| Message ID | 20241015044821.1488337-1-ppalka@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: checking ICE w/ lambda targ inside constexpr if [PR117054] | expand |
On 10/15/24 12:48 AM, Patrick Palka wrote: > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK > for trunk? OK. > -- >8 -- > > Here we're tripping over the assert in extract_locals_r which enforces > that an extra-args tree appearing inside another extra-args tree doesn't > actually have extra args. This invariant no longer always holds for > lambdas (which recently gained the extra-args mechanism), but it should > be safe to just disable the assert for them since cp_walk_subtrees doesn't > walk LAMBDA_EXPR_EXTRA_ARGS and so should be immune to the PR114303 issue > for now. > > PR c++/117054 > > gcc/cp/ChangeLog: > > * pt.cc (extract_locals_r): Disable tree_extra_args assert > for LAMBDA_EXPR. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp2a/lambda-targ9.C: New test. > --- > gcc/cp/pt.cc | 7 ++++++- > gcc/testsuite/g++.dg/cpp2a/lambda-targ9.C | 16 ++++++++++++++++ > 2 files changed, 22 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/cpp2a/lambda-targ9.C > > diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc > index c7cbf6df26c..b90447ae6a2 100644 > --- a/gcc/cp/pt.cc > +++ b/gcc/cp/pt.cc > @@ -13479,7 +13479,12 @@ extract_locals_r (tree *tp, int *walk_subtrees, void *data_) > outermost tree. Nested *_EXTRA_ARGS should naturally be empty since > the outermost (extra-args) tree will intercept any substitution before > a nested tree can. */ > - gcc_checking_assert (tree_extra_args (*tp) == NULL_TREE); > + gcc_checking_assert (tree_extra_args (*tp) == NULL_TREE > + /* Except a lambda nested inside an extra-args tree > + can have extra args if we deferred partial > + substitution into it at template parse time. But > + we don't walk LAMBDA_EXPR_EXTRA_ARGS anyway. */ > + || TREE_CODE (*tp) == LAMBDA_EXPR); > > if (TREE_CODE (*tp) == DECL_EXPR) > { > diff --git a/gcc/testsuite/g++.dg/cpp2a/lambda-targ9.C b/gcc/testsuite/g++.dg/cpp2a/lambda-targ9.C > new file mode 100644 > index 00000000000..00dd4b2406e > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/lambda-targ9.C > @@ -0,0 +1,16 @@ > +// PR c++/117054 > +// { dg-do compile { target c++20 } } > + > +template<auto = [] {}> > +constexpr bool a = true; > + > +template<typename> > +void f() { > + [](auto) { > + if constexpr (a<>) {} > + }; > +} > + > +int main() { > + f<int>(); > +}
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index c7cbf6df26c..b90447ae6a2 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -13479,7 +13479,12 @@ extract_locals_r (tree *tp, int *walk_subtrees, void *data_) outermost tree. Nested *_EXTRA_ARGS should naturally be empty since the outermost (extra-args) tree will intercept any substitution before a nested tree can. */ - gcc_checking_assert (tree_extra_args (*tp) == NULL_TREE); + gcc_checking_assert (tree_extra_args (*tp) == NULL_TREE + /* Except a lambda nested inside an extra-args tree + can have extra args if we deferred partial + substitution into it at template parse time. But + we don't walk LAMBDA_EXPR_EXTRA_ARGS anyway. */ + || TREE_CODE (*tp) == LAMBDA_EXPR); if (TREE_CODE (*tp) == DECL_EXPR) { diff --git a/gcc/testsuite/g++.dg/cpp2a/lambda-targ9.C b/gcc/testsuite/g++.dg/cpp2a/lambda-targ9.C new file mode 100644 index 00000000000..00dd4b2406e --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/lambda-targ9.C @@ -0,0 +1,16 @@ +// PR c++/117054 +// { dg-do compile { target c++20 } } + +template<auto = [] {}> +constexpr bool a = true; + +template<typename> +void f() { + [](auto) { + if constexpr (a<>) {} + }; +} + +int main() { + f<int>(); +}