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C++ PATCHes for c++/66297 and 70979, literal type issues

Message ID CADzB+2=iaNRcuRhB3Mf1YQx7NQ_HEXL1YL0i0uvKdeyOdtkgzg@mail.gmail.com
State New
Headers show

Commit Message

Jason Merrill May 9, 2017, 8:35 p.m. UTC 
66297: C++14 removed the requirement that a constexpr member function
must be a member of a literal class.

70979: We were failing to treat a C++14 lambda as non-literal; they
are only literal with the constexpr lambda addition in C++17.

Tested x86_64-pc-linux-gnu, applying to trunk.
commit 187ea37ce9cc03f4c9940b007de65d17ad94e777
Author: Jason Merrill <jason@redhat.com>
Date:   Mon Feb 13 15:39:12 2017 -0500

            PR c++/66297, DR 1684 - literal class and constexpr member fns
    
            * constexpr.c (is_valid_constexpr_fn): Only complain about
            non-literal enclosing class in C++11.
            * class.c (finalize_literal_type_property): Likewise.
commit fcb0b94da309fac966bf70eec9080ed4f4e10adf
Author: Jason Merrill <jason@redhat.com>
Date:   Mon Feb 13 15:43:15 2017 -0500

            PR c++/70979 - literal class and closure types
    
            * class.c (finalize_literal_type_property): Handle closures
            specifically.
            (explain_non_literal_class): Likewise.

diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index 89fa822..fc71766 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -5752,6 +5752,8 @@ finalize_literal_type_property (tree t)
   if (cxx_dialect < cxx11
       || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
     CLASSTYPE_LITERAL_P (t) = false;
+  else if (CLASSTYPE_LITERAL_P (t) && LAMBDA_TYPE_P (t))
+    CLASSTYPE_LITERAL_P (t) = (cxx_dialect >= cxx1z);
   else if (CLASSTYPE_LITERAL_P (t) && !TYPE_HAS_TRIVIAL_DFLT (t)
 	   && CLASSTYPE_NON_AGGREGATE (t)
 	   && !TYPE_HAS_CONSTEXPR_CTOR (t))
@@ -5794,10 +5796,14 @@ explain_non_literal_class (tree t)
     return;
 
   inform (0, "%q+T is not literal because:", t);
-  if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
+  if (cxx_dialect < cxx1z && LAMBDA_TYPE_P (t))
+    inform (0, "  %qT is a closure type, which is only literal in "
+	    "C++1z and later", t);
+  else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
     inform (0, "  %q+T has a non-trivial destructor", t);
   else if (CLASSTYPE_NON_AGGREGATE (t)
 	   && !TYPE_HAS_TRIVIAL_DFLT (t)
+	   && !LAMBDA_TYPE_P (t)
 	   && !TYPE_HAS_CONSTEXPR_CTOR (t))
     {
       inform (0, "  %q+T is not an aggregate, does not have a trivial "
diff --git a/gcc/testsuite/g++.dg/cpp1z/constexpr-lambda15.C b/gcc/testsuite/g++.dg/cpp1z/constexpr-lambda15.C
index 7e05481..358d4aa 100644
--- a/gcc/testsuite/g++.dg/cpp1z/constexpr-lambda15.C
+++ b/gcc/testsuite/g++.dg/cpp1z/constexpr-lambda15.C
@@ -1,9 +1,9 @@
 // PR c++/79461
-// { dg-options -std=c++1z }
+// { dg-do compile { target c++14 } }
 
 struct S {
   constexpr S(int i) {
-    auto f = [i]{};
+    auto f = [i]{};		// { dg-error "literal" "" { target c++14_only } }
   }
 };
 int main() {}
diff mbox

Patch

diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index 9b996e3..89fa822 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -5757,7 +5757,9 @@  finalize_literal_type_property (tree t)
 	   && !TYPE_HAS_CONSTEXPR_CTOR (t))
     CLASSTYPE_LITERAL_P (t) = false;
 
-  if (!CLASSTYPE_LITERAL_P (t))
+  /* C++14 DR 1684 removed this restriction.  */
+  if (cxx_dialect < cxx14
+      && !CLASSTYPE_LITERAL_P (t) && !LAMBDA_TYPE_P (t))
     for (fn = TYPE_METHODS (t); fn; fn = DECL_CHAIN (fn))
       if (DECL_DECLARED_CONSTEXPR_P (fn)
 	  && TREE_CODE (fn) != TEMPLATE_DECL
@@ -5765,12 +5767,11 @@  finalize_literal_type_property (tree t)
 	  && !DECL_CONSTRUCTOR_P (fn))
 	{
 	  DECL_DECLARED_CONSTEXPR_P (fn) = false;
-	  if (!DECL_GENERATED_P (fn) && !LAMBDA_TYPE_P (t))
-	    {
-	      error ("enclosing class of constexpr non-static member "
-		     "function %q+#D is not a literal type", fn);
-	      explain_non_literal_class (t);
-	    }
+	  if (!DECL_GENERATED_P (fn)
+	      && pedwarn (DECL_SOURCE_LOCATION (fn), OPT_Wpedantic,
+			  "enclosing class of constexpr non-static member "
+			  "function %q+#D is not a literal type", fn))
+	    explain_non_literal_class (t);
 	}
 }
 
