tools/gn/scope.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "tools/gn/scope.h"
   6
   7 #include "base/logging.h"
   8 #include "base/stl_util.h"
   9 #include "tools/gn/parse_tree.h"
  10 #include "tools/gn/template.h"
  11
  12 namespace {
  13
  14 // FLags set in the mode_flags_ of a scope. If a bit is set, it applies
  15 // recursively to all dependent scopes.
  16 const unsigned kProcessingBuildConfigFlag = 1;
  17 const unsigned kProcessingImportFlag = 2;
  18
  19 // Returns true if this variable name should be considered private. Private
  20 // values start with an underscore, and are not imported from "gni" files
  21 // when processing an import.
  22 bool IsPrivateVar(const base::StringPiece& name) {
  23   return name.empty() || name[0] == '_';
  24 }
  25
  26 }  // namespace
  27
  28 Scope::Scope(const Settings* settings)
  29     : const_containing_(NULL),
  30       mutable_containing_(NULL),
  31       settings_(settings),
  32       mode_flags_(0),
  33       item_collector_(NULL) {
  34 }
  35
  36 Scope::Scope(Scope* parent)
  37     : const_containing_(NULL),
  38       mutable_containing_(parent),
  39       settings_(parent->settings()),
  40       mode_flags_(0),
  41       item_collector_(NULL) {
  42 }
  43
  44 Scope::Scope(const Scope* parent)
  45     : const_containing_(parent),
  46       mutable_containing_(NULL),
  47       settings_(parent->settings()),
  48       mode_flags_(0),
  49       item_collector_(NULL) {
  50 }
  51
  52 Scope::~Scope() {
  53   STLDeleteContainerPairSecondPointers(target_defaults_.begin(),
  54                                        target_defaults_.end());
  55 }
  56
  57 const Value* Scope::GetValue(const base::StringPiece& ident,
  58                              bool counts_as_used) {
  59   // First check for programatically-provided values.
  60   for (ProviderSet::const_iterator i = programmatic_providers_.begin();
  61        i != programmatic_providers_.end(); ++i) {
  62     const Value* v = (*i)->GetProgrammaticValue(ident);
  63     if (v)
  64       return v;
  65   }
  66
  67   RecordMap::iterator found = values_.find(ident);
  68   if (found != values_.end()) {
  69     if (counts_as_used)
  70       found->second.used = true;
  71     return &found->second.value;
  72   }
  73
  74   // Search in the parent scope.
  75   if (const_containing_)
  76     return const_containing_->GetValue(ident);
  77   if (mutable_containing_)
  78     return mutable_containing_->GetValue(ident, counts_as_used);
  79   return NULL;
  80 }
  81
  82 Value* Scope::GetMutableValue(const base::StringPiece& ident,
  83                               bool counts_as_used) {
  84   // Don't do programatic values, which are not mutable.
  85   RecordMap::iterator found = values_.find(ident);
  86   if (found != values_.end()) {
  87     if (counts_as_used)
  88       found->second.used = true;
  89     return &found->second.value;
  90   }
  91
  92   // Search in the parent mutable scope, but not const one.
  93   if (mutable_containing_)
  94     return mutable_containing_->GetMutableValue(ident, counts_as_used);
  95   return NULL;
  96 }
  97
  98 Value* Scope::GetValueForcedToCurrentScope(const base::StringPiece& ident,
  99                                            const ParseNode* set_node) {
 100   RecordMap::iterator found = values_.find(ident);
 101   if (found != values_.end())
 102     return &found->second.value;  // Already have in the current scope.
 103
 104   // Search in the parent scope.
 105   if (containing()) {
 106     const Value* in_containing = containing()->GetValue(ident);
 107     if (in_containing) {
 108       // Promote to current scope.
 109       return SetValue(ident, *in_containing, set_node);
 110     }
 111   }
 112   return NULL;
 113 }
 114
 115 const Value* Scope::GetValue(const base::StringPiece& ident) const {
 116   RecordMap::const_iterator found = values_.find(ident);
 117   if (found != values_.end())
 118     return &found->second.value;
 119   if (containing())
 120     return containing()->GetValue(ident);
 121   return NULL;
 122 }
 123
 124 Value* Scope::SetValue(const base::StringPiece& ident,
 125                        const Value& v,
 126                        const ParseNode* set_node) {
 127   Record& r = values_[ident];  // Clears any existing value.
 128   r.value = v;
 129   r.value.set_origin(set_node);
 130   return &r.value;
 131 }
 132
 133 void Scope::RemoveIdentifier(const base::StringPiece& ident) {
 134   RecordMap::iterator found = values_.find(ident);
 135   if (found != values_.end())
 136     values_.erase(found);
 137 }
 138
 139 void Scope::RemovePrivateIdentifiers() {
 140   // Do it in two phases to avoid mutating while iterating. Our hash map is
 141   // currently backed by several different vendor-specific implementations and
 142   // I'm not sure if all of them support mutating while iterating. Since this
 143   // is not perf-critical, do the safe thing.
