On Mar 14, 2019, Jason Merrill <ja...@redhat.com> wrote:
>> You can use VAR_P for this.
> OK with that change.
Thanks, I went ahead and also added a test before dereferencing it,
since there was evidence shortly thereafter that it could possibly be
NULL.
Here's what I'm installing.
P0732R2 / C++ 2a introduce class literals as template parameters. The
front-end uses VAR_DECLs constructed from such literals to bind the
template PARM_DECLs, but dwarf2out.c used to reject such VAR_DECLs.
Taking DECL_INITIAL from such VAR_DECLs enables the generation of
DW_AT_const_value for them, at least when the class literal can
actually be represented as such.
for gcc/ChangeLog
PR c++/88534
PR c++/88537
* dwarf2out.c (generic_parameter_die): Follow DECL_INITIAL of
VAR_DECL args.
for gcc/ChangeLog
PR c++/88534
PR c++/88537
* g++.dg/cpp2a/pr88534.C: New.
* g++.dg/cpp2a/pr88537.C: New.
---
gcc/dwarf2out.c | 7 ++++
gcc/testsuite/g++.dg/cpp2a/pr88534.C | 65 ++++++++++++++++++++++++++++++++++
gcc/testsuite/g++.dg/cpp2a/pr88537.C | 16 ++++++++
3 files changed, 88 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/cpp2a/pr88534.C
create mode 100644 gcc/testsuite/g++.dg/cpp2a/pr88537.C
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index d9cefd3e1d3cf..251fff7b9ae96 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -13603,6 +13603,13 @@ generic_parameter_die (tree parm, tree arg,
dw_die_ref tmpl_die = NULL;
const char *name = NULL;
+ /* C++2a accepts class literals as template parameters, and var
+ decls with initializers represent them. The VAR_DECLs would be
+ rejected, but we can take the DECL_INITIAL constructor and
+ attempt to expand it. */
+ if (arg && VAR_P (arg))
+ arg = DECL_INITIAL (arg);
+
if (!parm || !DECL_NAME (parm) || !arg)
return NULL;
diff --git a/gcc/testsuite/g++.dg/cpp2a/pr88534.C
b/gcc/testsuite/g++.dg/cpp2a/pr88534.C
new file mode 100644
index 0000000000000..54faf385f11aa
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/pr88534.C
@@ -0,0 +1,65 @@
+// { dg-do compile { target c++2a } }
+// { dg-options "-g" }
+
+typedef __SIZE_TYPE__ size_t;
+
+namespace std
+{
+
+template <typename T, T... I>
+struct integer_sequence
+{
+ typedef T value_type;
+ static constexpr size_t size () noexcept { return sizeof...(I); }
+};
+
+template <typename T, T N>
+using make_integer_sequence = integer_sequence<T, __integer_pack (N)...>;
+
+template <size_t... I>
+using index_sequence = integer_sequence<size_t, I...>;
+
+template <size_t N>
+using make_index_sequence = make_integer_sequence<size_t, N>;
+}
+
+template <typename T, size_t N> struct S
+{
+ T content[N];
+ using char_type = T;
+ template <size_t... I>
+ constexpr S (const T (&input)[N], std::index_sequence<I...>) noexcept :
content{input[I]...} { }
+ constexpr S (const T (&input)[N]) noexcept : S (input,
std::make_index_sequence<N> ()) { }
+ constexpr size_t size () const noexcept
+ {
+ if (content[N - 1] == '\0')
+ return N - 1;
+ else
+ return N;
+ }
+ constexpr T operator[] (size_t i) const noexcept
+ {
+ return content[i];
+ }
+ constexpr const T *begin () const noexcept
+ {
+ return content;
+ }
+ constexpr const T *end () const noexcept
+ {
+ return content + size ();
+ }
+};
+
+template <typename T, size_t N> S (const T (&)[N]) -> S<T, N>;
+
+template <S S>
+struct F
+{
+};
+
+auto
+foo ()
+{
+ F<"test"> f;
+}
diff --git a/gcc/testsuite/g++.dg/cpp2a/pr88537.C
b/gcc/testsuite/g++.dg/cpp2a/pr88537.C
new file mode 100644
index 0000000000000..d558d45f57830
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/pr88537.C
@@ -0,0 +1,16 @@
+// { dg-do compile { target c++2a } }
+// { dg-options "-g" }
+
+struct pair {
+ unsigned a;
+ unsigned b;
+ constexpr pair(unsigned _a, unsigned _b) noexcept: a{_a}, b{_b} { }
+};
+
+template <pair p> void fnc() {
+
+}
+
+void f() {
+ fnc<pair(10,20)>();
+}
--
Alexandre Oliva, freedom fighter https://FSFLA.org/blogs/lxo
Be the change, be Free! FSF Latin America board member
GNU Toolchain Engineer Free Software Evangelist
Hay que enGNUrecerse, pero sin perder la terGNUra jamás-GNUChe
