|  | /* Convert symbols from GDB to GCC | 
|  |  | 
|  | Copyright (C) 2014-2024 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/>.  */ | 
|  |  | 
|  |  | 
|  | #include "compile-internal.h" | 
|  | #include "compile-cplus.h" | 
|  | #include "gdbsupport/gdb_assert.h" | 
|  | #include "symtab.h" | 
|  | #include "parser-defs.h" | 
|  | #include "block.h" | 
|  | #include "objfiles.h" | 
|  | #include "compile.h" | 
|  | #include "value.h" | 
|  | #include "exceptions.h" | 
|  | #include "gdbtypes.h" | 
|  | #include "dwarf2/loc.h" | 
|  | #include "cp-support.h" | 
|  | #include "cli/cli-cmds.h" | 
|  | #include "compile-c.h" | 
|  | #include "inferior.h" | 
|  |  | 
|  | /* Convert a given symbol, SYM, to the compiler's representation. | 
|  | INSTANCE is the compiler instance.  IS_GLOBAL is true if the | 
|  | symbol came from the global scope.  IS_LOCAL is true if the symbol | 
|  | came from a local scope.  (Note that the two are not strictly | 
|  | inverses because the symbol might have come from the static | 
|  | scope.)  */ | 
|  |  | 
|  | static void | 
|  | convert_one_symbol (compile_cplus_instance *instance, | 
|  | struct block_symbol sym, bool is_global, bool is_local) | 
|  | { | 
|  | /* Squash compiler warning.  */ | 
|  | gcc_type sym_type = 0; | 
|  | const char *filename = sym.symbol->symtab ()->filename; | 
|  | unsigned int line = sym.symbol->line (); | 
|  |  | 
|  | instance->error_symbol_once (sym.symbol); | 
|  |  | 
|  | if (sym.symbol->aclass () == LOC_LABEL) | 
|  | sym_type = 0; | 
|  | else | 
|  | sym_type = instance->convert_type (sym.symbol->type ()); | 
|  |  | 
|  | if (sym.symbol->domain () == STRUCT_DOMAIN) | 
|  | { | 
|  | /* Nothing to do.  */ | 
|  | } | 
|  | else | 
|  | { | 
|  | /* Squash compiler warning.  */ | 
|  | gcc_cp_symbol_kind_flags kind = GCC_CP_FLAG_BASE; | 
|  | CORE_ADDR addr = 0; | 
|  | std::string name; | 
|  | gdb::unique_xmalloc_ptr<char> symbol_name; | 
|  |  | 
|  | switch (sym.symbol->aclass ()) | 
|  | { | 
|  | case LOC_TYPEDEF: | 
|  | if (sym.symbol->type ()->code () == TYPE_CODE_TYPEDEF) | 
|  | kind = GCC_CP_SYMBOL_TYPEDEF; | 
|  | else  if (sym.symbol->type ()->code () == TYPE_CODE_NAMESPACE) | 
|  | return; | 
|  | break; | 
|  |  | 
|  | case LOC_LABEL: | 
|  | kind = GCC_CP_SYMBOL_LABEL; | 
|  | addr = sym.symbol->value_address (); | 
|  | break; | 
|  |  | 
|  | case LOC_BLOCK: | 
|  | { | 
|  | kind = GCC_CP_SYMBOL_FUNCTION; | 
|  | addr = sym.symbol->value_block()->start (); | 
|  | if (is_global && sym.symbol->type ()->is_gnu_ifunc ()) | 
|  | addr = gnu_ifunc_resolve_addr (current_inferior ()->arch (), | 
|  | addr); | 
|  | } | 
|  | break; | 
|  |  | 
|  | case LOC_CONST: | 
|  | if (sym.symbol->type ()->code () == TYPE_CODE_ENUM) | 
|  | { | 
|  | /* Already handled by convert_enum.  */ | 
|  | return; | 
|  | } | 
|  | instance->plugin ().build_constant | 
|  | (sym_type, sym.symbol->natural_name (), | 
|  | sym.symbol->value_longest (), filename, line); | 
|  | return; | 
|  |  | 
|  | case LOC_CONST_BYTES: | 
|  | error (_("Unsupported LOC_CONST_BYTES for symbol \"%s\"."), | 
