Add --cwd|-t option to env pseudo-builtin

8 files changed, 201 insertions, 80 deletions

diff --git a/doc/testscript.cli b/doc/testscript.cli
index 4721a88..50f975d 100644
--- a/doc/testscript.cli
+++ b/doc/testscript.cli
@@ -2437,11 +2437,12 @@ with a newline.
 \h#builtins-env|\c{env}|
 
 \
-env [-t <sec>] [-u <name>]... [-] [<name>=<value>]... -- <cmd>
+env [-t <sec>] [-c <dir>] [-u <name>]... [-] [<name>=<value>]... -- \
+    <cmd>
 \
 
-Run a command limiting its execution time and/or adding/removing the variables
-to/from the environment.
+Run a command limiting its execution time, changing its working directory,
+and/or adding/removing the variables to/from the environment.
 
 Note that \c{env} is a \i{pseudo-builtin}. In particular, its name and the
 \c{--} separator must be specified \i{literally} on the command line.
@@ -2463,6 +2464,10 @@ env - --unset=FOO -- $*
   Terminate the command if it fails to complete within the specified number
   of seconds. See also the \l{#builtins-timeout \c{timeout}} builtin.|
 
+\li|\n\c{-c|--cwd <dir>}
+
+  Change the command's working directory.|
+
 \li|\n\c{-u|--unset <name>}
 
   Remove the specified variable from the environment.||
diff --git a/libbuild2/script/parser.cxx b/libbuild2/script/parser.cxx
index ebfd5fc..f234d58 100644
--- a/libbuild2/script/parser.cxx
+++ b/libbuild2/script/parser.cxx
@@ -1028,8 +1028,9 @@ namespace build2
             if (prog && tt == type::word && t.value == "env")
             {
               parsed_env r (parse_env_builtin (t, tt));
+              c.cwd       = move (r.cwd);
               c.variables = move (r.variables);
-              c.timeout = r.timeout;
+              c.timeout   = r.timeout;
               env = true;
             }
 
@@ -1411,10 +1412,16 @@ namespace build2
           return r;
         };
 
+        auto bad = [&i, &o, this] (const string& v)
+        {
+          fail (i->second) << "env: invalid value '" << v << "' for option '"
+                           << o << "'";
+        };
+
         // As above but convert the option value to a number and fail on
         // error.
         //
-        auto num = [&i, &o, &str, this] (const char* ln, const char* sn)
+        auto num = [&str, &bad] (const char* ln, const char* sn)
         {
           optional<uint64_t> r;
           if (optional<string> s = str (ln, sn))
@@ -1422,8 +1429,29 @@ namespace build2
             r = parse_number (*s);
 
             if (!r)
-              fail (i->second) << "env: invalid value '" << *s
-                               << "' for option '" << o << "'";
+              bad (*s);
+          }
+
+          return r;
+        };
+
+        // As above but convert the option value to a directory path and fail
+        // on error.
+        //
+        auto dir = [&str, &bad] (const char* ln, const char* sn)
+        {
+          optional<dir_path> r;
+          if (optional<string> s = str (ln, sn))
+          try
+          {
+            // Note that we don't need to check that the path is not empty,
+            // since str() fails for empty values.
+            //
+            r = dir_path (move (*s));
+          }
+          catch (const invalid_path& e)
+          {
+            bad (e.path);
           }
 
           return r;
@@ -1435,6 +1463,10 @@ namespace build2
         {
           r.timeout = chrono::seconds (*v);
         }
+        else if (optional<dir_path> v = dir ("--cwd", "-c"))
+        {
+          r.cwd = move (*v);
+        }
         else if (optional<string> v = str ("--unset", "-u"))
         {
           verify_environment_var_name (*v, "env: ", i->second, o.c_str ());
diff --git a/libbuild2/script/parser.hxx b/libbuild2/script/parser.hxx
index 9098b3c..2a10311 100644
--- a/libbuild2/script/parser.hxx
+++ b/libbuild2/script/parser.hxx
@@ -130,15 +130,16 @@ namespace build2
       pre_parse_line_start (token&, token_type&, lexer_mode);
 
