Create binstubs for executables when activating a package.

sdk/lib/_internal/pub_generated/lib/src/global_packages.dart

Index: sdk/lib/_internal/pub_generated/lib/src/global_packages.dart
diff --git a/sdk/lib/_internal/pub_generated/lib/src/global_packages.dart b/sdk/lib/_internal/pub_generated/lib/src/global_packages.dart
index 85a1983f66e66f026736507a0325d3125e37b403..7035105649086102fafdaebc48d3a51b6b6737f7 100644
--- a/sdk/lib/_internal/pub_generated/lib/src/global_packages.dart
+++ b/sdk/lib/_internal/pub_generated/lib/src/global_packages.dart
@@ -11,18 +11,22 @@ import 'lock_file.dart';
 import 'log.dart' as log;
 import 'package.dart';
 import 'pubspec.dart';
-import 'system_cache.dart';
+import 'sdk.dart' as sdk;
 import 'solver/version_solver.dart';
 import 'source/cached.dart';
 import 'source/git.dart';
 import 'source/path.dart';
+import 'system_cache.dart';
 import 'utils.dart';
 import 'version.dart';
+final _binStubPackagePattern = new RegExp(r"Package: ([a-zA-Z0-9_-]+)");
 class GlobalPackages {
   final SystemCache cache;
   String get _directory => p.join(cache.rootDir, "global_packages");
+  String get _binStubDir => p.join(cache.rootDir, "bin");
   GlobalPackages(this.cache);
-  Future activateGit(String repo) {
+  Future activateGit(String repo, List<String> executables,
+      {bool overwriteBinStubs}) {
     final completer0 = new Completer();
     scheduleMicrotask(() {
       try {
@@ -34,7 +38,11 @@ class GlobalPackages {
             _installInCache(
                 new PackageDep(name, "git", VersionConstraint.any, repo)).then((x1) {
               try {
-                x1;
+                var package = x1;
+                _updateBinStubs(
+                    package,
+                    executables,
+                    overwriteBinStubs: overwriteBinStubs);
                 completer0.complete(null);
               } catch (e1) {
                 completer0.completeError(e1);
@@ -54,11 +62,35 @@ class GlobalPackages {
     });
     return completer0.future;
   }
-  Future activateHosted(String name, VersionConstraint constraint) {
-    _describeActive(name);
-    return _installInCache(new PackageDep(name, "hosted", constraint, name));
+  Future activateHosted(String name, VersionConstraint constraint,
+      List<String> executables, {bool overwriteBinStubs}) {
+    final completer0 = new Completer();
+    scheduleMicrotask(() {
+      try {
+        _describeActive(name);
+        _installInCache(
+            new PackageDep(name, "hosted", constraint, name)).then((x0) {
+          try {
+            var package = x0;
+            _updateBinStubs(
+                package,
+                executables,
+                overwriteBinStubs: overwriteBinStubs);
+            completer0.complete(null);
+          } catch (e0) {
+            completer0.completeError(e0);
+          }
+        }, onError: (e1) {
+          completer0.completeError(e1);
+        });
+      } catch (e2) {
+        completer0.completeError(e2);
+      }
+    });
+    return completer0.future;
   }
-  Future activatePath(String path) {
+  Future activatePath(String path, List<String> executables,
+      {bool overwriteBinStubs}) {
     final completer0 = new Completer();
     scheduleMicrotask(() {
       try {
@@ -77,6 +109,10 @@ class GlobalPackages {
             _writeLockFile(name, new LockFile([id]));
             var binDir = p.join(_directory, name, 'bin');
             join0() {
+              _updateBinStubs(
+                  entrypoint.root,
+                  executables,
+                  overwriteBinStubs: overwriteBinStubs);
               completer0.complete(null);
             }
             if (dirExists(binDir)) {
@@ -97,7 +133,7 @@ class GlobalPackages {
     });
     return completer0.future;
   }
-  Future _installInCache(PackageDep dep) {
+  Future<Package> _installInCache(PackageDep dep) {
     final completer0 = new Completer();
     scheduleMicrotask(() {
       try {
@@ -128,7 +164,7 @@ class GlobalPackages {
                         try {
                           x3;
                           _writeLockFile(dep.name, lockFile);
-                          completer0.complete(null);
+                          completer0.complete(graph.packages[dep.name]);
                         } catch (e3) {
                           completer0.completeError(e3);
                         }
@@ -255,14 +291,13 @@ class GlobalPackages {
       return null;
     }
   }
-  bool deactivate(String name, {bool logDeactivate: false}) {
+  bool deactivate(String name) {
     var dir = p.join(_directory, name);
     if (!dirExists(dir)) return false;
-    if (logDeactivate) {
-      var lockFile = new LockFile.load(_getLockFilePath(name), cache.sources);
-      var id = lockFile.packages[name];
-      log.message('Deactivated package ${_formatPackage(id)}.');
-    }
+    _deleteBinStubs(name);
+    var lockFile = new LockFile.load(_getLockFilePath(name), cache.sources);
