Replace OrderedSet<> instances with UniqueVector<>.

The OrderedSet<> template has a misleading name, because its
semantics are not those of an ordered set of items, but match
completely those of UniqueVector<>. The latter is also slightly
faster and uses less memory.

This CL replaces all instances of OrderedSet<> with UniqueVector<>
ones, and removes the template definition from the source tree.

Profiling shows no noticeable difference in performance or memory usage
with the Chrome and Fuchsia "gn gen" operations.

Change-Id: Ie9b8ecfc0724d07129f69c68db5e1205b49f3970
Reviewed-on: https://gn-review.googlesource.com/c/gn/+/11825
Commit-Queue: David Turner <[email protected]>
Reviewed-by: Sylvain Defresne <[email protected]>

src/gn/desc_builder.cc

@@ -581,7 +581,7 @@ class TargetDescBuilder : public BaseDescBuilder {
     // Libs can be part of any target and get recursively pushed up the chain,
     // so display them regardless of target type.
     if (what(variables::kLibs)) {
-      const OrderedSet<LibFile>& all_libs = target_->all_libs();
+      const UniqueVector<LibFile>& all_libs = target_->all_libs();
       if (!all_libs.empty()) {
         auto libs = std::make_unique<base::ListValue>();
         for (size_t i = 0; i < all_libs.size(); i++)
@@ -591,7 +591,7 @@ class TargetDescBuilder : public BaseDescBuilder {
     }
 
     if (what(variables::kLibDirs)) {
-      const OrderedSet<SourceDir>& all_lib_dirs = target_->all_lib_dirs();
+      const UniqueVector<SourceDir>& all_lib_dirs = target_->all_lib_dirs();
       if (!all_lib_dirs.empty()) {
         auto lib_dirs = std::make_unique<base::ListValue>();
         for (size_t i = 0; i < all_lib_dirs.size(); i++)

src/gn/ninja_binary_target_writer.cc

@@ -307,7 +307,7 @@ void NinjaBinaryTargetWriter::WriteLinkerFlags(
 
   // Followed by library search paths that have been recursively pushed
   // through the dependency tree.
-  const OrderedSet<SourceDir>& all_lib_dirs = target_->all_lib_dirs();
+  const UniqueVector<SourceDir>& all_lib_dirs = target_->all_lib_dirs();
   if (!all_lib_dirs.empty()) {
     // Since we're passing these on the command line to the linker and not
     // to Ninja, we need to do shell escaping.
@@ -345,7 +345,7 @@ void NinjaBinaryTargetWriter::WriteLibs(std::ostream& out, const Tool* tool) {
   // Libraries that have been recursively pushed through the dependency tree.
   EscapeOptions lib_escape_opts;
   lib_escape_opts.mode = ESCAPE_NINJA_COMMAND;
-  const OrderedSet<LibFile> all_libs = target_->all_libs();
+  const UniqueVector<LibFile>& all_libs = target_->all_libs();
   for (size_t i = 0; i < all_libs.size(); i++) {
     const LibFile& lib_file = all_libs[i];
     const std::string& lib_value = lib_file.value();

src/gn/ninja_c_binary_target_writer.cc

@@ -755,7 +755,7 @@ void NinjaCBinaryTargetWriter::WriteLinkerStuff(
   }
 
   // Libraries specified by paths.
-  const OrderedSet<LibFile>& libs = target_->all_libs();
+  const UniqueVector<LibFile>& libs = target_->all_libs();
   for (size_t i = 0; i < libs.size(); i++) {
     if (libs[i].is_source_file()) {
       implicit_deps.push_back(

src/gn/target.cc

@@ -374,13 +374,13 @@ bool Target::OnResolved(Err* err) {
   // order (local ones first, then the dependency's).
   for (ConfigValuesIterator iter(this); !iter.done(); iter.Next()) {
     const ConfigValues& cur = iter.cur();
-    all_lib_dirs_.append(cur.lib_dirs().begin(), cur.lib_dirs().end());
-    all_libs_.append(cur.libs().begin(), cur.libs().end());
+    all_lib_dirs_.Append(cur.lib_dirs().begin(), cur.lib_dirs().end());
+    all_libs_.Append(cur.libs().begin(), cur.libs().end());
 
