aboutsummaryrefslogtreecommitdiff
path: root/libbuild2/scope.hxx
blob: 39be143b463ebe97e36049557424ec43d6c08e9a (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
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
// file      : libbuild2/scope.hxx -*- C++ -*-
// license   : MIT; see accompanying LICENSE file

#ifndef LIBBUILD2_SCOPE_HXX
#define LIBBUILD2_SCOPE_HXX

#include <map>
#include <unordered_set>

#include <libbuild2/types.hxx>
#include <libbuild2/forward.hxx>
#include <libbuild2/utility.hxx>

#include <libbuild2/module.hxx>
#include <libbuild2/context.hxx>
#include <libbuild2/variable.hxx>
#include <libbuild2/rule-map.hxx>
#include <libbuild2/operation.hxx>
#include <libbuild2/target-key.hxx>
#include <libbuild2/target-type.hxx>
#include <libbuild2/target-state.hxx>

#include <libbuild2/export.hxx>

namespace build2
{
  class dir;

  class LIBBUILD2_SYMEXPORT scope
  {
  public:
    // Context this scope belongs to.
    //
    context& ctx;

    // Absolute and normalized.
    //
    const dir_path& out_path () const {return *out_path_;}
    const dir_path& src_path () const {return *src_path_;}

    // The first is a pointer to the key in scope_map. The second is a pointer
    // to the src_root/base variable value, if any (i.e., it can be NULL).
    //
    const dir_path* out_path_ = nullptr;
    const dir_path* src_path_ = nullptr;

    bool
    root () const {return root_ == this;}

    scope*       parent_scope ()       {return parent_;}
    const scope* parent_scope () const {return parent_;}

    // Root scope of this scope or NULL if this scope is not (yet) in any
    // (known) project. Note that if the scope itself is root, then this
    // function return this. To get to the outer root, query the root scope of
    // the parent.
    //
    scope*       root_scope ()       {return root_;}
    const scope* root_scope () const {return root_;}

    // Root scope of the outermost "strong" (source-based) amalgamation of
    // this scope or NULL if this scope is not (yet) in any (known) project.
    // If there is no strong amalgamation, then this function returns the root
    // scope of the project (in other words, in this case a project is treated
    // as its own strong amalgamation).
    //
    scope*       strong_scope ();
    const scope* strong_scope () const;

    // Root scope of the outermost amalgamation or NULL if this scope is not
    // (yet) in any (known) project. If there is no amalgamation, then this
    // function returns the root scope of the project (in other words, in this
    // case a project is treated as its own amalgamation).
    //
    scope*       weak_scope ();
    const scope* weak_scope () const;

    // Global scope.
    //
    scope&       global_scope () {return const_cast<scope&> (ctx.global_scope);}
    const scope& global_scope () const {return ctx.global_scope;}

    // Return true if the specified root scope is a sub-scope of this root
    // scope. Note that both scopes must be root.
    //
    bool
    sub_root (const scope&) const;

    // Variables.
    //
  public:
    variable_map vars;

    // Lookup, including in outer scopes. If you only want to lookup in this
    // scope, do it on the the variables map directly (and note that there
    // will be no overrides).
    //
    using lookup_type = build2::lookup;

    lookup_type
    operator[] (const variable& var) const
    {
      return lookup (var).first;
    }

    lookup_type
    operator[] (const variable* var) const // For cached variables.
    {
      assert (var != nullptr);
      return operator[] (*var);
    }

    lookup_type
    operator[] (const string& name) const
    {
      const variable* var (ctx.var_pool.find (name));
      return var != nullptr ? operator[] (*var) : lookup_type ();
    }

    // As above, but include target type/pattern-specific variables.
    //
    lookup_type
    lookup (const variable& var, const target_key& tk) const
    {
      return lookup (var, tk.type, tk.name).first;
    }

    lookup_type
    lookup (const variable& var, const target_type& tt, const string& tn) const
    {
      return lookup (var, &tt, &tn).first;
    }

    pair<lookup_type, size_t>
    lookup (const variable& var,
            const target_type* tt = nullptr,
            const string* tn = nullptr) const
    {
      auto p (lookup_original (var, tt, tn));
      return var.overrides == nullptr ? p : lookup_override (var, move (p));
    }

