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) 1992-2006, 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,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, 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.UF; use Fname.UF;
  34 with Lib.Load; use Lib.Load;
  35 with Uname;    use Uname;
  36 with Osint;    use Osint;
  37 with Sinput.L; use Sinput.L;
  38 with Stylesw;  use Stylesw;
  39 with Validsw;  use Validsw;
  40
  41 with GNAT.Spelling_Checker; use GNAT.Spelling_Checker;
  42
  43 separate (Par)
  44 procedure Load is
  45
  46    File_Name : File_Name_Type;
  47    --  Name of file for current unit, derived from unit name
  48
  49    Cur_Unum : constant Unit_Number_Type := Current_Source_Unit;
  50    --  Unit number of unit that we just finished parsing. Note that we need
  51    --  to capture this, because Source_Unit will change as we parse new
  52    --  source files in the multiple main source file case.
  53
  54    Curunit : constant Node_Id := Cunit (Cur_Unum);
  55    --  Compilation unit node for current compilation unit
  56
  57    Loc : Source_Ptr := Sloc (Curunit);
  58    --  Source location for compilation unit node
  59
  60    Save_Style_Check  : Boolean;
  61    Save_Style_Checks : Style_Check_Options;
  62    --  Save style check so it can be restored later
  63
  64    Save_Validity_Check  : Boolean;
  65    Save_Validity_Checks : Validity_Check_Options;
  66    --  Save validity check so it can be restored later
  67
  68    With_Cunit : Node_Id;
  69    --  Compilation unit node for withed unit
  70
  71    Context_Node : Node_Id;
  72    --  Next node in context items list
  73
  74    With_Node : Node_Id;
  75    --  N_With_Clause node
  76
  77    Spec_Name : Unit_Name_Type;
  78    --  Unit name of required spec
  79
  80    Body_Name : Unit_Name_Type;
  81    --  Unit name of corresponding body
  82
  83    Unum : Unit_Number_Type;
  84    --  Unit number of loaded unit
  85
  86    Limited_With_Found : Boolean := False;
  87    --  Set True if a limited WITH is found, used to ???
  88
  89    function Same_File_Name_Except_For_Case
  90      (Expected_File_Name : File_Name_Type;
  91       Actual_File_Name   : File_Name_Type) 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    ------------------------------------
  97    -- Same_File_Name_Except_For_Case --
  98    ------------------------------------
  99
 100    function Same_File_Name_Except_For_Case
 101      (Expected_File_Name : File_Name_Type;
 102       Actual_File_Name   : File_Name_Type) return Boolean
 103    is
 104    begin
 105       Get_Name_String (Actual_File_Name);
 106       Canonical_Case_File_Name (Name_Buffer (1 .. Name_Len));
 107
 108       declare
 109          Lower_Case_Actual_File_Name : String (1 .. Name_Len);
 110
 111       begin
 112          Lower_Case_Actual_File_Name := Name_Buffer (1 .. Name_Len);
 113          Get_Name_String (Expected_File_Name);
 114          Canonical_Case_File_Name (Name_Buffer (1 .. Name_Len));
 115          return Lower_Case_Actual_File_Name = Name_Buffer (1 .. Name_Len);
 116       end;
 117
 118    end Same_File_Name_Except_For_Case;
 119
 120 --  Start of processing for Load
 121
 122 begin
 123    --  Don't do any loads if we already had a fatal error
 124
 125    if Fatal_Error (Cur_Unum) then
 126       return;
 127    end if;
 128
 129    Save_Style_Check_Options (Save_Style_Checks);
 130    Save_Style_Check := Opt.Style_Check;
 131
 132    Save_Validity_Check_Options (Save_Validity_Checks);
 133    Save_Validity_Check := Opt.Validity_Checks_On;
 134
 135    --  If main unit, set Main_Unit_Entity (this will get overwritten if
 136    --  the main unit has a separate spec, that happens later on in Load)
 137
 138    if Cur_Unum = Main_Unit then
 139       Main_Unit_Entity := Cunit_Entity (Main_Unit);
 140    end if;
 141
 142    --  If we have no unit name, things are seriously messed up by previous
 143    --  errors, and we should not try to continue compilation.