-    all_framework_dirs_.append(cur.framework_dirs().begin(),
+    all_framework_dirs_.Append(cur.framework_dirs().begin(),
                                cur.framework_dirs().end());
-    all_frameworks_.append(cur.frameworks().begin(), cur.frameworks().end());
-    all_weak_frameworks_.append(cur.weak_frameworks().begin(),
+    all_frameworks_.Append(cur.frameworks().begin(), cur.frameworks().end());
+    all_weak_frameworks_.Append(cur.weak_frameworks().begin(),
                                 cur.weak_frameworks().end());
   }
 
@@ -722,12 +722,12 @@ void Target::PullDependentTargetLibsFrom(const Target* dep, bool is_public) {
 
   // Library settings are always inherited across static library boundaries.
   if (!dep->IsFinal() || dep->output_type() == STATIC_LIBRARY) {
-    all_lib_dirs_.append(dep->all_lib_dirs());
-    all_libs_.append(dep->all_libs());
+    all_lib_dirs_.Append(dep->all_lib_dirs());
+    all_libs_.Append(dep->all_libs());
 
-    all_framework_dirs_.append(dep->all_framework_dirs());
-    all_frameworks_.append(dep->all_frameworks());
-    all_weak_frameworks_.append(dep->all_weak_frameworks());
+    all_framework_dirs_.Append(dep->all_framework_dirs());
+    all_frameworks_.Append(dep->all_frameworks());
+    all_weak_frameworks_.Append(dep->all_weak_frameworks());
   }
 }
 

src/gn/target.h

@@ -21,7 +21,6 @@
 #include "gn/label_ptr.h"
 #include "gn/lib_file.h"
 #include "gn/metadata.h"
-#include "gn/ordered_set.h"
 #include "gn/output_file.h"
 #include "gn/rust_values.h"
 #include "gn/source_file.h"
@@ -286,16 +285,16 @@ class Target : public Item {
   RustValues& rust_values() { return rust_values_; }
   const RustValues& rust_values() const { return rust_values_; }
 
-  const OrderedSet<SourceDir>& all_lib_dirs() const { return all_lib_dirs_; }
-  const OrderedSet<LibFile>& all_libs() const { return all_libs_; }
+  const UniqueVector<SourceDir>& all_lib_dirs() const { return all_lib_dirs_; }
+  const UniqueVector<LibFile>& all_libs() const { return all_libs_; }
 
-  const OrderedSet<SourceDir>& all_framework_dirs() const {
+  const UniqueVector<SourceDir>& all_framework_dirs() const {
     return all_framework_dirs_;
   }
-  const OrderedSet<std::string>& all_frameworks() const {
+  const UniqueVector<std::string>& all_frameworks() const {
     return all_frameworks_;
   }
-  const OrderedSet<std::string>& all_weak_frameworks() const {
+  const UniqueVector<std::string>& all_weak_frameworks() const {
     return all_weak_frameworks_;
   }
 
@@ -460,14 +459,14 @@ class Target : public Item {
 
   // These libs and dirs are inherited from statically linked deps and all
   // configs applying to this target.
-  OrderedSet<SourceDir> all_lib_dirs_;
-  OrderedSet<LibFile> all_libs_;
+  UniqueVector<SourceDir> all_lib_dirs_;
+  UniqueVector<LibFile> all_libs_;
 
   // These frameworks and dirs are inherited from statically linked deps and
   // all configs applying to this target.
-  OrderedSet<SourceDir> all_framework_dirs_;
-  OrderedSet<std::string> all_frameworks_;
-  OrderedSet<std::string> all_weak_frameworks_;
+  UniqueVector<SourceDir> all_framework_dirs_;
+  UniqueVector<std::string> all_frameworks_;
+  UniqueVector<std::string> all_weak_frameworks_;
 
   // All hard deps from this target and all dependencies. Filled in when this
   // target is marked resolved. This will not include the current target.

src/gn/unique_vector.h

@@ -126,6 +126,10 @@ class UniqueVector {
       push_back(*i);
   }
 
+  void Append(const UniqueVector& other) {
+    Append(other.begin(), other.end());
+  }
+
   // Returns the index of the item matching the given value in the list, or
   // (size_t)(-1) if it's not found.
   size_t IndexOf(const T& t) const {