    // Implementation details (used by scope target lookup). The start_depth
    // can be used to skip a number of initial lookups.
    //
    pair<lookup_type, size_t>
    lookup_original (
      const variable&,
      const target_type* tt = nullptr, const string* tn = nullptr,
      const target_type* gt = nullptr, const string* gn = nullptr,
      size_t start_depth = 1) const;

    pair<lookup_type, size_t>
    lookup_override (const variable& var,
                     pair<lookup_type, size_t> original,
                     bool target = false,
                     bool rule = false) const
    {
      return lookup_override_info (var, original, target, rule).lookup;
    }

    // As above but also return an indication of whether the resulting value
    // is/is based (e.g., via append/prepend overrides) on the original or an
    // "outright" override. Note that it will always be false if there is no
    // original.
    //
    struct override_info
    {
      pair<lookup_type, size_t> lookup;
      bool original;
    };

    override_info
    lookup_override_info (const variable&,
                          pair<lookup_type, size_t> original,
                          bool target = false,
                          bool rule = false) const;

    // Return a value suitable for assignment (or append if you only want to
    // append to the value from this scope). If the value does not exist in
    // this scope's map, then a new one with the NULL value is added and
    // returned. Otherwise the existing value is returned.
    //
    value&
    assign (const variable& var) {return vars.assign (var);}

    value&
    assign (const variable* var) {return vars.assign (var);} // For cached.

    // Assign an untyped non-overridable variable with project visibility.
    //
    value&
    assign (string name)
    {
      return assign (var_pool ().insert (move (name)));
    }

    // As above, but assign a typed variable.
    //
    template <typename T>
    value&
    assign (string name)
    {
      return vars.assign (var_pool ().insert<T> (move (name)));
    }

    template <typename T>
    T&
    assign (string name, T&& val)
    {
      value& v (assign<T> (move (name)) = forward<T> (val));
      return v.as<T> ();
    }

    template <typename T>
    T&
    assign (const variable& var, T&& val)
    {
      value& v (assign (var) = forward<T> (val));
      return v.as<T> ();
    }

    template <typename T>
    T&
    assign (const variable* var, T&& val)
    {
      value& v (assign (var) = forward<T> (val));
      return v.as<T> ();
    }

    // Return a value suitable for appending. If the variable does not
    // exist in this scope's map, then outer scopes are searched for
    // the same variable. If found then a new variable with the found
    // value is added to this scope and returned. Otherwise this
    // function proceeds as assign().
    //
    value&
    append (const variable&);

    // Target type/pattern-specific variables.
    //
    variable_type_map target_vars;

    // Set of buildfiles already loaded for this scope. The included
    // buildfiles are checked against the project's root scope while
    // imported -- against the global scope (global_scope).
    //
  public:
    std::unordered_set<path> buildfiles;

    // Target types.
    //
    // Note that target types are project-wide (even if the module that
    // registers them is loaded in a base scope). The thinking here is that
    // having target types only visible in certain scopes of a project just
    // complicates and confuses things (e.g., you cannot refer to a target
    // whose buildfile you just included). On the other hand, it feels highly
    // unlikely that a target type will somehow need to be different for
    // different parts of the project (unlike, say, a rule).
    //
    // The target types are also project-local. This means one has to use
    // import to refer to targets across projects, even in own subprojects
    // (because we stop searching at project boundaries).
    //
    // See also context::global_target_types.
    //
  public:
    const target_type&
    insert_target_type (const target_type& tt)
    {
      return root_extra->target_types.insert (tt);
    }

    template <typename T>
    const target_type&
    insert_target_type ()
    {
      return root_extra->target_types.insert<T> ();
    }

    void
    insert_target_type_file (const string& n, const target_type& tt)
    {
      root_extra->target_types.insert_file (n, tt);
    }

    const target_type*
    find_target_type (const string&) const;

    // Given a target name, figure out its type, taking into account
    // extensions, special names (e.g., '.' and '..'), or anything else that
    // might be relevant. Process the name (in place) by extracting (and
    // returning) extension, adjusting dir/leaf, etc., (note that the dir is
    // not necessarily normalized). Return NULL if not found.
    //
    pair<const target_type*, optional<string>>
    find_target_type (name&, const location&) const;

