Add support for end step id in worker

2 files changed, 136 insertions, 89 deletions

diff --git a/bbot/worker/worker.cxx b/bbot/worker/worker.cxx
index 6952af6..edbad5c 100644
--- a/bbot/worker/worker.cxx
+++ b/bbot/worker/worker.cxx
@@ -178,7 +178,8 @@ enum class step_id
   bpkg_test_separate_installed_configure_build,
   bpkg_test_separate_installed_update,
   bpkg_test_separate_installed_test,
-  bpkg_uninstall
+  bpkg_uninstall,
+  end
 };
 
 static const strings step_id_str {
@@ -207,7 +208,8 @@ static const strings step_id_str {
   "bpkg.test-separate-installed.configure.build",
   "bpkg.test-separate-installed.update",
   "bpkg.test-separate-installed.test",
-  "bpkg.uninstall"};
+  "bpkg.uninstall",
+  "end"};
 
 using std::regex;
 namespace regex_constants = std::regex_constants;
@@ -223,6 +225,9 @@ using regexes = vector<regex>;
 // execution. If bkp_status is present, then ask for that if the command
 // execution results with the specified or more critical status.
 //
+// For the special end step no command is executed. In this case only the user
+// is potentially prompted and the step is traced/logged.
+//
 template <typename... A>
 static result_status
 run_cmd (step_id step,
@@ -288,42 +293,47 @@ run_cmd (step_id step,
     }
   };
 
+  auto prompt_step = [step, &t, &log, &bkp_step, &prompt] ()
+  {
+    const string& sid (step_id_str[static_cast<size_t> (step)]);
+
+    // Prompt the user if the breakpoint is reached.
+    //
+    if (bkp_step && *bkp_step == step)
+      prompt (sid + " step is reached");
+
+    string ts (to_string (system_clock::now (),
+                          "%Y-%m-%d %H:%M:%S%[.N] %Z",
+                          true /* special */,
+                          true /* local */));
+
+    // Log the step id and the command to be executed.
+    //
+    l3 ([&]{t << "step id: " << sid << ' ' << ts;});
+
+#ifndef _WIN32
+    log += "# step id: ";
+#else
+    log += "rem step id: ";
+#endif
+    log += sid;
+    log += ' ';
+    log += ts;
+    log += '\n';
+  };
+
   try
   {
     // Trace, log, and save the command line.
     //
-    auto cmdc = [step, &t, &log, &bkp_step, &next_cmd, &prompt]
+    auto cmdc = [step, &t, &log, &bkp_step, &next_cmd, &prompt, &prompt_step]
                 (const char* c[], size_t n)
     {
-      const string& sid (step_id_str[static_cast<size_t> (step)]);
-
       std::ostringstream os;
       process::print (os, c, n);
       next_cmd = os.str ();
 
-      // Prompt the user if the breakpoint is reached.
-      //
-      if (bkp_step && *bkp_step == step)
-        prompt (sid + " step is reached");
-
-      string ts (to_string (system_clock::now (),
-                            "%Y-%m-%d %H:%M:%S%[.N] %Z",
-                            true /* special */,
-                            true /* local */));
-
-      // Log the step id and the command to be executed.
-      //
-      l3 ([&]{t << "step id: " << sid << ' ' << ts;});
-
-#ifndef _WIN32
-      log += "# step id: ";
-#else
-      log += "rem step id: ";
-#endif
-      log += sid;
-      log += ' ';
-      log += ts;
-      log += '\n';
+      prompt_step ();
 
       t (c, n);
 
@@ -331,65 +341,87 @@ run_cmd (step_id step,
       log += '\n';
     };
 
-    fdpipe pipe (fdopen_pipe ()); // Text mode seems appropriate.
-
-    process pr (
-      process_start_callback (cmdc,
-                              fdopen_null (), // Never reads from stdin.
-                              2,              // 1>&2
-                              pipe,
-                              pe,
-                              forward<A> (a)...));
-
-    pipe.out.close ();
-
     result_status r (result_status::success);
 
+    if (step != step_id::end)
     {
-      ifdstream is (move (pipe.in), fdstream_mode::skip); // Skip on exception.
-
-      for (string l; is.peek () != ifdstream::traits_type::eof (); )
+      try
       {
-        getline (is, l);
+        fdpipe pipe (fdopen_pipe ()); // Text mode seems appropriate.
+
+        process pr (
+          process_start_callback (cmdc,
+                                  fdopen_null (), // Never reads from stdin.
+                                  2,              // 1>&2
+                                  pipe,
+                                  pe,
+                                  forward<A> (a)...));
+
+        pipe.out.close ();
 