       // Parse the env pseudo-builtin arguments up to the program name. Return
-      // the program execution timeout, the list of the variables that should
-      // be unset ("name") and/or set ("name=value") in the command
+      // the program execution timeout, CWD, the list of the variables that
+      // should be unset ("name") and/or set ("name=value") in the command
       // environment, and the token/type that starts the program name. Note
       // that the variable unsets come first, if present.
       //
       struct parsed_env
       {
         optional<duration> timeout;
-        environment_vars variables;
+        optional<dir_path> cwd;
+        environment_vars   variables;
       };
 
       parsed_env
diff --git a/libbuild2/script/run.cxx b/libbuild2/script/run.cxx
index 91fc9ac..f3b5cad 100644
--- a/libbuild2/script/run.cxx
+++ b/libbuild2/script/run.cxx
@@ -1227,6 +1227,8 @@ namespace build2
       //
       const command& c (*bc);
 
+      const dir_path& wdir (*env.work_dir.path);
+
       // Register the command explicit cleanups. Verify that the path being
       // cleaned up is a sub-path of the script working directory. Fail if
       // this is not the case.
@@ -1234,7 +1236,7 @@ namespace build2
       for (const auto& cl: c.cleanups)
       {
         const path& p (cl.path);
-        path np (normalize (p, *env.work_dir.path, ll));
+        path np (normalize (p, wdir, ll));
 
         const string& ls (np.leaf ().string ());
         bool wc (ls == "*" || ls == "**" || ls == "***");
@@ -1320,6 +1322,10 @@ namespace build2
         if (!first || !last)
           fail (ll) << program << " builtin must be the only pipe command";
 
+        if (c.cwd)
+          fail (ll) << "current working directory cannot be specified for "
+                    << program << " builtin";
+
         if (!c.variables.empty ())
           fail (ll) << "environment variables cannot be (un)set for "
                     << program << " builtin";
@@ -1455,7 +1461,7 @@ namespace build2
           }
         case redirect_type::file:
           {
-            isp = normalize (in.file.path, *env.work_dir.path, ll);
+            isp = normalize (in.file.path, wdir, ll);
 
             open_stdin ();
             break;
@@ -1549,9 +1555,9 @@ namespace build2
       // or null-device descriptor for merge, pass or null redirects
       // respectively (not opening any file).
       //
-      auto open = [&env, &ll, &std_path] (const redirect& r,
-                                          int dfd,
-                                          path& p) -> auto_fd
+      auto open = [&env, &wdir, &ll, &std_path] (const redirect& r,
+                                                 int dfd,
+                                                 path& p) -> auto_fd
       {
         assert (dfd == 1 || dfd == 2);
         const char* what (dfd == 1 ? "stdout" : "stderr");
@@ -1592,7 +1598,7 @@ namespace build2
             //
             p = r.file.mode == redirect_fmode::compare
               ? std_path (what)
-              : normalize (r.file.path, *env.work_dir.path, ll);
+              : normalize (r.file.path, wdir, ll);
 
             m |= r.file.mode == redirect_fmode::append
               ? fdopen_mode::at_end
@@ -1810,6 +1816,28 @@ namespace build2
         }
       };
 
+      // Derive the process/builtin CWD.
+      //
+      // If the process/builtin CWD is specified via the env pseudo-builtin,
+      // then use that, completing it relative to the script environment work
+      // directory, if it is relative. Otherwise, use the script environment
+      // work directory.
+      //
+      dir_path completed_cwd;
+      if (c.cwd && c.cwd->relative ())
+        completed_cwd = wdir / *c.cwd;
+
+      const dir_path& cwd (!completed_cwd.empty () ? completed_cwd :
+                           c.cwd                   ? *c.cwd        :
+                                                     wdir);
+
+      // Unless CWD is the script environment work directory (which always
+      // exists), verify that it exists and fail if it doesn't.
+      //
+      if (&cwd != &wdir && !exists (cwd))
+        fail (ll) << "specified working directory " << cwd
+                  << " does not exist";
+
       // Absent if the process/builtin misses the "unsuccessful" deadline.
       //
       optional<process_exit> exit;
@@ -2069,7 +2097,7 @@ namespace build2
           builtin b (bi->function (r,
                                    c.arguments,
                                    move (ifd), move (ofd.out), move (efd),
-                                   *env.work_dir.path,
+                                   cwd,
                                    bcs));
 
           pipe_command pc (b, c, ll, prev_cmd);
@@ -2159,7 +2187,7 @@ namespace build2
                 program (path (s, 1, s.size () - 1));
             }
             else
-              program (*env.work_dir.path / p);
+              program (wdir / p);
           }
         }
         catch (const invalid_path& e)
@@ -2189,7 +2217,7 @@ namespace build2
             *pe.path,
             args.data (),
             {ifd.get (), -1}, process::pipe (ofd), {-1, efd.get ()},
-            env.work_dir.path->string ().c_str (),
+            cwd.string ().c_str (),
             pe.vars);
 