    // As above but process the potentially out-qualified target name further
    // by completing (relative to this scope) and normalizing the directories
    // and also issuing appropriate diagnostics if the target type is unknown.
    // If the first argument has the pair flag true, then the second should be
    // the out directory.
    //
    pair<const target_type&, optional<string>>
    find_target_type (name&, name&, const location&) const;

    // As above, but return the result as a target key (with its members
    // shallow-pointing to processed parts in the two names).
    //
    target_key
    find_target_key (name&, name&, const location&) const;

    // As above, but the names are passed as a vector. Issue appropriate
    // diagnostics if the wrong number of names is passed.
    //
    target_key
    find_target_key (names&, const location&) const;

    // Dynamically derive a new target type from an existing one. Return the
    // reference to the target type and an indicator of whether it was
    // actually created.
    //
    pair<reference_wrapper<const target_type>, bool>
    derive_target_type (const string& name, const target_type& base);

    template <typename T>
    pair<reference_wrapper<const target_type>, bool>
    derive_target_type (const string& name)
    {
      return derive_target_type (name, T::static_type);
    }

    // Rules.
    //
  public:
    rule_map rules;

    template <typename T>
    void
    insert_rule (action_id a, const char* hint, const rule& r)
    {
      rules.insert<T> (a, hint, r);
    }

    template <typename T>
    void
    insert_rule (meta_operation_id mid, operation_id oid,
                 const char* hint,
                 const rule& r)
    {
      rules.insert<T> (mid, oid, hint, r);
    }

    // Operation callbacks.
    //
    // An entity (module, core) can register a function that will be called
    // when an action is executed on the dir{} target that corresponds to this
    // scope. The pre callback is called just before the recipe and the post
    // -- immediately after. The callbacks are only called if the recipe
    // (including noop recipe) is executed for the corresponding target. The
    // callbacks should only be registered during the load phase.
    //
    // It only makes sense for callbacks to return target_state changed or
    // unchanged and to throw failed in case of an error. These pre/post
    // states will be merged with the recipe state and become the target
    // state. See execute_recipe() for details.
    //
  public:
    struct operation_callback
    {
      using callback = target_state (action, const scope&, const dir&);

      function<callback> pre;
      function<callback> post;
    };

    using operation_callback_map = std::multimap<action_id,
                                                 operation_callback>;

    operation_callback_map operation_callbacks;

    // Extra root scope-only data.
    //
  public:
    struct root_extra_type
    {
      bool altn; // True if using alternative build file/directory naming.

      // Build file/directory naming scheme used by this project.
      //
      const string&   build_ext;        // build        or  build2     (no dot)
      const dir_path& build_dir;        // build/       or  build2/
      const path&     buildfile_file;   // buildfile    or  build2file
      const path&     buildignore_file; // buildignore  or  build2ignore

      const dir_path& root_dir;       // build[2]/root/
      const dir_path& bootstrap_dir;  // build[2]/bootstrap/

      const path&     bootstrap_file; // build[2]/bootstrap.build[2]
      const path&     root_file;      // build[2]/root.build[2]
      const path&     export_file;    // build[2]/export.build[2]
      const path&     src_root_file;  // build[2]/bootstrap/src-root.build[2]
      const path&     out_root_file;  // build[2]/bootstrap/src-root.build[2]

      // Meta/operations supported by this project.
      //
      build2::meta_operations meta_operations;
      build2::operations operations;

      // Modules loaded by this project.
      //
      module_map modules;

      // Variable override cache.
      //
      mutable variable_override_cache override_cache;

      // Target types.
      //
      target_type_map target_types;
    };

    unique_ptr<root_extra_type> root_extra;

    void
    insert_operation (operation_id id, const operation_info& in)
    {
      root_extra->operations.insert (id, in);
    }

    void
    insert_meta_operation (meta_operation_id id, const meta_operation_info& in)
    {
      root_extra->meta_operations.insert (id, in);
    }

    bool
    find_module (const string& name) const
    {
      return root_extra->modules.find_module<module> (name) != nullptr;
    }

    template <typename T>
    T*
    find_module (const string& name) const
    {
      return root_extra->modules.find_module<T> (name);
    }

  public:
    // RW access.
    //
    scope&
    rw () const
    {
      assert (ctx.phase == run_phase::load);
      return const_cast<scope&> (*this);
    }

    variable_pool&
    var_pool ()
    {
      return ctx.var_pool.rw (*this);
    }

  private:
    friend class parser;
    friend class scope_map;
    friend class temp_scope;

