/* varobj support for C and C++. Copyright (C) 1999-2015 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ #include "defs.h" #include "value.h" #include "varobj.h" #include "gdbthread.h" #include "valprint.h" static void cplus_class_num_children (struct type *type, int children[3]); /* The names of varobjs representing anonymous structs or unions. */ #define ANONYMOUS_STRUCT_NAME _("") #define ANONYMOUS_UNION_NAME _("") /* Does CHILD represent a child with no name? This happens when the child is an anonmous struct or union and it has no field name in its parent variable. This has already been determined by *_describe_child. The easiest thing to do is to compare the child's name with ANONYMOUS_*_NAME. */ int varobj_is_anonymous_child (struct varobj *child) { return (strcmp (child->name, ANONYMOUS_STRUCT_NAME) == 0 || strcmp (child->name, ANONYMOUS_UNION_NAME) == 0); } /* Given the value and the type of a variable object, adjust the value and type to those necessary for getting children of the variable object. This includes dereferencing top-level references to all types and dereferencing pointers to structures. If LOOKUP_ACTUAL_TYPE is set the enclosing type of the value will be fetched and if it differs from static type the value will be casted to it. Both TYPE and *TYPE should be non-null. VALUE can be null if we want to only translate type. *VALUE can be null as well -- if the parent value is not known. If WAS_PTR is not NULL, set *WAS_PTR to 0 or 1 depending on whether pointer was dereferenced in this function. */ static void adjust_value_for_child_access (struct value **value, struct type **type, int *was_ptr, int lookup_actual_type) { gdb_assert (type && *type); if (was_ptr) *was_ptr = 0; *type = check_typedef (*type); /* The type of value stored in varobj, that is passed to us, is already supposed to be reference-stripped. */ gdb_assert (TYPE_CODE (*type) != TYPE_CODE_REF); /* Pointers to structures are treated just like structures when accessing children. Don't dererences pointers to other types. */ if (TYPE_CODE (*type) == TYPE_CODE_PTR) { struct type *target_type = get_target_type (*type); if (TYPE_CODE (target_type) == TYPE_CODE_STRUCT || TYPE_CODE (target_type) == TYPE_CODE_UNION) { if (value && *value) { volatile struct gdb_exception except; TRY_CATCH (except, RETURN_MASK_ERROR) { *value = value_ind (*value); } if (except.reason < 0) *value = NULL; } *type = target_type; if (was_ptr) *was_ptr = 1; } } /* The 'get_target_type' function calls check_typedef on result, so we can immediately check type code. No need to call check_typedef here. */ /* Access a real type of the value (if necessary and possible). */ if (value && *value && lookup_actual_type) { struct type *enclosing_type; int real_type_found = 0; enclosing_type = value_actual_type (*value, 1, &real_type_found); if (real_type_found) { *type = enclosing_type; *value = value_cast (enclosing_type, *value); } } } /* Is VAR a path expression parent, i.e., can it be used to construct a valid path expression? */ static int c_is_path_expr_parent (struct varobj *var) { struct type *type; /* "Fake" children are not path_expr parents. */ if (CPLUS_FAKE_CHILD (var)) return 0; type = varobj_get_gdb_type (var); /* Anonymous unions and structs are also not path_expr parents. */ if ((TYPE_CODE (type) == TYPE_CODE_STRUCT || TYPE_CODE (type) == TYPE_CODE_UNION) && TYPE_NAME (type) == NULL && TYPE_TAG_NAME (type) == NULL) { struct varobj *parent = var->parent; while (parent != NULL && CPLUS_FAKE_CHILD (parent)) parent = parent->parent; if (parent != NULL) { struct type *parent_type; int was_ptr; parent_type = varobj_get_value_type (parent); adjust_value_for_child_access (NULL, &parent_type, &was_ptr, 0); if (TYPE_CODE (parent_type) == TYPE_CODE_STRUCT || TYPE_CODE (parent_type) == TYPE_CODE_UNION) { const char *field_name; gdb_assert (var->index < TYPE_NFIELDS (parent_type)); field_name = TYPE_FIELD_NAME (parent_type, var->index); return !