| /* Convert symbols from GDB to GCC | 
 |  | 
 |    Copyright (C) 2014-2021 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/>.  */ | 
 |  | 
 |  | 
 | #include "defs.h" | 
 | #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 "gdbcmd.h" | 
 | #include "compile-c.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 = symbol_symtab (sym.symbol)->filename; | 
 |   unsigned short line = SYMBOL_LINE (sym.symbol); | 
 |  | 
 |   instance->error_symbol_once (sym.symbol); | 
 |  | 
 |   if (SYMBOL_CLASS (sym.symbol) == LOC_LABEL) | 
 |     sym_type = 0; | 
 |   else | 
 |     sym_type = instance->convert_type (SYMBOL_TYPE (sym.symbol)); | 
 |  | 
 |   if (SYMBOL_DOMAIN (sym.symbol) == 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 (SYMBOL_CLASS (sym.symbol)) | 
 | 	{ | 
 | 	case LOC_TYPEDEF: | 
 | 	  if (SYMBOL_TYPE (sym.symbol)->code () == TYPE_CODE_TYPEDEF) | 
 | 	    kind = GCC_CP_SYMBOL_TYPEDEF; | 
 | 	  else  if (SYMBOL_TYPE (sym.symbol)->code () == TYPE_CODE_NAMESPACE) | 
 | 	    return; | 
 | 	  break; | 
 |  | 
 | 	case LOC_LABEL: | 
 | 	  kind = GCC_CP_SYMBOL_LABEL; | 
 | 	  addr = SYMBOL_VALUE_ADDRESS (sym.symbol); | 
 | 	  break; | 
 |  | 
 | 	case LOC_BLOCK: | 
 | 	  { | 
 | 	    kind = GCC_CP_SYMBOL_FUNCTION; | 
 | 	    addr = BLOCK_START (SYMBOL_BLOCK_VALUE (sym.symbol)); | 
 | 	    if (is_global && SYMBOL_TYPE (sym.symbol)->is_gnu_ifunc ()) | 
 | 	      addr = gnu_ifunc_resolve_addr (target_gdbarch (), addr); | 
 | 	  } | 
 | 	  break; | 
 |  | 
 | 	case LOC_CONST: | 
 | 	  if (SYMBOL_TYPE (sym.symbol)->code () == TYPE_CODE_ENUM) | 
 | 	    { | 
 | 	      /* Already handled by convert_enum.  */ | 
 | 	      return; | 
 | 	    } | 
 | 	  instance->plugin ().build_constant | 
 | 	    (sym_type, sym.symbol->natural_name (), | 
 | 	     SYMBOL_VALUE (sym.symbol), filename, line); | 
 | 	  return; | 
 |  | 
 | 	case LOC_CONST_BYTES: | 
 | 	  error (_("Unsupported LOC_CONST_BYTES for symbol \"%s\"."), | 
 | 		 sym.symbol->print_name ()); | 
 |  | 
 | 	case LOC_UNDEF: | 
 | 	  internal_error (__FILE__, __LINE__, _("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; | 
 | 	    struct frame_info *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 (VALUE_LVAL (val) != 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 = value_address (val); | 
 | 	  } | 
 | 	  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 = SYMBOL_VALUE_ADDRESS (sym.symbol); | 
 | 	  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 (), | 
 | 				       SYMBOL_TYPE (sym.symbol)); | 
 | 	      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_enum 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 = block_static_block (sym.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 != block_static_block (global_sym.block)) | 
 | 	{ | 
 | 	  if (compile_debug) | 
 | 	    fprintf_unfiltered (gdb_stdlog, | 
 | 				"gcc_convert_symbol \"%s\": global symbol\n", | 
 | 				identifier); | 
 | 	  convert_one_symbol (instance, global_sym, true, false); | 
 | 	} | 
 |     } | 
 |  | 
 |   if (compile_debug) | 
 |     fprintf_unfiltered (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 = MSYMBOL_VALUE_ADDRESS (objfile, msym); | 
 |  | 
 |   /* Conversion copied from write_exp_msymbol.  */ | 
 |   switch (MSYMBOL_TYPE (msym)) | 
 |     { | 
 |     case mst_text: | 
 |     case mst_file_text: | 
 |     case mst_solib_trampoline: | 
