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| author | Jason Merrill <jason@redhat.com> | 2020-05-05 17:39:19 -0400 |
|---|---|---|
| committer | Jason Merrill <jason@redhat.com> | 2020-05-05 17:39:31 -0400 |
| commit | 04b89192ace3a766a17374d5bef8fb19d9be2d7c (patch) | |
| tree | 5311f78e69d7c223b1fbbee8f33d64a0f3a351f3 /gcc/cp | |
| parent | d0aed8d5ba77e0756f3c9ebcd65eba1bfb11f24b (diff) | |
| download | gcc-04b89192ace3a766a17374d5bef8fb19d9be2d7c.zip gcc-04b89192ace3a766a17374d5bef8fb19d9be2d7c.tar.gz gcc-04b89192ace3a766a17374d5bef8fb19d9be2d7c.tar.bz2 | |
c++: constexpr and lambda capture [PR90212]
This is the same issue as PR86429, just in potential_constant_expression_1
rather than cxx_eval_constant_expression. As in that case, when we're
trying to evaluate a constant expression within a lambda, we don't have a
constant closure object to refer to, but we can try to refer directly to the
captured variable.
gcc/cp/ChangeLog
2020-05-05 Jason Merrill <jason@redhat.com>
PR c++/90212
* constexpr.c (potential_constant_expression_1): In a lambda
function, consider a captured variable directly.
Diffstat (limited to 'gcc/cp')
| -rw-r--r-- | gcc/cp/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/cp/constexpr.c | 8 |
2 files changed, 13 insertions, 1 deletions
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 17e24d2..71ca21f 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,9 @@ +2020-05-05 Jason Merrill <jason@redhat.com> + + PR c++/90212 + * constexpr.c (potential_constant_expression_1): In a lambda + function, consider a captured variable directly. + 2020-05-05 Iain Sandoe <iain@sandoe.co.uk> * coroutines.cc (transform_await_wrapper): Check that we have diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c index 637cb74..706d8a1 100644 --- a/gcc/cp/constexpr.c +++ b/gcc/cp/constexpr.c @@ -7520,12 +7520,18 @@ potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, variable with automatic storage duration defined outside that lambda-expression, where the reference would be an odr-use. */ + + if (want_rval) + /* Since we're doing an lvalue-rvalue conversion, this might + not be an odr-use, so evaluate the variable directly. */ + return RECUR (DECL_CAPTURED_VARIABLE (t), rval); + if (flags & tf_error) { tree cap = DECL_CAPTURED_VARIABLE (t); error ("lambda capture of %qE is not a constant expression", cap); - if (!want_rval && decl_constant_var_p (cap)) + if (decl_constant_var_p (cap)) inform (input_location, "because it is used as a glvalue"); } return false; |