Hi!
As mentioned in the PR, lambda templates are something that in the end
didn't end up in C++14 nor C++17 (only generic lambdas with auto arguments
made it). This patch pedwarns on them if -pedantic{,-errors}.
Bootstrapped/regtested on x86_64-linux and i686-linux, acked by Jason in the
PR, committed to trunk.
2017-01-25 Jakub Jelinek <ja...@redhat.com>
PR c++/77914
* parser.c (cp_parser_lambda_declarator_opt): Pedwarn with
OPT_Wpedantic on lambda templates for -std=c++14 and higher.
* g++.dg/cpp1y/lambda-generic-77914.C: New test.
* g++.dg/cpp1y/lambda-generic-dep.C: Add -pedantic to dg-options,
expect a warning.
* g++.dg/cpp1y/lambda-generic-x.C: Add -Wpedantic to dg-options,
expect warnings.
* g++.dg/cpp1y/lambda-generic-mixed.C: Add empty dg-options.
* g++.dg/cpp1y/pr59636.C: Likewise.
* g++.dg/cpp1y/pr60190.C: Likewise.
--- gcc/cp/parser.c.jj 2017-01-25 19:23:46.240197073 +0100
+++ gcc/cp/parser.c 2017-01-25 19:26:17.397274647 +0100
@@ -10174,6 +10174,9 @@ cp_parser_lambda_declarator_opt (cp_pars
pedwarn (parser->lexer->next_token->location, 0,
"lambda templates are only available with "
"-std=c++14 or -std=gnu++14");
+ else
+ pedwarn (parser->lexer->next_token->location, OPT_Wpedantic,
+ "ISO C++ does not support lambda templates");
cp_lexer_consume_token (parser->lexer);
--- gcc/testsuite/g++.dg/cpp1y/lambda-generic-77914.C.jj 2017-01-25
19:26:17.398274634 +0100
+++ gcc/testsuite/g++.dg/cpp1y/lambda-generic-77914.C 2017-01-25
21:41:40.964310527 +0100
@@ -0,0 +1,9 @@
+// PR c++/77914
+// { dg-do compile { target c++14 } }
+
+int
+main ()
+{
+ auto l = [] <typename T> () {}; // { dg-error "does not support lambda
templates" }
+ l.operator () <void> ();
+}
--- gcc/testsuite/g++.dg/cpp1y/lambda-generic-dep.C.jj 2014-09-25
15:02:34.340817869 +0200
+++ gcc/testsuite/g++.dg/cpp1y/lambda-generic-dep.C 2017-01-25
19:26:17.400274609 +0100
@@ -1,5 +1,6 @@
// Generic lambda type dependence test part from N3690 5.1.2.12
// { dg-do compile { target c++14 } }
+// { dg-options "-pedantic" }
void f(int, const int (&)[2] = {}) { } // #1
void f(const int&, const int (&)[1]) { } // #2
@@ -26,7 +27,7 @@ struct S {
int main()
{
- auto f = [] <typename T> (T const& s) mutable {
+ auto f = [] <typename T> (T const& s) mutable { // { dg-warning "does
not support lambda templates" }
typename T::N x;
return x.test ();
};
--- gcc/testsuite/g++.dg/cpp1y/lambda-generic-x.C.jj 2014-09-25
15:02:34.352817644 +0200
+++ gcc/testsuite/g++.dg/cpp1y/lambda-generic-x.C 2017-01-25
19:26:17.400274609 +0100
@@ -1,21 +1,22 @@
// Explicit generic lambda test from N3690 5.1.2.5
// { dg-do compile { target c++14 } }
+// { dg-options "-Wpedantic" }
#include <iostream>
int main()
{
- auto glambda = [] <typename A, typename B> (A a, B&& b) { return a < b; };
+ auto glambda = [] <typename A, typename B> (A a, B&& b) { return a < b; };
// { dg-warning "does not support lambda templates" }
bool b = glambda(3, 3.14); // OK
- auto vglambda = [] <typename P> (P printer) {
+ auto vglambda = [] <typename P> (P printer) {
// { dg-warning "does not support lambda templates" }
return [=] <typename... T> (T&& ... ts) { // OK: ts is a function
parameter pack
- printer(std::forward<decltype(ts)>(ts)...);
+ printer(std::forward<decltype(ts)>(ts)...);
// { dg-warning "does not support lambda templates" "" { target *-*-* } .-1 }
return [=]() {
printer(ts ...);
};
};
};
- auto p = vglambda( [] <typename A,
+ auto p = vglambda( [] <typename A,
// { dg-warning "does not support lambda templates" }
typename B,
typename C> (A v1, B v2, C v3)
{ std::cout << v1 << v2 << v3; } );
--- gcc/testsuite/g++.dg/cpp1y/lambda-generic-mixed.C.jj 2014-09-25
15:02:34.348817719 +0200
+++ gcc/testsuite/g++.dg/cpp1y/lambda-generic-mixed.C 2017-01-25
19:26:17.401274596 +0100
@@ -1,5 +1,6 @@
// Mixed explicit and implicit generic lambda test.
// { dg-do compile { target c++14 } }
+// { dg-options "" }
int main()
{
--- gcc/testsuite/g++.dg/cpp1y/pr59636.C.jj 2014-09-25 15:02:34.000000000
+0200
+++ gcc/testsuite/g++.dg/cpp1y/pr59636.C 2017-01-25 21:42:29.946690283
+0100
@@ -1,4 +1,5 @@
// PR c++/59636
// { dg-do compile { target c++14 } }
+// { dg-options "" }
auto f = []() { return []<>() {}; }; // { dg-error "expected identifier" }
--- gcc/testsuite/g++.dg/cpp1y/pr60190.C.jj 2014-09-25 15:02:34.000000000
+0200
+++ gcc/testsuite/g++.dg/cpp1y/pr60190.C 2017-01-25 21:42:54.058384967
+0100
@@ -1,4 +1,5 @@
// PR c++/60190
// { dg-do compile { target c++14 } }
+// { dg-options "" }
auto f = []<int>() -> int() {}; // { dg-error "returning a function|expected" }
Jakub
