gcc/ada/par-load.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             P A R . L O A D                              --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2001 Free Software Foundation, Inc.          --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  20 -- MA 02111-1307, USA.                                                      --
  21 --                                                                          --
  22 -- GNAT was originally developed  by the GNAT team at  New York University. --
  23 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  24 --                                                                          --
  25 ------------------------------------------------------------------------------
  26
  27 --  The Par.Load procedure loads all units that are definitely required before
  28 --  it makes any sense at all to proceed with semantic analysis, including
  29 --  with'ed units, corresponding specs for bodies, parents of child specs,
  30 --  and parents of subunits. All these units are loaded and pointers installed
  31 --  in the tree as described in the spec of package Lib.
  32
  33 with Fname;    use Fname;
  34 with Fname.UF; use Fname.UF;
  35 with Lib.Load; use Lib.Load;
  36 with Uname;    use Uname;
  37 with Namet;    use Namet;
  38 with Casing;   use Casing;
  39 with Opt;      use Opt;
  40 with Osint;    use Osint;
  41 with Sinput.L; use Sinput.L;
  42 with Stylesw;  use Stylesw;
  43 with Validsw;  use Validsw;
  44
  45 separate (Par)
  46 procedure Load is
  47
  48    File_Name : File_Name_Type;
  49    --  Name of file for current unit, derived from unit name
  50
  51    Cur_Unum : Unit_Number_Type := Current_Source_Unit;
  52    --  Unit number of unit that we just finished parsing. Note that we need
  53    --  to capture this, because Source_Unit will change as we parse new
  54    --  source files in the multiple main source file case.
  55
  56    Curunit : constant Node_Id := Cunit (Cur_Unum);
  57    --  Compilation unit node for current compilation unit
  58
  59    Loc : Source_Ptr := Sloc (Curunit);
  60    --  Source location for compilation unit node
  61
  62    Save_Style_Check  : Boolean;
  63    Save_Style_Checks : Style_Check_Options;
  64    --  Save style check so it can be restored later
  65
  66    Save_Validity_Check  : Boolean;
  67    Save_Validity_Checks : Validity_Check_Options;
  68    --  Save validity check so it can be restored later
  69
  70    With_Cunit : Node_Id;
  71    --  Compilation unit node for withed unit
  72
  73    Context_Node : Node_Id;
  74    --  Next node in context items list
  75
  76    With_Node : Node_Id;
  77    --  N_With_Clause node
  78
  79    Spec_Name : Unit_Name_Type;
  80    --  Unit name of required spec
  81
  82    Body_Name : Unit_Name_Type;
  83    --  Unit name of corresponding body
  84
  85    Unum : Unit_Number_Type;
  86    --  Unit number of loaded unit
  87
  88    function Same_File_Name_Except_For_Case
  89      (Expected_File_Name : File_Name_Type;
  90       Actual_File_Name   : File_Name_Type)
  91       return               Boolean;
  92    --  Given an actual file name and an expected file name (the latter being
  93    --  derived from the unit name), determine if they are the same except for
  94    --  possibly different casing of letters.
