GCC C语言处理主要函数之dbxout_init

/* At the beginning of compilation, start writing the symbol table.   Initialize `typevec' and output the standard data types of C.  */
static voiddbxout_init (const char *input_file_name){  char ltext_label_name[100];  bool used_ltext_label_name = false;  tree syms = lang_hooks.decls.getdecls ();  const char *mapped_name;
  typevec_len = 100;  typevec = ggc_cleared_vec_alloc<typeinfo> (typevec_len);
  /* stabstr_ob contains one string, which will be just fine with     1-byte alignment.  */  obstack_specify_allocation (&stabstr_ob, 0, 1, xmalloc, free);
  /* Convert Ltext into the appropriate format for local labels in case     the system doesn't insert underscores in front of user generated     labels.  */  ASM_GENERATE_INTERNAL_LABEL (ltext_label_name, "Ltext", 0);
  /* Put the current working directory in an N_SO symbol.  */  if (use_gnu_debug_info_extensions && !NO_DBX_MAIN_SOURCE_DIRECTORY)    {      static const char *cwd;
      if (!cwd) {   cwd = get_src_pwd ();   if (cwd[0] == '\0')     cwd = "/";   else if (!IS_DIR_SEPARATOR (cwd[strlen (cwd) - 1]))     cwd = concat (cwd, "/", NULL);   cwd = remap_debug_filename (cwd); }#ifdef DBX_OUTPUT_MAIN_SOURCE_DIRECTORY      DBX_OUTPUT_MAIN_SOURCE_DIRECTORY (asm_out_file, cwd);#else /* no DBX_OUTPUT_MAIN_SOURCE_DIRECTORY */      dbxout_begin_simple_stabs_desc (cwd, N_SO, get_lang_number ());      dbxout_stab_value_label (ltext_label_name);      used_ltext_label_name = true;#endif /* no DBX_OUTPUT_MAIN_SOURCE_DIRECTORY */    }
  mapped_name = remap_debug_filename (input_file_name);#ifdef DBX_OUTPUT_MAIN_SOURCE_FILENAME  DBX_OUTPUT_MAIN_SOURCE_FILENAME (asm_out_file, mapped_name);#else  dbxout_begin_simple_stabs_desc (mapped_name, N_SO, get_lang_number ());  dbxout_stab_value_label (ltext_label_name);  used_ltext_label_name = true;#endif
  if (used_ltext_label_name)    {      switch_to_section (text_section);      targetm.asm_out.internal_label (asm_out_file, "Ltext", 0);    }
  /* Emit an N_OPT stab to indicate that this file was compiled by GCC.     The string used is historical.  */#ifndef NO_DBX_GCC_MARKER  dbxout_begin_simple_stabs ("gcc2_compiled.", N_OPT);  dbxout_stab_value_zero ();#endif
  base_input_file = lastfile = input_file_name;
  next_type_number = 1;
#ifdef DBX_USE_BINCL  current_file = XNEW (struct dbx_file);  current_file->next = NULL;  current_file->file_number = 0;  current_file->next_type_number = 1;  next_file_number = 1;  current_file->prev = NULL;  current_file->bincl_status = BINCL_NOT_REQUIRED;  current_file->pending_bincl_name = NULL;#endif
  /* Get all permanent types that have typedef names, and output them     all, except for those already output.  Some language front ends     put these declarations in the top-level scope; some do not;     the latter are responsible for calling debug_hooks->type_decl from     their record_builtin_type function.  */  dbxout_typedefs (syms);
  if (preinit_symbols)    {      tree t;      for (t = nreverse (preinit_symbols); t; t = TREE_CHAIN (t)) dbxout_symbol (TREE_VALUE (t), 0);      preinit_symbols = 0;    }}