diff options
Diffstat (limited to 'gcc/cp/class.c')
| -rw-r--r-- | gcc/cp/class.c | 287 |
1 files changed, 108 insertions, 179 deletions
diff --git a/gcc/cp/class.c b/gcc/cp/class.c index d189686..0dffc62 100644 --- a/gcc/cp/class.c +++ b/gcc/cp/class.c @@ -87,6 +87,9 @@ typedef struct vtbl_init_data_s /* Nonzero if we are building the initializer for a construction vtable. */ int ctor_vtbl_p; + /* True when adding vcall offset entries to the vtable. False when + merely computing the indices. */ + bool generate_vcall_entries; } vtbl_init_data; /* The type of a function passed to walk_subobject_offsets. */ @@ -209,6 +212,7 @@ static tree dfs_base_derived_from (tree, void *); static bool base_derived_from (tree, tree); static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree); static tree end_of_base (tree); +static tree get_vcall_index (tree, tree); /* Macros for dfs walking during vtt construction. See dfs_ctor_vtable_bases_queue_p, dfs_build_secondary_vptr_vtt_inits @@ -540,21 +544,14 @@ get_vtable_decl (type, complete) tree type; int complete; { - tree name = get_vtable_name (type); - tree decl = IDENTIFIER_GLOBAL_VALUE (name); - - if (decl) - { - my_friendly_assert (TREE_CODE (decl) == VAR_DECL - && DECL_VIRTUAL_P (decl), 20000118); - return decl; - } - - decl = build_vtable (type, name, void_type_node); - decl = pushdecl_top_level (decl); - my_friendly_assert (IDENTIFIER_GLOBAL_VALUE (name) == decl, - 20000517); + tree decl; + + if (CLASSTYPE_VTABLES (type)) + return CLASSTYPE_VTABLES (type); + decl = build_vtable (type, get_vtable_name (type), void_type_node); + CLASSTYPE_VTABLES (type) = decl; + /* At one time the vtable info was grabbed 2 words at a time. This fails on sparc unless you have 8-byte alignment. (tiemann) */ DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node), @@ -581,10 +578,7 @@ copy_virtuals (binfo) copies = copy_list (BINFO_VIRTUALS (binfo)); for (t = copies; t; t = TREE_CHAIN (t)) - { - BV_VCALL_INDEX (t) = NULL_TREE; - BV_USE_VCALL_INDEX_P (t) = 0; - } + BV_VCALL_INDEX (t) = NULL_TREE; return copies; } @@ -1559,7 +1553,6 @@ set_primary_base (t, binfo) TYPE_BINFO_VTABLE (t) = TYPE_BINFO_VTABLE (basetype); TYPE_BINFO_VIRTUALS (t) = TYPE_BINFO_VIRTUALS (basetype); TYPE_VFIELD (t) = TYPE_VFIELD (basetype); - CLASSTYPE_RTTI (t) = CLASSTYPE_RTTI (basetype); } /* Determine the primary class for T. */ @@ -1585,12 +1578,6 @@ determine_primary_base (t) if (TYPE_CONTAINS_VPTR_P (basetype)) { - /* Even a virtual baseclass can contain our RTTI - information. But, we prefer a non-virtual polymorphic - baseclass. */ - if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t)) - CLASSTYPE_RTTI (t) = CLASSTYPE_RTTI (basetype); - /* We prefer a non-virtual base, although a virtual one will do. */ if (TREE_VIA_VIRTUAL (base_binfo)) @@ -2325,21 +2312,23 @@ find_final_overrider (t, binfo, fn) return ffod.candidates; } -/* Returns the function from the BINFO_VIRTUALS entry in T which matches - the signature of FUNCTION_DECL FN, or NULL_TREE if none. In other words, - the function that the slot in T's primary vtable points to. */ +/* Return the index of the vcall offset for FN when TYPE is used as a + virtual base. */ -static tree get_matching_virtual PARAMS ((tree, tree)); static tree -get_matching_virtual (t, fn) - tree t, fn; +get_vcall_index (tree fn, tree type) { - tree f; + tree v; - for (f = BINFO_VIRTUALS (TYPE_BINFO (t)); f; f = TREE_CHAIN (f)) - if (same_signature_p (BV_FN (f), fn)) - return BV_FN (f); - return NULL_TREE; + for (v = CLASSTYPE_VCALL_INDICES (type); v; v = TREE_CHAIN (v)) + if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (TREE_PURPOSE (v))) + || same_signature_p (fn, TREE_PURPOSE (v))) + break; + + /* There should always be an appropriate index. */ + my_friendly_assert (v, 20021103); + + return TREE_VALUE (v); } /* Update an entry in the vtable for BINFO, which is in the hierarchy @@ -2407,7 +2396,6 @@ update_vtable_entry_for_fn (t, binfo, fn, virtuals) /* Compute the constant adjustment to the `this' pointer. The `this' pointer, when this function is called, will point at BINFO (or one of its primary bases, which are