| /* Go language support routines for GDB, the GNU debugger. |
| |
| Copyright (C) 2012-2021 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 <http://www.gnu.org/licenses/>. */ |
| |
| /* TODO: |
| - split stacks |
| - printing of native types |
| - goroutines |
| - lots more |
| - gccgo mangling needs redoing |
| It's too hard, for example, to know whether one is looking at a mangled |
| Go symbol or not, and their are ambiguities, e.g., the demangler may |
| get passed *any* symbol, including symbols from other languages |
| and including symbols that are already demangled. |
| One thought is to at least add an _G prefix. |
| - 6g mangling isn't supported yet |
| */ |
| |
| #include "defs.h" |
| #include "gdb_obstack.h" |
| #include "block.h" |
| #include "symtab.h" |
| #include "language.h" |
| #include "varobj.h" |
| #include "go-lang.h" |
| #include "c-lang.h" |
| #include "parser-defs.h" |
| #include "gdbarch.h" |
| |
| #include <ctype.h> |
| |
| /* The main function in the main package. */ |
| static const char GO_MAIN_MAIN[] = "main.main"; |
| |
| /* Function returning the special symbol name used by Go for the main |
| procedure in the main program if it is found in minimal symbol list. |
| This function tries to find minimal symbols so that it finds them even |
| if the program was compiled without debugging information. */ |
| |
| const char * |
| go_main_name (void) |
| { |
| struct bound_minimal_symbol msym; |
| |
| msym = lookup_minimal_symbol (GO_MAIN_MAIN, NULL, NULL); |
| if (msym.minsym != NULL) |
| return GO_MAIN_MAIN; |
| |
| /* No known entry procedure found, the main program is probably not Go. */ |
| return NULL; |
| } |
| |
| /* Return non-zero if TYPE is a gccgo string. |
| We assume CHECK_TYPEDEF has already been done. */ |
| |
| static int |
| gccgo_string_p (struct type *type) |
| { |
| /* gccgo strings don't necessarily have a name we can use. */ |
| |
| if (type->num_fields () == 2) |
| { |
| struct type *type0 = type->field (0).type (); |
| struct type *type1 = type->field (1).type (); |
| |
| type0 = check_typedef (type0); |
| type1 = check_typedef (type1); |
| |
| if (type0->code () == TYPE_CODE_PTR |
| && strcmp (type->field (0).name (), "__data") == 0 |
| && type1->code () == TYPE_CODE_INT |
| && strcmp (type->field (1).name (), "__length") == 0) |
| { |
| struct type *target_type = TYPE_TARGET_TYPE (type0); |
| |
| target_type = check_typedef (target_type); |
| |
| if (target_type->code () == TYPE_CODE_INT |
| && TYPE_LENGTH (target_type) == 1 |
| && strcmp (target_type->name (), "uint8") == 0) |
| return 1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* Return non-zero if TYPE is a 6g string. |
| We assume CHECK_TYPEDEF has already been done. */ |
| |
| static int |
| sixg_string_p (struct type *type) |
| { |
| if (type->num_fields () == 2 |
| && type->name () != NULL |
| && strcmp (type->name (), "string") == 0) |
| return 1; |
| |
| return 0; |
| } |
| |
| /* Classify the kind of Go object that TYPE is. |
| TYPE is a TYPE_CODE_STRUCT, used to represent a Go object. */ |
| |
| enum go_type |
| go_classify_struct_type (struct type *type) |
| { |
| type = check_typedef (type); |
| |
| /* Recognize strings as they're useful to be able to print without |
| pretty-printers. */ |
| if (gccgo_string_p (type) |
| || sixg_string_p (type)) |
| return GO_TYPE_STRING; |
| |
| return GO_TYPE_NONE; |
| } |
| |
| /* Subroutine of unpack_mangled_go_symbol to simplify it. |
| Given "[foo.]bar.baz", store "bar" in *PACKAGEP and "baz" in *OBJECTP. |
| We stomp on the last '.' to nul-terminate "bar". |
| The caller is responsible for memory management. */ |
| |
| static void |
| unpack_package_and_object (char *buf, |
| const char **packagep, const char **objectp) |
| { |
| char *last_dot; |
| |
| last_dot = strrchr (buf, '.'); |
| gdb_assert (last_dot != NULL); |
| *objectp = last_dot + 1; |
| *last_dot = '\0'; |
| last_dot = strrchr (buf, '.'); |
| if (last_dot != NULL) |
| *packagep = last_dot + 1; |
| else |
| *packagep = buf; |
| } |
| |