|  | sym.symbol->print_name ()); | 
|  |  | 
|  | case LOC_UNDEF: | 
|  | internal_error (_("LOC_UNDEF found for \"%s\"."), | 
|  | sym.symbol->print_name ()); | 
|  |  | 
|  | case LOC_COMMON_BLOCK: | 
|  | error (_("Fortran common block is unsupported for compilation " | 
|  | "evaluaton of symbol \"%s\"."), | 
|  | sym.symbol->print_name ()); | 
|  |  | 
|  | case LOC_OPTIMIZED_OUT: | 
|  | error (_("Symbol \"%s\" cannot be used for compilation evaluation " | 
|  | "as it is optimized out."), | 
|  | sym.symbol->print_name ()); | 
|  |  | 
|  | case LOC_COMPUTED: | 
|  | if (is_local) | 
|  | goto substitution; | 
|  | /* Probably TLS here.  */ | 
|  | warning (_("Symbol \"%s\" is thread-local and currently can only " | 
|  | "be referenced from the current thread in " | 
|  | "compiled code."), | 
|  | sym.symbol->print_name ()); | 
|  | [[fallthrough]]; | 
|  | case LOC_UNRESOLVED: | 
|  | /* 'symbol_name' cannot be used here as that one is used only for | 
|  | local variables from compile_dwarf_expr_to_c. | 
|  | Global variables can be accessed by GCC only by their address, not | 
|  | by their name.  */ | 
|  | { | 
|  | struct value *val; | 
|  | frame_info_ptr frame = nullptr; | 
|  |  | 
|  | if (symbol_read_needs_frame (sym.symbol)) | 
|  | { | 
|  | frame = get_selected_frame (nullptr); | 
|  | if (frame == nullptr) | 
|  | error (_("Symbol \"%s\" cannot be used because " | 
|  | "there is no selected frame"), | 
|  | sym.symbol->print_name ()); | 
|  | } | 
|  |  | 
|  | val = read_var_value (sym.symbol, sym.block, frame); | 
|  | if (val->lval () != lval_memory) | 
|  | error (_("Symbol \"%s\" cannot be used for compilation " | 
|  | "evaluation as its address has not been found."), | 
|  | sym.symbol->print_name ()); | 
|  |  | 
|  | kind = GCC_CP_SYMBOL_VARIABLE; | 
|  | addr = val->address (); | 
|  | } | 
|  | break; | 
|  |  | 
|  |  | 
|  | case LOC_REGISTER: | 
|  | case LOC_ARG: | 
|  | case LOC_REF_ARG: | 
|  | case LOC_REGPARM_ADDR: | 
|  | case LOC_LOCAL: | 
|  | substitution: | 
|  | kind = GCC_CP_SYMBOL_VARIABLE; | 
|  | symbol_name = c_symbol_substitution_name (sym.symbol); | 
|  | break; | 
|  |  | 
|  | case LOC_STATIC: | 
|  | kind = GCC_CP_SYMBOL_VARIABLE; | 
|  | addr = sym.symbol->value_address (); | 
|  | break; | 
|  |  | 
|  | case LOC_FINAL_VALUE: | 
|  | default: | 
|  | gdb_assert_not_reached ("Unreachable case in convert_one_symbol."); | 
|  | } | 
|  |  | 
|  | /* Don't emit local variable decls for a raw expression.  */ | 
|  | if (instance->scope () != COMPILE_I_RAW_SCOPE || symbol_name == nullptr) | 
|  | { | 
|  | /* For non-local symbols, create/push a new scope so that the | 
|  | symbol is properly scoped to the plug-in.  */ | 
|  | if (!is_local) | 
|  | { | 
|  | compile_scope scope | 
|  | = instance->new_scope (sym.symbol->natural_name (), | 
|  | sym.symbol->type ()); | 
|  | if (scope.nested_type () != GCC_TYPE_NONE) | 
|  | { | 
|  | /* We found a symbol for this type that was defined inside | 
|  | some other symbol, e.g., a class typedef defined.  */ | 
|  | return; | 
|  | } | 
|  |  | 
|  | instance->enter_scope (std::move (scope)); | 
