When a declaration of a function is missing an exception specification

that was present in a prior declaration, emit a warning rather than a
hard error (which we did before, and still do with mismatched
exception specifications). Moreover, provide a fix-it hint with the
throw() clause that should be added, e.g.,

t.C:10:7: warning: 'operator new' is missing exception specification
      'throw(std::bad_alloc)'
void *operator new(unsigned long sz)
      ^
                                     throw(std::bad_alloc)

As part of this, disable the warning when we're missing an exception
specification on operator new, operator new[], operator delete, or
operator delete[] when exceptions are turned off (-fno-exceptions).

Fixes PR5957.

llvm-svn: 99388

4 files changed, 25 insertions, 6 deletions

diff --git a/clang/test/CXX/basic/basic.stc/basic.stc.dynamic/p2-noexceptions.cpp b/clang/test/CXX/basic/basic.stc/basic.stc.dynamic/p2-noexceptions.cpp
new file mode 100644
index 00000000000..4567c469e81
--- /dev/null
+++ b/clang/test/CXX/basic/basic.stc/basic.stc.dynamic/p2-noexceptions.cpp
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+namespace std {
+  class bad_alloc { };
+  
+  typedef __SIZE_TYPE__ size_t;
+}
+
+class foo { virtual ~foo(); };
+
+void* operator new(std::size_t); 
+void* operator new[](std::size_t);
+void operator delete(void*);
+void operator delete[](void*);
diff --git a/clang/test/CXX/basic/basic.stc/basic.stc.dynamic/p2.cpp b/clang/test/CXX/basic/basic.stc/basic.stc.dynamic/p2.cpp
index f4860bb9bab..37a4f976bad 100644
--- a/clang/test/CXX/basic/basic.stc/basic.stc.dynamic/p2.cpp
+++ b/clang/test/CXX/basic/basic.stc/basic.stc.dynamic/p2.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fsyntax-only -fexceptions -verify %s
 int *use_new(int N) {
   if (N == 1)
     return new int;
@@ -19,7 +19,10 @@ namespace std {
   typedef __SIZE_TYPE__ size_t;
 }
 
-void* operator new(std::size_t) throw(std::bad_alloc); 
+void* operator new(std::size_t) throw(std::bad_alloc); // expected-note{{previous declaration}}
 void* operator new[](std::size_t) throw(std::bad_alloc); 
-void operator delete(void*) throw(); 
+void operator delete(void*) throw(); // expected-note{{previous declaration}}
 void operator delete[](void*) throw();
+
+void* operator new(std::size_t); // expected-warning{{'operator new' is missing exception specification 'throw(std::bad_alloc)'}}
+void operator delete(void*); // expected-warning{{'operator delete' is missing exception specification 'throw()'}}
diff --git a/clang/test/FixIt/fixit.cpp b/clang/test/FixIt/fixit.cpp
index ee93755775e..79c294b1d92 100644
--- a/clang/test/FixIt/fixit.cpp
+++ b/clang/test/FixIt/fixit.cpp
@@ -37,3 +37,6 @@ protected:
 class B : public A {
   A::foo; // expected-warning{{access declarations are deprecated}}
 };
+
+void f() throw();
+void f(); // expected-warning{{missing exception specification}}
diff --git a/clang/test/SemaCXX/exception-spec.cpp b/clang/test/SemaCXX/exception-spec.cpp
index 782cf838569..498611ee859 100644
--- a/clang/test/SemaCXX/exception-spec.cpp
+++ b/clang/test/SemaCXX/exception-spec.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -fms-extensions %s
+// RUN: %clang_cc1 -fsyntax-only -verify -fexceptions -fms-extensions %s
 
 // Straight from the standard:
 // Plain function with spec
@@ -50,7 +50,7 @@ void r4() throw(int, float);
 void r4() throw(float, int);
 
 void r5() throw(int); // expected-note {{previous declaration}}
-void r5(); // expected-error {{exception specification in declaration does not match}}
+void r5(); // expected-warning {{missing exception specification}}
 
 void r6() throw(...); // expected-note {{previous declaration}}
 void r6() throw(int); // expected-error {{exception specification in declaration does not match}}
@@ -170,7 +170,7 @@ void fnptrs()
 // Member function stuff
 
 struct Str1 { void f() throw(int); }; // expected-note {{previous declaration}}
-void Str1::f() // expected-error {{does not match previous declaration}}
+void Str1::f() // expected-warning {{missing exception specification}}
 {
 }