| /* Given a mangled Go symbol, find its package name, object name, and |
| method type (if present). |
| E.g., for "libgo_net.textproto.String.N33_libgo_net.textproto.ProtocolError" |
| *PACKAGEP = "textproto" |
| *OBJECTP = "String" |
| *METHOD_TYPE_PACKAGEP = "textproto" |
| *METHOD_TYPE_OBJECTP = "ProtocolError" |
| |
| Space for the resulting strings is malloc'd in one buffer. |
| PACKAGEP,OBJECTP,METHOD_TYPE* will (typically) point into this buffer. |
| [There are a few exceptions, but the caller is still responsible for |
| freeing the resulting pointer.] |
| A pointer to this buffer is returned, or NULL if symbol isn't a |
| mangled Go symbol. |
| The caller is responsible for freeing the result. |
| |
| *METHOD_TYPE_IS_POINTERP is set to a boolean indicating if |
| the method type is a pointer. |
| |
| There may be value in returning the outer container, |
| i.e., "net" in the above example, but for now it's not needed. |
| Plus it's currently not straightforward to compute, |
| it comes from -fgo-prefix, and there's no algorithm to compute it. |
| |
| If we ever need to unpack the method type, this routine should work |
| for that too. */ |
| |
| static char * |
| unpack_mangled_go_symbol (const char *mangled_name, |
| const char **packagep, |
| const char **objectp, |
| const char **method_type_packagep, |
| const char **method_type_objectp, |
| int *method_type_is_pointerp) |
| { |
| char *buf; |
| char *p; |
| int len = strlen (mangled_name); |
| /* Pointer to last digit in "N<digit(s)>_". */ |
| char *saw_digit; |
| /* Pointer to "N" if valid "N<digit(s)>_" found. */ |
| char *method_type; |
| /* Pointer to the first '.'. */ |
| const char *first_dot; |
| /* Pointer to the last '.'. */ |
| const char *last_dot; |
| /* Non-zero if we saw a pointer indicator. */ |
| int saw_pointer; |
| |
| *packagep = *objectp = NULL; |
| *method_type_packagep = *method_type_objectp = NULL; |
| *method_type_is_pointerp = 0; |
| |
| /* main.init is mangled specially. */ |
| if (strcmp (mangled_name, "__go_init_main") == 0) |
| { |
| char *package = xstrdup ("main"); |
| |
| *packagep = package; |
| *objectp = "init"; |
| return package; |
| } |
| |
| /* main.main is mangled specially (missing prefix). */ |
| if (strcmp (mangled_name, "main.main") == 0) |
| { |
| char *package = xstrdup ("main"); |
| |
| *packagep = package; |
| *objectp = "main"; |
| return package; |
| } |
| |
| /* We may get passed, e.g., "main.T.Foo", which is *not* mangled. |
| Alas it looks exactly like "prefix.package.object." |
| To cope for now we only recognize the following prefixes: |
| |
| go: the default |
| libgo_.*: used by gccgo's runtime |
| |
| Thus we don't support -fgo-prefix (except as used by the runtime). */ |
| if (!startswith (mangled_name, "go.") |
| && !startswith (mangled_name, "libgo_")) |
| return NULL; |
| |
| /* Quick check for whether a search may be fruitful. */ |
| /* Ignore anything with @plt, etc. in it. */ |
| if (strchr (mangled_name, '@') != NULL) |
| return NULL; |
| /* It must have at least two dots. */ |
| first_dot = strchr (mangled_name, '.'); |
| if (first_dot == NULL) |
| return NULL; |
| /* Treat "foo.bar" as unmangled. It can collide with lots of other |
| languages and it's not clear what the consequences are. |
| And except for main.main, all gccgo symbols are at least |
| prefix.package.object. */ |
| last_dot = strrchr (mangled_name, '.'); |
| if (last_dot == first_dot) |
| return NULL; |
| |
| /* More quick checks. */ |
| if (last_dot[1] == '\0' /* foo. */ |
| || last_dot[-1] == '.') /* foo..bar */ |
| return NULL; |
| |
| /* At this point we've decided we have a mangled Go symbol. */ |
| |
| buf = xstrdup (mangled_name); |
| |
| /* Search backwards looking for "N<digit(s)>". */ |
| p = buf + len; |
| saw_digit = method_type = NULL; |
| saw_pointer = 0; |
| while (p > buf) |
| { |
| int current = *(const unsigned char *) --p; |
| int current_is_digit = isdigit (current); |
| |
| if (saw_digit) |
| { |
| if (current_is_digit) |
| continue; |
| if (current == 'N' |
| && ((p > buf && p[-1] == '.') |