at the same offset). */ - if (virtual_base) /* The `this' pointer needs to be adjusted from the declaration to the nearest virtual base. */ @@ -2420,36 +2408,11 @@ update_vtable_entry_for_fn (t, binfo, fn, virtuals) will be zero, as it will be a primary base. */ delta = size_zero_node; else - { - /* The `this' pointer needs to be adjusted from pointing to - BINFO to pointing at the base where the final overrider - appears. */ - delta = size_diffop (BINFO_OFFSET (TREE_VALUE (overrider)), - BINFO_OFFSET (binfo)); - - if (! integer_zerop (delta)) - { - /* We'll need a thunk. But if we have a (perhaps formerly) - primary virtual base, we have a vcall slot for this function, - so we can use it rather than create a non-virtual thunk. */ - - b = get_primary_binfo (first_defn); - for (; b; b = get_primary_binfo (b)) - { - tree f = get_matching_virtual (BINFO_TYPE (b), fn); - if (!f) - /* b doesn't have this function; no suitable vbase. */ - break; - if (TREE_VIA_VIRTUAL (b)) - { - /* Found one; we can treat ourselves as a virtual base. */ - virtual_base = binfo; - delta = size_zero_node; - break; - } - } - } - } + /* The `this' pointer needs to be adjusted from pointing to + BINFO to pointing at the base where the final overrider + appears. */ + delta = size_diffop (BINFO_OFFSET (TREE_VALUE (overrider)), + BINFO_OFFSET (binfo)); modify_vtable_entry (t, binfo, @@ -2458,7 +2421,9 @@ update_vtable_entry_for_fn (t, binfo, fn, virtuals) virtuals); if (virtual_base) - BV_USE_VCALL_INDEX_P (*virtuals) = 1; + BV_VCALL_INDEX (*virtuals) + = get_vcall_index (TREE_PURPOSE (overrider), + BINFO_TYPE (virtual_base)); } /* Called from modify_all_vtables via dfs_walk. */ @@ -5101,32 +5066,8 @@ layout_class_type (tree t, tree *virtuals_p) splay_tree_delete (empty_base_offsets); } -/* Create a RECORD_TYPE or UNION_TYPE node for a C struct or union declaration - (or C++ class declaration). - - For C++, we must handle the building of derived classes. - Also, C++ allows static class members. The way that this is - handled is to keep the field name where it is (as the DECL_NAME - of the field), and place the overloaded decl in the bit position - of the field. layout_record and layout_union will know about this. - - More C++ hair: inline functions have text in their - DECL_PENDING_INLINE_INFO nodes which must somehow be parsed into - meaningful tree structure. After the struct has been laid out, set - things up so that this can happen. - - And still more: virtual functions. In the case of single inheritance, - when a new virtual function is seen which redefines a virtual function - from the base class, the new virtual function is placed into - the virtual function table at exactly the same address that - it had in the base class. When this is extended to multiple - inheritance, the same thing happens, except that multiple virtual - function tables must be maintained. The first virtual function - table is treated in exactly the same way as in the case of single - inheritance. Additional virtual function tables have different - DELTAs, which tell how to adjust `this' to point to the right thing. - - ATTRIBUTES is the set of decl attributes to be applied, if any. */ +/* Perform processing required when the definition of T (a class type) + is complete. */ void finish_struct_1 (t) @@ -5153,7 +5094,6 @@ finish_struct_1 (t) TYPE_SIZE (t) = NULL_TREE; CLASSTYPE_GOT_SEMICOLON (t) = 0; CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE; - CLASSTYPE_RTTI (t) = NULL_TREE; fixup_inline_methods (t); @@ -5210,24 +5150,6 @@ finish_struct_1 (t) /* Here we know enough to change the type of our virtual function table, but we will wait until later this function. */ build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t); - - /* If this type has basetypes with constructors, then those - constructors might clobber the virtual function table. But - they don't if the derived class shares the exact vtable of the base - class. */ - CLASSTYPE_NEEDS_VIRTUAL_REINIT (t) = 1; - } - /* If we didn't need a new vtable, see if we should copy one from - the base. */ - else if (CLASSTYPE_HAS_PRIMARY_BASE_P (t)) - { - tree