           // Can't throw.
diff --git a/libbuild2/script/script.cxx b/libbuild2/script/script.cxx
index 298d71f..9e6eeed 100644
--- a/libbuild2/script/script.cxx
+++ b/libbuild2/script/script.cxx
@@ -411,7 +411,7 @@ namespace build2
       {
         // Print the env builtin if any of its options/arguments are present.
         //
-        if (!c.variables.empty () || c.timeout)
+        if (c.timeout || c.cwd || !c.variables.empty ())
         {
           o << "env";
 
@@ -421,6 +421,14 @@ namespace build2
             o << " -t "
               << chrono::duration_cast<chrono::seconds> (*c.timeout).count ();
 
+          // CWD.
+          //
+          if (c.cwd)
+          {
+            o << " -c ";
+            print_path (*c.cwd);
+          }
+
           // Variable unsets/sets.
           //
           auto b (c.variables.begin ()), i (b), e (c.variables.end ());
diff --git a/libbuild2/script/script.hxx b/libbuild2/script/script.hxx
index dd31e33..d162900 100644
--- a/libbuild2/script/script.hxx
+++ b/libbuild2/script/script.hxx
@@ -324,6 +324,7 @@ namespace build2
       process_path program;
 
       strings            arguments;
+      optional<dir_path> cwd;       // From env builtin.
       environment_vars   variables; // From env builtin.
       optional<duration> timeout;   // From env builtin.
 
diff --git a/tests/test/script/runner/driver.cxx b/tests/test/script/runner/driver.cxx
index 9c05e27..b84f167 100644
--- a/tests/test/script/runner/driver.cxx
+++ b/tests/test/script/runner/driver.cxx
@@ -17,6 +17,7 @@
 #include <exception>
 
 #include <libbutl/path.hxx>
+#include <libbutl/path-io.hxx>
 #include <libbutl/optional.hxx>
 #include <libbutl/fdstream.hxx>
 #include <libbutl/filesystem.hxx>
@@ -45,8 +46,8 @@ main (int argc, char* argv[])
   // Usage: driver [-i <int>] (-o <string>)* (-e <string>)* (-f <file>)*
   //        (-d <dir>)* (-v <name>)* [(-t (a|m|s|z)) | (-s <int>)]
   //
-  // Execute actions specified by -i, -o, -e, -f, -d, -v, and -l options in
-  // the order as they appear on the command line. After that terminate
+  // Execute actions specified by -i, -o, -e, -f, -d, -w, -v, and -l options
+  // in the order as they appear on the command line. After that terminate
   // abnormally if -t option is provided, otherwise exit normally with the
   // status specified by -s option (0 by default).
   //
@@ -67,6 +68,9 @@ main (int argc, char* argv[])
   //    Create a directory with the path specified. Create parent directories
   //    if required.
   //
+  // -w
+  //    Print CWD to stdout.
+  //
   // -v <name>
   //    If the specified variable is set then print its value to stdout and
   //    the string '<none>' otherwise.
@@ -95,10 +99,7 @@ main (int argc, char* argv[])
 
   for (int i (1); i < argc; ++i)
   {
-    string o (argv[i++]);
-    assert (i < argc);
-
-    string v (argv[i]);
+    string o (argv[i]);
 
     auto toi = [] (const string& s) -> int
     {
@@ -118,69 +119,80 @@ main (int argc, char* argv[])
       return r;
     };
 
-    if (o == "-i")
+    if (o == "-w")
     {
-      assert (ifd == 3); // Make sure is not set yet.
-
-      ifd = toi (v);
-      assert (ifd >= 0 && ifd < 3);
+      cout << dir_path::current_directory () << endl;
+    }
+    else // Handle options other than flags.
+    {
+      ++i;
+      assert (i < argc);
+      string v (argv[i]);
 
