Here we crash when issuing the "constraint C has type T, not bool"
error, because pp_cxx_parameter_mapping wasn't prepared to see an
anonymous template parameter. With this patch we print
error: constraint 'auto(<lambda>) [with <unnamed> = 0]' has type '<lambda()>',
not 'bool'
The "<unnamed>" is what this patch adds.
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
PR c++/103408
gcc/cp/ChangeLog:
* cxx-pretty-print.c (pp_cxx_parameter_mapping): Print "<unnamed>"
rather than crash on an unnamed template parameter.
gcc/testsuite/ChangeLog:
* g++.dg/cpp23/concepts-err1.C: New test.
---
gcc/cp/cxx-pretty-print.c | 4 +++-
gcc/testsuite/g++.dg/cpp23/concepts-err1.C | 6 ++++++
2 files changed, 9 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp23/concepts-err1.C
diff --git a/gcc/cp/cxx-pretty-print.c b/gcc/cp/cxx-pretty-print.c
index 25cabfee39f..3ea357deb80 100644
--- a/gcc/cp/cxx-pretty-print.c
+++ b/gcc/cp/cxx-pretty-print.c
@@ -2891,8 +2891,10 @@ pp_cxx_parameter_mapping (cxx_pretty_printer *pp, tree
map)
if (TYPE_P (parm))
pp->type_id (parm);
+ else if (tree name = DECL_NAME (TEMPLATE_PARM_DECL (parm)))
+ pp_cxx_tree_identifier (pp, name);
else
- pp_cxx_tree_identifier (pp, DECL_NAME (TEMPLATE_PARM_DECL (parm)));
+ pp->translate_string ("<unnamed>");
pp_cxx_whitespace (pp);
pp_equal (pp);
diff --git a/gcc/testsuite/g++.dg/cpp23/concepts-err1.C
b/gcc/testsuite/g++.dg/cpp23/concepts-err1.C
new file mode 100644
index 00000000000..e5bdc542bad
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp23/concepts-err1.C
@@ -0,0 +1,6 @@
+// PR c++/103408
+// { dg-do compile { target c++23 } }
+
+template<int>
+concept C = auto([]{}); // { dg-error "constraint" }
+static_assert(C<0>); // { dg-error "non-constant condition for static
assertion" }
base-commit: 6b8ecbc6d6652d061d7c72c64352d51eca2df6ca
--
2.33.1
