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// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "gn/scope.h"
#include <memory>
#include "base/logging.h"
#include "gn/parse_tree.h"
#include "gn/source_file.h"
#include "gn/template.h"
namespace {
// FLags set in the mode_flags_ of a scope. If a bit is set, it applies
// recursively to all dependent scopes.
const unsigned kProcessingBuildConfigFlag = 1;
const unsigned kProcessingImportFlag = 2;
// Returns true if this variable name should be considered private. Private
// values start with an underscore, and are not imported from "gni" files
// when processing an import.
bool IsPrivateVar(const std::string_view& name) {
return name.empty() || name[0] == '_';
}
} // namespace
// Defaults to all false, which are the things least likely to cause errors.
Scope::MergeOptions::MergeOptions()
: clobber_existing(false),
skip_private_vars(false),
mark_dest_used(false) {}
Scope::MergeOptions::~MergeOptions() = default;
Scope::ProgrammaticProvider::~ProgrammaticProvider() {
scope_->RemoveProvider(this);
}
Scope::Scope(const Settings* settings)
: const_containing_(nullptr),
mutable_containing_(nullptr),
settings_(settings),
mode_flags_(0),
item_collector_(nullptr) {}
Scope::Scope(Scope* parent)
: const_containing_(nullptr),
mutable_containing_(parent),
settings_(parent->settings()),
mode_flags_(0),
item_collector_(nullptr),
build_dependency_files_(parent->build_dependency_files_) {}
Scope::Scope(const Scope* parent)
: const_containing_(parent),
mutable_containing_(nullptr),
settings_(parent->settings()),
mode_flags_(0),
item_collector_(nullptr),
build_dependency_files_(parent->build_dependency_files_) {}
Scope::~Scope() = default;
void Scope::DetachFromContaining() {
const_containing_ = nullptr;
mutable_containing_ = nullptr;
}
bool Scope::HasValues(SearchNested search_nested) const {
DCHECK(search_nested == SEARCH_CURRENT);
return !values_.empty();
}
const Value* Scope::GetValue(const std::string_view& ident,
bool counts_as_used) {
const Scope* found_in_scope = nullptr;
return GetValueWithScope(ident, counts_as_used, &found_in_scope);
}
const Value* Scope::GetValueWithScope(const std::string_view& ident,
bool counts_as_used,
const Scope** found_in_scope) {
// First check for programmatically-provided values.
for (auto* provider : programmatic_providers_) {
const Value* v = provider->GetProgrammaticValue(ident);
if (v) {
*found_in_scope = nullptr;
return v;
}
}
RecordMap::iterator found = values_.find(ident);
if (found != values_.end()) {
if (counts_as_used)
found->second.used = true;
*found_in_scope = this;
return &found->second.value;
}
// Search in the parent scope.
if (const_containing_)
return const_containing_->GetValueWithScope(ident, found_in_scope);
if (mutable_containing_) {
return mutable_containing_->GetValueWithScope(ident, counts_as_used,
found_in_scope);
}
return nullptr;
}
Value* Scope::GetMutableValue(const std::string_view& ident,
SearchNested search_mode,
bool counts_as_used) {
// Don't do programmatic values, which are not mutable.
RecordMap::iterator found = values_.find(ident);
if (found != values_.end()) {
if (counts_as_used)
found->second.used = true;
return &found->second.value;
}
// Search in the parent mutable scope if requested, but not const one.
if (search_mode == SEARCH_NESTED && mutable_containing_) {
return mutable_containing_->GetMutableValue(ident, Scope::SEARCH_NESTED,
counts_as_used);
}
return nullptr;
}
std::string_view Scope::GetStorageKey(const std::string_view& ident) const {
RecordMap::const_iterator found = values_.find(ident);
if (found != values_.end())
return found->first;
// Search in parent scope.
