[gcc r14-6797] c++: sizeof... mangling with alias template [PR95298]
Jason Merrill
jason@gcc.gnu.org
Fri Dec 22 00:23:44 GMT 2023
https://gcc.gnu.org/g:d26f589e61a178e898d8b247042b487287ffe121
commit r14-6797-gd26f589e61a178e898d8b247042b487287ffe121
Author: Jason Merrill <jason@redhat.com>
Date: Sat Nov 18 14:35:22 2023 -0500
c++: sizeof... mangling with alias template [PR95298]
We were getting sizeof... mangling wrong when the argument after
substitution was a pack expansion that is not a simple T..., such as
list<T>... in variadic-mangle4.C or (A+1)... in variadic-mangle5.C. In the
former case we ICEd; in the latter case we wrongly mangled it as sZ
<expression>.
PR c++/95298
gcc/cp/ChangeLog:
* mangle.cc (write_expression): Handle v18 sizeof... bug.
* pt.cc (tsubst_pack_expansion): Keep TREE_VEC for sizeof...
(tsubst_expr): Don't strip TREE_VEC here.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/variadic-mangle2.C: Add non-member.
* g++.dg/cpp0x/variadic-mangle4.C: New test.
* g++.dg/cpp0x/variadic-mangle5.C: New test.
* g++.dg/cpp0x/variadic-mangle5a.C: New test.
Diff:
---
gcc/cp/mangle.cc | 14 +++++++++++++
gcc/cp/pt.cc | 12 ++++++++---
gcc/testsuite/g++.dg/cpp0x/variadic-mangle2.C | 8 +++++++
gcc/testsuite/g++.dg/cpp0x/variadic-mangle4.C | 29 ++++++++++++++++++++++++++
gcc/testsuite/g++.dg/cpp0x/variadic-mangle5.C | 13 ++++++++++++
gcc/testsuite/g++.dg/cpp0x/variadic-mangle5a.C | 13 ++++++++++++
6 files changed, 86 insertions(+), 3 deletions(-)
diff --git a/gcc/cp/mangle.cc b/gcc/cp/mangle.cc
index 365d470f46e..36c5ac5c4da 100644
--- a/gcc/cp/mangle.cc
+++ b/gcc/cp/mangle.cc
@@ -3444,6 +3444,7 @@ write_expression (tree expr)
if (PACK_EXPANSION_P (op))
{
+ sizeof_pack:
if (abi_check (11))
{
/* sZ rather than szDp. */
@@ -3464,6 +3465,19 @@ write_expression (tree expr)
int length = TREE_VEC_LENGTH (args);
if (abi_check (10))
{
+ /* Before v19 we wrongly mangled all single pack expansions with
+ sZ, but now only for expressions, as types ICEd (95298). */
+ if (length == 1)
+ {
+ tree arg = TREE_VEC_ELT (args, 0);
+ if (TREE_CODE (arg) == EXPR_PACK_EXPANSION
+ && !abi_check (19))
+ {
+ op = arg;
+ goto sizeof_pack;
+ }
+ }
+
/* sP <template-arg>* E # sizeof...(T), size of a captured
template parameter pack from an alias template */
write_string ("sP");
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 2817657a8bb..5278ef6e981 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -13572,7 +13572,15 @@ tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
/* If the argument pack is a single pack expansion, pull it out. */
if (TREE_VEC_LENGTH (args) == 1
&& pack_expansion_args_count (args))
- return TREE_VEC_ELT (args, 0);
+ {
+ tree arg = TREE_VEC_ELT (args, 0);
+ if (PACK_EXPANSION_SIZEOF_P (t)
+ && !TEMPLATE_PARM_P (PACK_EXPANSION_PATTERN (arg)))
+ /* Except if this isn't a simple sizeof...(T) which gets sZ
+ mangling, keep the TREE_VEC to get sP mangling. */;
+ else
+ return TREE_VEC_ELT (args, 0);
+ }
/* Types need no adjustment, nor does sizeof..., and if we still have