(field_name == NULL || *field_name == '\0'); } } return 0; } return 1; } /* C */ static int c_number_of_children (struct varobj *var) { struct type *type = varobj_get_value_type (var); int children = 0; struct type *target; adjust_value_for_child_access (NULL, &type, NULL, 0); target = get_target_type (type); switch (TYPE_CODE (type)) { case TYPE_CODE_ARRAY: if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (target) > 0 && !TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED (type)) children = TYPE_LENGTH (type) / TYPE_LENGTH (target); else /* If we don't know how many elements there are, don't display any. */ children = 0; break; case TYPE_CODE_STRUCT: case TYPE_CODE_UNION: children = TYPE_NFIELDS (type); break; case TYPE_CODE_PTR: /* The type here is a pointer to non-struct. Typically, pointers have one child, except for function ptrs, which have no children, and except for void*, as we don't know what to show. We can show char* so we allow it to be dereferenced. If you decide to test for it, please mind that a little magic is necessary to properly identify it: char* has TYPE_CODE == TYPE_CODE_INT and TYPE_NAME == "char". */ if (TYPE_CODE (target) == TYPE_CODE_FUNC || TYPE_CODE (target) == TYPE_CODE_VOID) children = 0; else children = 1; break; default: /* Other types have no children. */ break; } return children; } static char * c_name_of_variable (struct varobj *parent) { return xstrdup (parent->name); } /* Return the value of element TYPE_INDEX of a structure value VALUE. VALUE's type should be a structure, or union, or a typedef to struct/union. Returns NULL if getting the value fails. Never throws. */ static struct value * value_struct_element_index (struct value *value, int type_index) { struct value *result = NULL; volatile struct gdb_exception e; struct type *type = value_type (value); type = check_typedef (type); gdb_assert (TYPE_CODE (type) == TYPE_CODE_STRUCT || TYPE_CODE (type) == TYPE_CODE_UNION); TRY_CATCH (e, RETURN_MASK_ERROR) { if (field_is_static (&TYPE_FIELD (type, type_index))) result = value_static_field (type, type_index); else result = value_primitive_field (value, 0, type_index, type); } if (e.reason < 0) { return NULL; } else { return result; } } /* Obtain the information about child INDEX of the variable object PARENT. If CNAME is not null, sets *CNAME to the name of the child relative to the parent. If CVALUE is not null, sets *CVALUE to the value of the child. If CTYPE is not null, sets *CTYPE to the type of the child. If any of CNAME, CVALUE, or CTYPE is not null, but the corresponding information cannot be determined, set *CNAME, *CVALUE, or *CTYPE to NULL. */ static void c_describe_child (struct varobj *parent, int index, char **cname, struct value **cvalue, struct type **ctype, char **cfull_expression) { struct value *value = parent->value; struct type *type = varobj_get_value_type (parent); char *parent_expression = NULL; int was_ptr; volatile struct gdb_exception except; if (cname) *cname = NULL; if (cvalue) *cvalue = NULL; if (ctype) *ctype = NULL; if (cfull_expression) { *cfull_expression = NULL; parent_expression = varobj_get_path_expr (varobj_get_path_expr_parent (parent)); } adjust_value_for_child_access (&value, &type, &was_ptr, 0); switch (TYPE_CODE (type)) { case TYPE_CODE_ARRAY: if (cname) *cname = xstrdup (int_string (index + TYPE_LOW_BOUND (TYPE_INDEX_TYPE (type)), 10, 1, 0, 0)); if (cvalue && value) { int real_index = index + TYPE_LOW_BOUND (TYPE_INDEX_TYPE (type)); TRY_CATCH (except, RETURN_MASK_ERROR) { *cvalue = value_subscript (value, real_index); } } if (ctype) *ctype = get_target_type (type); if (cfull_expression) *cfull_expression = xstrprintf ("(%s)[%s]", parent_expression, int_string (index + TYPE_LOW_BOUND (TYPE_INDEX_TYPE (type)), 10, 1, 0, 0)); break; case TYPE_CODE_STRUCT: case TYPE_CODE_UNION: { const char *field_name; /* If the type is anonymous and the field has no name, set an appropriate name. */ field_name = TYPE_FIELD_NAME (type, index); if (field_name == NULL || *field_name == '\0') { if (cname) { if (TYPE_CODE (TYPE_FIELD_TYPE (type, index)) == TYPE_CODE_STRUCT) *cname = xstrdup (ANONYMOUS_STRUCT_NAME); else *cname = xstrdup (ANONYMOUS_UNION_NAME); } if (cfull_expression) *cfull_expression = xstrdup (""); } else { if (cname) *cname = xstrdup (field_name); if (cfull_expression) { char *join = was_ptr ? "->" : "."; *cfull_expression = xstrprintf ("(%s)%s%s", parent_expression, join, field_name); } } if (cvalue && value) { /* For C, varobj index