if (containing())
return containing()->GetStorageKey(ident);
return std::string_view();
}
const Value* Scope::GetValue(const std::string_view& ident) const {
const Scope* found_in_scope = nullptr;
return GetValueWithScope(ident, &found_in_scope);
}
const Value* Scope::GetValueWithScope(const std::string_view& ident,
const Scope** found_in_scope) const {
RecordMap::const_iterator found = values_.find(ident);
if (found != values_.end()) {
*found_in_scope = this;
return &found->second.value;
}
if (containing())
return containing()->GetValueWithScope(ident, found_in_scope);
return nullptr;
}
Value* Scope::SetValue(const std::string_view& ident,
Value v,
const ParseNode* set_node) {
Record& r = values_[ident]; // Clears any existing value.
r.value = std::move(v);
r.value.set_origin(set_node);
return &r.value;
}
void Scope::RemoveIdentifier(const std::string_view& ident) {
RecordMap::iterator found = values_.find(ident);
if (found != values_.end())
values_.erase(found);
}
void Scope::RemovePrivateIdentifiers() {
// Do it in two phases to avoid mutating while iterating. Our hash map is
// currently backed by several different vendor-specific implementations and
// I'm not sure if all of them support mutating while iterating. Since this
// is not perf-critical, do the safe thing.
std::vector<std::string_view> to_remove;
for (const auto& cur : values_) {
if (IsPrivateVar(cur.first))
to_remove.push_back(cur.first);
}
for (const auto& cur : to_remove)
values_.erase(cur);
}
bool Scope::AddTemplate(const std::string& name, const Template* templ) {
if (GetTemplate(name))
return false;
templates_[name] = templ;
return true;
}
const Template* Scope::GetTemplate(const std::string& name) const {
TemplateMap::const_iterator found = templates_.find(name);
if (found != templates_.end())
return found->second.get();
if (containing())
return containing()->GetTemplate(name);
return nullptr;
}
void Scope::MarkUsed(const std::string_view& ident) {
RecordMap::iterator found = values_.find(ident);
if (found == values_.end()) {
NOTREACHED();
return;
}
found->second.used = true;
}
void Scope::MarkAllUsed() {
for (auto& cur : values_)
cur.second.used = true;
}
void Scope::MarkAllUsed(const std::set<std::string>& excluded_values) {
for (auto& cur : values_) {
if (!excluded_values.empty() &&
excluded_values.find(std::string(cur.first)) != excluded_values.end()) {
continue; // Skip this excluded value.
}
cur.second.used = true;
}
}
void Scope::MarkUnused(const std::string_view& ident) {
RecordMap::iterator found = values_.find(ident);
if (found == values_.end()) {
NOTREACHED();
return;
}
found->second.used = false;
}
bool Scope::IsSetButUnused(const std::string_view& ident) const {
RecordMap::const_iterator found = values_.find(ident);
if (found != values_.end()) {
if (!found->second.used) {
return true;
}
}
return false;
}
bool Scope::CheckForUnusedVars(Err* err) const {
for (const auto& pair : values_) {
if (!pair.second.used) {
std::string help =
"You set the variable \"" + std::string(pair.first) +
"\" here and it was unused before it went\nout of scope.";
const BinaryOpNode* binary = pair.second.value.origin()->AsBinaryOp();
if (binary && binary->op().type() == Token::EQUAL) {
// Make a nicer error message for normal var sets.
*err =
Err(binary->left()->GetRange(), "Assignment had no effect.", help);
} else {
// This will happen for internally-generated variables.
*err =
Err(pair.second.value.origin(), "Assignment had no effect.", help);
}
return false;
}
}
return true;
}
void Scope::GetCurrentScopeValues(KeyValueMap* output) const {
for (const auto& pair : values_)
(*output)[pair.first] = pair.second.value;
}
bool Scope::CheckCurrentScopeValuesEqual(const Scope* other) const {
// If there are containing scopes, equality shouldn't work.
if (containing()) {
return false;
}
if (values_.size() != other->values_.size()) {
return false;
}
for (const auto& pair : values_) {
const Value* v = other->GetValue(pair.first);
if (!v || *v != pair.second.value) {
return false;
}
}
return true;
}
bool Scope::NonRecursiveMergeTo(Scope* dest,
const MergeOptions& options,
const ParseNode* node_for_err,
const char* desc_for_err,
Err* err) const {
// Values.
for (const auto& pair : values_) {
const std::string_view& current_name = pair.first;
if (options.skip_private_vars && IsPrivateVar(current_name))
continue; // Skip this private var.
if (!options.excluded_values.empty() &&
options.excluded_values.find(std::string(current_name)) !=
options.excluded_values.end()) {
continue; // Skip this excluded value.
