Here, we are calling template_class_depth on a FIELD_DECL corresponding
to a lambda that is used inside variable template. template_class_depth
however does not see that this FIELD_DECL is used inside a variable
template binding because its chain of DECL_CONTEXTs does not include the
corresponding VAR_DECL. So template_class_depth returns the wrong
template nesting level which causes its callers to malfunction. In
particular we strip a template argument level in
tsubst_copy [FIELD_DECL] when we shouldn't have.
This patch makes template_class_depth look at a lambda type's
LAMBDA_TYPE_EXTRA_SCOPE field instead of its TYPE_CONTEXT, so that it
can iterate into an enclosing variable template, if applicable.
Tested on x86_64-pc-linux gnu, no new regressions. Also tested against
Boost. Is this OK to commit?
gcc/cp/ChangeLog:
PR c++/66786
* pt.c (template_class_depth): Given a lambda type, iterate
into its LAMBDA_TYPE_EXTRA_SCOPE field instead of its
TYPE_CONTEXT. Given a VAR_DECL, iterate into its
CP_DECL_CONTEXT.
gcc/testsuite/ChangeLog:
PR c++/66786
* g++.dg/cpp1y/var-templ48.C: New test.
* g++.dg/cpp1y/var-templ49.C: New test.
---
gcc/cp/pt.c | 12 ++++++++----
gcc/testsuite/g++.dg/cpp1y/var-templ48.C | 5 +++++
gcc/testsuite/g++.dg/cpp1y/var-templ49.C | 9 +++++++++
3 files changed, 22 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/var-templ48.C
create mode 100644 gcc/testsuite/g++.dg/cpp1y/var-templ49.C
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 4d405cf..5c344c1 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -369,16 +369,20 @@ template_class_depth (tree type)
{
int depth;
- for (depth = 0;
- type && TREE_CODE (type) != NAMESPACE_DECL;
- type = (TREE_CODE (type) == FUNCTION_DECL)
- ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
+ for (depth = 0; type && TREE_CODE (type) != NAMESPACE_DECL; )
{
tree tinfo = get_template_info (type);
if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
&& uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
++depth;
+
+ if (VAR_OR_FUNCTION_DECL_P (type))
+ type = CP_DECL_CONTEXT (type);
+ else if (LAMBDA_TYPE_P (type))
+ type = LAMBDA_TYPE_EXTRA_SCOPE (type);
+ else
+ type = CP_TYPE_CONTEXT (type);
}
return depth;
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ48.C
b/gcc/testsuite/g++.dg/cpp1y/var-templ48.C
new file mode 100644
index 0000000..f0c7693
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ48.C
@@ -0,0 +1,5 @@
+// PR c++/66786
+// { dg-do compile { target c++14 } }
+
+template <typename... T> auto list = [](T... xs) { [=](auto f) { f(xs...); };
};
+int main() { list<int>(0); }
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ49.C
b/gcc/testsuite/g++.dg/cpp1y/var-templ49.C
new file mode 100644
index 0000000..cd3f230
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ49.C
@@ -0,0 +1,9 @@
+// PR c++/66786
+// { dg-do compile { target c++14 } }
+
+int f (int, bool);
+
+template <typename>
+auto list = [](auto... xs) { return [=](auto f, auto... ys) { return f(xs...,
ys...); }; };
+
+const int &a = list<int>(0, true)(f);
--
2.7.1.257.g925a48d