binfo = CLASSTYPE_PRIMARY_BINFO (t); - - /* If this class uses a different vtable than its primary base - then when we will need to initialize our vptr after the base - class constructor runs. */ - if (TYPE_BINFO_VTABLE (t) != BINFO_VTABLE (binfo)) - CLASSTYPE_NEEDS_VIRTUAL_REINIT (t) = 1; } if (TYPE_CONTAINS_VPTR_P (t)) @@ -5253,6 +5175,9 @@ finish_struct_1 (t) ? TARGET_VTABLE_USES_DESCRIPTORS : 1)) if (TREE_CODE (DECL_VINDEX (BV_FN (fn))) != INTEGER_CST) DECL_VINDEX (BV_FN (fn)) = build_shared_int_cst (vindex); + + /* Add this class to the list of dynamic classes. */ + dynamic_classes = tree_cons (NULL_TREE, t, dynamic_classes); } finish_struct_bits (t); @@ -7068,8 +6993,10 @@ build_vtt (t) /* Now, build the VTT object itself. */ vtt = build_vtable (t, get_vtt_name (t), type); - pushdecl_top_level (vtt); initialize_array (vtt, inits); + /* Add the VTT to the vtables list. */ + TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t)); + TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt; dump_vtt (t, vtt); } @@ -7404,7 +7331,7 @@ build_ctor_vtbl_group (binfo, t) TREE_TYPE (vtbl) = type; /* Initialize the construction vtable. */ - pushdecl_top_level (vtbl); + CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl); initialize_array (vtbl, inits); dump_vtable (t, binfo, vtbl); } @@ -7621,6 +7548,7 @@ build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo, non_fn_entries_p) vid.last_init = &vid.inits; vid.primary_vtbl_p = (binfo == TYPE_BINFO (t)); vid.ctor_vtbl_p = !same_type_p (BINFO_TYPE (rtti_binfo), t); + vid.generate_vcall_entries = true; /* The first vbase or vcall offset is at index -3 in the vtable. */ vid.index = ssize_int (-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE); @@ -7704,14 +7632,7 @@ build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo, non_fn_entries_p) /* Pull the offset for `this', and the function to call, out of the list. */ delta = BV_DELTA (v); - - if (BV_USE_VCALL_INDEX_P (v)) - { - vcall_index = BV_VCALL_INDEX (v); - my_friendly_assert (vcall_index != NULL_TREE, 20000621); - } - else - vcall_index = NULL_TREE; + vcall_index = BV_VCALL_INDEX (v); my_friendly_assert (TREE_CODE (delta) == INTEGER_CST, 19990727); my_friendly_assert (TREE_CODE (fn) == FUNCTION_DECL, 19990727); @@ -7900,31 +7821,37 @@ build_vcall_offset_vtbl_entries (binfo, vid) tree binfo; vtbl_init_data *vid; { - /* We only need these entries if this base is a virtual base. */ - if (!TREE_VIA_VIRTUAL (binfo)) - return; - - /* We need a vcall offset for each of the virtual functions in this - vtable. For example: + /* We only need these entries if this base is a virtual base. We + compute the indices -- but do not add to the vtable -- when + building the main vtable for a class. */ + if (TREE_VIA_VIRTUAL (binfo) || binfo == TYPE_BINFO (vid->derived)) + { + /* We need a vcall offset for each of the virtual functions in this + vtable. For example: - class A { virtual void f (); }; - class B1 : virtual public A { virtual void f (); }; - class B2 : virtual public A { virtual void f (); }; - class C: public B1, public B2 { virtual void f (); }; + class A { virtual void f (); }; + class B1 : virtual public A { virtual void f (); }; + class B2 : virtual public A { virtual void f (); }; + class C: public B1, public B2 { virtual void f (); }; - A C object has a primary base of B1, which has a primary base of A. A - C also has a secondary base of B2, which no longer has a primary base - of A. So the B2-in-C construction vtable needs a secondary vtable for - A, which will adjust the A* to a B2* to call f. We have no way of - knowing what (or even whether) this offset will be when we define B2, - so we store this "vcall offset" in the A sub-vtable and look it up in - a "virtual thunk" for B2::f. + A C object has a primary base of B1, which has a primary base of A. A + C also has a secondary base of B2, which no longer has a primary base + of A. So the B2-in-C construction vtable needs a secondary vtable for + A, which will adjust the A* to a B2* to call f. We have no way of + knowing what (or even whether) this offset will be when we define B2, + so we store