On 11/7/23 14:52, Patrick Palka wrote:
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk?
OK.
-- >8 -- We usually don't see capture proxies in finish_decltype_type because process_outer_var_ref is a no-op inside an unevaluated context and so a use of a capture inside decltype refers directly to the captured variable. But we can still see a capture proxy during decltype(auto) deduction and for decltype of an init-capture, which suggests we need to handle capture proxies specially within finish_decltype_type (since they're always implicitly const). This patch adds such handling. PR c++/79378 PR c++/96917 gcc/cp/ChangeLog: * semantics.cc (finish_decltype_type): Handle an id-expression naming a capture proxy specially. gcc/testsuite/ChangeLog: * g++.dg/cpp1y/decltype-auto7.C: New test. * g++.dg/cpp1y/lambda-init20.C: New test. --- gcc/cp/semantics.cc | 28 +++++++++-- gcc/testsuite/g++.dg/cpp1y/decltype-auto7.C | 53 +++++++++++++++++++++ gcc/testsuite/g++.dg/cpp1y/lambda-init20.C | 22 +++++++++ 3 files changed, 98 insertions(+), 5 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp1y/decltype-auto7.C create mode 100644 gcc/testsuite/g++.dg/cpp1y/lambda-init20.C diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc index 4059e74bdb7..f583dedd6cf 100644 --- a/gcc/cp/semantics.cc +++ b/gcc/cp/semantics.cc @@ -11643,12 +11643,30 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p, /* Fall through for fields that aren't bitfields. */ gcc_fallthrough ();- case FUNCTION_DECL:case VAR_DECL: - case CONST_DECL: - case PARM_DECL: - case RESULT_DECL: - case TEMPLATE_PARM_INDEX: + if (is_capture_proxy (expr)) + { + if (is_normal_capture_proxy (expr)) + { + expr = DECL_CAPTURED_VARIABLE (expr); + type = TREE_TYPE (expr); + type = non_reference (type); + } + else + { + expr = DECL_VALUE_EXPR (expr); + gcc_assert (TREE_CODE (expr) == COMPONENT_REF); + expr = TREE_OPERAND (expr, 1); + type = TREE_TYPE (expr); + } + break; + } + /* Fall through. */ + case FUNCTION_DECL: + case CONST_DECL: + case PARM_DECL: + case RESULT_DECL: + case TEMPLATE_PARM_INDEX: expr = mark_type_use (expr); type = TREE_TYPE (expr); if (VAR_P (expr) && DECL_NTTP_OBJECT_P (expr)) diff --git a/gcc/testsuite/g++.dg/cpp1y/decltype-auto7.C b/gcc/testsuite/g++.dg/cpp1y/decltype-auto7.C new file mode 100644 index 00000000000..a37b9db38d4 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/decltype-auto7.C @@ -0,0 +1,53 @@ +// PR c++/96917 +// { dg-do compile { target c++14 } } + +int main() { + int x = 0; + int y = 0; + const int cx = 0; + const int cy = 0; + + [x, &y, cx, &cy] { + decltype(auto) a = x; + using ty1 = int; + using ty1 = decltype(x); + using ty1 = decltype(a); + + decltype(auto) b = y; + using ty2 = int; + using ty2 = decltype(y); + using ty2 = decltype(b); + + decltype(auto) ca = cx; + using ty3 = const int; + using ty3 = decltype(cx); + using ty3 = decltype(ca); + + decltype(auto) cb = cy; + using ty4 = const int; + using ty4 = decltype(cy); + using ty4 = decltype(cb); + }; + + [x=x, &y=y, cx=cx, &cy=cy] { + decltype(auto) a = x; + using ty1 = int; + using ty1 = decltype(x); + using ty1 = decltype(a); + + decltype(auto) b = y; + using ty2 = int&; + using ty2 = decltype(y); + using ty2 = decltype(b); + + decltype(auto) ca = cx; + using ty3 = int; + using ty3 = decltype(cx); + using ty3 = decltype(ca); + + decltype(auto) cb = cy; + using ty4 = const int&; + using ty4 = decltype(cy); + using ty4 = decltype(cb); + }; +} diff --git a/gcc/testsuite/g++.dg/cpp1y/lambda-init20.C b/gcc/testsuite/g++.dg/cpp1y/lambda-init20.C new file mode 100644 index 00000000000..a06b77a664d --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/lambda-init20.C @@ -0,0 +1,22 @@ +// PR c++/79378 +// { dg-do compile { target c++14 } } + +int main() { + int x = 0; + [x=x, &r=x] { + using ty1 = int; + using ty1 = decltype(x); + + using ty2 = int&; + using ty2 = decltype(r); + }; + + const int cx = 0; + [x=cx, &r=cx] { + using ty1 = int; + using ty1 = decltype(x); + + using ty2 = const int&; + using ty2 = decltype(r); + }; +}