  95
  96    function Same_File_Name_Except_For_Case
  97      (Expected_File_Name : File_Name_Type;
  98       Actual_File_Name   : File_Name_Type)
  99       return               Boolean
 100    is
 101    begin
 102       Get_Name_String (Actual_File_Name);
 103       Canonical_Case_File_Name (Name_Buffer (1 .. Name_Len));
 104
 105       declare
 106          Lower_Case_Actual_File_Name : String (1 .. Name_Len);
 107
 108       begin
 109          Lower_Case_Actual_File_Name := Name_Buffer (1 .. Name_Len);
 110          Get_Name_String (Expected_File_Name);
 111          Canonical_Case_File_Name (Name_Buffer (1 .. Name_Len));
 112          return Lower_Case_Actual_File_Name = Name_Buffer (1 .. Name_Len);
 113       end;
 114
 115    end Same_File_Name_Except_For_Case;
 116
 117 --  Start of processing for Load
 118
 119 begin
 120    --  Don't do any loads if we already had a fatal error
 121
 122    if Fatal_Error (Cur_Unum) then
 123       return;
 124    end if;
 125
 126    Save_Style_Check_Options (Save_Style_Checks);
 127    Save_Style_Check := Opt.Style_Check;
 128
 129    Save_Validity_Check_Options (Save_Validity_Checks);
 130    Save_Validity_Check := Opt.Validity_Checks_On;
 131
 132    --  If main unit, set Main_Unit_Entity (this will get overwritten if
 133    --  the main unit has a separate spec, that happens later on in Load)
 134
 135    if Cur_Unum = Main_Unit then
 136       Main_Unit_Entity := Cunit_Entity (Main_Unit);
 137    end if;
 138
 139    --  If we have no unit name, things are seriously messed up by previous
 140    --  errors, and we should not try to continue compilation.
 141
 142    if Unit_Name (Cur_Unum) = No_Name then
 143       raise Unrecoverable_Error;
 144    end if;
 145
 146    --  Next step, make sure that the unit name matches the file name
 147    --  and issue a warning message if not. We only output this for the
 148    --  main unit, since for other units it is more serious and is
 149    --  caught in a separate test below.
 150
 151    File_Name :=
 152      Get_File_Name
 153        (Unit_Name (Cur_Unum),
 154         Subunit => Nkind (Unit (Cunit (Cur_Unum))) = N_Subunit);
 155
 156    if Cur_Unum = Main_Unit
 157      and then File_Name /= Unit_File_Name (Cur_Unum)
 158      and then (File_Names_Case_Sensitive
 159                 or not Same_File_Name_Except_For_Case
 160                          (File_Name, Unit_File_Name (Cur_Unum)))
 161    then
 162       Error_Msg_Name_1 := File_Name;
 163       Error_Msg
 164         ("?file name does not match unit name, should be{", Sloc (Curunit));
 165    end if;
 166
 167    --  For units other than the main unit, the expected unit name is set and
 168    --  must be the same as the actual unit name, or we are in big trouble, and
 169    --  abandon the compilation since there are situations where this really
 170    --  gets us into bad trouble (e.g. some subunit situations).
 171
 172    if Cur_Unum /= Main_Unit
 173      and then Expected_Unit (Cur_Unum) /= Unit_Name (Cur_Unum)
 174    then
 175       Loc := Error_Location (Cur_Unum);
 176       Error_Msg_Name_1 := Unit_File_Name (Cur_Unum);
 177       Get_Name_String (Error_Msg_Name_1);
 178
 179       --  Check for predefined file case
 180
 181       if Name_Len > 1
 182         and then Name_Buffer (2) = '-'
 183         and then (Name_Buffer (1) = 'a'
 184                     or else
 185                   Name_Buffer (1) = 's'
 186                     or else
 187                   Name_Buffer (1) = 'i'
 188                     or else
 189                   Name_Buffer (1) = 'g')
 190       then
 191          --  In the predefined file case, we know the user did not construct
 192          --  their own package, but we got the wrong one. This means that the
 193          --  name supplied by the user crunched to something we recognized,
 194          --  but then the file did not contain the unit expected. Most likely
 195          --  this is due to a misspelling, e.g.
 196
 197          --    with Ada.Calender;
 198
 199          --  This crunches to a-calend, which indeed contains the unit
 200          --  Ada.Calendar, and we can diagnose the misspelling. This is
 201          --  a simple heuristic, but it catches many common cases of
 202          --  misspelling of predefined unit names without needing a full
 203          --  list of them.
