except.c

   1 #include "global.h"
   2
   3 static Token longjmp_stack_t, unwind_t, longjmp_base;
   4 static Token longjmp_ctx_top;
   5 static Token longjmp_ctx;
   6
   7 void init_except ()
   8 {
   9         longjmp_stack_t = new_symbol ("longjmp_StaCk");
  10         unwind_t = new_symbol ("AuToDt_t");
  11         longjmp_ctx_top = new_symbol ("longjmp_StaCkTop");
  12         longjmp_ctx = new_symbol ("longjmp_CoNtExT");
  13         longjmp_base = new_symbol ("longjmp_iNiTObjFaKe");
  14 }
  15
  16 static char _lwcbuiltin_estack [] =
  17 "static inline void *__lwcbuiltin_get_estack ()\n"
  18 "{\n"
  19 "       return longjmp_StaCkTop;\n"
  20 "}\n"
  21 "static inline void __lwcbuiltin_set_estack (void *v)\n"
  22 "{\n"
  23 "       longjmp_StaCkTop = v;\n"
  24 "}\n";
  25
  26 static char _Unwind_gcc [] =
  27 " /*"COLS"*** gcc unwind internals ***"COLE"*/\n"
  28 " static _Unwind_Reason_Code"
  29 " ThRoW_sToP ( )"
  30 " {"
  31 "  return _URC_NO_REASON ;"
  32 " }"
  33 ""
  34 " void __lwc_unwind (void*) __attribute__ ((noreturn, noinline));"
  35 " void __lwc_unwind ( void *i )"
  36 " {"
  37 "  struct _Unwind_Exception * exc = malloc ( sizeof * exc ) ;"
  38 "  exc -> exception_class = 0 ;"
  39 "  exc -> exception_cleanup = 0 ;"
  40 "  longjmp_StaCkTop -> X = i ;"
  41 "  longjmp_StaCkTop -> i = exc ;"
  42 #ifndef __USING_SJLJ_EXCEPTIONS__
  43 "  _Unwind_ForcedUnwind ( exc , ThRoW_sToP,  0 ) ;"
  44 #else
  45 "  _Unwind_SjLj_ForcedUnwind ( exc , ThRoW_sToP , 0 ) ;"
  46 #endif
  47 " \n/* did you forget -fexceptions ? */ * ( int * ) 0 = 0 ;"
  48 " __lwc_unwind (i);"
  49 "} \n"
  50 " void __lwc_landingpad ( int * i ) "
  51 " {"
  52 "  if ( ! * i ) "
  53 "   longjmp ( * longjmp_StaCkTop -> x , 1 ) ;"
  54 " }";
  55
  56 #define IFEH if (EHUnwind) {
  57 #define IFNEH if (!EHUnwind) {
  58 #define ELSE } else {
  59 #define ENDIF }
  60
  61 void decl_except_data ()
  62 {
  63         outprintf (INCLUDE, include_sys_header_s ("setjmp.h"), -1);
  64 IFEH    // include <unwind.h>
  65         outprintf (INCLUDE, include_sys_header_s ("unwind.h"), -1);
  66 ENDIF
  67
  68 IFNEH   // declare manual unwind accounting
  69         outprintf (STRUCTS,
  70                 RESERVED_struct, unwind_t, '{',
  71                 RESERVED_const, RESERVED_struct, unwind_t, '*', RESERVED_X, ';',
  72                 RESERVED_void, '*', RESERVED_x, ';',
  73                 RESERVED_void, '*', '(', '*' , RESERVED_y, ')', '(', RESERVED_void, '*', ')', ';',
  74                 '}', ';', -1);
  75 ENDIF
  76
  77         outprintf (STRUCTS,
  78                 RESERVED_struct, longjmp_stack_t, '{',
  79                 RESERVED_jmp_buf, '*', RESERVED_x, ';',
  80                 RESERVED_struct, longjmp_stack_t, '*', RESERVED_y, ';',
  81                 RESERVED_void, '*', RESERVED_X, ';', -1);
  82 IFEH    // cleanup eh mess
  83         outprintf (STRUCTS, RESERVED_void, '*', RESERVED_i, ';', -1);
  84 ELSE    // accounting member
  85         outprintf (STRUCTS, RESERVED_const, RESERVED_struct, unwind_t, '*', RESERVED_i, ';', -1);
  86 ENDIF
  87         outprintf (STRUCTS, '}', ';', -1);
  88
  89         if (MainModule)
