extract_local_specs wasn't finding the mention of 'an' as a template
argument because we weren't walking into template arguments. So here I
changed cp_walk_subtrees to do so--only walking into template arguments in
the spelling of the type or expression, not any hidden behind typedefs. The
change to use typedef_variant_p avoids looking through typedefs spelled with
'typedef' as well as those spelled with 'using'. And then I removed some
now-redundant code for walking into template arguments in a couple of
walk_tree callbacks.
Tested x86_64-pc-linux-gnu, applying to trunk.
PR c++/92654
* tree.c (cp_walk_subtrees): Walk into type template arguments.
* cp-tree.h (TYPE_TEMPLATE_INFO_MAYBE_ALIAS): Use typedef_variant_p
instead of TYPE_ALIAS_P.
* pt.c (push_template_decl_real): Likewise.
(find_parameter_packs_r): Likewise. Remove dead code.
* error.c (find_typenames_r): Remove dead code.
---
gcc/cp/cp-tree.h | 2 +-
gcc/cp/error.c | 6 ---
gcc/cp/pt.c | 40 ++++---------------
gcc/cp/tree.c | 5 +++
.../g++.dg/cpp1z/constexpr-if-lambda2.C | 12 ++++++
5 files changed, 25 insertions(+), 40 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1z/constexpr-if-lambda2.C
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index b8035b4360d..c46d1e92b3b 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -3482,7 +3482,7 @@ struct GTY(()) lang_decl {
for the alias template (if any). Otherwise behave as
TYPE_TEMPLATE_INFO. */
#define TYPE_TEMPLATE_INFO_MAYBE_ALIAS(NODE) \
- (TYPE_ALIAS_P (NODE) \
+ (typedef_variant_p (NODE) \
? TYPE_ALIAS_TEMPLATE_INFO (NODE) \
: TYPE_TEMPLATE_INFO (NODE))
diff --git a/gcc/cp/error.c b/gcc/cp/error.c
index 973b3034e12..ab8638fbaec 100644
--- a/gcc/cp/error.c
+++ b/gcc/cp/error.c
@@ -1526,12 +1526,6 @@ find_typenames_r (tree *tp, int *walk_subtrees, void
*data)
if (mv && (mv == *tp || !d->p_set->add (mv)))
vec_safe_push (d->typenames, mv);
- /* Search into class template arguments, which cp_walk_subtrees
- doesn't do. */
- if (CLASS_TYPE_P (*tp) && CLASSTYPE_TEMPLATE_INFO (*tp))
- cp_walk_tree (&CLASSTYPE_TI_ARGS (*tp), find_typenames_r,
- data, d->p_set);
-
return NULL_TREE;
}
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 01bade85cdf..2fb52caa5d4 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -3818,9 +3818,12 @@ find_parameter_packs_r (tree *tp, int *walk_subtrees,
void* data)
(struct find_parameter_pack_data*)data;
bool parameter_pack_p = false;
- /* Handle type aliases/typedefs. */
- if (TYPE_ALIAS_P (t))
+ /* Don't look through typedefs; we are interested in whether a
+ parameter pack is actually written in the expression/type we're
+ looking at, not the target type. */
+ if (TYPE_P (t) && typedef_variant_p (t))
{
+ /* But do look at arguments for an alias template. */
if (tree tinfo = TYPE_ALIAS_TEMPLATE_INFO (t))
cp_walk_tree (&TI_ARGS (tinfo),
&find_parameter_packs_r,
@@ -3903,27 +3906,13 @@ find_parameter_packs_r (tree *tp, int *walk_subtrees,
void* data)
&find_parameter_packs_r, ppd, ppd->visited);
/* This switch statement will return immediately if we don't find a
- parameter pack. */
+ parameter pack. ??? Should some of these be in cp_walk_subtrees? */
switch (TREE_CODE (t))
{
- case TEMPLATE_PARM_INDEX:
- return NULL_TREE;
-
case BOUND_TEMPLATE_TEMPLATE_PARM:
/* Check the template itself. */
cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
&find_parameter_packs_r, ppd, ppd->visited);
- /* Check the template arguments. */
- cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
- ppd->visited);
- *walk_subtrees = 0;
- return NULL_TREE;
-
- case TEMPLATE_TYPE_PARM:
- case TEMPLATE_TEMPLATE_PARM:
- return NULL_TREE;
-
- case PARM_DECL:
return NULL_TREE;
case DECL_EXPR:
@@ -3932,20 +3921,6 @@ find_parameter_packs_r (tree *tp, int *walk_subtrees,
void* data)
*walk_subtrees = 0;
return NULL_TREE;
- case RECORD_TYPE:
- if (TYPE_PTRMEMFUNC_P (t))
- return NULL_TREE;
- /* Fall through. */
-
- case UNION_TYPE:
- case ENUMERAL_TYPE:
- if (TYPE_TEMPLATE_INFO (t))
- cp_walk_tree (&TYPE_TI_ARGS (t),
- &find_parameter_packs_r, ppd, ppd->visited);
-
- *walk_subtrees = 0;
- return NULL_TREE;
-
case TEMPLATE_DECL:
if (!DECL_TEMPLATE_TEMPLATE_PARM_P (t))
return NULL_TREE;
@@ -5794,8 +5769,7 @@ push_template_decl_real (tree decl, bool is_friend)
if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
}
- else if (check_for_bare_parameter_packs ((TREE_CODE (decl) == TYPE_DECL
- && TYPE_DECL_ALIAS_P (decl))
+ else if (check_for_bare_parameter_packs (is_typedef_decl (decl)
? DECL_ORIGINAL_TYPE (decl)
: TREE_TYPE (decl)))
{
diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
index 21f733af486..fda630790a2 100644
--- a/gcc/cp/tree.c
+++ b/gcc/cp/tree.c
@@ -4918,6 +4918,11 @@ cp_walk_subtrees (tree *tp, int *walk_subtrees_p,
walk_tree_fn func,
} \
while (0)
+ if (TYPE_P (*tp))
+ /* Walk into template args without looking through typedefs. */
+ if (tree ti = TYPE_TEMPLATE_INFO_MAYBE_ALIAS (*tp))
+ WALK_SUBTREE (TI_ARGS (ti));
+
/* Not one of the easy cases. We must explicitly go through the
children. */
result = NULL_TREE;
diff --git a/gcc/testsuite/g++.dg/cpp1z/constexpr-if-lambda2.C
b/gcc/testsuite/g++.dg/cpp1z/constexpr-if-lambda2.C
new file mode 100644
index 00000000000..fb26ac716d4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/constexpr-if-lambda2.C
@@ -0,0 +1,12 @@
+// PR c++/92654
+// { dg-do compile { target c++17 } }
+
+template <unsigned long> struct C;
+template <auto I>
+void am() {
+ [](auto an)
+ {
+ if constexpr (C<an>::ap) ; // { dg-error "constant" }
+ }(42);
+}
+void fn() { am<42>(); }
base-commit: c8dd2446f597e6d1581414a9c02ff329285181a9
--
2.18.1