 204
 205          Error_Msg_Name_1 := Expected_Unit (Cur_Unum);
 206          Error_Msg ("% is not a predefined library unit!", Loc);
 207          Error_Msg_Name_1 := Unit_Name (Cur_Unum);
 208          Error_Msg ("possible misspelling of %!", Loc);
 209
 210       --  Non-predefined file name case
 211
 212       else
 213          Error_Msg ("file { does not contain expected unit!", Loc);
 214          Error_Msg_Unit_1 := Expected_Unit (Cur_Unum);
 215          Error_Msg ("expected unit $!", Loc);
 216          Error_Msg_Unit_1 := Unit_Name (Cur_Unum);
 217          Error_Msg ("found unit $!", Loc);
 218       end if;
 219
 220       raise Unrecoverable_Error;
 221    end if;
 222
 223    --  If current unit is a body, load its corresponding spec
 224
 225    if Nkind (Unit (Curunit)) = N_Package_Body
 226      or else Nkind (Unit (Curunit)) = N_Subprogram_Body
 227    then
 228       Spec_Name := Get_Spec_Name (Unit_Name (Cur_Unum));
 229       Unum :=
 230         Load_Unit
 231           (Load_Name  => Spec_Name,
 232            Required   => False,
 233            Subunit    => False,
 234            Error_Node => Curunit,
 235            Corr_Body  => Cur_Unum);
 236
 237       --  If we successfully load the unit, then set the spec pointer. Once
 238       --  again note that if the loaded unit has a fatal error, Load will
 239       --  have set our Fatal_Error flag to propagate this condition.
 240
 241       if Unum /= No_Unit then
 242          Set_Library_Unit (Curunit, Cunit (Unum));
 243
 244          --  If this is a separate spec for the main unit, then we reset
 245          --  Main_Unit_Entity to point to the entity for this separate spec
 246
 247          if Cur_Unum = Main_Unit then
 248             Main_Unit_Entity := Cunit_Entity (Unum);
 249          end if;
 250
 251       --  If we don't find the spec, then if we have a subprogram body, we
 252       --  are still OK, we just have a case of a body acting as its own spec
 253
 254       elsif Nkind (Unit (Curunit)) = N_Subprogram_Body then
 255          Set_Acts_As_Spec (Curunit, True);
 256          Set_Library_Unit (Curunit, Curunit);
 257
 258       --  Otherwise we do have an error, repeat the load request for the spec
 259       --  with Required set True to generate an appropriate error message.
 260
 261       else
 262          Unum :=
 263            Load_Unit
 264              (Load_Name  => Spec_Name,
 265               Required   => True,
 266               Subunit    => False,
 267               Error_Node => Curunit);
 268          return;
 269       end if;
 270
 271    --  If current unit is a child unit spec, load its parent
 272
 273    elsif Nkind (Unit (Curunit)) = N_Package_Declaration
 274      or else Nkind (Unit (Curunit)) =  N_Subprogram_Declaration
 275      or else Nkind (Unit (Curunit)) in N_Generic_Declaration
 276      or else Nkind (Unit (Curunit)) in N_Generic_Instantiation
 277      or else Nkind (Unit (Curunit)) in N_Renaming_Declaration
 278    then
 279       --  Turn style and validity checks off for parent unit
 280
 281       if not GNAT_Mode then
 282          Reset_Style_Check_Options;
 283          Reset_Validity_Check_Options;
 284       end if;
 285
 286       Spec_Name := Get_Parent_Spec_Name (Unit_Name (Cur_Unum));
 287
 288       if Spec_Name /= No_Name then
 289          Unum :=
 290            Load_Unit
 291              (Load_Name  => Spec_Name,
 292               Required   => True,
 293               Subunit    => False,
 294               Error_Node => Curunit);
 295
 296          if Unum /= No_Unit then
 297             Set_Parent_Spec (Unit (Curunit), Cunit (Unum));
 298          end if;
 299       end if;
 300
 301    --  If current unit is a subunit, then load its parent body
 302
 303    elsif Nkind (Unit (Curunit)) = N_Subunit then
 304       Body_Name := Get_Parent_Body_Name (Unit_Name (Cur_Unum));
 305       Unum :=
 306         Load_Unit
 307           (Load_Name  => Body_Name,
 308            Required   => True,