this "vcall offset" in the A sub-vtable and look it up in + a "virtual thunk" for B2::f. - We need entries for all the functions in our primary vtable and - in our non-virtual bases' secondary vtables. */ - vid->vbase = binfo; - /* Now, walk through the non-virtual bases, adding vcall offsets. */ - add_vcall_offset_vtbl_entries_r (binfo, vid); + We need entries for all the functions in our primary vtable and + in our non-virtual bases' secondary vtables. */ + vid->vbase = binfo; + /* If we are just computing the vcall indices -- but do not need + the actual entries -- not that. */ + if (!TREE_VIA_VIRTUAL (binfo)) + vid->generate_vcall_entries = false; + /* Now, walk through the non-virtual bases, adding vcall offsets. */ + add_vcall_offset_vtbl_entries_r (binfo, vid); + } } /* Build vcall offsets, starting with those for BINFO. */ @@ -8025,8 +7952,6 @@ add_vcall_offset_vtbl_entries_1 (binfo, vid) { tree orig_fn; tree fn; - tree base; - tree base_binfo; size_t i; tree vcall_offset; @@ -8057,42 +7982,17 @@ add_vcall_offset_vtbl_entries_1 (binfo, vid) even though there are two virtual table entries. */ || (DECL_DESTRUCTOR_P (BV_FN (derived_entry)) && DECL_DESTRUCTOR_P (fn))) - { - if (!vid->ctor_vtbl_p) - BV_VCALL_INDEX (derived_virtuals) - = BV_VCALL_INDEX (derived_entry); - break; - } + break; } if (i != VARRAY_ACTIVE_SIZE (vid->fns)) continue; - /* The FN comes from BASE. So, we must calculate the adjustment from - vid->vbase to BASE. We can just look for BASE in the complete - object because we are converting from a virtual base, so if there - were multiple copies, there would not be a unique final overrider - and vid->derived would be ill-formed. */ - base = DECL_CONTEXT (fn); - base_binfo = lookup_base (vid->derived, base, ba_any, NULL); - - /* Compute the vcall offset. */ - /* As mentioned above, the vbase we're working on is a primary base of - vid->binfo. But it might be a lost primary, so its BINFO_OFFSET - might be wrong, so we just use the BINFO_OFFSET from vid->binfo. */ - vcall_offset = BINFO_OFFSET (vid->binfo); - vcall_offset = size_diffop (BINFO_OFFSET (base_binfo), - vcall_offset); - vcall_offset = fold (build1 (NOP_EXPR, vtable_entry_type, - vcall_offset)); - - *vid->last_init = build_tree_list (NULL_TREE, vcall_offset); - vid->last_init = &TREE_CHAIN (*vid->last_init); - - /* Keep track of the vtable index where this vcall offset can be - found. For a construction vtable, we already made this - annotation when we built the original vtable. */ - if (!vid->ctor_vtbl_p) - BV_VCALL_INDEX (derived_virtuals) = vid->index; + /* If we are building these vcall offsets as part of building + the vtable for the most derived class, remember the vcall + offset. */ + if (vid->binfo == TYPE_BINFO (vid->derived)) + CLASSTYPE_VCALL_INDICES (vid->derived) + = tree_cons (fn, vid->index, CLASSTYPE_VCALL_INDICES (vid->derived)); /* The next vcall offset will be found at a more negative offset. */ @@ -8101,6 +8001,35 @@ add_vcall_offset_vtbl_entries_1 (binfo, vid) /* Keep track of this function. */ VARRAY_PUSH_TREE (vid->fns, derived_virtuals); + + if (vid->generate_vcall_entries) + { + tree base; + tree base_binfo; + + /* The FN comes from BASE. So, we must calculate the + adjustment from vid->vbase to BASE. We can just look for + BASE in the complete object because we are converting + from a virtual base, so if there were multiple copies, + there would not be a unique final overrider and + vid->derived would be ill-formed. */ + base = DECL_CONTEXT (fn); + base_binfo = lookup_base (vid->derived, base, ba_any, NULL); + + /* Compute the vcall offset. */ + /* As mentioned above, the vbase we're working on is a + primary base of vid->binfo. But it might be a lost + primary, so its BINFO_OFFSET might be wrong, so we just + use the BINFO_OFFSET from vid->binfo. */ + vcall_offset = BINFO_OFFSET (vid->binfo); + vcall_offset = size_diffop (BINFO_OFFSET (base_binfo), + vcall_offset); + vcall_offset = fold (build1 (NOP_EXPR, vtable_entry_type, + vcall_offset)); + + *vid->last_init = build_tree_list (NULL_TREE, vcall_offset); + vid->last_init = &TREE_CHAIN (*vid->last_init); + } } } |