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| author | Patrick Palka <ppalka@redhat.com> | 2020-04-18 06:22:21 -0400 |
|---|---|---|
| committer | Patrick Palka <ppalka@redhat.com> | 2020-04-18 06:23:10 -0400 |
| commit | f83adb68ed9cef1fbd4c16447eb4e89676df9f62 (patch) | |
| tree | 97bb61c32c64d9d0a95801581efccfae9a5b7831 /gcc/testsuite | |
| parent | e43b28ae7f09c0b7a30ab0dd976db761eeb1b0f9 (diff) | |
| download | gcc-f83adb68ed9cef1fbd4c16447eb4e89676df9f62.tar.gz | |
c++: spec_hasher::equal and PARM_DECLs [PR94632]
In the testcase below, during specialization of c<int>::d, we build two
identical specializations of the parameter type b<decltype(e)::k> -- one when
substituting into c<int>::d's TYPE_ARG_TYPES and another when substituting into
c<int>::d's DECL_ARGUMENTS.
We don't reuse the first specialization the second time around as a consequence
of the fix for PR c++/56247 which made PARM_DECLs always compare different from
one another during spec_hasher::equal. As a result, when looking up existing
specializations of 'b', spec_hasher::equal considers the template argument
decltype(e')::k to be different from decltype(e'')::k, where e' and e'' are the
result of two calls to tsubst_copy on the PARM_DECL e.
Since the two specializations are considered different due to the mentioned fix,
their TYPE_CANONICAL points to themselves even though they are otherwise
identical types, and this triggers an ICE in maybe_rebuild_function_decl_type
when comparing the TYPE_ARG_TYPES of c<int>::d to its DECL_ARGUMENTS.
This patch fixes this issue at the spec_hasher::equal level by ignoring the
'comparing_specializations' flag in cp_tree_equal whenever the DECL_CONTEXTs of
the two parameters are identical. This seems to be a sufficient condition to be
able to correctly compare PARM_DECLs structurally. (This also subsumes the
CONSTRAINT_VAR_P check since constraint variables all have empty, and therefore
identical, DECL_CONTEXTs.)
gcc/cp/ChangeLog:
PR c++/94632
* tree.c (cp_tree_equal) <case PARM_DECL>: Ignore
comparing_specializations if the parameters' contexts are identical.
gcc/testsuite/ChangeLog:
PR c++/94632
* g++.dg/template/canon-type-14.C: New test.
Diffstat (limited to 'gcc/testsuite')
| -rw-r--r-- | gcc/testsuite/ChangeLog | 3 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/template/canon-type-14.C | 8 |
2 files changed, 11 insertions, 0 deletions
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 08bef53e911..a41cc03f6fa 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,5 +1,8 @@ 2020-04-18 Patrick Palka <ppalka@redhat.com> + PR c++/94632 + * g++.dg/template/canon-type-14.C: New test. + PR c++/92187 * g++.dg/concepts/abbrev5.C: New test. * g++.dg/concepts/abbrev6.C: New test. diff --git a/gcc/testsuite/g++.dg/template/canon-type-14.C b/gcc/testsuite/g++.dg/template/canon-type-14.C new file mode 100644 index 00000000000..fa05bdb9a74 --- /dev/null +++ b/gcc/testsuite/g++.dg/template/canon-type-14.C @@ -0,0 +1,8 @@ +// PR c++/94632 +// { dg-do compile { target c++11 } } + +template <bool> struct b; +template <typename> class c { + template <typename f> static void d(f e, b<decltype(e)::k>); +}; +template class c<int>; |