 |       type = objfile_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 = objfile_type (objfile)->nodebug_text_symbol; | 
 |       kind = GCC_CP_SYMBOL_FUNCTION; | 
 |       addr = gnu_ifunc_resolve_addr (target_gdbarch (), addr); | 
 |       break; | 
 |  | 
 |     case mst_data: | 
 |     case mst_file_data: | 
 |     case mst_bss: | 
 |     case mst_file_bss: | 
 |       type = objfile_type (objfile)->nodebug_data_symbol; | 
 |       kind = GCC_CP_SYMBOL_VARIABLE; | 
 |       break; | 
 |  | 
 |     case mst_slot_got_plt: | 
 |       type = objfile_type (objfile)->nodebug_got_plt_symbol; | 
 |       kind = GCC_CP_SYMBOL_FUNCTION; | 
 |       break; | 
 |  | 
 |     default: | 
 |       type = objfile_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) | 
 |     fprintf_unfiltered (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 (), VAR_DOMAIN, nullptr); | 
 |  | 
 |       if (sym.symbol != nullptr) | 
 | 	{ | 
 | 	  found = true; | 
 | 	  convert_symbol_sym (instance, identifier, sym, VAR_DOMAIN); | 
 | 	} | 
 |  | 
 |       /* 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, | 
 | 				 ALL_DOMAIN, 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, | 
 | 				  SYMBOL_DOMAIN (it.symbol)); | 
 | 	    } | 
 | 	} | 
 |  | 
 |       /* 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) | 
 |     fprintf_unfiltered (gdb_stdlog, | 
 | 			"gcc_convert_symbol \"%s\": lookup_symbol failed\n", | 
 | 			identifier); | 
 |  | 
 |   if (compile_debug) | 
 |     { | 
 |       if (found) | 
 | 	fprintf_unfiltered (gdb_stdlog, "found type for %s\n", identifier); | 
 |       else | 
 | 	{ | 
 | 	  fprintf_unfiltered (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) | 
 |     fprintf_unfiltered (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, VAR_DOMAIN, nullptr).symbol; | 
 |  | 
 |       if (sym != nullptr && SYMBOL_CLASS (sym) == LOC_BLOCK) | 
 | 	{ | 
 | 	  if (compile_debug) | 
 | 	    fprintf_unfiltered (gdb_stdlog, | 
 | 				"gcc_symbol_address \"%s\": full symbol\n", | 
 | 				identifier); | 
 | 	  result = BLOCK_START (SYMBOL_BLOCK_VALUE (sym)); | 
 | 	  if (SYMBOL_TYPE (sym)->is_gnu_ifunc ()) | 
 | 	    result = gnu_ifunc_resolve_addr (target_gdbarch (), result); | 
 | 	  found = 1; | 
 | 	} | 
 |       else | 
 | 	{ | 
 | 	  struct bound_minimal_symbol msym; | 
 |  | 
 | 	  msym = lookup_bound_minimal_symbol (identifier); | 
 | 	  if (msym.minsym != nullptr) | 
 | 	    { | 
 | 	      if (compile_debug) | 
 | 		fprintf_unfiltered (gdb_stdlog, | 
 | 				    "gcc_symbol_address \"%s\": minimal " | 
 | 				    "symbol\n", | 
 | 				    identifier); | 
 | 	      result = BMSYMBOL_VALUE_ADDRESS (msym); | 
 | 	      if (MSYMBOL_TYPE (msym.minsym) == mst_text_gnu_ifunc) | 
 | 		result = gnu_ifunc_resolve_addr (target_gdbarch (), result); | 
 | 	      found = 1; | 
 | 	    } | 
 | 	} | 
 |     } | 
 |  | 
 |   catch (const gdb_exception_error &e) | 
 |     { | 
 |       instance->plugin ().error (e.what ()); | 
 |     } | 
 |  | 
 |   if (compile_debug && !found) | 
 |     fprintf_unfiltered (gdb_stdlog, | 
 | 			"gcc_symbol_address \"%s\": failed\n", | 
 | 			identifier); | 
 |  | 
 |   if (compile_debug) | 
 |     { | 
 |       if (found) | 
 | 	fprintf_unfiltered (gdb_stdlog, "found address for %s!\n", identifier); | 
 |       else | 
 | 	fprintf_unfiltered (gdb_stdlog, | 
 | 			    "did not find address for %s\n", identifier); | 
 |     } | 
 |  | 
 |   return result; | 
 | } |