  90                 outprintf (GVARS, Reentrant ? RESERVED___thread : BLANKT,
  91                            RESERVED_struct, longjmp_stack_t, longjmp_base, ',', '*',
  92                            RESERVED___restrict, longjmp_ctx_top, '=', '&', longjmp_base, ';', -1);
  93         else
  94                 outprintf (GVARS, RESERVED_extern,
  95                            Reentrant ? RESERVED___thread : BLANKT,
  96                            RESERVED_struct, longjmp_stack_t, '*', longjmp_ctx_top, ';', -1);
  97
  98 #define EHTOP longjmp_ctx_top, POINTSAT
  99 #define ADTOP EHTOP, RESERVED_i
 100         if (!MainModule) {
 101                 outprintf (GVARS, RESERVED_extern, RESERVED_void, RESERVED___lwc_unwind,
 102                            '(', RESERVED_void, '*', ')', -1);
 103 #ifdef  HAVE_GNUC_ATTR_NORETURN
 104                 outprintf (GVARS, RESERVED___attribute__, '(', '(',RESERVED_noreturn,')', ')', -1);
 105 #endif
 106                 output_itoken (GVARS, ';');
 107 IFEH            // landing pad prototype
 108                 outprintf (GVARS, RESERVED_extern, RESERVED_void, RESERVED___lwc_landingpad,
 109                            '(', RESERVED_int, '*', ')', ';', -1);
 110 ENDIF
 111         } else
 112                 if (!EHUnwind)
 113                 outprintf (GVARS, RESERVED_void, RESERVED___lwc_unwind, '(', RESERVED_void, '*',')',
 114                            RESERVED___attribute__, '(', '(', RESERVED_noreturn, ')', ')', ';',
 115                            RESERVED_void, RESERVED___lwc_unwind, '(', RESERVED_void, '*',
 116                            RESERVED_X, ')', '{',
 117                            EHTOP, RESERVED_X, '=', RESERVED_X, ';',
 118                            RESERVED_while, '(', ADTOP, ')', '{',
 119                            ADTOP, POINTSAT, RESERVED_y, '(', ADTOP, POINTSAT, RESERVED_x, ')', ';',
 120                            ADTOP, '=', ADTOP, POINTSAT, RESERVED_X, ';', '}',
 121                            RESERVED_longjmp, '(', '*',
 122                            EHTOP, RESERVED_x, ',', RESERVED_1, ')', ';', '}', -1);
 123                 else output_itoken (GVARS, new_symbol (_Unwind_gcc));
 124         if (!EHUnwind)
 125                 outprintf (GVARS, new_symbol (_lwcbuiltin_estack), -1);
 126 }
 127
 128
 129 /* member 'r' is normally a recID, but if a symbol, it's
 130    the name of the custom dtor function.  Useful for arrdtor  */
 131 #define DTOR_OF(x) ISSYMBOL(x) ? x : dtor_name (x)
 132
 133 bool did_unwind;
 134
 135 void push_unwind (OUTSTREAM o, recID r, Token arg)
 136 {
 137         if (EHUnwind) return;
 138         did_unwind = true;
 139 #define NOWARNONTYPE '(', RESERVED___typeof__, '(', u, '.', RESERVED_y, ')', ')'
 140         Token u = name_unwind_var (arg);
 141         outprintf (o, UWMARK, RESERVED_const, RESERVED_struct, unwind_t, u, '=', '{',
 142                    '.', RESERVED_X, '=', ADTOP, ',',
 143                    '.', RESERVED_x, '=', '&', arg, ',',
 144                    '.', RESERVED_y, '=', NOWARNONTYPE, DTOR_OF (r), ',',
 145                    '}', ';', ADTOP, '=', '&', u, ';', UWMARK, -1);
 146 }
 147
 148 void pop_unwind (OUTSTREAM o)
