/* Support for printing C values for GDB, the GNU debugger. Copyright (C) 1986, 1988-1989, 1991-2001, 2003, 2005-2012 Free Software Foundation, Inc. This file is part of GDB. 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 "gdb_string.h" #include "symtab.h" #include "gdbtypes.h" #include "expression.h" #include "value.h" #include "valprint.h" #include "language.h" #include "c-lang.h" #include "cp-abi.h" #include "target.h" /* A helper for c_textual_element_type. This checks the name of the typedef. This is bogus but it isn't apparent that the compiler provides us the help we may need. */ static int textual_name (const char *name) { return (!strcmp (name, "wchar_t") || !strcmp (name, "char16_t") || !strcmp (name, "char32_t")); } /* Apply a heuristic to decide whether an array of TYPE or a pointer to TYPE should be printed as a textual string. Return non-zero if it should, or zero if it should be treated as an array of integers or pointer to integers. FORMAT is the current format letter, or 0 if none. We guess that "char" is a character. Explicitly signed and unsigned character types are also characters. Integer data from vector types is not. The user can override this by using the /s format letter. */ int c_textual_element_type (struct type *type, char format) { struct type *true_type, *iter_type; if (format != 0 && format != 's') return 0; /* We also rely on this for its side effect of setting up all the typedef pointers. */ true_type = check_typedef (type); /* TYPE_CODE_CHAR is always textual. */ if (TYPE_CODE (true_type) == TYPE_CODE_CHAR) return 1; /* Any other character-like types must be integral. */ if (TYPE_CODE (true_type) != TYPE_CODE_INT) return 0; /* We peel typedefs one by one, looking for a match. */ iter_type = type; while (iter_type) { /* Check the name of the type. */ if (TYPE_NAME (iter_type) && textual_name (TYPE_NAME (iter_type))) return 1; if (TYPE_CODE (iter_type) != TYPE_CODE_TYPEDEF) break; /* Peel a single typedef. If the typedef doesn't have a target type, we use check_typedef and hope the result is ok -- it might be for C++, where wchar_t is a built-in type. */ if (TYPE_TARGET_TYPE (iter_type)) iter_type = TYPE_TARGET_TYPE (iter_type); else iter_type = check_typedef (iter_type); } if (format == 's') { /* Print this as a string if we can manage it. For now, no wide character support. */ if (TYPE_CODE (true_type) == TYPE_CODE_INT && TYPE_LENGTH (true_type) == 1) return 1; } else { /* If a one-byte TYPE_CODE_INT is missing the not-a-character flag, then we treat it as text; otherwise, we assume it's being used as data. */ if (TYPE_CODE (true_type) == TYPE_CODE_INT && TYPE_LENGTH (true_type) == 1 && !TYPE_NOTTEXT (true_type)) return 1; } return 0; } /* See val_print for a description of the various parameters of this function; they are identical. The semantics of the return value is also identical to val_print. */ int c_val_print (struct type *type, const gdb_byte *valaddr, int embedded_offset, CORE_ADDR address, struct ui_file *stream, int recurse, const struct value *original_value, const struct value_print_options *options) { struct gdbarch *gdbarch = get_type_arch (type); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); unsigned int i = 0; /* Number of characters printed. */ unsigned len; struct type *elttype, *unresolved_elttype; struct type *unresolved_type = type; unsigned eltlen; LONGEST val; CORE_ADDR addr; CHECK_TYPEDEF (type); switch (TYPE_CODE (type)) { case TYPE_CODE_ARRAY: unresolved_elttype = TYPE_TARGET_TYPE (type); elttype = check_typedef (unresolved_elttype); if (TYPE_LENGTH (type) > 0 && TYPE_LENGTH (unresolved_elttype) > 0) { LONGEST low_bound, high_bound; if (!get_array_bounds (type, &low_bound, &high_bound)) error (_("Could not determine the array high bound")); eltlen = TYPE_LENGTH (elttype); len = high_bound - low_bound + 1; if (options->prettyprint_arrays) { print_spaces_filtered (2 + 2 * recurse, stream); } /* Print arrays of textual chars with a string syntax, as long as the entire array is valid. */ if (c_textual_element_type (unresolved_elttype, options->format) && value_bytes_available (original_value, embedded_offset, TYPE_LENGTH (type)) && value_bits_valid (original_value, TARGET_CHAR_BIT * embedded_offset, TARGET_CHAR_BIT * TYPE_LENGTH (type))) { /* If requested, look for the first null char and only print elements up to it. */ if (options->stop_print_at_null) { unsigned int temp_len; for (temp_len = 0; (temp_len < len && temp_len < options->print_max && extract_unsigned_integer (valaddr + embedded_offset + temp_len * eltlen, eltlen, byte_order) != 0); ++temp_len) ; len = temp_len; } LA_PRINT_STRING (stream, unresolved_elttype, valaddr + embedded_offset, len, NULL, 0, options); i = len; } else { fprintf_filtered (stream, "{"); /* If this is a virtual function table, print the 0th entry specially, and the rest of the members normally. */ if (cp_is_vtbl_ptr_type (elttype)) { i = 1; fprintf_filtered (stream, _("%d vtable entries"), len - 1); } else { i = 0; } val_print_array_elements (type, valaddr, embedded_offset, address, stream, recurse, original_value, options, i); fprintf_filtered (stream, "}"); } break; } /* Array of unspecified length: treat like pointer to first elt. */ addr = address + embedded_offset; goto print_unpacked_pointer; case TYPE_CODE_MEMBERPTR: if (options->format) { val_print_scalar_formatted (type, valaddr, embedded_offset, original_value, options, 0, stream); break; } cp_print_class_member (valaddr + embedded_offset, type, stream, "&"); break; case TYPE_CODE_METHODPTR: cplus_print_method_ptr (valaddr + embedded_offset, type, stream); break; case TYPE_CODE_PTR: if (options->format && options->format != 's') { val_print_scalar_formatted (type, valaddr, embedded_offset, original_value, options, 0, stream); break; } if (options->vtblprint && cp_is_vtbl_ptr_type (type)) { /* Print the unmangled name if desired. */ /* Print vtable entry - we only get here if we ARE using -fvtable_thunks. (Otherwise, look under TYPE_CODE_STRUCT.) */ CORE_ADDR addr = extract_typed_address (valaddr + embedded_offset, type); print_function_pointer_address (gdbarch, addr, stream, options->addressprint); break; } unresolved_elttype = TYPE_TARGET_TYPE (type); elttype = check_typedef (unresolved_elttype); { addr = unpack_pointer (type, valaddr + embedded_offset); print_unpacked_pointer: if (TYPE_CODE (elttype) == TYPE_CODE_FUNC) { /* Try to print what function it points to. */ print_function_pointer_address (gdbarch, addr, stream, options->addressprint); /* Return value is irrelevant except for string pointers. */ return (0); } if (options->addressprint) fputs_filtered (paddress (gdbarch, addr), stream); /* For a pointer to a textual type, also print the string pointed to, unless pointer is null. */ if (c_textual_element_type (unresolved_elttype, options->format) && addr != 0) { i = val_print_string (unresolved_elttype, NULL, addr, -1, stream, options); } else if (cp_is_vtbl_member (type)) { /* Print vtbl's nicely. */ CORE_ADDR vt_address = unpack_pointer (type, valaddr + embedded_offset); struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (vt_address); if ((msymbol != NULL) && (vt_address == SYMBOL_VALUE_ADDRESS (msymbol))) { fputs_filtered (" <", stream); fputs_filtered (SYMBOL_PRINT_NAME (msymbol), stream); fputs_filtered (">", stream); } if (vt_address && options->vtblprint) { struct value *vt_val; struct symbol *wsym = (struct symbol *) NULL; struct type *wtype; struct block *block = (struct block *) NULL; int is_this_fld; if (msymbol != NULL) wsym = lookup_symbol (SYMBOL_LINKAGE_NAME (msymbol), block, VAR_DOMAIN, &is_this_fld); if (wsym) { wtype = SYMBOL_TYPE (wsym); } else { wtype = unresolved_elttype; } vt_val = value_at (wtype, vt_address); common_val_print (vt_val, stream, recurse + 1, options, current_language); if (options->pretty) { fprintf_filtered (stream, "\n"); print_spaces_filtered (2 + 2 * recurse, stream); } } } /* Return number of characters printed, including the terminating '\0' if we reached the end. val_print_string takes care including the terminating '\0' if necessary. */ return i; } break; case TYPE_CODE_REF: elttype = check_typedef (TYPE_TARGET_TYPE (type)); if (options->addressprint) { CORE_ADDR addr = extract_typed_address (valaddr + embedded_offset, type); fprintf_filtered (stream, "@"); fputs_filtered (paddress (gdbarch, addr), stream); if (options->deref_ref) fputs_filtered (": ", stream); } /* De-reference the reference. */ if (options->deref_ref) { if (TYPE_CODE (elttype) != TYPE_CODE_UNDEF) { struct value *deref_val; deref_val = coerce_ref_if_computed (original_value); if (deref_val != NULL) { /* More complicated computed references are not supported. */ gdb_assert (embedded_offset == 0); } else deref_val = value_at (TYPE_TARGET_TYPE (type), unpack_pointer (type, (valaddr + embedded_offset))); common_val_print (deref_val, stream, recurse, options, current_language); } else fputs_filtered ("???", stream); } break; case TYPE_CODE_UNION: if (recurse && !options->unionprint) { fprintf_filtered (stream, "{...}"); break; } /* Fall through. */ case TYPE_CODE_STRUCT: /*FIXME: Abstract this away. */ if (options->vtblprint && cp_is_vtbl_ptr_type (type)) { /* Print the unmangled name if desired. */ /* Print vtable entry - we only get here if NOT using -fvtable_thunks. (Otherwise, look under TYPE_CODE_PTR.) */ int offset = (embedded_offset + TYPE_FIELD_BITPOS (type, VTBL_FNADDR_OFFSET) / 8); struct type *field_type = TYPE_FIELD_TYPE (type, VTBL_FNADDR_OFFSET); CORE_ADDR addr = extract_typed_address (valaddr + offset, field_type); print_function_pointer_address (gdbarch, addr, stream, options->addressprint); } else cp_print_value_fields_rtti (type, valaddr, embedded_offset, address, stream, recurse, original_value, options, NULL, 0); break; case TYPE_CODE_ENUM: if (options->format) { val_print_scalar_formatted (type, valaddr, embedded_offset, original_value, options, 0, stream); break; } len = TYPE_NFIELDS (type); val = unpack_long (type, valaddr + embedded_offset); for (i = 0; i < len; i++) { QUIT; if (val == TYPE_FIELD_BITPOS (type, i)) { break; } } if (i < len) { fputs_filtered (TYPE_FIELD_NAME (type, i), stream); } else if (TYPE_FLAG_ENUM (type)) { int first = 1; /* We have a "flag" enum, so we try to decompose it into pieces as appropriate. A flag enum has disjoint constants by definition. */ fputs_filtered ("(", stream); for (i = 0; i < len; ++i) { QUIT; if ((val & TYPE_FIELD_BITPOS (type, i)) != 0) { if (!first) fputs_filtered (" | ", stream); first = 0; val &= ~TYPE_FIELD_BITPOS (type, i); fputs_filtered (TYPE_FIELD_NAME (type, i), stream); } } if (first || val != 0) { if (!first) fputs_filtered (" | ", stream); fputs_filtered ("unknown: ", stream); print_longest (stream, 'd', 0, val); } fputs_filtered (")", stream); } else print_longest (stream, 'd', 0, val); break; case TYPE_CODE_FLAGS: if (options->format) val_print_scalar_formatted (type, valaddr, embedded_offset, original_value, options, 0, stream); else val_print_type_code_flags (type, valaddr + embedded_offset, stream); break; case TYPE_CODE_FUNC: case TYPE_CODE_METHOD: if (options->format) { val_print_scalar_formatted (type, valaddr, embedded_offset, original_value, options, 0, stream); break; } /* FIXME, we should consider, at least for ANSI C language, eliminating the distinction made between FUNCs and POINTERs to FUNCs. */ fprintf_filtered (stream, "{"); type_print (type, "", stream, -1); fprintf_filtered (stream, "} "); /* Try to print what function it points to, and its address. */ print_address_demangle (gdbarch, address, stream, demangle); break; case TYPE_CODE_BOOL: if (options->format || options->output_format) { struct value_print_options opts = *options; opts.format = (options->format ? options->format : options->output_format); val_print_scalar_formatted (type, valaddr, embedded_offset, original_value, &opts, 0, stream); } else { val = unpack_long (type, valaddr + embedded_offset); if (val == 0) fputs_filtered ("false", stream); else if (val == 1) fputs_filtered ("true", stream); else print_longest (stream, 'd', 0, val); } break; case TYPE_CODE_RANGE: /* FIXME: create_range_type does not set the unsigned bit in a range type (I think it probably should copy it from the target type), so we won't print values which are too large to fit in a signed integer correctly. */ /* FIXME: Doesn't handle ranges of enums correctly. (Can't just print with the target type, though, because the size of our type and the target type might differ). */ /* FALLTHROUGH */ case TYPE_CODE_INT: if (options->format || options->output_format) { struct value_print_options opts = *options; opts.format = (options->format ? options->format : options->output_format); val_print_scalar_formatted (type, valaddr, embedded_offset, original_value, &opts, 0, stream); } else { val_print_type_code_int (type, valaddr + embedded_offset, stream); /* C and C++ has no single byte int type, char is used instead. Since we don't know whether the value is really intended to be used as an integer or a character, print the character equivalent as well. */ if (c_textual_element_type (unresolved_type, options->format)) { fputs_filtered (" ", stream); LA_PRINT_CHAR (unpack_long (type, valaddr + embedded_offset), unresolved_type, stream); } } break; case TYPE_CODE_CHAR: if (options->format || options->output_format) { struct value_print_options opts = *options; opts.format = (options->format ? options->format : options->output_format); val_print_scalar_formatted (type, valaddr, embedded_offset, original_value, &opts, 0, stream); } else { val = unpack_long (type, valaddr + embedded_offset); if (TYPE_UNSIGNED (type)) fprintf_filtered (stream, "%u", (unsigned int) val); else fprintf_filtered (stream, "%d", (int) val); fputs_filtered (" ", stream); LA_PRINT_CHAR (val, unresolved_type, stream); } break; case TYPE_CODE_FLT: if (options->format) { val_print_scalar_formatted (type, valaddr, embedded_offset, original_value, options, 0, stream); } else { print_floating (valaddr + embedded_offset, type, stream); } break; case TYPE_CODE_DECFLOAT: if (options->format) val_print_scalar_formatted (type, valaddr, embedded_offset, original_value, options, 0, stream); else print_decimal_floating (valaddr + embedded_offset, type, stream); break; case TYPE_CODE_VOID: fprintf_filtered (stream, "void"); break; case TYPE_CODE_ERROR: fprintf_filtered (stream, "%s", TYPE_ERROR_NAME (type)); break; case TYPE_CODE_UNDEF: /* This happens (without TYPE_FLAG_STUB set) on systems which don't use dbx xrefs (NO_DBX_XREFS in gcc) if a file has a "struct foo *bar" and no complete type for struct foo in that file. */ fprintf_filtered (stream, _("")); break; case TYPE_CODE_COMPLEX: if (options->format) val_print_scalar_formatted (TYPE_TARGET_TYPE (type), valaddr, embedded_offset, original_value, options, 0, stream); else print_floating (valaddr + embedded_offset, TYPE_TARGET_TYPE (type), stream); fprintf_filtered (stream, " + "); if (options->format) val_print_scalar_formatted (TYPE_TARGET_TYPE (type), valaddr, embedded_offset + TYPE_LENGTH (TYPE_TARGET_TYPE (type)), original_value, options, 0, stream); else print_floating (valaddr + embedded_offset + TYPE_LENGTH (TYPE_TARGET_TYPE (type)), TYPE_TARGET_TYPE (type), stream); fprintf_filtered (stream, " * I"); break; default: error (_("Invalid C/C++ type code %d in symbol table."), TYPE_CODE (type)); } gdb_flush (stream); return (0); } void c_value_print (struct value *val, struct ui_file *stream, const struct value_print_options *options) { struct type *type, *real_type, *val_type; int full, top, using_enc; struct value_print_options opts = *options; opts.deref_ref = 1; /* If it is a pointer, indicate what it points to. Print type also if it is a reference. C++: if it is a member pointer, we will take care of that when we print it. */ /* Preserve the original type before stripping typedefs. We prefer to pass down the original type when possible, but for local checks it is better to look past the typedefs. */ val_type = value_type (val); type = check_typedef (val_type); if (TYPE_CODE (type) == TYPE_CODE_PTR || TYPE_CODE (type) == TYPE_CODE_REF) { /* Hack: remove (char *) for char strings. Their type is indicated by the quoted string anyway. (Don't use c_textual_element_type here; quoted strings are always exactly (char *), (wchar_t *), or the like. */ if (TYPE_CODE (val_type) == TYPE_CODE_PTR && TYPE_NAME (val_type) == NULL && TYPE_NAME (TYPE_TARGET_TYPE (val_type)) != NULL && (strcmp (TYPE_NAME (TYPE_TARGET_TYPE (val_type)), "char") == 0 || textual_name (TYPE_NAME (TYPE_TARGET_TYPE (val_type))))) { /* Print nothing. */ } else if (options->objectprint && (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_CLASS)) { if (TYPE_CODE(type) == TYPE_CODE_REF) { /* Copy value, change to pointer, so we don't get an error about a non-pointer type in value_rtti_target_type. */ struct value *temparg; temparg=value_copy(val); deprecated_set_value_type (temparg, lookup_pointer_type (TYPE_TARGET_TYPE (type))); val = temparg; } /* Pointer to class, check real type of object. */ fprintf_filtered (stream, "("); if (value_entirely_available (val)) { real_type = value_rtti_indirect_type (val, &full, &top, &using_enc); if (real_type) { /* RTTI entry found. */ type = real_type; /* Need to adjust pointer value. */ val = value_from_pointer (type, value_as_address (val) - top); /* Note: When we look up RTTI entries, we don't get any information on const or volatile attributes. */ } } type_print (type, "", stream, -1); fprintf_filtered (stream, ") "); val_type = type; } else { /* normal case */ fprintf_filtered (stream, "("); type_print (value_type (val), "", stream, -1); fprintf_filtered (stream, ") "); } } if (!value_initialized (val)) fprintf_filtered (stream, " [uninitialized] "); if (options->objectprint && (TYPE_CODE (type) == TYPE_CODE_CLASS)) { /* Attempt to determine real type of object. */ real_type = value_rtti_type (val, &full, &top, &using_enc); if (real_type) { /* We have RTTI information, so use it. */ val = value_full_object (val, real_type, full, top, using_enc); fprintf_filtered (stream, "(%s%s) ", TYPE_NAME (real_type), full ? "" : _(" [incomplete object]")); /* Print out object: enclosing type is same as real_type if full. */ val_print (value_enclosing_type (val), value_contents_for_printing (val), 0, value_address (val), stream, 0, val, &opts, current_language); return; /* Note: When we look up RTTI entries, we don't get any information on const or volatile attributes. */ } else if (type != check_typedef (value_enclosing_type (val))) { /* No RTTI information, so let's do our best. */ fprintf_filtered (stream, "(%s ?) ", TYPE_NAME (value_enclosing_type (val))); val_print (value_enclosing_type (val), value_contents_for_printing (val), 0, value_address (val), stream, 0, val, &opts, current_language); return; } /* Otherwise, we end up at the return outside this "if". */ } val_print (val_type, value_contents_for_printing (val), value_embedded_offset (val), value_address (val), stream, 0, val, &opts, current_language); }