 144   std::vector<base::StringPiece> to_remove;
 145   for (RecordMap::const_iterator i = values_.begin(); i != values_.end(); ++i) {
 146     if (IsPrivateVar(i->first))
 147       to_remove.push_back(i->first);
 148   }
 149
 150   for (size_t i = 0; i < to_remove.size(); i++)
 151     values_.erase(to_remove[i]);
 152 }
 153
 154 bool Scope::AddTemplate(const std::string& name, const Template* templ) {
 155   if (GetTemplate(name))
 156     return false;
 157   templates_[name] = templ;
 158   return true;
 159 }
 160
 161 const Template* Scope::GetTemplate(const std::string& name) const {
 162   TemplateMap::const_iterator found = templates_.find(name);
 163   if (found != templates_.end())
 164     return found->second.get();
 165   if (containing())
 166     return containing()->GetTemplate(name);
 167   return NULL;
 168 }
 169
 170 void Scope::MarkUsed(const base::StringPiece& ident) {
 171   RecordMap::iterator found = values_.find(ident);
 172   if (found == values_.end()) {
 173     NOTREACHED();
 174     return;
 175   }
 176   found->second.used = true;
 177 }
 178
 179 void Scope::MarkUnused(const base::StringPiece& ident) {
 180   RecordMap::iterator found = values_.find(ident);
 181   if (found == values_.end()) {
 182     NOTREACHED();
 183     return;
 184   }
 185   found->second.used = false;
 186 }
 187
 188 bool Scope::IsSetButUnused(const base::StringPiece& ident) const {
 189   RecordMap::const_iterator found = values_.find(ident);
 190   if (found != values_.end()) {
 191     if (!found->second.used) {
 192       return true;
 193     }
 194   }
 195   return false;
 196 }
 197
 198 bool Scope::CheckForUnusedVars(Err* err) const {
 199   for (RecordMap::const_iterator i = values_.begin();
 200        i != values_.end(); ++i) {
 201     if (!i->second.used) {
 202       std::string help = "You set the variable \"" + i->first.as_string() +
 203           "\" here and it was unused before it went\nout of scope.";
 204
 205       const BinaryOpNode* binary = i->second.value.origin()->AsBinaryOp();
 206       if (binary && binary->op().type() == Token::EQUAL) {
 207         // Make a nicer error message for normal var sets.
 208         *err = Err(binary->left()->GetRange(), "Assignment had no effect.",
 209                    help);
 210       } else {
 211         // This will happen for internally-generated variables.
 212         *err = Err(i->second.value.origin(), "Assignment had no effect.", help);
 213       }
 214       return false;
 215     }
 216   }
 217   return true;
 218 }
 219
 220 void Scope::GetCurrentScopeValues(KeyValueMap* output) const {
 221   for (RecordMap::const_iterator i = values_.begin(); i != values_.end(); ++i)
 222     (*output)[i->first] = i->second.value;
 223 }
 224
 225 bool Scope::NonRecursiveMergeTo(Scope* dest,
 226                                 const MergeOptions& options,
 227                                 const ParseNode* node_for_err,
 228                                 const char* desc_for_err,
 229                                 Err* err) const {
 230   // Values.
 231   for (RecordMap::const_iterator i = values_.begin(); i != values_.end(); ++i) {
 232     if (options.skip_private_vars && IsPrivateVar(i->first))
 233       continue;  // Skip this private var.
 234
 235     const Value& new_value = i->second.value;
 236     if (!options.clobber_existing) {
 237       const Value* existing_value = dest->GetValue(i->first);
 238       if (existing_value && new_value != *existing_value) {
 239         // Value present in both the source and the dest.