|  | } | 
|  |  | 
|  | /* Get the `raw' name of the symbol.  */ | 
|  | if (name.empty () && sym.symbol->natural_name () != nullptr) | 
|  | name = compile_cplus_instance::decl_name | 
|  | (sym.symbol->natural_name ()).get (); | 
|  |  | 
|  | /* Define the decl.  */ | 
|  | instance->plugin ().build_decl | 
|  | ("variable", name.c_str (), kind.raw (), sym_type, | 
|  | symbol_name.get (), addr, filename, line); | 
|  |  | 
|  | /* Pop scope for non-local symbols.  */ | 
|  | if (!is_local) | 
|  | instance->leave_scope (); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | /* Convert a full symbol to its gcc form.  CONTEXT is the compiler to | 
|  | use, IDENTIFIER is the name of the symbol, SYM is the symbol | 
|  | itself, and DOMAIN is the domain which was searched.  */ | 
|  |  | 
|  | static void | 
|  | convert_symbol_sym (compile_cplus_instance *instance, | 
|  | const char *identifier, struct block_symbol sym, | 
|  | domain_search_flags domain) | 
|  | { | 
|  | /* If we found a symbol and it is not in the  static or global | 
|  | scope, then we should first convert any static or global scope | 
|  | symbol of the same name.  This lets this unusual case work: | 
|  |  | 
|  | int x; // Global. | 
|  | int func(void) | 
|  | { | 
|  | int x; | 
|  | // At this spot, evaluate "extern int x; x" | 
|  | } | 
|  | */ | 
|  |  | 
|  | const struct block *static_block = nullptr; | 
|  | if (sym.block != nullptr) | 
|  | static_block = sym.block->static_block (); | 
|  | /* STATIC_BLOCK is NULL if FOUND_BLOCK is the global block.  */ | 
|  | bool is_local_symbol = (sym.block != static_block && static_block != nullptr); | 
|  | if (is_local_symbol) | 
|  | { | 
|  | struct block_symbol global_sym; | 
|  |  | 
|  | global_sym = lookup_symbol (identifier, nullptr, domain, nullptr); | 
|  | /* If the outer symbol is in the static block, we ignore it, as | 
|  | it cannot be referenced.  */ | 
|  | if (global_sym.symbol != nullptr | 
|  | && global_sym.block != global_sym.block->static_block ()) | 
|  | { | 
|  | if (compile_debug) | 
|  | gdb_printf (gdb_stdlog, | 
|  | "gcc_convert_symbol \"%s\": global symbol\n", | 
|  | identifier); | 
|  | convert_one_symbol (instance, global_sym, true, false); | 
|  | } | 
|  | } | 
|  |  | 
|  | if (compile_debug) | 
|  | gdb_printf (gdb_stdlog, | 
|  | "gcc_convert_symbol \"%s\": local symbol\n", | 
|  | identifier); | 
|  | convert_one_symbol (instance, sym, false, is_local_symbol); | 
|  | } | 
|  |  | 
|  | /* Convert a minimal symbol to its gcc form.  CONTEXT is the compiler | 
|  | to use and BMSYM is the minimal symbol to convert.  */ | 
|  |  | 
|  | static void | 
|  | convert_symbol_bmsym (compile_cplus_instance *instance, | 
|  | struct bound_minimal_symbol bmsym) | 
|  | { | 
|  | struct minimal_symbol *msym = bmsym.minsym; | 
|  | struct objfile *objfile = bmsym.objfile; | 
|  | struct type *type; | 
|  | gcc_cp_symbol_kind_flags kind; | 
|  | gcc_type sym_type; | 
|  | CORE_ADDR addr; | 
|  |  | 
|  | addr = msym->value_address (objfile); | 
|  |  | 
|  | /* Conversion copied from write_exp_msymbol.  */ | 
|  | switch (msym->type ()) | 