 309            Subunit    => True,
 310            Error_Node => Name (Unit (Curunit)));
 311
 312       if Unum /= No_Unit then
 313          Set_Library_Unit (Curunit, Cunit (Unum));
 314       end if;
 315
 316    end if;
 317
 318    --  Now we load with'ed units, with style/validity checks turned off
 319
 320    if not GNAT_Mode then
 321       Reset_Style_Check_Options;
 322       Reset_Validity_Check_Options;
 323    end if;
 324
 325    --  Loop through context items
 326
 327    Context_Node := First (Context_Items (Curunit));
 328    while Present (Context_Node) loop
 329
 330       if Nkind (Context_Node) = N_With_Clause then
 331          With_Node := Context_Node;
 332          Spec_Name := Get_Unit_Name (With_Node);
 333
 334          Unum :=
 335            Load_Unit
 336              (Load_Name  => Spec_Name,
 337               Required   => False,
 338               Subunit    => False,
 339               Error_Node => With_Node,
 340               Renamings  => True);
 341
 342          --  If we find the unit, then set spec pointer in the N_With_Clause
 343          --  to point to the compilation unit for the spec. Remember that
 344          --  the Load routine itself sets our Fatal_Error flag if the loaded
 345          --  unit gets a fatal error, so we don't need to worry about that.
 346
 347          if Unum /= No_Unit then
 348             Set_Library_Unit (With_Node, Cunit (Unum));
 349
 350          --  If the spec isn't found, then try finding the corresponding
 351          --  body, since it is possible that we have a subprogram body
 352          --  that is acting as a spec (since no spec is present).
 353
 354          else
 355             Body_Name := Get_Body_Name (Spec_Name);
 356             Unum :=
 357               Load_Unit
 358                 (Load_Name  => Body_Name,
 359                  Required   => False,
 360                  Subunit    => False,
 361                  Error_Node => With_Node,
 362                  Renamings  => True);
 363
 364             --  If we got a subprogram body, then mark that we are using
 365             --  the body as a spec in the file table, and set the spec
 366             --  pointer in the N_With_Clause to point to the body entity.
 367
 368             if Unum /= No_Unit
 369               and then Nkind (Unit (Cunit (Unum))) = N_Subprogram_Body
 370             then
 371                With_Cunit := Cunit (Unum);
 372                Set_Library_Unit (With_Node, With_Cunit);
 373                Set_Acts_As_Spec (With_Cunit, True);
 374                Set_Library_Unit (With_Cunit, With_Cunit);
 375
 376             --  If we couldn't find the body, or if it wasn't a body spec
 377             --  then we are in trouble. We make one more call to Load to
 378             --  require the spec. We know it will fail of course, the
 379             --  purpose is to generate the required error message (we prefer
 380             --  that this message refer to the missing spec, not the body)
 381
 382             else
 383                Unum :=
 384                  Load_Unit
 385                    (Load_Name  => Spec_Name,
 386                     Required   => True,
 387                     Subunit    => False,
 388                     Error_Node => With_Node,
 389                     Renamings  => True);
 390
 391                --  Here we create a dummy package unit for the missing unit
 392
 393                Unum := Create_Dummy_Package_Unit (With_Node, Spec_Name);
 394                Set_Library_Unit (With_Node, Cunit (Unum));
 395             end if;
 396          end if;
 397       end if;
 398
 399       Next (Context_Node);
 400    end loop;
 401
 402    --  Restore style/validity check mode for main unit
 403
 404    Set_Style_Check_Options (Save_Style_Checks);
 405    Opt.Style_Check := Save_Style_Check;
 406    Set_Validity_Check_Options (Save_Validity_Checks);
 407    Opt.Validity_Checks_On := Save_Validity_Check;
 408 end Load;