 240         std::string desc_string(desc_for_err);
 241         *err = Err(node_for_err, "Value collision.",
 242             "This " + desc_string + " contains \"" + i->first.as_string() +
 243             "\"");
 244         err->AppendSubErr(Err(i->second.value, "defined here.",
 245             "Which would clobber the one in your current scope"));
 246         err->AppendSubErr(Err(*existing_value, "defined here.",
 247             "Executing " + desc_string + " should not conflict with anything "
 248             "in the current\nscope unless the values are identical."));
 249         return false;
 250       }
 251     }
 252     dest->values_[i->first] = i->second;
 253
 254     if (options.mark_used)
 255       dest->MarkUsed(i->first);
 256   }
 257
 258   // Target defaults are owning pointers.
 259   for (NamedScopeMap::const_iterator i = target_defaults_.begin();
 260        i != target_defaults_.end(); ++i) {
 261     if (!options.clobber_existing) {
 262       if (dest->GetTargetDefaults(i->first)) {
 263         // TODO(brettw) it would be nice to know the origin of a
 264         // set_target_defaults so we can give locations for the colliding target
 265         // defaults.
 266         std::string desc_string(desc_for_err);
 267         *err = Err(node_for_err, "Target defaults collision.",
 268             "This " + desc_string + " contains target defaults for\n"
 269             "\"" + i->first + "\" which would clobber one for the\n"
 270             "same target type in your current scope. It's unfortunate that I'm "
 271             "too stupid\nto tell you the location of where the target defaults "
 272             "were set. Usually\nthis happens in the BUILDCONFIG.gn file.");
 273         return false;
 274       }
 275     }
 276
 277     // Be careful to delete any pointer we're about to clobber.
 278     Scope** dest_scope = &dest->target_defaults_[i->first];
 279     if (*dest_scope)
 280       delete *dest_scope;
 281     *dest_scope = new Scope(settings_);
 282     i->second->NonRecursiveMergeTo(*dest_scope, options, node_for_err,
 283                                    "<SHOULDN'T HAPPEN>", err);
 284   }
 285
 286   // Sources assignment filter.
 287   if (sources_assignment_filter_) {
 288     if (!options.clobber_existing) {
 289       if (dest->GetSourcesAssignmentFilter()) {
 290         // Sources assignment filter present in both the source and the dest.
 291         std::string desc_string(desc_for_err);
 292         *err = Err(node_for_err, "Assignment filter collision.",
 293             "The " + desc_string + " contains a sources_assignment_filter "
 294             "which\nwould clobber the one in your current scope.");
 295         return false;
 296       }
 297     }
 298     dest->sources_assignment_filter_.reset(
 299         new PatternList(*sources_assignment_filter_));
 300   }
 301
 302   // Templates.
 303   for (TemplateMap::const_iterator i = templates_.begin();
 304        i != templates_.end(); ++i) {
 305     if (options.skip_private_vars && IsPrivateVar(i->first))
 306       continue;  // Skip this private template.
 307
 308     if (!options.clobber_existing) {
 309       const Template* existing_template = dest->GetTemplate(i->first);
 310       if (existing_template) {
 311         // Rule present in both the source and the dest.
 312         std::string desc_string(desc_for_err);
 313         *err = Err(node_for_err, "Template collision.",
 314             "This " + desc_string + " contains a template \"" +
 315             i->first + "\"");
 316         err->AppendSubErr(Err(i->second->GetDefinitionRange(), "defined here.",
 317             "Which would clobber the one in your current scope"));
 318         err->AppendSubErr(Err(existing_template->GetDefinitionRange(),
 319             "defined here.",
 320             "Executing " + desc_string + " should not conflict with anything "
 321             "in the current\nscope."));
 322         return false;
 323       }
 324     }
 325
 326     // Be careful to delete any pointer we're about to clobber.
 327     dest->templates_[i->first] = i->second;
 328   }
 329
 330   return true;
 331 }
 332
 333 scoped_ptr<Scope> Scope::MakeClosure() const {
 334   scoped_ptr<Scope> result;
 335   if (const_containing_) {
 336     // We reached the top of the mutable scope stack. The result scope just
 337     // references the const scope (which will never change).
 338     result.reset(new Scope(const_containing_));
 339   } else if (mutable_containing_) {
 340     // There are more nested mutable scopes. Recursively go up the stack to
 341     // get the closure.
 342     result = mutable_containing_->MakeClosure();
 343   } else {
 344     // This is a standalone scope, just copy it.
 345     result.reset(new Scope(settings_));
 346   }
 347
 348   // Want to clobber since we've flattened some nested scopes, and our parent
 349   // scope may have a duplicate value set.
