From 7ac42374abc01d89235c862cc44da0c6c930489c Mon Sep 17 00:00:00 2001
From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Thu, 5 Sep 2019 01:23:47 +0000
Subject: [c++20] Fix some ambiguities in our mangling of lambdas with explicit
 template parameters.

This finishes the implementation of the proposal described in
https://github.com/itanium-cxx-abi/cxx-abi/issues/31. (We already
implemented the <lambda-sig> extensions, but didn't take them into
account when computing mangling numbers, and didn't deal properly with
expanded parameter packs, and didn't disambiguate between different
levels of template parameters in manglings.)

llvm-svn: 371004
---
 .../mangle-lambda-explicit-template-params.cpp     | 59 ++++++++++++++++++++++
 1 file changed, 59 insertions(+)

(limited to 'clang/test/CodeGenCXX/mangle-lambda-explicit-template-params.cpp')

diff --git a/clang/test/CodeGenCXX/mangle-lambda-explicit-template-params.cpp b/clang/test/CodeGenCXX/mangle-lambda-explicit-template-params.cpp
index b88b0d56fd9..dba10fbf01d 100644
--- a/clang/test/CodeGenCXX/mangle-lambda-explicit-template-params.cpp
+++ b/clang/test/CodeGenCXX/mangle-lambda-explicit-template-params.cpp
@@ -33,9 +33,68 @@ void call_inline_func() {
   inline_func();
 }
 
+template<typename T, int> struct X {};
+
+inline auto pack = []<typename ...T, T ...N>(T (&...)[N]) {};
+int arr1[] = {1};
+int arr2[] = {1, 2};
+// CHECK: @_ZNK4packMUlTpTyTpTnT_DpRAT0__S_E_clIJiiEJLi1ELi2EEEEDaS2_(
+void use_pack() { pack(arr1, arr2); }
+
+inline void collision() {
+  auto a = []<typename T, template<typename U, T> typename>{};
+  auto b = []<typename T, template<typename U, U> typename>{};
+  auto c = []<typename T, template<typename U, T> typename>{};
+  a.operator()<int, X>();
+  // CHECK: @_ZZ9collisionvENKUlTyTtTyTnT_EvE_clIi1XEEDav
+  b.operator()<int, X>();
+  // CHECK: @_ZZ9collisionvENKUlTyTtTyTnTL0__EvE_clIi1XEEDav
+  c.operator()<int, X>();
+  // CHECK: @_ZZ9collisionvENKUlTyTtTyTnT_EvE0_clIi1XEEDav
+}
+void use_collision() { collision(); }
+
 template<typename> void f() {
   // CHECK: define linkonce_odr {{.*}} @_ZZ1fIiEvvENKUlT_E_clIiEEDaS0_(
   auto x = [](auto){};
   x(0);
 }
 void use_f() { f<int>(); }
+
+template<typename> struct Y {
+  template<int> struct Z {};
+};
+
+template<typename ...T> void expanded() {
+  auto x = []<T..., template<T> typename...>{};
+  auto y = []<int, template<int> typename>{};
+  auto z = []<int, int, template<int> typename, template<int> typename>{};
+  // FIXME: Should we really require 'template' for y and z?
+  x.template operator()<(T())..., Y<T>::template Z...>();
+  y.template operator()<0, Y<int>::Z>();
+  y.template operator()<1, Y<int>::Z>();
+  z.template operator()<1, 2, Y<int>::Z, Y<float>::Z>();
+}
+void use_expanded() {
+  // CHECK: @_ZZ8expandedIJEEvvENKUlvE_clIJEJEEEDav(
+  // CHECK: @_ZZ8expandedIJEEvvENKUlTniTtTniEvE_clILi0EN1YIiE1ZEEEDav(
+  // CHECK: @_ZZ8expandedIJEEvvENKUlTniTtTniEvE_clILi1EN1YIiE1ZEEEDav(
+  // CHECK: @_ZZ8expandedIJEEvvENKUlTniTniTtTniETtTniEvE_clILi1ELi2EN1YIiE1ZENS2_IfE1ZEEEDav(
+  expanded<>();
+
+  // FIXME: Should we really be using J...E for arguments corresponding to an
+  // expanded parameter pack?
+  // Note that the <lambda-sig>s of 'x' and 'y' collide here, after pack expansion.
+  // CHECK: @_ZZ8expandedIJiEEvvENKUlTniTtTniEvE_clIJLi0EEJN1YIiE1ZEEEEDav(
+  // CHECK: @_ZZ8expandedIJiEEvvENKUlTniTtTniEvE0_clILi0EN1YIiE1ZEEEDav(
+  // CHECK: @_ZZ8expandedIJiEEvvENKUlTniTtTniEvE0_clILi1EN1YIiE1ZEEEDav(
+  // CHECK: @_ZZ8expandedIJiEEvvENKUlTniTniTtTniETtTniEvE_clILi1ELi2EN1YIiE1ZENS2_IfE1ZEEEDav(
+  expanded<int>();
+
+  // Note that the <lambda-sig>s of 'x' and 'z' collide here, after pack expansion.
+  // CHECK: @_ZZ8expandedIJiiEEvvENKUlTniTniTtTniETtTniEvE_clIJLi0ELi0EEJN1YIiE1ZES4_EEEDav(
+  // CHECK: @_ZZ8expandedIJiiEEvvENKUlTniTtTniEvE_clILi0EN1YIiE1ZEEEDav(
+  // CHECK: @_ZZ8expandedIJiiEEvvENKUlTniTtTniEvE_clILi1EN1YIiE1ZEEEDav(
+  // CHECK: @_ZZ8expandedIJiiEEvvENKUlTniTniTtTniETtTniEvE0_clILi1ELi2EN1YIiE1ZENS2_IfE1ZEEEDav(
+  expanded<int, int>();
+}
-- 
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