-        // Match the log line with the warning-detecting regular expressions
-        // until the first match.
-        //
-        if (r != result_status::warning)
         {
-          for (const regex& re: warn_detect)
+          // Skip on exception.
+          //
+          ifdstream is (move (pipe.in), fdstream_mode::skip);
+
+          for (string l; is.peek () != ifdstream::traits_type::eof (); )
           {
-            // Only examine the first 512 bytes. Long lines (e.g., linker
-            // command lines) could trigger implementation-specific limitations
-            // (like stack overflow). Plus, it is a performance concern.
+            getline (is, l);
+
+            // Match the log line with the warning-detecting regular
+            // expressions until the first match.
             //
-            if (regex_search (l.begin (),
-                              l.size () < 512 ? l.end () : l.begin () + 512,
-                              re))
+            if (r != result_status::warning)
             {
-              r = result_status::warning;
-              break;
+              for (const regex& re: warn_detect)
+              {
+                // Only examine the first 512 bytes. Long lines (e.g., linker
+                // command lines) could trigger implementation-specific
+                // limitations (like stack overflow). Plus, it is a
+                // performance concern.
+                //
+                if (regex_search (l.begin (),
+                                  l.size () < 512 ? l.end () : l.begin () + 512,
+                                  re))
+                {
+                  r = result_status::warning;
+                  break;
+                }
+              }
             }
+
+            add (move (l), false /* trace */);
           }
         }
 
-        add (move (l), false /* trace */);
-      }
-    }
-
-    if (!pr.wait ())
-    {
-      const process_exit& e (*pr.exit);
-      add (name + " " + to_string (e));
-      r = e.normal () ? result_status::error : result_status::abnormal;
-    }
+        if (!pr.wait ())
+        {
+          const process_exit& e (*pr.exit);
+          add (name + " " + to_string (e));
+          r = e.normal () ? result_status::error : result_status::abnormal;
+        }
 
-    last_cmd = move (next_cmd);
+        last_cmd = move (next_cmd);
 
-    if (bkp_status && r >= *bkp_status)
+        if (bkp_status && r >= *bkp_status)
+        {
+          next_cmd.clear (); // Note: used by prompt().
+          prompt (!r ? "error occured" : "warning is issued");
+        }
+      }
+      catch (const process_error& e)
+      {
+        fail << "unable to execute " << name << ": " << e;
+      }
+      catch (const io_error& e)
+      {
+        fail << "unable to read " << name << " diagnostics: " << e;
+      }
+    }
+    else
     {
-      next_cmd.clear (); // Note: used by prompt().
-      prompt (!r ? "error occured" : "warning is issued");
+      next_cmd.clear (); // Note: used by prompt_step().
+      prompt_step ();
     }
 
     return r;
@@ -398,14 +430,6 @@ run_cmd (step_id step,
   {
     return result_status::abort;
   }
-  catch (const process_error& e)
-  {
-    fail << "unable to execute " << name << ": " << e << endf;
-  }
-  catch (const io_error& e)
-  {
-    fail << "unable to read " << name << " diagnostics: " << e << endf;
-  }
 }
 
 template <typename V, typename... A>
@@ -665,6 +689,15 @@ build (size_t argc, const char* argv[])
 
   dir_path rwd; // Root working directory.
 
+  // Resolve the breakpoint specified by the interactive manifest value into
+  // the step id or the result status breakpoint. If the breakpoint is
+  // invalid, then log the error and abort the build. Note that we reuse the
+  // configure operation log here not to complicate things.
+  //
+  optional<step_id> bkp_step;
+  optional<result_status> bkp_status;
+  string last_cmd; // Used in the user prompt.
+
   for (;;) // The "breakout" loop.
   {
     // Regular expressions that detect different forms of build2 toolchain
@@ -684,15 +717,6 @@ build (size_t argc, const char* argv[])
     for (const string& re: tm.unquoted_warning_regex ())
       wre.emplace_back (re, f);
 
-    // Resolve the breakpoint specified by the interactive manifest value into
-    // the step id or the result status breakpoint. If the breakpoint is
-    // invalid, then log the error and abort the build. Note that we reuse the
-    // configure operation log here not to complicate things.
-    //
-    optional<step_id> bkp_step;
-    optional<result_status> bkp_status;
-    string last_cmd; // Used in the user prompt.
-
     if (tm.interactive)
     {
       const string& b (*tm.interactive);
@@ -2014,7 +2038,9 @@ build (size_t argc, const char* argv[])
 
   if (!rm.results.empty ())
   {
-    rm.status |= rm.results.back ().status; // Merge last in case of a break.
+    operation_result& r (rm.results.back ());
+
+    rm.status |= r.status; // Merge last in case of a break.
 
     // Also merge statuses of the configure and test operations, which logs
     // can potentially be shared across multiple steps and which results may
@@ -2025,6 +2051,23 @@ build (size_t argc, const char* argv[])
 
     if (test_result != nullptr)
       rm.status |= test_result->status;
+
+    // Unless there is an error (or worse) encountered, log the special 'end'
+    // step and, if this step is specified in the interactive manifest value,
+    // ask the user if to continue the task execution.
+    //
+    bool error (!rm.status);
+
+    if (!error)
+    {
+      r.status |= run_cmd (step_id::end,
+                           trace, r.log, regexes (),
+                           "" /* name */,
+                           bkp_step, bkp_status, last_cmd,
+                           process_env ());
+
+      rm.status |= r.status;
+    }
   }
   else
     assert (rm.status == result_status::abort);
diff --git a/doc/manual.cli b/doc/manual.cli
index d08a6ff..4326a5b 100644
--- a/doc/manual.cli
+++ b/doc/manual.cli
@@ -948,6 +948,10 @@ bpkg -v update <package-name>
   #
   bpkg -v uninstall <package-name>
 }
+
+# end
+#
+# This step id can only be used as a breakpoint.
 \
 
 For details on configuring and testing installation refer to