| || (p > buf + 1 && p[-1] == 'p' && p[-2] == '.'))) |
| { |
| if (atoi (p + 1) == strlen (saw_digit + 2)) |
| { |
| if (p[-1] == '.') |
| method_type = p - 1; |
| else |
| { |
| gdb_assert (p[-1] == 'p'); |
| saw_pointer = 1; |
| method_type = p - 2; |
| } |
| break; |
| } |
| } |
| /* Not what we're looking for, reset and keep looking. */ |
| saw_digit = NULL; |
| saw_pointer = 0; |
| continue; |
| } |
| if (current_is_digit && p[1] == '_') |
| { |
| /* Possible start of method "this" [sic] type. */ |
| saw_digit = p; |
| continue; |
| } |
| } |
| |
| if (method_type != NULL |
| /* Ensure not something like "..foo". */ |
| && (method_type > buf && method_type[-1] != '.')) |
| { |
| unpack_package_and_object (saw_digit + 2, |
| method_type_packagep, method_type_objectp); |
| *method_type = '\0'; |
| *method_type_is_pointerp = saw_pointer; |
| } |
| |
| unpack_package_and_object (buf, packagep, objectp); |
| return buf; |
| } |
| |
| /* Implements the la_demangle language_defn routine for language Go. |
| |
| N.B. This may get passed *any* symbol, including symbols from other |
| languages and including symbols that are already demangled. |
| Both of these situations are kinda unfortunate, but that's how things |
| are today. |
| |
| N.B. This currently only supports gccgo's mangling. |
| |
| N.B. gccgo's mangling needs, I think, changing. |
| This demangler can't work in all situations, |
| thus not too much effort is currently put into it. */ |
| |
| gdb::unique_xmalloc_ptr<char> |
| go_language::demangle_symbol (const char *mangled_name, int options) const |
| { |
| const char *package_name; |
| const char *object_name; |
| const char *method_type_package_name; |
| const char *method_type_object_name; |
| int method_type_is_pointer; |
| |
| if (mangled_name == NULL) |
| return NULL; |
| |
| gdb::unique_xmalloc_ptr<char> name_buf |
| (unpack_mangled_go_symbol (mangled_name, |
| &package_name, &object_name, |
| &method_type_package_name, |
| &method_type_object_name, |
| &method_type_is_pointer)); |
| if (name_buf == NULL) |
| return NULL; |
| |
| auto_obstack tempbuf; |
| |
| /* Print methods as they appear in "method expressions". */ |
| if (method_type_package_name != NULL) |
| { |
| /* FIXME: Seems like we should include package_name here somewhere. */ |
| if (method_type_is_pointer) |
| obstack_grow_str (&tempbuf, "(*"); |
| obstack_grow_str (&tempbuf, method_type_package_name); |
| obstack_grow_str (&tempbuf, "."); |
| obstack_grow_str (&tempbuf, method_type_object_name); |
| if (method_type_is_pointer) |
| obstack_grow_str (&tempbuf, ")"); |
| obstack_grow_str (&tempbuf, "."); |
| obstack_grow_str (&tempbuf, object_name); |
| } |
| else |
| { |
| obstack_grow_str (&tempbuf, package_name); |
| obstack_grow_str (&tempbuf, "."); |
| obstack_grow_str (&tempbuf, object_name); |
| } |
| obstack_grow_str0 (&tempbuf, ""); |
| |
| return make_unique_xstrdup ((const char *) obstack_finish (&tempbuf)); |
| } |
| |
| /* Given a Go symbol, return its package or NULL if unknown. |
| Space for the result is malloc'd, caller must free. */ |
| |
| char * |
| go_symbol_package_name (const struct symbol *sym) |
| { |
| const char *mangled_name = sym->linkage_name (); |
| const char *package_name; |
| const char *object_name; |
| const char *method_type_package_name; |
| const char *method_type_object_name; |
| int method_type_is_pointer; |
| char *name_buf; |
| char *result; |
| |
| gdb_assert (sym->language () == language_go); |
| name_buf = unpack_mangled_go_symbol (mangled_name, |
| &package_name, &object_name, |
| &method_type_package_name, |
| &method_type_object_name, |
| &method_type_is_pointer); |
| /* Some Go symbols don't have mangled form we interpret (yet). */ |
| if (name_buf == NULL) |
| return NULL; |
| result = xstrdup (package_name); |
| xfree (name_buf); |
| return result; |
| } |
| |
| /* Return the package that BLOCK is in, or NULL if there isn't one. |
| Space for the result is malloc'd, caller must free. */ |
| |
| char * |
| go_block_package_name (const struct block *block) |
| { |
| while (block != NULL) |
| { |