|  | { | 
|  | case mst_text: | 
|  | case mst_file_text: | 
|  | case mst_solib_trampoline: | 
|  | type = builtin_type (objfile)->nodebug_text_symbol; | 
|  | kind = GCC_CP_SYMBOL_FUNCTION; | 
|  | break; | 
|  |  | 
|  | case mst_text_gnu_ifunc: | 
|  | /* nodebug_text_gnu_ifunc_symbol would cause: | 
|  | function return type cannot be function  */ | 
|  | type = builtin_type (objfile)->nodebug_text_symbol; | 
|  | kind = GCC_CP_SYMBOL_FUNCTION; | 
|  | addr = gnu_ifunc_resolve_addr (current_inferior ()->arch (), addr); | 
|  | break; | 
|  |  | 
|  | case mst_data: | 
|  | case mst_file_data: | 
|  | case mst_bss: | 
|  | case mst_file_bss: | 
|  | type = builtin_type (objfile)->nodebug_data_symbol; | 
|  | kind = GCC_CP_SYMBOL_VARIABLE; | 
|  | break; | 
|  |  | 
|  | case mst_slot_got_plt: | 
|  | type = builtin_type (objfile)->nodebug_got_plt_symbol; | 
|  | kind = GCC_CP_SYMBOL_FUNCTION; | 
|  | break; | 
|  |  | 
|  | default: | 
|  | type = builtin_type (objfile)->nodebug_unknown_symbol; | 
|  | kind = GCC_CP_SYMBOL_VARIABLE; | 
|  | break; | 
|  | } | 
|  |  | 
|  | sym_type = instance->convert_type (type); | 
|  | instance->plugin ().push_namespace (""); | 
|  | instance->plugin ().build_decl | 
|  | ("minsym", msym->natural_name (), kind.raw (), sym_type, nullptr, addr, | 
|  | nullptr, 0); | 
|  | instance->plugin ().pop_binding_level (""); | 
|  | } | 
|  |  | 
|  | /* See compile-cplus.h.  */ | 
|  |  | 
|  | void | 
|  | gcc_cplus_convert_symbol (void *datum, | 
|  | struct gcc_cp_context *gcc_context, | 
|  | enum gcc_cp_oracle_request request, | 
|  | const char *identifier) | 
|  | { | 
|  | if (compile_debug) | 
|  | gdb_printf (gdb_stdlog, | 
|  | "got oracle request for \"%s\"\n", identifier); | 
|  |  | 
|  | bool found = false; | 
|  | compile_cplus_instance *instance = (compile_cplus_instance *) datum; | 
|  |  | 
|  | try | 
|  | { | 
|  | /* Symbol searching is a three part process unfortunately.  */ | 
|  |  | 
|  | /* First do a "standard" lookup, converting any found symbols. | 
|  | This will find variables in the current scope.  */ | 
|  |  | 
|  | struct block_symbol sym | 
|  | = lookup_symbol (identifier, instance->block (), SEARCH_VFT, nullptr); | 
|  |  | 
|  | if (sym.symbol != nullptr) | 
|  | { | 
|  | found = true; | 
|  | convert_symbol_sym (instance, identifier, sym, SEARCH_VFT); | 
|  | } | 
|  |  | 
|  | /* Then use linespec.c's multi-symbol search.  This should find | 
|  | all non-variable symbols for which we have debug info.  */ | 
|  |  | 
|  | symbol_searcher searcher; | 
|  | searcher.find_all_symbols (identifier, current_language, | 
|  | SEARCH_ALL_DOMAINS, nullptr, nullptr); | 
|  |  | 
|  | /* Convert any found symbols.  */ | 
|  | for (const auto &it : searcher.matching_symbols ()) | 
|  | { | 
|  | /* Don't convert the symbol found above, if any, twice!  */ | 
|  | if (it.symbol != sym.symbol) | 
|  | { | 
|  | found = true; | 
|  | convert_symbol_sym (instance, identifier, it, | 
|  | to_search_flags (it.symbol->domain ())); | 
|  | } | 
|  | } | 
|  |  | 
|  | /* Finally, if no symbols have been found, fall back to minsyms.  */ | 