+    var id = lockFile.packages[name];
+    log.message('Deactivated package ${_formatPackage(id)}.');
     deleteEntry(dir);
     return true;
   }
@@ -357,4 +392,132 @@ class GlobalPackages {
       return '${log.bold(id.name)} ${id.version}';
     }
   }
+  void _updateBinStubs(Package package, List<String> executables,
+      {bool overwriteBinStubs}) {
+    _deleteBinStubs(package.name);
+    if ((executables != null && executables.isEmpty) ||
+        package.pubspec.executables.isEmpty) {
+      return;
+    }
+    ensureDir(_binStubDir);
+    var installed = [];
+    var collided = {};
+    var allExecutables = ordered(package.pubspec.executables.keys);
+    for (var executable in allExecutables) {
+      if (executables != null && !executables.contains(executable)) continue;
+      var script = package.pubspec.executables[executable];
+      var previousPackage =
+          _createBinStub(package, executable, script, overwrite: overwriteBinStubs);
+      if (previousPackage != null) {
+        collided[executable] = previousPackage;
+        if (!overwriteBinStubs) continue;
+      }
+      installed.add(executable);
+    }
+    if (installed.isNotEmpty) {
+      var names = namedSequence("executable", installed.map(log.bold));
+      log.message("Installed $names.");
+    }
+    if (collided.isNotEmpty) {
+      for (var command in ordered(collided.keys)) {
+        if (overwriteBinStubs) {
+          log.warning(
+              "Replaced ${log.bold(command)} previously installed from "
+                  "${log.bold(collided[command])}.");
+        } else {
+          log.warning(
+              "Executable ${log.bold(command)} was already installed "
+                  "from ${log.bold(collided[command])}.");
+        }
+      }
+      if (!overwriteBinStubs) {
+        log.warning(
+            "Deactivate the other package(s) or activate "
+                "${log.bold(package.name)} using --overwrite-executables.");
+      }
+    }
+    if (executables != null) {
+      var unknown = ordered(
+          executables.where((exe) => !package.pubspec.executables.keys.contains(exe)));
+      if (unknown.isNotEmpty) {
+        dataError("Unknown ${namedSequence('executable', unknown)}.");
+      }
+    }
+    var binFiles = package.listFiles(
+        beneath: "bin",
+        recursive: false).map((path) => p.relative(path, from: package.dir)).toList();
+    for (var executable in installed) {
+      var script = package.pubspec.executables[executable];
+      var scriptPath = p.join("bin", "$script.dart");
+      if (!binFiles.contains(scriptPath)) {
+        log.warning(
+            'Warning: Executable "$executable" runs "$scriptPath", '
+                'which was not found in ${log.bold(package.name)}.');
+      }
+    }
+  }
+  String _createBinStub(Package package, String executable, String script,
+      {bool overwrite}) {
+    var binStubPath = p.join(_binStubDir, executable);
+    var previousPackage;
+    if (fileExists(binStubPath)) {
+      var contents = readTextFile(binStubPath);
+      var match = _binStubPackagePattern.firstMatch(contents);
+      if (match != null) {
+        previousPackage = match[1];
+        if (!overwrite) return previousPackage;
+      } else {
+        log.fine("Could not parse binstub $binStubPath:\n$contents");
+      }
+    }
+    if (Platform.operatingSystem == "windows") {
+      var batch = """
+@echo off
+rem This file was created by pub v${sdk.version}.
+rem Package: ${package.name}
+rem Version: ${package.version}
+rem Executable: ${executable}
+rem Script: ${script}
+pub global run ${package.name}:$script "%*"
+""";
+      writeTextFile(binStubPath, batch);
+    } else {
+      var bash = """
+# This file was created by pub v${sdk.version}.
+# Package: ${package.name}
+# Version: ${package.version}
+# Executable: ${executable}
+# Script: ${script}
+pub global run ${package.name}:$script "\$@"
+""";
+      writeTextFile(binStubPath, bash);
+      var result = Process.runSync('chmod', ['+x', binStubPath]);
+      if (result.exitCode != 0) {
+        try {
+          deleteEntry(binStubPath);
+        } on IOException catch (err) {
+          log.fine("Could not delete binstub:\n$err");
+        }
+        fail(
+            'Could not make "$binStubPath" executable (exit code '
+                '${result.exitCode}):\n${result.stderr}');
+      }
+    }
+    return previousPackage;
+  }
+  void _deleteBinStubs(String package) {
+    if (!dirExists(_binStubDir)) return;
+    for (var file in listDir(_binStubDir, includeDirs: false)) {
+      var contents = readTextFile(file);
+      var match = _binStubPackagePattern.firstMatch(contents);
+      if (match == null) {
+        log.fine("Could not parse binstub $file:\n$contents");
+        continue;
+      }
+      if (match[1] == package) {
+        log.fine("Deleting old binstub $file");
+        deleteEntry(file);
+      }
+    }
+  }
 }