r349206 - Revert "Add extension to always default-initialize nullptr_t."

[Erich Keane via cfe-commits]

Author: erichkeane
Date: Fri Dec 14 14:41:18 2018
New Revision: 349206

URL: http://llvm.org/viewvc/llvm-project?rev=349206&view=rev
Log:
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.

Removed:
    cfe/trunk/test/SemaCXX/nullptr_t-init.cpp
Modified:
    cfe/trunk/lib/Sema/SemaInit.cpp
    cfe/trunk/test/Analysis/nullptr.cpp
    cfe/trunk/test/SemaCXX/ast-print-crash.cpp

Modified: cfe/trunk/lib/Sema/SemaInit.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaInit.cpp?rev=349206&r1=349205&r2=349206&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaInit.cpp (original)
+++ cfe/trunk/lib/Sema/SemaInit.cpp Fri Dec 14 14:41:18 2018
@@ -4881,13 +4881,6 @@ static void TryDefaultInitialization(Sem
     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

Modified: cfe/trunk/test/Analysis/nullptr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/nullptr.cpp?rev=349206&r1=349205&r2=349206&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/nullptr.cpp (original)
+++ cfe/trunk/test/Analysis/nullptr.cpp Fri Dec 14 14:41:18 2018
@@ -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 at -1{{Taking false branch}}
-                   // expected-note at -2{{Assuming the condition is true}}
-                   // expected-note at -3{{Taking true branch}}
-    invokeF(p); // expected-note{{Passing null pointer value via 1st parameter 'x'}}
-                // expected-note at -1{{Calling 'invokeF'}}
+                   // expected-note at -2{{Assuming the condition is false}}
+                   // expected-note at -3{{Taking false branch}}
+                   // expected-note at -4{{Assuming the condition is true}}
+                   // expected-note at -5{{Taking true branch}}
+    invokeF(p); // expected-warning{{1st function call argument is an uninitialized value}}
+                // expected-note at -1{{1st function call argument is an uninitialized value}}
   if (getSymbol()) // expected-note   {{Assuming the condition is false}}
                    // expected-note at -1{{Taking false branch}}
-    invokeF(nullptr);
+                   // expected-note at -2{{Assuming the condition is true}}
+                   // expected-note at -3{{Taking true branch}}
+    invokeF(nullptr); // expected-note   {{Calling 'invokeF'}}
+                      // expected-note at -1{{Passing null pointer value via 1st parameter 'x'}}
   if (getSymbol()) {  // expected-note  {{Assuming the condition is true}}
                       // expected-note at -1{{Taking true branch}}
     X *xx = Type().x; // expected-note   {{Null pointer value stored to field 'x'}}

Modified: cfe/trunk/test/SemaCXX/ast-print-crash.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/ast-print-crash.cpp?rev=349206&r1=349205&r2=349206&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/ast-print-crash.cpp (original)
+++ cfe/trunk/test/SemaCXX/ast-print-crash.cpp Fri Dec 14 14:41:18 2018
@@ -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;

Removed: cfe/trunk/test/SemaCXX/nullptr_t-init.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/nullptr_t-init.cpp?rev=349205&view=auto
==============================================================================
--- cfe/trunk/test/SemaCXX/nullptr_t-init.cpp (original)
+++ cfe/trunk/test/SemaCXX/nullptr_t-init.cpp (removed)
@@ -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;
-}