}
const Value& new_value = pair.second.value;
if (!options.clobber_existing) {
const Value* existing_value = dest->GetValue(current_name);
if (existing_value && new_value != *existing_value) {
// Value present in both the source and the dest.
std::string desc_string(desc_for_err);
*err = Err(node_for_err, "Value collision.",
"This " + desc_string + " contains \"" +
std::string(current_name) + "\"");
err->AppendSubErr(
Err(pair.second.value, "defined here.",
"Which would clobber the one in your current scope"));
err->AppendSubErr(
Err(*existing_value, "defined here.",
"Executing " + desc_string +
" should not conflict with anything "
"in the current\nscope unless the values are identical."));
return false;
}
}
dest->values_[current_name] = pair.second;
if (options.mark_dest_used)
dest->MarkUsed(current_name);
}
// Target defaults are owning pointers.
for (const auto& pair : target_defaults_) {
const std::string& current_name = pair.first;
if (!options.excluded_values.empty() &&
options.excluded_values.find(current_name) !=
options.excluded_values.end()) {
continue; // Skip the excluded value.
}
if (!options.clobber_existing) {
const Scope* dest_defaults = dest->GetTargetDefaults(current_name);
if (dest_defaults) {
if (RecordMapValuesEqual(pair.second->values_,
dest_defaults->values_)) {
// Values of the two defaults are equivalent, just ignore the
// collision.
continue;
} else {
// TODO(brettw) it would be nice to know the origin of a
// set_target_defaults so we can give locations for the colliding
// target defaults.
std::string desc_string(desc_for_err);
*err = Err(node_for_err, "Target defaults collision.",
"This " + desc_string +
" contains target defaults for\n"
"\"" +
current_name +
"\" which would clobber one for the\n"
"same target type in your current scope. It's "
"unfortunate that "
"I'm too stupid\nto tell you the location of where "
"the target "
"defaults were set. Usually\nthis happens in the "
"BUILDCONFIG.gn "
"file or in a related .gni file.\n");
return false;
}
}
}
std::unique_ptr<Scope>& dest_scope = dest->target_defaults_[current_name];
dest_scope = std::make_unique<Scope>(settings_);
pair.second->NonRecursiveMergeTo(dest_scope.get(), options, node_for_err,
"<SHOULDN'T HAPPEN>", err);
}
// Templates.
for (const auto& pair : templates_) {
const std::string& current_name = pair.first;
if (options.skip_private_vars && IsPrivateVar(current_name))
continue; // Skip this private template.
if (!options.excluded_values.empty() &&
options.excluded_values.find(current_name) !=
options.excluded_values.end()) {
continue; // Skip the excluded value.
}
if (!options.clobber_existing) {
const Template* existing_template = dest->GetTemplate(current_name);
// Since templates are refcounted, we can check if it's the same one by
// comparing pointers.
if (existing_template && pair.second.get() != existing_template) {
// Rule present in both the source and the dest, and they're not the
// same one.
std::string desc_string(desc_for_err);
*err = Err(node_for_err, "Template collision.",
"This " + desc_string + " contains a template \"" +
current_name + "\"");
err->AppendSubErr(
Err(pair.second->GetDefinitionRange(), "defined here.",
"Which would clobber the one in your current scope"));
err->AppendSubErr(Err(existing_template->GetDefinitionRange(),
"defined here.",
"Executing " + desc_string +
" should not conflict with anything "
"in the current\nscope."));
return false;
}
}
// Be careful to delete any pointer we're about to clobber.
dest->templates_[current_name] = pair.second;
}
// Propogate build dependency files,
dest->AddBuildDependencyFiles(build_dependency_files_);
return true;
}
std::unique_ptr<Scope> Scope::MakeClosure() const {
std::unique_ptr<Scope> result;
if (const_containing_) {
// We reached the top of the mutable scope stack. The result scope just
// references the const scope (which will never change).
result = std::make_unique<Scope>(const_containing_);
} else if (mutable_containing_) {
// There are more nested mutable scopes. Recursively go up the stack to
// get the closure.
result = mutable_containing_->MakeClosure();
} else {
// This is a standalone scope, just copy it.
result = std::make_unique<Scope>(settings_);
}
// Want to clobber since we've flattened some nested scopes, and our parent
// scope may have a duplicate value set.
