From b95eba48a1a25284ce7385bbfa0ee733124cb84b Mon Sep 17 00:00:00 2001 From: Nathan Sidwell Date: Wed, 22 Jul 2020 12:00:02 -0700 Subject: [PATCH] c++: Name as_base type The as-base type never got a name. For modules I needed to give it a name to serialize properly, and it's useful when debugging the compiler, so we may as well have it on trunk. There's also a bug where its fields can have NSDMIs from the main class. This happens to be silent on trunk, but can be a GC leak where we retain a deferred parse node there. (On modules it blows up, because we're not prepared to serialize deferred parse nodes, as they should never survive parsing. gcc/cp/ * cp-tree.h (enum cp_tree_index): Add CPTI_AS_BASE_IDENTIFIER. (as_base_identifier): Define. * decl.c (initialize_predifined_identifiers): Initialize as_base identifier. * class.c (layout_class_type): Name the as-base type. Zap NSDMI its fields may have. --- gcc/cp/class.c | 9 +++++++-- gcc/cp/cp-tree.h | 2 ++ gcc/cp/decl.c | 1 + 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/gcc/cp/class.c b/gcc/cp/class.c index a3913f4ce0b..ba96113bc88 100644 --- a/gcc/cp/class.c +++ b/gcc/cp/class.c @@ -6715,6 +6715,10 @@ layout_class_type (tree t, tree *virtuals_p) /* T needs a different layout as a base (eliding virtual bases or whatever). Create that version. */ tree base_t = make_node (TREE_CODE (t)); + tree base_d = create_implicit_typedef (as_base_identifier, base_t); + + TYPE_CONTEXT (base_t) = t; + DECL_CONTEXT (base_d) = t; /* If the ABI version is not at least two, and the last field was a bit-field, RLI may not be on a byte @@ -6751,6 +6755,9 @@ layout_class_type (tree t, tree *virtuals_p) if (TREE_CODE (field) == FIELD_DECL) { *next_field = copy_node (field); + /* Zap any NSDMI, it's not needed and might be a deferred + parse. */ + DECL_INITIAL (*next_field) = NULL_TREE; DECL_CONTEXT (*next_field) = base_t; next_field = &DECL_CHAIN (*next_field); } @@ -6760,8 +6767,6 @@ layout_class_type (tree t, tree *virtuals_p) needs a mode. */ compute_record_mode (base_t); - TYPE_CONTEXT (base_t) = t; - /* Record the base version of the type. */ CLASSTYPE_AS_BASE (t) = base_t; } diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h index d43c53ae29a..2377fc052bb 100644 --- a/gcc/cp/cp-tree.h +++ b/gcc/cp/cp-tree.h @@ -148,6 +148,7 @@ enum cp_tree_index CPTI_DELTA_IDENTIFIER, CPTI_IN_CHARGE_IDENTIFIER, CPTI_VTT_PARM_IDENTIFIER, + CPTI_AS_BASE_IDENTIFIER, CPTI_THIS_IDENTIFIER, CPTI_PFN_IDENTIFIER, CPTI_VPTR_IDENTIFIER, @@ -289,6 +290,7 @@ extern GTY(()) tree cp_global_trees[CPTI_MAX]; /* The name of the parameter that contains a pointer to the VTT to use for this subobject constructor or destructor. */ #define vtt_parm_identifier cp_global_trees[CPTI_VTT_PARM_IDENTIFIER] +#define as_base_identifier cp_global_trees[CPTI_AS_BASE_IDENTIFIER] #define this_identifier cp_global_trees[CPTI_THIS_IDENTIFIER] #define pfn_identifier cp_global_trees[CPTI_PFN_IDENTIFIER] #define vptr_identifier cp_global_trees[CPTI_VPTR_IDENTIFIER] diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c index de53a7b8b73..385b1f3a0c4 100644 --- a/gcc/cp/decl.c +++ b/gcc/cp/decl.c @@ -4202,6 +4202,7 @@ initialize_predefined_identifiers (void) {"__dt_del ", &deleting_dtor_identifier, cik_dtor}, {"__conv_op ", &conv_op_identifier, cik_conv_op}, {"__in_chrg", &in_charge_identifier, cik_normal}, + {"__as_base ", &as_base_identifier, cik_normal}, {"this", &this_identifier, cik_normal}, {"__delta", &delta_identifier, cik_normal}, {"__pfn", &pfn_identifier, cik_normal}, -- 2.30.2