 144
 145    if Unit_Name (Cur_Unum) = No_Name then
 146       raise Unrecoverable_Error;
 147    end if;
 148
 149    --  Next step, make sure that the unit name matches the file name
 150    --  and issue a warning message if not. We only output this for the
 151    --  main unit, since for other units it is more serious and is
 152    --  caught in a separate test below. We also inhibit the message in
 153    --  multiple unit per file mode, because in this case the relation
 154    --  between file name and unit name is broken.
 155
 156    File_Name :=
 157      Get_File_Name
 158        (Unit_Name (Cur_Unum),
 159         Subunit => Nkind (Unit (Cunit (Cur_Unum))) = N_Subunit);
 160
 161    if Cur_Unum = Main_Unit
 162      and then Multiple_Unit_Index = 0
 163      and then File_Name /= Unit_File_Name (Cur_Unum)
 164      and then (File_Names_Case_Sensitive
 165                 or not Same_File_Name_Except_For_Case
 166                          (File_Name, Unit_File_Name (Cur_Unum)))
 167    then
 168       Error_Msg_Name_1 := File_Name;
 169       Error_Msg
 170         ("?file name does not match unit name, should be{", Sloc (Curunit));
 171    end if;
 172
 173    --  For units other than the main unit, the expected unit name is set and
 174    --  must be the same as the actual unit name, or we are in big trouble, and
 175    --  abandon the compilation since there are situations where this really
 176    --  gets us into bad trouble (e.g. some subunit situations).
 177
 178    if Cur_Unum /= Main_Unit
 179      and then Expected_Unit (Cur_Unum) /= Unit_Name (Cur_Unum)
 180    then
 181       Loc := Error_Location (Cur_Unum);
 182       Error_Msg_Name_1 := Unit_File_Name (Cur_Unum);
 183       Get_Name_String (Error_Msg_Name_1);
 184
 185       --  Check for predefined file case
 186
 187       if Name_Len > 1
 188         and then Name_Buffer (2) = '-'
 189         and then (Name_Buffer (1) = 'a'
 190                     or else
 191                   Name_Buffer (1) = 's'
 192                     or else
 193                   Name_Buffer (1) = 'i'
 194                     or else
 195                   Name_Buffer (1) = 'g')
 196       then
 197          declare
 198             Expect_Name : constant Name_Id := Expected_Unit (Cur_Unum);
 199             Actual_Name : constant Name_Id := Unit_Name (Cur_Unum);
 200
 201          begin
 202             Error_Msg_Name_1 := Expect_Name;
 203             Error_Msg ("% is not a predefined library unit!", Loc);
 204
 205             --  In the predefined file case, we know the user did not
 206             --  construct their own package, but we got the wrong one.
 207             --  This means that the name supplied by the user crunched
 208             --  to something we recognized, but then the file did not
 209             --  contain the unit expected. Most likely this is due to
 210             --  a misspelling, e.g.
 211
 212             --    with Ada.Calender;
 213
 214             --  This crunches to a-calend, which indeed contains the unit
 215             --  Ada.Calendar, and we can diagnose the misspelling. This
 216             --  is a simple heuristic, but it catches many common cases
 217             --  of misspelling of predefined unit names without needing
 218             --  a full list of them.
 219
 220             --  Before actually issinying the message, we will check that the
 221             --  unit name is indeed a plausible misspelling of the one we got.
 222
 223             if Is_Bad_Spelling_Of
 224               (Found  => Get_Name_String (Expect_Name),
 225                Expect => Get_Name_String (Actual_Name))
 226             then
 227                Error_Msg_Name_1 := Actual_Name;
 228                Error_Msg ("possible misspelling of %!", Loc);
 229             end if;
 230          end;
 231
 232       --  Non-predefined file name case. In this case we generate a message
 233       --  and then we quit, because we are in big trouble, and if we try
 234       --  to continue compilation, we get into some nasty situations
 235       --  (for example in some subunit cases).
 236
 237       else
 238          Error_Msg ("file { does not contain expected unit!", Loc);
 239          Error_Msg_Unit_1 := Expected_Unit (Cur_Unum);
 240          Error_Msg ("expected unit $!", Loc);
 241          Error_Msg_Unit_1 := Unit_Name (Cur_Unum);
 242          Error_Msg ("found unit $!", Loc);
 243       end if;
 244
 245       --  In both cases, remove the unit if it is the last unit (which it
 246       --  normally (always?) will be) so that it is out of the way later.
