PR c++/91979 - mangling nullptr expression

2019-11-04  Kamlesh Kumar  <kamleshbhalui@gmail.com>

gcc/cp
        * cp/mangle.c (write_template_arg_literal): Handle nullptr
        mangling.
gcc
	* common.opt (-fabi-version): Document =14.
	* doc/invoke.texi (C++ Dialect Options): Likewise.
gcc/c-family
        * c-opts.c (c_common_post_options): Update
        latest_abi_version.
libiberty
        * cp-demangle.c (d_expr_primary): Handle
        nullptr demangling.
        * testsuite/demangle-expected: Added test.

From-SVN: r277801

gcc/ChangeLog

@@ -1,3 +1,8 @@
+2019-11-04  Kamlesh Kumar  <kamleshbhalui@gmail.com>
+
+	* common.opt (-fabi-version): Document =14.
+	* doc/invoke.texi (C++ Dialect Options): Likewise.
+
 2019-11-04  Aldy Hernandez  <aldyh@redhat.com>
 
 	* tree-vrp.c (value_range_base::set): Do not special case pointers.

gcc/c-family/ChangeLog

@@ -1,3 +1,8 @@
+2019-11-04  Kamlesh Kumar  <kamleshbhalui@gmail.com>
+
+	* c-opts.c (c_common_post_options): Update
+	latest_abi_version.
+
 2019-11-02  Jakub Jelinek  <jakub@redhat.com>
 
 	* c-common.h (c_omp_get_context_selector): Remove.

gcc/c-family/c-opts.c

@@ -937,7 +937,7 @@ c_common_post_options (const char **pfilename)
 
   /* Change flag_abi_version to be the actual current ABI level, for the
      benefit of c_cpp_builtins, and to make comparison simpler.  */
-  const int latest_abi_version = 13;
+  const int latest_abi_version = 14;
   /* Generate compatibility aliases for ABI v11 (7.1) by default.  */
   const int abi_compat_default = 11;
 

gcc/common.opt

@@ -951,6 +951,8 @@ Driver Undocumented
 ; 13: Fixes the accidental change in 12 to the calling convention for classes
 ;     with deleted copy constructor and trivial move constructor.
 ;     Default in G++ 8.2.
+; 14: Corrects the mangling of nullptr expression.
+;     Default in G++ 10.
 ;
 ; Additional positive integers will be assigned as new versions of
 ; the ABI become the default version of the ABI.

gcc/cp/ChangeLog

@@ -1,3 +1,9 @@
+2019-11-04  Kamlesh Kumar  <kamleshbhalui@gmail.com>
+
+	PR c++/91979 - mangling nullptr expression
+	* cp/mangle.c (write_template_arg_literal): Handle nullptr
+	mangling.
+
 2019-11-04  Jason Merrill  <jason@redhat.com>
 
 	* typeck.c (check_return_expr): Avoid redundant error.

gcc/cp/mangle.c

@@ -3400,7 +3400,9 @@ write_template_arg_literal (const tree value)
       case INTEGER_CST:
 	gcc_assert (!same_type_p (TREE_TYPE (value), boolean_type_node)
 		    || integer_zerop (value) || integer_onep (value));
-	write_integer_cst (value);
+	if (!(abi_version_at_least (14)
+	      && NULLPTR_TYPE_P (TREE_TYPE (value))))
+	  write_integer_cst (value);
 	break;
 
       case REAL_CST:

gcc/doc/invoke.texi

@@ -2413,6 +2413,9 @@ trivial move constructor.
 Version 13, which first appeared in G++ 8.2, fixes the accidental
 change in version 12.
 
+Version 14, which first appeared in G++ 10, corrects the mangling of
+the nullptr expression.
+
 See also @option{-Wabi}.
 
 @item -fabi-compat-version=@var{n}

gcc/testsuite/g++.dg/abi/macro0.C

@@ -1,6 +1,6 @@
 // This testcase will need to be kept in sync with c_common_post_options.
 // { dg-options "-fabi-version=0" }
 
-#if __GXX_ABI_VERSION != 1013
+#if __GXX_ABI_VERSION != 1014
 #error "Incorrect value of __GXX_ABI_VERSION"
 #endif

gcc/testsuite/g++.dg/cpp0x/nullptr27.C

@@ -1,7 +1,7 @@
 // PR c++/52706
 // { dg-do compile { target c++11 } }
 // { dg-options "-fabi-version=0" }
-// { dg-final { scan-assembler "_Z1fIDnLDn0EEiT_" } }
+// { dg-final { scan-assembler "_Z1fIDnLDnEEiT_" } }
 
 template<class T, decltype(nullptr) = nullptr>
 int f(T);

gcc/testsuite/g++.dg/cpp0x/nullptr43.C

@@ -0,0 +1,9 @@
+// PR c++/91979
+// { dg-do compile { target c++11 } }
+// { dg-options "-fabi-version=13" }
+// { dg-final { scan-assembler "_Z1fIDnLDn0EEiT_" } }
+
+template<class T, decltype(nullptr) = nullptr>
+int f(T);
+
+int i2 = f(nullptr);

gcc/testsuite/g++.dg/cpp0x/nullptr44.C

@@ -0,0 +1,15 @@
+// PR c++/91979
+// { dg-do compile { target c++11 } }
+// { dg-final { scan-assembler "_Z3fooILPv0EEvPN9enable_ifIXeqT_LDnEEvE4typeE" } }
+
+template <bool, typename T = void>
+struct enable_if {};
+
+template <typename T>
+struct enable_if<true, T> { typedef T type; };
+
+template <void *P>
+void foo(typename enable_if<P == nullptr>::type* = 0) {}
+
+template void foo<(void *)0>(void *);
+

libiberty/ChangeLog

@@ -1,3 +1,9 @@
+2019-11-04  Kamlesh Kumar  <kamleshbhalui@gmail.com>
+
+	* cp-demangle.c (d_expr_primary): Handle
+	nullptr demangling.
+	* testsuite/demangle-expected: Added test.
+
 2019-10-29 Paul Pluzhnikov  <ppluzhnikov@google.com>
 
 	* cp-demangle.c (d_number): Avoid signed int overflow.

libiberty/cp-demangle.c

@@ -3577,6 +3577,17 @@ d_expr_primary (struct d_info *di)
 	  && type->u.s_builtin.type->print != D_PRINT_DEFAULT)
 	di->expansion -= type->u.s_builtin.type->len;
 
+      if (type->type == DEMANGLE_COMPONENT_BUILTIN_TYPE
+	  && strcmp (type->u.s_builtin.type->name,
+		     cplus_demangle_builtin_types[33].name) == 0)
+	{
+	  if (d_peek_char (di) == 'E')
+	    {
+	      d_advance (di, 1);
+	      return type;
+	    }
+	}
+
       /* Rather than try to interpret the literal value, we just
 	 collect it as a string.  Note that it's possible to have a
 	 floating point literal here.  The ABI specifies that the

libiberty/testsuite/demangle-expected

@@ -1446,3 +1446,7 @@ Foo<int>()::X::fn
 _ZZZ3FooIiEfvENKUlT_E_clIcEEDaS0_EN1X2fnEv
 Foo<int>()::{lambda(auto:1)#1}::operator()<char>(char) const::X::fn()
 Foo<int>()::{lambda(auto:1)#1}::operator()<char>(char) const::X::fn
+#PR91979 demangling nullptr expression
+
+_Z3fooILPv0EEvPN9enable_ifIXeqT_LDnEEvE4typeE
+void foo<(void*)0>(enable_if<((void*)0)==((decltype(nullptr))), void>::type*)