 149 {
 150         if (EHUnwind) return;
 151         outprintf (o, UWMARK, ADTOP, '=', ADTOP, POINTSAT, RESERVED_X, ';', UWMARK, -1);
 152 }
 153
 154 void remove_unwind_stuff (Token *str)
 155 {
 156         int i, j, k;
 157         for (i = 0; str [i] != -1;)
 158                 if (str [i] == UWMARK) {
 159                         for (j = i + 1; str [j] != UWMARK; j++);
 160                         for (k = i, j += 1;;)
 161                                 if ((str [k++] = str [j++]) == -1)
 162                                         break;
 163                 } else i++;
 164 }
 165
 166 void leave_escope (OUTSTREAM o)
 167 {
 168 IFEH
 169         outprintf (o, internal_identifier3 (), '=', RESERVED_1, ';', -1);
 170 ENDIF
 171         outprintf (o, longjmp_ctx_top, '=', longjmp_ctx_top, POINTSAT, RESERVED_y, ';',  -1);
 172 }
 173
 174 NormPtr throw_statement (OUTSTREAM o, NormPtr p)
 175 {
 176         may_throw = true;
 177
 178         outprintf (o, RESERVED___lwc_unwind, '(', -1);
 179
 180         if (CODE [p] == ';')
 181                 output_itoken (o, RESERVED_0);
 182         else {
 183                 exprret E;
 184                 p = parse_expression_retconv (p, &E, typeID_voidP, NORMAL_EXPR);
 185                 if (!E.ok) return p + 1;
 186                 outprintf (o, ISTR (E.newExpr), -1);
 187
 188                 free (E.newExpr);
 189                 if (CODE [p] != ';')
 190                         parse_error (p, "excepted ';' after throw expression");
 191         }
 192
 193         outprintf (o, ')', ';', -1);
 194
 195         return p + 1;
 196 }
 197
 198 NormPtr try_statement (OUTSTREAM o, NormPtr p)
 199 {
 200         Token x = RESERVED_x;
 201         Token y = RESERVED_y;
 202         Token X = RESERVED_X;
 203         Token i = RESERVED_i;
 204         Token ii = internal_identifier2 ();
 205         Token i3 = internal_identifier3 ();
 206         Token retcode = 0;
 207         bool have_retcode;
 208
 209         outprintf (o, '{', RESERVED_struct, longjmp_stack_t, longjmp_ctx, ';', -1);
 210
 211         if (have_retcode = CODE [p] == '(') {
 212                 NormPtr p2;
 213                 p = skip_parenthesis (p2 = p + 1) - 1;
 214                 CODE [p] = ';';
 215                 open_local_scope ();
 216                 local_declaration (o, p2);
 217                 CODE [p++] = ')';
 218                 retcode = recent_obj ();
 219         }
 220
 221         outprintf (o, RESERVED_jmp_buf, ii, ';', longjmp_ctx, '.', x, '=', '&', ii, ';',
 222                    longjmp_ctx, '.', y, '=', longjmp_ctx_top, ';', longjmp_ctx_top,
 223                    '=', '&', longjmp_ctx, ';', longjmp_ctx, '.', X, '=', RESERVED_0, ';', -1);
 224
 225 IFNEH   // init manual accounting
 226         outprintf (o, longjmp_ctx, '.', RESERVED_i, '=', RESERVED_0, ';', -1);
 227 ENDIF
 228         outprintf (o,
 229                    RESERVED_if, '(', '!', '(', RESERVED_setjmp, '(', ii, ')', ')',
 230                    ')', '{', -1);
 231
 232 IFEH    // cleanup with landing pad
 233         outprintf (o, RESERVED_int, i3, cleanup_func (RESERVED___lwc_landingpad),
 234                                  '=', RESERVED_0, ';', -1);