|  | if (!found) | 
|  | { | 
|  | for (const auto &it : searcher.matching_msymbols ()) | 
|  | { | 
|  | found = true; | 
|  | convert_symbol_bmsym (instance, it); | 
|  | } | 
|  | } | 
|  | } | 
|  | catch (const gdb_exception &e) | 
|  | { | 
|  | /* We can't allow exceptions to escape out of this callback.  Safest | 
|  | is to simply emit a gcc error.  */ | 
|  | instance->plugin ().error (e.what ()); | 
|  | } | 
|  |  | 
|  | if (compile_debug && !found) | 
|  | gdb_printf (gdb_stdlog, | 
|  | "gcc_convert_symbol \"%s\": lookup_symbol failed\n", | 
|  | identifier); | 
|  |  | 
|  | if (compile_debug) | 
|  | { | 
|  | if (found) | 
|  | gdb_printf (gdb_stdlog, "found type for %s\n", identifier); | 
|  | else | 
|  | { | 
|  | gdb_printf (gdb_stdlog, "did not find type for %s\n", | 
|  | identifier); | 
|  | } | 
|  | } | 
|  |  | 
|  | return; | 
|  | } | 
|  |  | 
|  | /* See compile-cplus.h.  */ | 
|  |  | 
|  | gcc_address | 
|  | gcc_cplus_symbol_address (void *datum, struct gcc_cp_context *gcc_context, | 
|  | const char *identifier) | 
|  | { | 
|  | compile_cplus_instance *instance = (compile_cplus_instance *) datum; | 
|  | gcc_address result = 0; | 
|  | int found = 0; | 
|  |  | 
|  | if (compile_debug) | 
|  | gdb_printf (gdb_stdlog, | 
|  | "got oracle request for address of %s\n", identifier); | 
|  |  | 
|  | /* We can't allow exceptions to escape out of this callback.  Safest | 
|  | is to simply emit a gcc error.  */ | 
|  | try | 
|  | { | 
|  | struct symbol *sym | 
|  | = lookup_symbol (identifier, nullptr, SEARCH_FUNCTION_DOMAIN, | 
|  | nullptr).symbol; | 
|  |  | 
|  | if (sym != nullptr) | 
|  | { | 
|  | if (compile_debug) | 
|  | gdb_printf (gdb_stdlog, | 
|  | "gcc_symbol_address \"%s\": full symbol\n", | 
|  | identifier); | 
|  | result = sym->value_block ()->start (); | 
|  | if (sym->type ()->is_gnu_ifunc ()) | 
|  | result = gnu_ifunc_resolve_addr (current_inferior ()->arch (), | 
|  | result); | 
|  | found = 1; | 
|  | } | 
|  | else | 
|  | { | 
|  | struct bound_minimal_symbol msym; | 
|  |  | 
|  | msym = lookup_bound_minimal_symbol (identifier); | 
|  | if (msym.minsym != nullptr) | 
|  | { | 
|  | if (compile_debug) | 
|  | gdb_printf (gdb_stdlog, | 
|  | "gcc_symbol_address \"%s\": minimal " | 
|  | "symbol\n", | 
|  | identifier); | 
|  | result = msym.value_address (); | 
|  | if (msym.minsym->type () == mst_text_gnu_ifunc) | 
|  | result = gnu_ifunc_resolve_addr (current_inferior ()->arch (), | 
|  | result); | 
|  | found = 1; | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | catch (const gdb_exception_error &e) | 
|  | { | 
|  | instance->plugin ().error (e.what ()); | 
|  | } | 
|  |  | 
|  | if (compile_debug && !found) | 
|  | gdb_printf (gdb_stdlog, | 
|  | "gcc_symbol_address \"%s\": failed\n", | 
|  | identifier); | 
|  |  | 
|  | if (compile_debug) | 
|  | { | 
|  | if (found) | 
|  | gdb_printf (gdb_stdlog, "found address for %s!\n", identifier); | 
|  | else | 
|  | gdb_printf (gdb_stdlog, | 
|  | "did not find address for %s\n", identifier); | 
|  | } | 
|  |  | 
|  | return result; | 
|  | } |