 247
 248       Remove_Unit (Cur_Unum);
 249    end if;
 250
 251    --  If current unit is a body, load its corresponding spec
 252
 253    if Nkind (Unit (Curunit)) = N_Package_Body
 254      or else Nkind (Unit (Curunit)) = N_Subprogram_Body
 255    then
 256       Spec_Name := Get_Spec_Name (Unit_Name (Cur_Unum));
 257       Unum :=
 258         Load_Unit
 259           (Load_Name  => Spec_Name,
 260            Required   => False,
 261            Subunit    => False,
 262            Error_Node => Curunit,
 263            Corr_Body  => Cur_Unum);
 264
 265       --  If we successfully load the unit, then set the spec pointer. Once
 266       --  again note that if the loaded unit has a fatal error, Load will
 267       --  have set our Fatal_Error flag to propagate this condition.
 268
 269       if Unum /= No_Unit then
 270          Set_Library_Unit (Curunit, Cunit (Unum));
 271
 272          --  If this is a separate spec for the main unit, then we reset
 273          --  Main_Unit_Entity to point to the entity for this separate spec
 274
 275          if Cur_Unum = Main_Unit then
 276             Main_Unit_Entity := Cunit_Entity (Unum);
 277          end if;
 278
 279       --  If we don't find the spec, then if we have a subprogram body, we
 280       --  are still OK, we just have a case of a body acting as its own spec
 281
 282       elsif Nkind (Unit (Curunit)) = N_Subprogram_Body then
 283          Set_Acts_As_Spec (Curunit, True);
 284          Set_Library_Unit (Curunit, Curunit);
 285
 286       --  Otherwise we do have an error, repeat the load request for the spec
 287       --  with Required set True to generate an appropriate error message.
 288
 289       else
 290          Unum :=
 291            Load_Unit
 292              (Load_Name  => Spec_Name,
 293               Required   => True,
 294               Subunit    => False,
 295               Error_Node => Curunit);
 296          return;
 297       end if;
 298
 299    --  If current unit is a child unit spec, load its parent. If the child unit
 300    --  is loaded through a limited with, the parent must be as well.
 301
 302    elsif     Nkind (Unit (Curunit)) =  N_Package_Declaration
 303      or else Nkind (Unit (Curunit)) =  N_Subprogram_Declaration
 304      or else Nkind (Unit (Curunit)) in N_Generic_Declaration
 305      or else Nkind (Unit (Curunit)) in N_Generic_Instantiation
 306      or else Nkind (Unit (Curunit)) in N_Renaming_Declaration
 307    then
 308       --  Turn style and validity checks off for parent unit
 309
 310       if not GNAT_Mode then
 311          Reset_Style_Check_Options;
 312          Reset_Validity_Check_Options;
 313       end if;
 314
 315       Spec_Name := Get_Parent_Spec_Name (Unit_Name (Cur_Unum));
 316
 317       if Spec_Name /= No_Name then
 318          Unum :=
 319            Load_Unit
 320              (Load_Name         => Spec_Name,
 321               Required          => True,
 322               Subunit           => False,
 323               Error_Node        => Curunit,
 324               From_Limited_With => From_Limited_With);
 325
 326          if Unum /= No_Unit then
 327             Set_Parent_Spec (Unit (Curunit), Cunit (Unum));
 328          end if;
 329       end if;
 330
 331    --  If current unit is a subunit, then load its parent body
 332
 333    elsif Nkind (Unit (Curunit)) = N_Subunit then
 334       Body_Name := Get_Parent_Body_Name (Unit_Name (Cur_Unum));
 335       Unum :=
 336         Load_Unit
 337           (Load_Name  => Body_Name,
 338            Required   => True,
 339            Subunit    => True,
 340            Error_Node => Name (Unit (Curunit)));
 341
 342       if Unum /= No_Unit then
 343          Set_Library_Unit (Curunit, Cunit (Unum));
 344       end if;
 345    end if;
 346
 347    --  Now we load with'ed units, with style/validity checks turned off
 348
 349    if not GNAT_Mode then
 350       Reset_Style_Check_Options;
 351       Reset_Validity_Check_Options;
 352    end if;
 353
 354    --  Load the context items in two rounds: the first round handles normal
 355    --  withed units and the second round handles Ada 2005 limited-withed units.