MergeOptions options;
options.clobber_existing = true;
// Add in our variables and we're done.
Err err;
NonRecursiveMergeTo(result.get(), options, nullptr, "<SHOULDN'T HAPPEN>",
&err);
DCHECK(!err.has_error());
return result;
}
Scope* Scope::MakeTargetDefaults(const std::string& target_type) {
std::unique_ptr<Scope>& dest = target_defaults_[target_type];
dest = std::make_unique<Scope>(settings_);
return dest.get();
}
const Scope* Scope::GetTargetDefaults(const std::string& target_type) const {
NamedScopeMap::const_iterator found = target_defaults_.find(target_type);
if (found != target_defaults_.end())
return found->second.get();
if (containing())
return containing()->GetTargetDefaults(target_type);
return nullptr;
}
void Scope::SetProcessingBuildConfig() {
DCHECK((mode_flags_ & kProcessingBuildConfigFlag) == 0);
mode_flags_ |= kProcessingBuildConfigFlag;
}
void Scope::ClearProcessingBuildConfig() {
DCHECK(mode_flags_ & kProcessingBuildConfigFlag);
mode_flags_ &= ~(kProcessingBuildConfigFlag);
}
bool Scope::IsProcessingBuildConfig() const {
if (mode_flags_ & kProcessingBuildConfigFlag)
return true;
if (containing())
return containing()->IsProcessingBuildConfig();
return false;
}
void Scope::SetProcessingImport() {
DCHECK((mode_flags_ & kProcessingImportFlag) == 0);
mode_flags_ |= kProcessingImportFlag;
}
void Scope::ClearProcessingImport() {
DCHECK(mode_flags_ & kProcessingImportFlag);
mode_flags_ &= ~(kProcessingImportFlag);
}
bool Scope::IsProcessingImport() const {
if (mode_flags_ & kProcessingImportFlag)
return true;
if (containing())
return containing()->IsProcessingImport();
return false;
}
const SourceDir& Scope::GetSourceDir() const {
if (!source_dir_.is_null())
return source_dir_;
if (containing())
return containing()->GetSourceDir();
return source_dir_;
}
void Scope::AddBuildDependencyFile(const SourceFile& build_dependency_file) {
build_dependency_files_.insert(build_dependency_file);
}
void Scope::AddBuildDependencyFiles(
const SourceFileSet& build_dependency_files) {
build_dependency_files_.insert(build_dependency_files.begin(),
build_dependency_files.end());
}
Scope::ItemVector* Scope::GetItemCollector() {
if (item_collector_)
return item_collector_;
if (mutable_containing())
return mutable_containing()->GetItemCollector();
return nullptr;
}
void Scope::SetProperty(const void* key, void* value) {
if (!value) {
DCHECK(properties_.find(key) != properties_.end());
properties_.erase(key);
} else {
properties_[key] = value;
}
}
void* Scope::GetProperty(const void* key, const Scope** found_on_scope) const {
PropertyMap::const_iterator found = properties_.find(key);
if (found != properties_.end()) {
if (found_on_scope)
*found_on_scope = this;
return found->second;
}
if (containing())
return containing()->GetProperty(key, found_on_scope);
return nullptr;
}
void Scope::AddProvider(ProgrammaticProvider* p) {
programmatic_providers_.insert(p);
}
void Scope::RemoveProvider(ProgrammaticProvider* p) {
DCHECK(programmatic_providers_.find(p) != programmatic_providers_.end());
programmatic_providers_.erase(p);
}
// static
bool Scope::RecordMapValuesEqual(const RecordMap& a, const RecordMap& b) {
if (a.size() != b.size())
return false;
for (const auto& pair : a) {
const auto& found_b = b.find(pair.first);
if (found_b == b.end())
return false; // Item in 'a' but not 'b'.
if (pair.second.value != found_b->second.value)
return false; // Values for variable in 'a' and 'b' are different.
}
return true;
}