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index 34d25ba..157b20d 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -210,16 +210,17 @@  is_valid_constexpr_fn (tree fun, bool complain)
 	    }
 	}
 
-      if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fun)
+      /* C++14 DR 1684 removed this restriction.  */
+      if (cxx_dialect < cxx14
+	  && DECL_NONSTATIC_MEMBER_FUNCTION_P (fun)
 	  && !CLASSTYPE_LITERAL_P (DECL_CONTEXT (fun)))
 	{
 	  ret = false;
-	  if (complain)
-	    {
-	      error ("enclosing class of constexpr non-static member "
-		     "function %q+#D is not a literal type", fun);
-	      explain_non_literal_class (DECL_CONTEXT (fun));
-	    }
+	  if (complain
+	      && pedwarn (DECL_SOURCE_LOCATION (fun), OPT_Wpedantic,
+			  "enclosing class of constexpr non-static member "
+			  "function %q+#D is not a literal type", fun))
+	    explain_non_literal_class (DECL_CONTEXT (fun));
 	}
     }
   else if (CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fun)))
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-data1.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-data1.C
index f49c56a..9078533 100644
--- a/gcc/testsuite/g++.dg/cpp0x/constexpr-data1.C
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-data1.C
@@ -36,7 +36,7 @@  class debug_flag
 {
 public:
    explicit debug_flag(bool);
-   constexpr bool is_on(); // { dg-error "enclosing class .* not a literal type" }
+   constexpr bool is_on(); // { dg-error "enclosing class .* not a literal type" "" { target c++11_only } }
 private:
    bool flag;
 };
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-diag1.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-diag1.C
index 6b908b6..450a0b5 100644
--- a/gcc/testsuite/g++.dg/cpp0x/constexpr-diag1.C
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-diag1.C
@@ -5,7 +5,7 @@  template <class T>
 struct A
 {
   T t;
-  constexpr int f() const { return 42; } // { dg-error "enclosing class" }
+  constexpr int f() const { return 42; } // { dg-error "enclosing class" "" { target c++11_only } }
 };
 
 struct B { B(); operator int(); };
@@ -13,7 +13,7 @@  struct B { B(); operator int(); };
 constexpr A<int> ai = { 42 };
 constexpr int i = ai.f();
 
-constexpr int b = A<B>().f();	// { dg-error "non-constexpr function" }
+constexpr int b = A<B>().f();	// { dg-error "" }
 
 template <class T>
 constexpr int f (T t) { return 42; } // { dg-error "parameter" }
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-diag3.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-diag3.C
index 580fceb..27aad93 100644
--- a/gcc/testsuite/g++.dg/cpp0x/constexpr-diag3.C
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-diag3.C
@@ -16,7 +16,7 @@  int main()
 struct complex 			// { dg-message "no constexpr constructor" }
 {
   complex(double r, double i) : re(r), im(i) { }
-  constexpr double real() const { return re; } // { dg-error "not a literal type" }
+  constexpr double real() const { return re; } // { dg-error "not a literal type" "" { target c++11_only } }
   double imag() const { return im; }
 
 private:
@@ -25,7 +25,7 @@  private:
 };
 
 constexpr complex co1(0, 1);	   // { dg-error "not literal" }
-constexpr double dd2 = co1.real(); // { dg-error "non-constexpr function" }
+constexpr double dd2 = co1.real(); // { dg-error "" }
 
 // --------------------
 
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-memfn1.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-memfn1.C
index 775c103..d59f465 100644
--- a/gcc/testsuite/g++.dg/cpp0x/constexpr-memfn1.C
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-memfn1.C
@@ -13,6 +13,6 @@  constexpr X X::g(X x) { return x; }
 struct Y
 {
   Y() { }
-  constexpr Y f(Y y);		// { dg-error "not a literal type" }
+  constexpr Y f(Y y) {}		// { dg-error "constexpr" }
   static constexpr Y g(Y y) {}	// { dg-error "constexpr" }
 };
diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-neg1.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-neg1.C
index 58b5d32..9c832b1 100644
--- a/gcc/testsuite/g++.dg/cpp0x/constexpr-neg1.C
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-neg1.C
@@ -45,7 +45,7 @@  constexpr int g(int x, int n) {
 class debug_flag {
 public:
   explicit debug_flag(bool);
-  constexpr bool is_on();	// { dg-error "not a literal type" } debug_flag not literal type
+  constexpr bool is_on(); // { dg-error "not a literal type" "" { target c++11_only } } debug_flag not literal type
 private:
   bool flag;
 };
diff --git a/gcc/testsuite/g++.dg/cpp1y/constexpr-dr1684.C b/gcc/testsuite/g++.dg/cpp1y/constexpr-dr1684.C
new file mode 100644
index 0000000..04ffcfd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/constexpr-dr1684.C
@@ -0,0 +1,7 @@ 
+// DR 1684
+// { dg-do compile { target c++11 } }
+
+struct A {
+  A(int);
+  constexpr int foo() { return 0; } // { dg-error "literal" "" { target c++11_only } }
+};