some pack expansion args we won't do anything yet. */
@@ -20261,8 +20269,6 @@ tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl)
{
if (PACK_EXPANSION_P (expanded))
/* OK. */;
- else if (TREE_VEC_LENGTH (expanded) == 1)
- expanded = TREE_VEC_ELT (expanded, 0);
else
expanded = make_argument_pack (expanded);
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic-mangle2.C b/gcc/testsuite/g++.dg/cpp0x/variadic-mangle2.C
index ea96ef87308..596242ab8b7 100644
--- a/gcc/testsuite/g++.dg/cpp0x/variadic-mangle2.C
+++ b/gcc/testsuite/g++.dg/cpp0x/variadic-mangle2.C
@@ -8,6 +8,11 @@ struct A {
template<typename...T> using M = int[sizeof...(T)];
template<typename...A> void g(M<A...> &);
};
+
+template<typename ...T> using N = int[sizeof...(T)];
+template<typename ...T> void f(N<T...> &);
+// equivalent to template<typename ...T> void f(int(&)[sizeof...(T)])
+
void g(A a)
{
int arr[3];
@@ -15,4 +20,7 @@ void g(A a)
a.f<1,2,3>(arr);
// { dg-final { scan-assembler "_ZN1A1gIJiiiEEEvRAsZT__i" } }
a.g<int,int,int>(arr);
+ // { dg-final { scan-assembler "_Z1fIJiiiEEvRAsZT__i" } }
+ f<int,int,int>(arr);
}
+
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic-mangle4.C b/gcc/testsuite/g++.dg/cpp0x/variadic-mangle4.C
new file mode 100644
index 00000000000..6930180d777
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/variadic-mangle4.C
@@ -0,0 +1,29 @@
+// PR c++/95298
+// { dg-do compile { target c++11 } }
+// { dg-additional-options -fabi-compat-version=0 }
+
+template<class...>
+struct list{};
+
+template<int n>
+struct _func_select
+{
+ using f = void;
+};
+
+struct func
+{
+ template<class... seqs>
+ using f = typename _func_select<sizeof...(seqs)>::f;
+};
+
+template<class... T>
+func::f<list<T>...> foo(T&&...)
+{}
+
+// { dg-final { scan-assembler "_Z3fooIJEEN12_func_selectIXsPDp4listIJT_EEEEE1fEDpOS2_" } }
+
+int main()
+{
+ foo();
+}
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic-mangle5.C b/gcc/testsuite/g++.dg/cpp0x/variadic-mangle5.C
new file mode 100644
index 00000000000..e22a33dad61
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/variadic-mangle5.C
@@ -0,0 +1,13 @@
+// { dg-do compile { target c++11 } }
+// { dg-additional-options "-fabi-version=0 -fabi-compat-version=0" }
+
+template<int...T> using N = int[sizeof...(T)];
+template<int...A> void f(N<(A+1)...> &);
+
+void g()
+{
+ int arr[3];
+
+ // { dg-final { scan-assembler "_Z1fIJLi1ELi2ELi3EEEvRAsPXspplT_Li1EEE_i" } }
+ f<1,2,3>(arr);
+}
diff --git a/gcc/testsuite/g++.dg/cpp0x/variadic-mangle5a.C b/gcc/testsuite/g++.dg/cpp0x/variadic-mangle5a.C
new file mode 100644
index 00000000000..eb1b0847a99
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/variadic-mangle5a.C
@@ -0,0 +1,13 @@
+// { dg-do compile { target c++11 } }
+// { dg-additional-options "-fabi-version=18 -fabi-compat-version=18" }
+
+template<int...T> using N = int[sizeof...(T)];
+template<int...A> void f(N<(A+1)...> &);
+
+void g()
+{
+ int arr[3];
+
+ // { dg-final { scan-assembler "_Z1fIJLi1ELi2ELi3EEEvRAsZplT_Li1E_i" } }
+ f<1,2,3>(arr);
+}
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