Taking true branch}}
-    invokeF(p); // expected-note{{Passing null pointer value via 1st parameter 'x'}}
-                // expected-note@-1{{Calling 'invokeF'}}
+                   // expected-note@-2{{Assuming the condition is false}}
+                   // expected-note@-3{{Taking false branch}}
+                   // expected-note@-4{{Assuming the condition is true}}
+                   // expected-note@-5{{Taking true branch}}
+    invokeF(p); // expected-warning{{1st function call argument is an uninitialized value}}
+                // expected-note@-1{{1st function call argument is an uninitialized value}}
   if (getSymbol()) // expected-note   {{Assuming the condition is false}}
                    // expected-note@-1{{Taking false branch}}
-    invokeF(nullptr);
+                   // expected-note@-2{{Assuming the condition is true}}
+                   // expected-note@-3{{Taking true branch}}
+    invokeF(nullptr); // expected-note   {{Calling 'invokeF'}}
+                      // expected-note@-1{{Passing null pointer value via 1st parameter 'x'}}
   if (getSymbol()) {  // expected-note  {{Assuming the condition is true}}
                       // expected-note@-1{{Taking true branch}}
     X *xx = Type().x; // expected-note   {{Null pointer value stored to field 'x'}}
diff --git a/test/SemaCXX/ast-print-crash.cpp b/test/SemaCXX/ast-print-crash.cpp
index 33edc34823..c108f666d7 100644
--- a/test/SemaCXX/ast-print-crash.cpp
+++ b/test/SemaCXX/ast-print-crash.cpp
@@ -7,6 +7,6 @@
 
 // CHECK:      struct {
 // CHECK-NEXT: } dont_crash_on_syntax_error;
-// CHECK-NEXT: decltype(nullptr) p(/*implicit*/(decltype(nullptr))0);
+// CHECK-NEXT: decltype(nullptr) p;
 struct {
 } dont_crash_on_syntax_error /* missing ; */ decltype(nullptr) p;
diff --git a/test/SemaCXX/nullptr_t-init.cpp b/test/SemaCXX/nullptr_t-init.cpp
deleted file mode 100644
index f7843de1bc..0000000000
--- a/test/SemaCXX/nullptr_t-init.cpp
+++ /dev/null
@@ -1,10 +0,0 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -ffreestanding -Wuninitialized %s
-// expected-no-diagnostics
-typedef decltype(nullptr) nullptr_t;
-
-// Ensure no 'uninitialized when used here' warnings (Wuninitialized), for 
-// nullptr_t always-initialized extension.
-nullptr_t default_init() {
-  nullptr_t a;
-  return a;
-}