Reapply r152745 (reverted in 152765) now that compiler-rt is fixed.

Original commit message:

Provide -Wnull-conversion separately from -Wconversion.

Like GCC, provide a NULL conversion to non-pointer conversion as a separate
flag, on by default. GCC's flag is "conversion-null" which we provide for
cross compatibility, but in the interests of consistency (with
-Wint-conversion, -Wbool-conversion, etc) the canonical Clang flag is called
-Wnull-conversion.

Patch by Lubos Lunak.
Review feedback by myself, Chandler Carruth, and Chad Rosier.

llvm-svn: 152774

3 files changed, 7 insertions, 3 deletions

diff --git a/clang/test/Analysis/nullptr.cpp b/clang/test/Analysis/nullptr.cpp
index c0fed872428..3119b4fc390 100644
--- a/clang/test/Analysis/nullptr.cpp
+++ b/clang/test/Analysis/nullptr.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -std=c++11 -analyze -analyzer-checker=core -analyzer-store region -verify %s
+// RUN: %clang_cc1 -std=c++11 -Wno-conversion-null -analyze -analyzer-checker=core -analyzer-store region -verify %s
 
 // test to see if nullptr is detected as a null pointer
 void foo1(void) {
diff --git a/clang/test/SemaCXX/__null.cpp b/clang/test/SemaCXX/__null.cpp
index 1989a45fb5f..56e59c06f16 100644
--- a/clang/test/SemaCXX/__null.cpp
+++ b/clang/test/SemaCXX/__null.cpp
@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -fsyntax-only -verify
-// RUN: %clang_cc1 -triple i686-unknown-unknown %s -fsyntax-only -verify
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown %s -Wno-null-conversion -fsyntax-only -verify
+// RUN: %clang_cc1 -triple i686-unknown-unknown %s -Wno-null-conversion -fsyntax-only -verify
 
 void f() {
   int* i = __null;
diff --git a/clang/test/SemaCXX/conversion.cpp b/clang/test/SemaCXX/conversion.cpp
index b069abc263f..d9ba07ab5b5 100644
--- a/clang/test/SemaCXX/conversion.cpp
+++ b/clang/test/SemaCXX/conversion.cpp
@@ -53,10 +53,14 @@ namespace test2 {
   };
 }
 
+// This file tests -Wnull-conversion, a subcategory of -Wconversion
+// which is on by default.
+
 void test3() {
   int a = NULL; // expected-warning {{implicit conversion of NULL constant to integer}}
   int b;
   b = NULL; // expected-warning {{implicit conversion of NULL constant to integer}}
+  long l = NULL; // FIXME: this should also warn, but currently does not if sizeof(NULL)==sizeof(inttype)
   int c = ((((NULL)))); // expected-warning {{implicit conversion of NULL constant to integer}}
   int d;
   d = ((((NULL)))); // expected-warning {{implicit conversion of NULL constant to integer}}