 356    --  This is required to allow the low-level circuitry that detects circular
 357    --  dependencies of units the correct notification of the following error:
 358
 359    --       limited with D;
 360    --       with D;                  with C;
 361    --       package C is ...         package D is ...
 362
 363    for Round in 1 .. 2 loop
 364       Context_Node := First (Context_Items (Curunit));
 365       while Present (Context_Node) loop
 366
 367          --  During the first round we check if there is some limited-with
 368          --  context clause; otherwise the second round will be skipped
 369
 370          if Nkind (Context_Node) = N_With_Clause
 371            and then Round = 1
 372            and then Limited_Present (Context_Node)
 373          then
 374             Limited_With_Found := True;
 375          end if;
 376
 377          if Nkind (Context_Node) = N_With_Clause
 378            and then ((Round = 1 and then not Limited_Present (Context_Node))
 379                         or else
 380                      (Round = 2 and then Limited_Present (Context_Node)))
 381          then
 382             With_Node := Context_Node;
 383             Spec_Name := Get_Unit_Name (With_Node);
 384
 385             Unum :=
 386               Load_Unit
 387                 (Load_Name         => Spec_Name,
 388                  Required          => False,
 389                  Subunit           => False,
 390                  Error_Node        => With_Node,
 391                  Renamings         => True,
 392                  From_Limited_With => From_Limited_With
 393                                         or else
 394                                       Limited_Present (Context_Node));
 395
 396             --  If we find the unit, then set spec pointer in the N_With_Clause
 397             --  to point to the compilation unit for the spec. Remember that
 398             --  the Load routine itself sets our Fatal_Error flag if the loaded
 399             --  unit gets a fatal error, so we don't need to worry about that.
 400
 401             if Unum /= No_Unit then
 402                Set_Library_Unit (With_Node, Cunit (Unum));
 403
 404             --  If the spec isn't found, then try finding the corresponding
 405             --  body, since it is possible that we have a subprogram body
 406             --  that is acting as a spec (since no spec is present).
 407
 408             else
 409                Body_Name := Get_Body_Name (Spec_Name);
 410                Unum :=
 411                  Load_Unit
 412                    (Load_Name  => Body_Name,
 413                     Required   => False,
 414                     Subunit    => False,
 415                     Error_Node => With_Node,
 416                     Renamings  => True);
 417
 418                --  If we got a subprogram body, then mark that we are using
 419                --  the body as a spec in the file table, and set the spec
 420                --  pointer in the N_With_Clause to point to the body entity.
 421
 422                if Unum /= No_Unit
 423                  and then Nkind (Unit (Cunit (Unum))) = N_Subprogram_Body
 424                then
 425                   With_Cunit := Cunit (Unum);
 426                   Set_Library_Unit (With_Node, With_Cunit);
 427                   Set_Acts_As_Spec (With_Cunit, True);
 428                   Set_Library_Unit (With_Cunit, With_Cunit);
 429
 430                --  If we couldn't find the body, or if it wasn't a body spec
 431                --  then we are in trouble. We make one more call to Load to
 432                --  require the spec. We know it will fail of course, the
 433                --  purpose is to generate the required error message (we prefer
 434                --  that this message refer to the missing spec, not the body)
 435
 436                else
 437                   Unum :=
 438                     Load_Unit
 439                       (Load_Name  => Spec_Name,
 440                        Required   => True,
 441                        Subunit    => False,
 442                        Error_Node => With_Node,
 443                        Renamings  => True);
 444
 445                   --  Here we create a dummy package unit for the missing unit
 446
 447                   Unum := Create_Dummy_Package_Unit (With_Node, Spec_Name);
 448                   Set_Library_Unit (With_Node, Cunit (Unum));
 449                end if;
 450             end if;
 451          end if;
 452
 453          Next (Context_Node);
 454       end loop;
 455
 456       exit when not Limited_With_Found;
 457    end loop;
 458
 459    --  Restore style/validity check mode for main unit
 460
 461    Set_Style_Check_Options (Save_Style_Checks);
 462    Opt.Style_Check := Save_Style_Check;
 463    Set_Validity_Check_Options (Save_Validity_Checks);
 464    Opt.Validity_Checks_On := Save_Validity_Check;
 465 end Load;