| struct symbol *function = BLOCK_FUNCTION (block); |
| |
| if (function != NULL) |
| { |
| char *package_name = go_symbol_package_name (function); |
| |
| if (package_name != NULL) |
| return package_name; |
| |
| /* Stop looking if we find a function without a package name. |
| We're most likely outside of Go and thus the concept of the |
| "current" package is gone. */ |
| return NULL; |
| } |
| |
| block = BLOCK_SUPERBLOCK (block); |
| } |
| |
| return NULL; |
| } |
| |
| /* See language.h. */ |
| |
| void |
| go_language::language_arch_info (struct gdbarch *gdbarch, |
| struct language_arch_info *lai) const |
| { |
| const struct builtin_go_type *builtin = builtin_go_type (gdbarch); |
| |
| /* Helper function to allow shorter lines below. */ |
| auto add = [&] (struct type * t) -> struct type * |
| { |
| lai->add_primitive_type (t); |
| return t; |
| }; |
| |
| add (builtin->builtin_void); |
| add (builtin->builtin_char); |
| add (builtin->builtin_bool); |
| add (builtin->builtin_int); |
| add (builtin->builtin_uint); |
| add (builtin->builtin_uintptr); |
| add (builtin->builtin_int8); |
| add (builtin->builtin_int16); |
| add (builtin->builtin_int32); |
| add (builtin->builtin_int64); |
| add (builtin->builtin_uint8); |
| add (builtin->builtin_uint16); |
| add (builtin->builtin_uint32); |
| add (builtin->builtin_uint64); |
| add (builtin->builtin_float32); |
| add (builtin->builtin_float64); |
| add (builtin->builtin_complex64); |
| add (builtin->builtin_complex128); |
| |
| lai->set_string_char_type (builtin->builtin_char); |
| lai->set_bool_type (builtin->builtin_bool, "bool"); |
| } |
| |
| /* Single instance of the Go language class. */ |
| |
| static go_language go_language_defn; |
| |
| static void * |
| build_go_types (struct gdbarch *gdbarch) |
| { |
| struct builtin_go_type *builtin_go_type |
| = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct builtin_go_type); |
| |
| builtin_go_type->builtin_void |
| = arch_type (gdbarch, TYPE_CODE_VOID, TARGET_CHAR_BIT, "void"); |
| builtin_go_type->builtin_char |
| = arch_character_type (gdbarch, 8, 1, "char"); |
| builtin_go_type->builtin_bool |
| = arch_boolean_type (gdbarch, 8, 0, "bool"); |
| builtin_go_type->builtin_int |
| = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 0, "int"); |
| builtin_go_type->builtin_uint |
| = arch_integer_type (gdbarch, gdbarch_int_bit (gdbarch), 1, "uint"); |
| builtin_go_type->builtin_uintptr |
| = arch_integer_type (gdbarch, gdbarch_ptr_bit (gdbarch), 1, "uintptr"); |
| builtin_go_type->builtin_int8 |
| = arch_integer_type (gdbarch, 8, 0, "int8"); |
| builtin_go_type->builtin_int16 |
| = arch_integer_type (gdbarch, 16, 0, "int16"); |
| builtin_go_type->builtin_int32 |
| = arch_integer_type (gdbarch, 32, 0, "int32"); |
| builtin_go_type->builtin_int64 |
| = arch_integer_type (gdbarch, 64, 0, "int64"); |
| builtin_go_type->builtin_uint8 |
| = arch_integer_type (gdbarch, 8, 1, "uint8"); |
| builtin_go_type->builtin_uint16 |
| = arch_integer_type (gdbarch, 16, 1, "uint16"); |
| builtin_go_type->builtin_uint32 |
| = arch_integer_type (gdbarch, 32, 1, "uint32"); |
| builtin_go_type->builtin_uint64 |
| = arch_integer_type (gdbarch, 64, 1, "uint64"); |
| builtin_go_type->builtin_float32 |
| = arch_float_type (gdbarch, 32, "float32", floatformats_ieee_single); |
| builtin_go_type->builtin_float64 |
| = arch_float_type (gdbarch, 64, "float64", floatformats_ieee_double); |
| builtin_go_type->builtin_complex64 |
| = init_complex_type ("complex64", builtin_go_type->builtin_float32); |
| builtin_go_type->builtin_complex128 |
| = init_complex_type ("complex128", builtin_go_type->builtin_float64); |
| |
| return builtin_go_type; |
| } |
| |
| static struct gdbarch_data *go_type_data; |
| |
| const struct builtin_go_type * |
| builtin_go_type (struct gdbarch *gdbarch) |
| { |
| return (const struct builtin_go_type *) gdbarch_data (gdbarch, go_type_data); |
| } |
| |
| void _initialize_go_language (); |
| void |
| _initialize_go_language () |
| { |
| go_type_data = gdbarch_data_register_post_init (build_go_types); |
| } |