summaryrefslogtreecommitdiff
path: root/gcc/ada/frontend.adb
blob: fd83b5d5b5c802228d89ff4c69fe4196d3991290 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                             F R O N T E N D                              --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 1992-2010, Free Software Foundation, Inc.         --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT 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  distributed with GNAT; see file COPYING3.  If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license.          --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

with System.Strings; use System.Strings;

with Atree;    use Atree;
with Checks;
with CStand;
with Debug;    use Debug;
with Elists;
with Exp_Dbug;
with Fmap;
with Fname.UF;
with Inline;   use Inline;
with Lib;      use Lib;
with Lib.Load; use Lib.Load;
with Live;     use Live;
with Namet;    use Namet;
with Nlists;   use Nlists;
with Opt;      use Opt;
with Osint;
with Par;
with Prep;
with Prepcomp;
with Restrict; use Restrict;
with Rident;   use Rident;
with Rtsfind;  use Rtsfind;
with Snames;   use Snames;
with Sprint;
with Scn;      use Scn;
with Sem;      use Sem;
with Sem_Aux;
with Sem_Ch8;  use Sem_Ch8;
with Sem_SCIL;
with Sem_Elab; use Sem_Elab;
with Sem_Prag; use Sem_Prag;
with Sem_Warn; use Sem_Warn;
with Sinfo;    use Sinfo;
with Sinput;   use Sinput;
with Sinput.L; use Sinput.L;
with SCIL_LL;  use SCIL_LL;
with Targparm; use Targparm;
with Tbuild;   use Tbuild;
with Types;    use Types;

procedure Frontend is
   Config_Pragmas : List_Id;
   --  Gather configuration pragmas

begin
   --  Carry out package initializations. These are initializations which might
   --  logically be performed at elaboration time, were it not for the fact
   --  that we may be doing things more than once in the big loop over files.
   --  Like elaboration, the order in which these calls are made is in some
   --  cases important. For example, Lib cannot be initialized before Namet,
   --  since it uses names table entries.

   Rtsfind.Initialize;
   Atree.Initialize;
   Nlists.Initialize;
   Elists.Initialize;
   Lib.Load.Initialize;
   Sem_Aux.Initialize;
   Sem_Ch8.Initialize;
   Sem_Prag.Initialize;
   Fname.UF.Initialize;
   Checks.Initialize;
   Sem_Warn.Initialize;
   Prep.Initialize;

   if Generate_SCIL then
      SCIL_LL.Initialize;
   end if;

   --  Create package Standard

   CStand.Create_Standard;

   --  Check possible symbol definitions specified by -gnateD switches

   Prepcomp.Process_Command_Line_Symbol_Definitions;

   --  If -gnatep= was specified, parse the preprocessing data file

   if Preprocessing_Data_File /= null then
      Name_Len := Preprocessing_Data_File'Length;
      Name_Buffer (1 .. Name_Len) := Preprocessing_Data_File.all;
      Prepcomp.Parse_Preprocessing_Data_File (Name_Find);

   --  Otherwise, check if there were preprocessing symbols on the command
   --  line and set preprocessing if there are.

   else
      Prepcomp.Check_Symbols;
   end if;

   --  We set Parsing_Main_Extended_Source true here to cover processing of all
   --  the configuration pragma files, as well as the main source unit itself.

   Parsing_Main_Extended_Source := True;

   --  Now that the preprocessing situation is established, we are able to
   --  load the main source (this is no longer done by Lib.Load.Initialize).

   Lib.Load.Load_Main_Source;

   --  Return immediately if the main source could not be found

   if Sinput.Main_Source_File = No_Source_File then
      return;
   end if;

   --  Read and process configuration pragma files if present

   declare
      Save_Style_Check : constant Boolean := Opt.Style_Check;
      --  Save style check mode so it can be restored later

      Source_Config_File : Source_File_Index;
      --  Source reference for -gnatec configuration file

      Prag : Node_Id;

   begin
      --  We always analyze config files with style checks off, since
      --  we don't want a miscellaneous gnat.adc that is around to
      --  discombobulate intended -gnatg or -gnaty compilations. We
      --  also disconnect checking for maximum line length.