 350   MergeOptions options;
 351   options.clobber_existing = true;
 352
 353   // Add in our variables and we're done.
 354   Err err;
 355   NonRecursiveMergeTo(result.get(), options, NULL, "<SHOULDN'T HAPPEN>", &err);
 356   DCHECK(!err.has_error());
 357   return result.Pass();
 358 }
 359
 360 Scope* Scope::MakeTargetDefaults(const std::string& target_type) {
 361   if (GetTargetDefaults(target_type))
 362     return NULL;
 363
 364   Scope** dest = &target_defaults_[target_type];
 365   if (*dest) {
 366     NOTREACHED();  // Already set.
 367     return *dest;
 368   }
 369   *dest = new Scope(settings_);
 370   return *dest;
 371 }
 372
 373 const Scope* Scope::GetTargetDefaults(const std::string& target_type) const {
 374   NamedScopeMap::const_iterator found = target_defaults_.find(target_type);
 375   if (found != target_defaults_.end())
 376     return found->second;
 377   if (containing())
 378     return containing()->GetTargetDefaults(target_type);
 379   return NULL;
 380 }
 381
 382 const PatternList* Scope::GetSourcesAssignmentFilter() const {
 383   if (sources_assignment_filter_)
 384     return sources_assignment_filter_.get();
 385   if (containing())
 386     return containing()->GetSourcesAssignmentFilter();
 387   return NULL;
 388 }
 389
 390 void Scope::SetProcessingBuildConfig() {
 391   DCHECK((mode_flags_ & kProcessingBuildConfigFlag) == 0);
 392   mode_flags_ |= kProcessingBuildConfigFlag;
 393 }
 394
 395 void Scope::ClearProcessingBuildConfig() {
 396   DCHECK(mode_flags_ & kProcessingBuildConfigFlag);
 397   mode_flags_ &= ~(kProcessingBuildConfigFlag);
 398 }
 399
 400 bool Scope::IsProcessingBuildConfig() const {
 401   if (mode_flags_ & kProcessingBuildConfigFlag)
 402     return true;
 403   if (containing())
 404     return containing()->IsProcessingBuildConfig();
 405   return false;
 406 }
 407
 408 void Scope::SetProcessingImport() {
 409   DCHECK((mode_flags_ & kProcessingImportFlag) == 0);
 410   mode_flags_ |= kProcessingImportFlag;
 411 }
 412
 413 void Scope::ClearProcessingImport() {
 414   DCHECK(mode_flags_ & kProcessingImportFlag);
 415   mode_flags_ &= ~(kProcessingImportFlag);
 416 }
 417
 418 bool Scope::IsProcessingImport() const {
 419   if (mode_flags_ & kProcessingImportFlag)
 420     return true;
 421   if (containing())
 422     return containing()->IsProcessingImport();
 423   return false;
 424 }
 425
 426 const SourceDir& Scope::GetSourceDir() const {
 427   if (!source_dir_.is_null())
 428     return source_dir_;
 429   if (containing())
 430     return containing()->GetSourceDir();
 431   return source_dir_;
 432 }
 433
 434 Scope::ItemVector* Scope::GetItemCollector() {
 435   if (item_collector_)
 436     return item_collector_;
 437   if (mutable_containing())
 438     return mutable_containing()->GetItemCollector();
 439   return NULL;
 440 }
 441
 442 void Scope::SetProperty(const void* key, void* value) {
 443   if (!value) {
 444     DCHECK(properties_.find(key) != properties_.end());
 445     properties_.erase(key);
 446   } else {
 447     properties_[key] = value;
 448   }
 449 }
 450
 451 void* Scope::GetProperty(const void* key, const Scope** found_on_scope) const {
 452   PropertyMap::const_iterator found = properties_.find(key);
 453   if (found != properties_.end()) {
 454     if (found_on_scope)
 455       *found_on_scope = this;
 456     return found->second;
 457   }
 458   if (containing())
 459     return containing()->GetProperty(key, found_on_scope);
 460   return NULL;
 461 }
 462
 463 void Scope::AddProvider(ProgrammaticProvider* p) {
 464   programmatic_providers_.insert(p);
 465 }
 466
 467 void Scope::RemoveProvider(ProgrammaticProvider* p) {
 468   DCHECK(programmatic_providers_.find(p) != programmatic_providers_.end());
 469   programmatic_providers_.erase(p);
 470 }