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| author | Patrick Palka <ppalka@redhat.com> | 2022-12-20 17:02:37 -0500 |
|---|---|---|
| committer | Patrick Palka <ppalka@redhat.com> | 2022-12-20 17:02:37 -0500 |
| commit | 8aa045c97485d75e0b6eb1068464c0ddaa6beacb (patch) | |
| tree | 2ebeed3776c7a98b39f4196f08169daa8bb3b9b0 /gcc/tree.cc | |
| parent | aed5584ff6891560dc567e54517b9722dadc503e (diff) | |
| download | gcc-8aa045c97485d75e0b6eb1068464c0ddaa6beacb.zip gcc-8aa045c97485d75e0b6eb1068464c0ddaa6beacb.tar.gz gcc-8aa045c97485d75e0b6eb1068464c0ddaa6beacb.tar.bz2 | |
c++, tree: walk TREE_VEC (and VECTOR_CST) in natural order [PR101886]
Unfortunately the extract_autos_r fix in r13-4799-ga7c8036b26082d is
derailed by the fact that walk_tree_1 currently walks the elements of a
TREE_VEC in reverse, which means for A<auto, auto> in the below testcase
extract_autos_r ends up adjusting the TEMPLATE_TYPE_IDX of the first
auto instead of the second one, and the first auto is the canonical auto
of level 2 (and index 0), so we rightfully trigger the sanity check
added in that commit.
It seems TREE_VEC and VECTOR_CST are the only trees we walk in reverse,
and this has been the case since r21884 whence the original version of
walk_tree_1 was introduced. But that's arguably unnatural and not
consistent with how we walk all other compound trees such as CONSTRUCTORs
and EXPR_P trees in forward order.
So this patch makes walk_tree_1 walk TREE_VEC (and VECTOR_CST) in
forward order as well, which fixes the testcase. Doing so revealed that
keep_template_parm grows the list of found template parameters from the
front, which previously compensated for the TREE_VEC behavior, so now we
should grow it from the back.
PR c++/101886
gcc/cp/ChangeLog:
* pt.cc (find_template_parameter_info::parm_list_tail):
New data member.
(keep_template_parm): Use parm_list_tail to append rather
than prepend to parm_list.
gcc/ChangeLog:
* tree.cc (walk_tree_1) <case TREE_VEC>: Walk the elements
in forward instead of reverse order.
<case VECTOR_CST>: Likewise.
gcc/testsuite/ChangeLog:
* g++.dg/concepts/diagnostic12.C: Adjust expected order of
template parameters within pretty printed parameter mapping.
* g++.dg/concepts/auto6.C: New test.
Diffstat (limited to 'gcc/tree.cc')
| -rw-r--r-- | gcc/tree.cc | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/gcc/tree.cc b/gcc/tree.cc index 0a51f9d..92199bb 100644 --- a/gcc/tree.cc +++ b/gcc/tree.cc @@ -11310,12 +11310,12 @@ walk_tree_1 (tree *tp, walk_tree_fn func, void *data, if (len == 0) break; - /* Walk all elements but the first. */ - while (--len) - WALK_SUBTREE (TREE_VEC_ELT (*tp, len)); + /* Walk all elements but the last. */ + for (int i = 0; i < len - 1; ++i) + WALK_SUBTREE (TREE_VEC_ELT (*tp, i)); - /* Now walk the first one as a tail call. */ - WALK_SUBTREE_TAIL (TREE_VEC_ELT (*tp, 0)); + /* Now walk the last one as a tail call. */ + WALK_SUBTREE_TAIL (TREE_VEC_ELT (*tp, len - 1)); } case VECTOR_CST: @@ -11323,11 +11323,11 @@ walk_tree_1 (tree *tp, walk_tree_fn func, void *data, unsigned len = vector_cst_encoded_nelts (*tp); if (len == 0) break; - /* Walk all elements but the first. */ - while (--len) - WALK_SUBTREE (VECTOR_CST_ENCODED_ELT (*tp, len)); - /* Now walk the first one as a tail call. */ - WALK_SUBTREE_TAIL (VECTOR_CST_ENCODED_ELT (*tp, 0)); + /* Walk all elements but the last. */ + for (unsigned i = 0; i < len - 1; ++i) + WALK_SUBTREE (VECTOR_CST_ENCODED_ELT (*tp, i)); + /* Now walk the last one as a tail call. */ + WALK_SUBTREE_TAIL (VECTOR_CST_ENCODED_ELT (*tp, len - 1)); } case COMPLEX_CST: |