Enhance GN introspection

tools/gn/command_ls.cc

Index: tools/gn/command_ls.cc
diff --git a/tools/gn/command_ls.cc b/tools/gn/command_ls.cc
index a2dc38ce75cd151630efea2498c60a43efcdfc56..ed4aaca2496a593a7d187ee56e8722d84ecee514 100644
--- a/tools/gn/command_ls.cc
+++ b/tools/gn/command_ls.cc
@@ -18,9 +18,10 @@ const char kLs[] = "ls";
 const char kLs_HelpShort[] =
     "ls: List matching targets.";
 const char kLs_Help[] =
-    "gn ls <out_dir> [<label_pattern>] [--out] [--all-toolchains]\n"
+    "gn ls <out_dir> [<label_pattern>] [--all-toolchains] [--as=...]\n"
+    "      [--type=...] [--testonly=...]\n"
     "\n"
-    "  Lists all targets matching the given pattern for the given builn\n"
+    "  Lists all targets matching the given pattern for the given build\n"
     "  directory. By default, only targets in the default toolchain will\n"
     "  be matched unless a toolchain is explicitly supplied.\n"
     "\n"
@@ -29,14 +30,19 @@ const char kLs_Help[] =
     "  \"gn help label_pattern\"). If you need more complex expressions,\n"
     "  pipe the result through grep.\n"
     "\n"
-    "  --out\n"
-    "      Lists the results as the files generated by the matching targets.\n"
-    "      These files will be relative to the build directory such that\n"
-    "      they can be specified on Ninja's command line as a file to build.\n"
+    "Options\n"
+    "\n"
+    TARGET_PRINTING_MODE_COMMAND_LINE_HELP
     "\n"
     "  --all-toolchains\n"
-    "      Matches all toolchains. If the label pattern does not specify an\n"
-    "      explicit toolchain, labels from all toolchains will be matched.\n"
+    "      Matches all toolchains. When set, if the label pattern does not\n"
+    "      specify an explicit toolchain, labels from all toolchains will be\n"
+    "      matched. When unset, only targets in the default toolchain will\n"
+    "      be matched unless an explicit toolchain in the label is set.\n"
+    "\n"
+    TARGET_TESTONLY_FILTER_COMMAND_LINE_HELP
+    "\n"
+    TARGET_TYPE_FILTER_COMMAND_LINE_HELP
     "\n"
     "Examples\n"
     "\n"
@@ -49,10 +55,13 @@ const char kLs_Help[] =
     "  gn ls out/Debug \"//base:*\"\n"
     "      Lists all targets defined in //base/BUILD.gn.\n"
     "\n"
-    "  gn ls out/Debug //base --out\n"
+    "  gn ls out/Debug //base --as=output\n"
     "      Lists the build output file for //base:base\n"
     "\n"
-    "  gn ls out/Debug \"//base/*\" --out | xargs ninja -C out/Debug\n"
+    "  gn ls out/Debug --type=executable\n"
+    "      Lists all executables produced by the build.\n"
+    "\n"
+    "  gn ls out/Debug \"//base/*\" --as=output | xargs ninja -C out/Debug\n"
     "      Builds all targets in //base and all subdirectories.\n"
     "\n"
     "  gn ls out/Debug //base --all-toolchains\n"
@@ -60,9 +69,9 @@ const char kLs_Help[] =
     "      in multiple toolchains).\n";
 
 int RunLs(const std::vector<std::string>& args) {
-  if (args.size() != 1 && args.size() != 2) {
+  if (args.size() == 0) {
     Err(Location(), "You're holding it wrong.",
-        "Usage: \"gn ls <build dir> [<label_pattern>]\"").PrintToStdout();
+        "Usage: \"gn ls <build dir> [<label_pattern>]*\"").PrintToStdout();
     return 1;
   }
 
@@ -73,13 +82,21 @@ int RunLs(const std::vector<std::string>& args) {
   const base::CommandLine* cmdline = base::CommandLine::ForCurrentProcess();
   bool all_toolchains = cmdline->HasSwitch("all-toolchains");
 
-  // Find matching targets.
   std::vector<const Target*> matches;
-  if (args.size() == 2) {
-    // Given a pattern, match it.
-    if (!ResolveTargetsFromCommandLinePattern(setup, args[1], all_toolchains,
-                                              &matches))
+  if (args.size() > 1) {
+    // Some patterns or explicit labels were specified.
+    std::vector<std::string> inputs(args.begin() + 1, args.end());
+
+    UniqueVector<const Target*> target_matches;
+    UniqueVector<const Config*> config_matches;
+    UniqueVector<const Toolchain*> toolchain_matches;
+    UniqueVector<SourceFile> file_matches;
+    if (!ResolveFromCommandLineInput(setup, inputs, all_toolchains,
+                                     &target_matches, &config_matches,
+                                     &toolchain_matches, &file_matches))
       return 1;
+    matches.insert(matches.begin(),
+                   target_matches.begin(), target_matches.end());
   } else if (all_toolchains) {
     // List all resolved targets.
     matches = setup->builder()->GetAllResolvedTargets();
@@ -90,29 +107,7 @@ int RunLs(const std::vector<std::string>& args) {
         matches.push_back(target);
     }
   }
-
-  if (cmdline->HasSwitch("out")) {
-    // List results as build files.
-    for (const auto& match : matches) {
-      OutputString(match->dependency_output_file().value());
-      OutputString("\n");
-    }
-  } else {
-    // List results as sorted labels.
-    std::vector<Label> sorted_matches;
-    for (const auto& match : matches)
-      sorted_matches.push_back(match->label());
-    std::sort(sorted_matches.begin(), sorted_matches.end());
-
-    Label default_tc_label = setup->loader()->default_toolchain_label();
-    for (const auto& match : sorted_matches) {
-      // Print toolchain only for ones not in the default toolchain.
-      OutputString(match.GetUserVisibleName(
-          match.GetToolchainLabel() != default_tc_label));
-      OutputString("\n");
-    }
-  }
-
+  FilterAndPrintTargets(false, &matches);
   return 0;
 }