Here instantiating the noexcept-specifier for bar<void>() means instantiating A<void>::value, which complains about the conversion from 0 to int* in the default argument of foo. Since my patch for PR99583, printing the error context involves looking at C<void>::type, which again wants to instantiate A<void>::value, which breaks. For now at least, let's break this recursion by avoiding looking into the noexcept-specifier in find_typenames, and limit that to just the uses_parameter_packs case that PR99583 cares about.
Tested x86_64-pc-linux-gnu, applying to trunk. gcc/cp/ChangeLog: PR c++/100101 PR c++/99583 * pt.c (find_parameter_packs_r) [FUNCTION_TYPE]: Walk into TYPE_RAISES_EXCEPTIONS here. * tree.c (cp_walk_subtrees): Not here. gcc/testsuite/ChangeLog: PR c++/100101 * g++.dg/cpp0x/noexcept67.C: New test. --- gcc/cp/pt.c | 11 +++++++++++ gcc/cp/tree.c | 5 ----- gcc/testsuite/g++.dg/cpp0x/noexcept67.C | 26 +++++++++++++++++++++++++ 3 files changed, 37 insertions(+), 5 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/noexcept67.C diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 0f119a55272..2190f83882a 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -3890,6 +3890,10 @@ find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data) (struct find_parameter_pack_data*)data; bool parameter_pack_p = false; +#define WALK_SUBTREE(NODE) \ + cp_walk_tree (&(NODE), &find_parameter_packs_r, \ + ppd, ppd->visited) \ + /* 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. */ @@ -4070,10 +4074,17 @@ find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data) ppd, ppd->visited); return NULL_TREE; + case FUNCTION_TYPE: + case METHOD_TYPE: + WALK_SUBTREE (TYPE_RAISES_EXCEPTIONS (t)); + break; + default: return NULL_TREE; } +#undef WALK_SUBTREE + return NULL_TREE; } diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c index 13cc61c3123..dca947bf52a 100644 --- a/gcc/cp/tree.c +++ b/gcc/cp/tree.c @@ -5415,11 +5415,6 @@ cp_walk_subtrees (tree *tp, int *walk_subtrees_p, walk_tree_fn func, } break; - case FUNCTION_TYPE: - case METHOD_TYPE: - WALK_SUBTREE (TYPE_RAISES_EXCEPTIONS (*tp)); - break; - default: return NULL_TREE; } diff --git a/gcc/testsuite/g++.dg/cpp0x/noexcept67.C b/gcc/testsuite/g++.dg/cpp0x/noexcept67.C new file mode 100644 index 00000000000..7f061034323 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/noexcept67.C @@ -0,0 +1,26 @@ +// PR c++/100101 +// { dg-do compile { target c++11 } } + +template <typename T> struct A +{ + template <typename U> static char foo(U*, int* = 0); + static const bool value = sizeof(foo(static_cast<T*>(nullptr))) > 0; +}; + +template <bool b> struct B +{ + static const bool value = b; +}; + +template <typename T> struct C +{ + typedef B<A<T>::value> type; +}; + +template <typename T> +void bar() noexcept(A<T>::value && C<T>::type::value) {} + +void baz() +{ + bar<void>(); +} base-commit: a25590f29d07a88f6bf1b2c1ab0e4e012725db98 -- 2.27.0