      Opt.Style_Check := False;
      Style_Check := False;

      --  Capture current suppress options, which may get modified

      Scope_Suppress := Opt.Suppress_Options;

      --  First deal with gnat.adc file

      if Opt.Config_File then
         Name_Buffer (1 .. 8) := "gnat.adc";
         Name_Len := 8;
         Source_gnat_adc := Load_Config_File (Name_Enter);

         if Source_gnat_adc /= No_Source_File then
            Initialize_Scanner (No_Unit, Source_gnat_adc);
            Config_Pragmas := Par (Configuration_Pragmas => True);
         else
            Config_Pragmas := Empty_List;
         end if;

      else
         Config_Pragmas := Empty_List;
      end if;

      --  Now deal with specified config pragmas files if there are any

      if Opt.Config_File_Names /= null then
         for Index in Opt.Config_File_Names'Range loop
            Name_Len := Config_File_Names (Index)'Length;
            Name_Buffer (1 .. Name_Len) := Config_File_Names (Index).all;
            Source_Config_File := Load_Config_File (Name_Enter);

            if Source_Config_File = No_Source_File then
               Osint.Fail
                 ("cannot find configuration pragmas file "
                  & Config_File_Names (Index).all);
            end if;

            Initialize_Scanner (No_Unit, Source_Config_File);
            Append_List_To
              (Config_Pragmas, Par (Configuration_Pragmas => True));
         end loop;
      end if;

      --  Now analyze all pragmas except those whose analysis must be
      --  deferred till after the main unit is analyzed.

      if Config_Pragmas /= Error_List
        and then Operating_Mode /= Check_Syntax
      then
         Prag := First (Config_Pragmas);
         while Present (Prag) loop
            if not Delay_Config_Pragma_Analyze (Prag) then
               Analyze_Pragma (Prag);
            end if;

            Next (Prag);
         end loop;
      end if;

      --  Restore style check, but if config file turned on checks, leave on!

      Opt.Style_Check := Save_Style_Check or Style_Check;

      --  Capture any modifications to suppress options from config pragmas

      Opt.Suppress_Options := Scope_Suppress;
   end;

   --  If there was a -gnatem switch, initialize the mappings of unit names to
   --  file names and of file names to path names from the mapping file.

   if Mapping_File_Name /= null then
      Fmap.Initialize (Mapping_File_Name.all);
   end if;

   --  Adjust Optimize_Alignment mode from debug switches if necessary

   if Debug_Flag_Dot_SS then
      Optimize_Alignment := 'S';
   elsif Debug_Flag_Dot_TT then
      Optimize_Alignment := 'T';
   end if;

   --  We have now processed the command line switches, and the configuration
   --  pragma files, so this is the point at which we want to capture the
   --  values of the configuration switches (see Opt for further details).

   Opt.Register_Opt_Config_Switches;

   --  Check for file which contains No_Body pragma

   if Source_File_Is_No_Body (Source_Index (Main_Unit)) then
      Change_Main_Unit_To_Spec;
   end if;

   --  Initialize the scanner. Note that we do this after the call to
   --  Create_Standard, which uses the scanner in its processing of
   --  floating-point bounds.

   Initialize_Scanner (Main_Unit, Source_Index (Main_Unit));

   --  Here we call the parser to parse the compilation unit (or units in
   --  the check syntax mode, but in that case we won't go on to the
   --  semantics in any case).

   Discard_List (Par (Configuration_Pragmas => False));
   Parsing_Main_Extended_Source := False;

   --  The main unit is now loaded, and subunits of it can be loaded,
   --  without reporting spurious loading circularities.

   Set_Loading (Main_Unit, False);

   --  Now that the main unit is installed, we can complete the analysis
   --  of the pragmas in gnat.adc and the configuration file, that require
   --  a context for their semantic processing.

   if Config_Pragmas /= Error_List
     and then Operating_Mode /= Check_Syntax
   then
      --  Pragmas that require some semantic activity, such as
      --  Interrupt_State, cannot be processed until the main unit
      --  is installed, because they require a compilation unit on
      --  which to attach with_clauses, etc. So analyze them now.

      declare
         Prag : Node_Id;

      begin
         Prag := First (Config_Pragmas);
         while Present (Prag) loop
            if Delay_Config_Pragma_Analyze (Prag) then
               Analyze_Pragma (Prag);
            end if;