-      if (ifd == 0)
-        cin.ignore (numeric_limits<streamsize>::max ());
-      else if (cin.peek () != istream::traits_type::eof ())
+      if (o == "-i")
       {
-        ostream& o (ifd == 1 ? cout : cerr);
-        o << cin.rdbuf ();
-        o.flush ();
+        assert (ifd == 3); // Make sure is not set yet.
+
+        ifd = toi (v);
+        assert (ifd >= 0 && ifd < 3);
+
+        if (ifd == 0)
+          cin.ignore (numeric_limits<streamsize>::max ());
+        else if (cin.peek () != istream::traits_type::eof ())
+        {
+          ostream& o (ifd == 1 ? cout : cerr);
+          o << cin.rdbuf ();
+          o.flush ();
+        }
       }
-    }
-    else if (o == "-o")
-    {
-      cout << v << endl;
-    }
-    else if (o == "-e")
-    {
-      cerr << v << endl;
-    }
-    else if (o == "-f")
-    {
-      ofdstream os (v);
-      os.close ();
-    }
-    else if (o == "-d")
-    {
-      try_mkdir_p (dir_path (v));
-    }
-    else if (o == "-v")
-    {
-      optional<string> var (getenv (v));
-      cout << (var ? *var : "<none>") << endl;
-    }
-    else if (o == "-l")
-    {
-      size_t t (toi (v));
+      else if (o == "-o")
+      {
+        cout << v << endl;
+      }
+      else if (o == "-e")
+      {
+        cerr << v << endl;
+      }
+      else if (o == "-f")
+      {
+        ofdstream os (v);
+        os.close ();
+      }
+      else if (o == "-d")
+      {
+        try_mkdir_p (dir_path (v));
+      }
+      else if (o == "-v")
+      {
+        optional<string> var (getenv (v));
+        cout << (var ? *var : "<none>") << endl;
+      }
+      else if (o == "-l")
+      {
+        size_t t (toi (v));
 
-       // MinGW GCC 4.9 doesn't implement this_thread so use Win32 Sleep().
-       //
+        // MinGW GCC 4.9 doesn't implement this_thread so use Win32 Sleep().
+        //
 #ifndef _WIN32
-      this_thread::sleep_for (chrono::seconds (t));
+        this_thread::sleep_for (chrono::seconds (t));
 #else
-      Sleep (static_cast<DWORD> (t * 1000));
+        Sleep (static_cast<DWORD> (t * 1000));
 #endif
+      }
+      else if (o == "-t")
+      {
+        assert (aterm == '\0' && !status); // Make sure exit method is not set.
+        assert (v.size () == 1 && v.find_first_of ("amsz") != string::npos);
+        aterm = v[0];
+      }
+      else if (o == "-s")
+      {
+        assert (!status && aterm == '\0'); // Make sure exit method is not set.
+        status = toi (v);
+      }
+      else
+        assert (false);
     }
-    else if (o == "-t")
-    {
-      assert (aterm == '\0' && !status); // Make sure exit method is not set.
-      assert (v.size () == 1 && v.find_first_of ("amsz") != string::npos);
-      aterm = v[0];
-    }
-    else if (o == "-s")
-    {
-      assert (!status && aterm == '\0'); // Make sure exit method is not set.
-      status = toi (v);
-    }
-    else
-      assert (false);
   }
 
   switch (aterm)
diff --git a/tests/test/script/runner/env.testscript b/tests/test/script/runner/env.testscript
index ef90c3b..512139a 100644
--- a/tests/test/script/runner/env.testscript
+++ b/tests/test/script/runner/env.testscript
@@ -3,6 +3,40 @@
 
 .include ../common.testscript
 
+: cwd
+:
+{
+  : not-exist
+  :
+  $c <'env -c a -- $* -w' && $b 2>>/~%EOE% != 0
+  %testscript:1:1: error: specified working directory .+/a/ does not exist%
+    info: test id: 1
+  EOE
+
+  : process
+  :
+  $c <<EOI && $b
+  mkdir a;
+  env -c a -- $* -w >/~%.+/a%
+  EOI
+
+  : builtin
+  :
+  $c <<EOI && $b
+  mkdir a;
+  env -c a -- touch b;
+  test -f a/b
+  EOI
+
+  : absolute
+  :
+  $c <<EOI && $b
+  mkdir a;
+  env -c $~/a -- touch b;
+  test -f a/b
+  EOI
+}
+
 : variables
 :
 {