 235 ENDIF
 236
 237         SAVE_VAR (may_throw, may_throw);
 238         int pos = get_stream_pos (o);
 239         p = statement (o, p);
 240         nowipeout_unwind (o, pos);
 241         RESTOR_VAR (may_throw);
 242
 243 IFEH    // mark landing pad normal termination
 244         outprintf (o, i3, '=', RESERVED_1, ';', -1);
 245 ENDIF
 246         outprintf (o, longjmp_ctx_top, '=', longjmp_ctx, '.', y, ';', '}', -1);
 247
 248         outprintf (o, RESERVED_else, '{', -1);
 249         if (have_retcode)
 250                 outprintf (o, retcode, '=', longjmp_ctx, '.', RESERVED_X, ';', -1);
 251 IFEH    // cleanup eh mess
 252         outprintf (o, RESERVED_free, '(', longjmp_ctx, '.', i, ')', ';', -1);
 253 ENDIF
 254         outprintf (o, longjmp_ctx_top, '=', longjmp_ctx, '.', y, ';', -1);
 255         if (CODE [p] == RESERVED_else)
 256                 p = statement (o, p + 1);
 257         output_itoken (o, '}');
 258
 259         output_itoken (o, '}');
 260
 261         if (have_retcode) close_local_scope ();
 262
 263         return p;
 264 }
 265
 266 NormPtr on_throw_statement (OUTSTREAM o, NormPtr p)
 267 {
 268         Token x = RESERVED_x;
 269         Token y = RESERVED_y;
 270         Token X = RESERVED_X;
 271         Token ii = internal_identifier2 ();
 272         Token i3 = internal_identifier3 ();
 273         Token retcode = 0;
 274         bool have_retcode;
 275
 276         // the exception handler is removed when the scope closes
 277         add_auto_destruction (LEAVE_ESCOPE, -1, 0);
 278
 279         outprintf (o, RESERVED_struct, longjmp_stack_t, longjmp_ctx, ';', -1);
 280
 281         if (have_retcode = CODE [p] == '(') {
 282                 NormPtr p2;
 283                 p = skip_parenthesis (p2 = p + 1) - 1;
 284                 CODE [p] = ';';
 285                 open_local_scope ();
 286                 local_declaration (o, p2);
 287                 CODE [p++] = ')';
 288                 retcode = recent_obj ();
 289         }
 290
 291         outprintf (o, RESERVED_jmp_buf, ii, ';', longjmp_ctx, '.', x, '=', '&', ii, ';',
 292                    longjmp_ctx, '.', y, '=', longjmp_ctx_top, ';', longjmp_ctx_top,
 293                    '=', '&', longjmp_ctx, ';', longjmp_ctx, '.', X, '=', RESERVED_0, ';', -1);
 294
 295 IFNEH   // init manual accounting
 296         outprintf (o, longjmp_ctx, '.', RESERVED_i, '=', RESERVED_0, ';', -1);
 297 ELSE    // install landing pad
 298         outprintf (o, RESERVED_int, i3, cleanup_func (RESERVED___lwc_landingpad),
 299                                  '=', RESERVED_0, ';', -1);
 300 ENDIF
 301
 302         outprintf (o,
 303                    RESERVED_if, '(', '(', RESERVED_setjmp, '(', ii, ')', ')', ')', '{', -1);
 304 IFNEH   // init manual accounting
 305         outprintf (o, longjmp_ctx, '.', RESERVED_i, '=', RESERVED_0, ';', -1);
 306 ENDIF
 307         if (have_retcode)
 308                 outprintf (o, retcode, '=', longjmp_ctx, '.', RESERVED_X, ';', -1);
 309
 310         p = statement (o, p);
 311         output_itoken (o, '}');
 312         if (have_retcode) close_local_scope ();
 313
 314         return p;
 315 }