            Next (Prag);
         end loop;
      end;
   end if;

   --  If we have restriction No_Exception_Propagation, and we did not have an
   --  explicit switch turning off Warn_On_Non_Local_Exception, then turn on
   --  this warning by default if we have encountered an exception handler.

   if Restriction_Check_Required (No_Exception_Propagation)
     and then not No_Warn_On_Non_Local_Exception
     and then Exception_Handler_Encountered
   then
      Warn_On_Non_Local_Exception := True;
   end if;

   --  Now on to the semantics. Skip if in syntax only mode

   if Operating_Mode /= Check_Syntax then

      --  Install the configuration pragmas in the tree

      Set_Config_Pragmas (Aux_Decls_Node (Cunit (Main_Unit)), Config_Pragmas);

      --  Following steps are skipped if we had a fatal error during parsing

      if not Fatal_Error (Main_Unit) then

         --  Reset Operating_Mode to Check_Semantics for subunits. We cannot
         --  actually generate code for subunits, so we suppress expansion.
         --  This also corrects certain problems that occur if we try to
         --  incorporate subunits at a lower level.

         if Operating_Mode = Generate_Code
           and then Nkind (Unit (Cunit (Main_Unit))) = N_Subunit
         then
            Operating_Mode := Check_Semantics;
         end if;

         --  Analyze (and possibly expand) main unit

         Scope_Suppress := Suppress_Options;
         Semantics (Cunit (Main_Unit));

         --  Cleanup processing after completing main analysis

         if Operating_Mode = Generate_Code
           or else (Operating_Mode = Check_Semantics
                     and then ASIS_Mode)
         then
            Instantiate_Bodies;
         end if;

         if Operating_Mode = Generate_Code then
            if Inline_Processing_Required then
               Analyze_Inlined_Bodies;
            end if;

            --  Remove entities from program that do not have any
            --  execution time references.

            if Debug_Flag_UU then
               Collect_Garbage_Entities;
            end if;

            Check_Elab_Calls;
         end if;

         --  List library units if requested

         if List_Units then
            Lib.List;
         end if;

         --  Output waiting warning messages

         Sem_Warn.Output_Non_Modified_In_Out_Warnings;
         Sem_Warn.Output_Unreferenced_Messages;
         Sem_Warn.Check_Unused_Withs;
         Sem_Warn.Output_Unused_Warnings_Off_Warnings;
      end if;
   end if;

   --  Qualify all entity names in inner packages, package bodies, etc.,
   --  except when compiling for the VM back-ends, which depend on
   --  having unqualified names in certain cases and handles the
   --  generation of qualified names when needed.

   if VM_Target = No_VM then
      Exp_Dbug.Qualify_All_Entity_Names;
   end if;

   --  SCIL backend requirement. Check that SCIL nodes associated with
   --  dispatching calls reference subprogram calls.

   if Generate_SCIL then
      pragma Debug (Sem_SCIL.Check_SCIL_Nodes (Cunit (Main_Unit)));
      null;
   end if;

   --  Dump the source now. Note that we do this as soon as the analysis
   --  of the tree is complete, because it is not just a dump in the case
   --  of -gnatD, where it rewrites all source locations in the tree.

   Sprint.Source_Dump;

   --  Check again for configuration pragmas that appear in the context of
   --  the main unit. These pragmas only affect the main unit, and the
   --  corresponding flag is reset after each call to Semantics, but they
   --  may affect the generated ali for the unit, and therefore the flag
   --  must be set properly after compilation. Currently we only check for
   --  Initialize_Scalars, but others should be checked: as well???

   declare
      Item  : Node_Id;

   begin
      Item := First (Context_Items (Cunit (Main_Unit)));
      while Present (Item) loop
         if Nkind (Item) = N_Pragma
           and then Pragma_Name (Item) = Name_Initialize_Scalars
         then
            Initialize_Scalars := True;
         end if;

         Next (Item);
      end loop;
   end;

   --  If a mapping file has been specified by a -gnatem switch, update
   --  it if there has been some sources that were not in the mappings.

   if Mapping_File_Name /= null then
      Fmap.Update_Mapping_File (Mapping_File_Name.all);
   end if;

   return;
end Frontend;