On 11/7/23 14:52, Patrick Palka wrote:
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk?-- >8 -- The capture decltype handling in finish_decltype_type wasn't looking through implicit INDIRECT_REF (added by convert_from_reference), which caused us to incorrectly resolve decltype((x)) to float& below. We still don't fully accept the example ultimately because when processing the decltype inside the first lambda's trailing return type, we're in lambda type scope but not yet in lambda function scope that the check looks for, which seems like an orthogonal bug. PR c++/79620 gcc/cp/ChangeLog: * cp-tree.h (STRIP_REFERENCE_REF): Define. * semantics.cc (finish_decltype_type): Use it to look through implicit INDIRECT_REF when deciding whether to call capture_decltype. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/lambda/lambda-decltype3.C: New test. --- gcc/cp/cp-tree.h | 4 +++ gcc/cp/semantics.cc | 4 +-- .../g++.dg/cpp0x/lambda/lambda-decltype3.C | 28 +++++++++++++++++++ 3 files changed, 34 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/lambda/lambda-decltype3.C diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index b2603d4830e..1fa710d7154 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -4084,6 +4084,10 @@ struct GTY(()) lang_decl { && TREE_TYPE (TREE_OPERAND (NODE, 0)) \ && TYPE_REF_P (TREE_TYPE (TREE_OPERAND ((NODE), 0))))+/* Look through an implicit INDIRECT_REF from convert_from_reference. */+#define STRIP_REFERENCE_REF(NODE) \ + (REFERENCE_REF_P (NODE) ? TREE_OPERAND (NODE, 0) : NODE) + /* True iff this represents an lvalue being treated as an rvalue during return or throw as per [class.copy.elision]. */ #define IMPLICIT_RVALUE_P(NODE) \ diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc index f583dedd6cf..8df4521bf7c 100644 --- a/gcc/cp/semantics.cc +++ b/gcc/cp/semantics.cc @@ -11717,10 +11717,10 @@ finish_decltype_type (tree expr, bool id_expression_or_member_access_p, transformed into an access to a corresponding data member of the closure type that would have been declared if x were a use of the denoted entity. */ - if (outer_automatic_var_p (expr) + if (outer_automatic_var_p (STRIP_REFERENCE_REF (expr))
Let's also have outer_automatic_var_p assert that its argument is not REFERENCE_REF_P. OK with that change (if no regressions).
Jason