is the same as type index. */ *cvalue = value_struct_element_index (value, index); } if (ctype) *ctype = TYPE_FIELD_TYPE (type, index); } break; case TYPE_CODE_PTR: if (cname) *cname = xstrprintf ("*%s", parent->name); if (cvalue && value) { TRY_CATCH (except, RETURN_MASK_ERROR) { *cvalue = value_ind (value); } if (except.reason < 0) *cvalue = NULL; } /* Don't use get_target_type because it calls check_typedef and here, we want to show the true declared type of the variable. */ if (ctype) *ctype = TYPE_TARGET_TYPE (type); if (cfull_expression) *cfull_expression = xstrprintf ("*(%s)", parent_expression); break; default: /* This should not happen. */ if (cname) *cname = xstrdup ("???"); if (cfull_expression) *cfull_expression = xstrdup ("???"); /* Don't set value and type, we don't know then. */ } } static char * c_name_of_child (struct varobj *parent, int index) { char *name; c_describe_child (parent, index, &name, NULL, NULL, NULL); return name; } static char * c_path_expr_of_child (struct varobj *child) { char *path_expr; c_describe_child (child->parent, child->index, NULL, NULL, NULL, &path_expr); return path_expr; } static struct value * c_value_of_child (struct varobj *parent, int index) { struct value *value = NULL; c_describe_child (parent, index, NULL, &value, NULL, NULL); return value; } static struct type * c_type_of_child (struct varobj *parent, int index) { struct type *type = NULL; c_describe_child (parent, index, NULL, NULL, &type, NULL); return type; } /* This returns the type of the variable. It also skips past typedefs to return the real type of the variable. */ static struct type * get_type (struct varobj *var) { struct type *type; type = var->type; if (type != NULL) type = check_typedef (type); return type; } static char * c_value_of_variable (struct varobj *var, enum varobj_display_formats format) { /* BOGUS: if val_print sees a struct/class, or a reference to one, it will print out its children instead of "{...}". So we need to catch that case explicitly. */ struct type *type = get_type (var); /* Strip top-level references. */ while (TYPE_CODE (type) == TYPE_CODE_REF) type = check_typedef (TYPE_TARGET_TYPE (type)); switch (TYPE_CODE (type)) { case TYPE_CODE_STRUCT: case TYPE_CODE_UNION: return xstrdup ("{...}"); /* break; */ case TYPE_CODE_ARRAY: { char *number; number = xstrprintf ("[%d]", var->num_children); return (number); } /* break; */ default: { if (var->value == NULL) { /* This can happen if we attempt to get the value of a struct member when the parent is an invalid pointer. This is an error condition, so we should tell the caller. */ return NULL; } else { if (var->not_fetched && value_lazy (var->value)) /* Frozen variable and no value yet. We don't implicitly fetch the value. MI response will use empty string for the value, which is OK. */ return NULL; gdb_assert (varobj_value_is_changeable_p (var)); gdb_assert (!value_lazy (var->value)); /* If the specified format is the current one, we can reuse print_value. */ if (format == var->format) return xstrdup (var->print_value); else return varobj_value_get_print_value (var->value, format, var); } } } } /* varobj operations for c. */ const struct lang_varobj_ops c_varobj_ops = { c_number_of_children, c_name_of_variable, c_name_of_child, c_path_expr_of_child, c_value_of_child, c_type_of_child, c_value_of_variable, varobj_default_value_is_changeable_p, NULL, /* value_has_mutated */ c_is_path_expr_parent /* is_path_expr_parent */ }; /* A little convenience enum for dealing with C++/Java. */ enum vsections { v_public = 0, v_private, v_protected }; /* C++ */ static int cplus_number_of_children (struct varobj *var) { struct value *value = NULL; struct type *type; int children, dont_know; int lookup_actual_type = 0; struct value_print_options opts; dont_know = 1; children = 0; get_user_print_options (&opts); if (!CPLUS_FAKE_CHILD (var)) { type = varobj_get_value_type (var); /* It is necessary to access a real type (via RTTI). */ if (opts.objectprint) { value = var->value; lookup_actual_type = (TYPE_CODE (var->type) == TYPE_CODE_REF || TYPE_CODE (var->type) == TYPE_CODE_PTR); } adjust_value_for_child_access (&value, &type, NULL, lookup_actual_type); if (((TYPE_CODE (type)) == TYPE_CODE_STRUCT) || ((TYPE_CODE (type)) == TYPE_CODE_UNION)) { int kids[3]; cplus_class_num_children (type, kids); if (kids[v_public] != 0) children++; if (kids[v_private] != 0) children++; if (kids[v_protected] != 0) children++; /* Add any baseclasses. */ children += TYPE_N_BASECLASSES (type); dont_know = 0; /* FIXME: save children in var. */ } } else { int kids[3]; type = varobj_get_value_type (var->parent); /* It is necessary to access a real type (via RTTI). */ if (opts.objectprint) { struct varobj *parent = var->parent; value = parent->value; lookup_actual_type = (TYPE_CODE (parent->type) == TYPE_CODE_REF || TYPE_CODE (parent->type) == TYPE_CODE_PTR); } adjust_value_for_child_access (&value, &type, NULL, lookup_actual_type); cplus_class_num_children (type, kids); if (strcmp (var->name, "public") == 0) children = kids[v_public]; else if (strcmp (var->name, "private") == 0) children = kids[v_private]; else children = kids[v_protected]; dont_know = 0; } if (dont_know) children = c_number_of_children (var); return children; } /* Compute # of public, private, and protected variables in this class. That means we need to descend into all baseclasses and find out how many are there, too. */ static void cplus_class_num_children (struct type *type, int children[3]) { int i, vptr_fieldno; struct type *basetype = NULL; children[v_public] = 0; children[v_private] = 0; children[v_protected] = 0; vptr_fieldno = get_vptr_fieldno (type, &basetype); for (i = TYPE_N_BASECLASSES (type); i < TYPE_NFIELDS (type); i++) { /* If we have a virtual table pointer, omit it. Even if virtual table pointers are not specifically marked in the debug info, they should be artificial. */ if ((type == basetype && i == vptr_fieldno) || TYPE_FIELD_ARTIFICIAL (type, i)) continue; if (TYPE_FIELD_PROTECTED (type, i)) children[v_protected]++; else if (TYPE_FIELD_PRIVATE (type, i)) children[v_private]++; else children[v_public]++; } } static char * cplus_name_of_variable (struct varobj *parent) { return c_name_of_variable (parent); } enum accessibility { private_field, protected_field, public_field }; /* Check if field INDEX of TYPE has the specified accessibility. Return 0 if so and 1 otherwise. */ static int match_accessibility (struct type *type, int index, enum accessibility acc) { if (acc == private_field && TYPE_FIELD_PRIVATE (type, index)) return 1; else if (acc == protected_field && TYPE_FIELD_PROTECTED (type, index)) return 1; else if (acc == public_field && !TYPE_FIELD_PRIVATE (type, index) && !TYPE_FIELD_PROTECTED (type, index)) return 1; else return 0; } static void cplus_describe_child (struct varobj *parent, int index, char **cname, struct value **cvalue, struct type **ctype, char **cfull_expression) { struct value *value; struct type *type; int was_ptr; int lookup_actual_type = 0; char *parent_expression = NULL; struct varobj *var; struct value_print_options opts; if (cname) *cname = NULL; if (cvalue) *cvalue = NULL; if (ctype) *ctype = NULL; if (cfull_expression) *cfull_expression = NULL; get_user_print_options (&opts); var = (CPLUS_FAKE_CHILD (parent)) ? parent->parent : parent; if (opts.objectprint) lookup_actual_type = (TYPE_CODE (var->type) == TYPE_CODE_REF || TYPE_CODE (var->type) == TYPE_CODE_PTR); value = var->value; type = varobj_get_value_type (var); if (cfull_expression) parent_expression = varobj_get_path_expr (varobj_get_path_expr_parent (var)); adjust_value_for_child_access (&value, &type, &was_ptr, lookup_actual_type); if (TYPE_CODE (type) == TYPE_CODE_STRUCT || TYPE_CODE (type) == TYPE_CODE_UNION) { char *join = was_ptr ? "->" : "."; if (CPLUS_FAKE_CHILD (parent)) { /* The fields of the class type are ordered as they appear in the class. We are given an index for a particular access control type ("public","protected", or "private"). We must skip over fields that don't have the access control we are looking for to properly find the indexed field. */ int type_index = TYPE_N_BASECLASSES (type); enum accessibility acc = public_field; int vptr_fieldno; struct type *basetype = NULL; const char *field_name; vptr_fieldno = get_vptr_fieldno (type, &basetype); if (strcmp (parent->name, "private") == 0) acc = private_field; else if (strcmp (parent->name, "protected") == 0) acc = protected_field; while (index >= 0) { if ((type == basetype && type_index == vptr_fieldno) || TYPE_FIELD_ARTIFICIAL (type, type_index)) ; /* ignore vptr */ else if (match_accessibility (type, type_index, acc)) --index; ++type_index; } --type_index; /* If the type is anonymous and the field has no name, set an appopriate name. */ field_name = TYPE_FIELD_NAME (type, type_index); if (field_name == NULL || *field_name == '\0') { if (cname) { if (TYPE_CODE (TYPE_FIELD_TYPE (type, type_index)) == TYPE_CODE_STRUCT) *cname = xstrdup (ANONYMOUS_STRUCT_NAME); else if (TYPE_CODE (TYPE_FIELD_TYPE (type, type_index)) == TYPE_CODE_UNION) *cname = xstrdup (ANONYMOUS_UNION_NAME); } if (cfull_expression) *cfull_expression = xstrdup (""); } else { if (cname) *cname = xstrdup (TYPE_FIELD_NAME (type, type_index)); if (cfull_expression) *cfull_expression = xstrprintf ("((%s)%s%s)", parent_expression, join, field_name); } if (cvalue && value) *cvalue = value_struct_element_index (value, type_index); if (ctype) *ctype = TYPE_FIELD_TYPE (type, type_index); } else if (index < TYPE_N_BASECLASSES (type)) { /* This is a baseclass. */ if (cname) *cname = xstrdup (TYPE_FIELD_NAME (type, index)); if (cvalue && value) *cvalue = value_cast (TYPE_FIELD_TYPE (type, index), value); if (ctype) { *ctype = TYPE_FIELD_TYPE (type, index); } if (cfull_expression) { char *ptr = was_ptr ? "*" : ""; /* Cast the parent to the base' type. Note that in gdb, expression like (Base1)d will create an lvalue, for all appearences, so we don't need to use more fancy: *(Base1*)(&d) construct. When we are in the scope of the base class or of one of its children, the type field name will be interpreted as a constructor, if it exists. Therefore, we must indicate that the name is a class name by using the 'class' keyword. See PR mi/11912 */ *cfull_expression = xstrprintf ("(%s(class %s%s) %s)", ptr, TYPE_FIELD_NAME (type, index), ptr, parent_expression); } } else { char *access = NULL; int children[3]; cplus_class_num_children (type, children); /* Everything beyond the baseclasses can only be "public", "private", or "protected" The special "fake" children are always output by varobj in this order. So if INDEX == 2, it MUST be "protected". */ index -= TYPE_N_BASECLASSES (type); switch (index) { case 0: if (children[v_public] > 0) access = "public"; else if (children[v_private] > 0) access = "private"; else access = "protected"; break; case 1: if (children[v_public] > 0) { if (children[v_private] > 0) access = "private"; else access = "protected"; } else if (children[v_private] > 0) access = "protected"; break; case 2: /* Must be protected. */ access = "protected"; break; default: /* error! */ break; } gdb_assert (access); if (cname) *cname = xstrdup (access); /* Value and type and full expression are null here. */ } } else { c_describe_child (parent, index, cname, cvalue, ctype, cfull_expression); } } static char * cplus_name_of_child (struct varobj *parent, int index) { char *name = NULL; cplus_describe_child (parent, index, &name, NULL, NULL, NULL); return name; } static char * cplus_path_expr_of_child (struct varobj *child) { char *path_expr; cplus_describe_child (child->parent, child->index, NULL, NULL, NULL, &path_expr); return path_expr; } static struct value * cplus_value_of_child (struct varobj *parent, int index) { struct value *value = NULL; cplus_describe_child (parent, index, NULL, &value, NULL, NULL); return value; } static struct type * cplus_type_of_child (struct varobj *parent, int index) { struct type *type = NULL; cplus_describe_child (parent, index, NULL, NULL, &type, NULL); return type; } static char * cplus_value_of_variable (struct varobj *var, enum varobj_display_formats format) { /* If we have one of our special types, don't print out any value. */ if (CPLUS_FAKE_CHILD (var)) return xstrdup (""); return c_value_of_variable (var, format); } /* varobj operations for c++. */ const struct lang_varobj_ops cplus_varobj_ops = { cplus_number_of_children, cplus_name_of_variable, cplus_name_of_child, cplus_path_expr_of_child, cplus_value_of_child, cplus_type_of_child, cplus_value_of_variable, varobj_default_value_is_changeable_p, NULL, /* value_has_mutated */ c_is_path_expr_parent /* is_path_expr_parent */ };