    // These two from <libbuild2/file.hxx> set strong_.
    //
    friend LIBBUILD2_SYMEXPORT void create_bootstrap_outer (scope&);
    friend LIBBUILD2_SYMEXPORT scope& create_bootstrap_inner (scope&,
                                                              const dir_path&);

    scope (context& c, bool global)
      : ctx (c), vars (c, global), target_vars (c, global) {}

    scope* parent_;
    scope* root_;
    scope* strong_ = nullptr; // Only set on root scopes.
                              // NULL means no strong amalgamtion.
  };

  inline ostream&
  operator<< (ostream& os, const scope& s)
  {
    // Always absolute.
    //
    return to_stream (os, s.out_path (), true /* representation */);
  }

  // Return the src/out directory corresponding to the given out/src. The
  // passed directory should be a sub-directory of out/src_root.
  //
  dir_path
  src_out (const dir_path& out, const scope& root);

  dir_path
  src_out (const dir_path& out,
           const dir_path& out_root, const dir_path& src_root);

  dir_path
  out_src (const dir_path& src, const scope& root);

  dir_path
  out_src (const dir_path& src,
           const dir_path& out_root, const dir_path& src_root);

  // Return the project name or empty if unnamed.
  //
  const project_name&
  project (const scope& root);

  // Return the name of the first innermost named project in the strong
  // amalgamation chain or empty if all are unnamed.
  //
  const project_name&
  named_project (const scope& root);

  // Temporary scope. The idea is to be able to create a temporary scope in
  // order not to change the variables in the current scope. Such a scope is
  // not entered in to the scope map. As a result it can only be used as a
  // temporary set of variables. In particular, defining targets directly in
  // such a scope will surely end up badly. Defining any nested scopes will be
  // as if defining such a scope in the parent (since path() returns parent's
  // path).
  //
  class temp_scope: public scope
  {
  public:
    temp_scope (scope& p)
        : scope (p.ctx, false /* global */)
    {
      out_path_ = p.out_path_;
      src_path_ = p.src_path_;
      parent_ = &p;
      root_ = p.root_;
      // No need to copy strong_ since we are never root scope.
    }
  };

  // Scope map.
  //
  // Protected by the phase mutex. Note that the scope map is only for paths
  // from the out tree.
  //
  using scope_map_base = dir_path_map<scope>;

  class scope_map: public scope_map_base
  {
  public:
    // Note that we assume the first insertion into the map is always the
    // global scope with empty key.
    //
    LIBBUILD2_SYMEXPORT iterator
    insert (const dir_path&, bool root = false);

    // Find the most qualified scope that encompasses this path.
    //
    const scope&
    find (const dir_path& d) const
    {
      return const_cast<scope_map*> (this)->find (d);
    }

    const scope&
    find (const path& p) const
    {
      // Natural thing to do here would be to call find (p.directory ()).
      // However, there could be a situation where the passed path is a
      // directory (i.e., the calling code does not know what it is dealing
      // with), so let's use the whole path.
      //
      // In fact, ideally, we should have used path_map instead of
      // dir_path_map to be able to search for both paths without any casting
      // (and copies). But currently we have too much stuff pointing to the
      // key.
      //
      return find (path_cast<dir_path> (p));
    }

    // RW access.
    //
  public:
    scope_map&
    rw () const
    {
      assert (ctx.phase == run_phase::load);
      return const_cast<scope_map&> (*this);
    }

    scope_map&
    rw (scope&) const {return const_cast<scope_map&> (*this);}

  private:
    friend class context;

    explicit
    scope_map (context& c): ctx (c) {}

    // Entities that can access bypassing the lock proof.
    //
    friend int main (int, char*[]);

    LIBBUILD2_SYMEXPORT scope&
    find (const dir_path&);

  private:
    context& ctx;
  };
}

#include <libbuild2/scope.ixx>

#endif // LIBBUILD2_SCOPE_HXX