Implement manifests and build_config

9 files changed, 1577 insertions, 0 deletions

diff --git a/bbot/build-config b/bbot/build-config
new file mode 100644
index 0000000..0a3ecb3
--- /dev/null
+++ b/bbot/build-config
@@ -0,0 +1,54 @@
+// file      : bbot/build-config -*- C++ -*-
+// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef BBOT_BUILD_CONFIG
+#define BBOT_BUILD_CONFIG
+
+#include <string>
+#include <vector>
+#include <iosfwd>
+
+#include <butl/path>
+#include <butl/optional>
+#include <butl/tab-parser>
+#include <butl/target-triplet>
+
+#include <bbot/export>
+
+#include <bbot/variable>
+
+namespace bbot
+{
+  // Build configuration matching specific machine names. Used by bbot
+  // controllers.
+  //
+  struct build_config
+  {
+    std::string machine_pattern; // Machine name pattern.
+    std::string name;            // Configuration name.
+
+    butl::optional<butl::target_triplet> target;
+
+    variables vars;
+  };
+
+  using build_configs = std::vector<build_config>;
+
+  // Parse buildtab stream or file. Throw tab_parsing on parsing error,
+  // ios::failure on the underlying OS error.
+  //
+  // buildtab consists of lines in the following format:
+  //
+  // <machine-name-pattern> <config-name> [<target>] [<config-vars>]
+  //
+  using butl::tab_parsing;
+
+  LIBBBOT_EXPORT build_configs
+  parse_buildtab (std::istream&, const std::string& name);
+
+  LIBBBOT_EXPORT build_configs
+  parse_buildtab (const butl::path&);
+}
+
+#endif // BBOT_BUILD_CONFIG
diff --git a/bbot/build-config.cxx b/bbot/build-config.cxx
new file mode 100644
index 0000000..226ead3
--- /dev/null
+++ b/bbot/build-config.cxx
@@ -0,0 +1,121 @@
+// file      : bbot/build-config.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <bbot/build-config>
+
+#include <string>
+#include <cstddef>   // size_t
+#include <utility>   // move()
+#include <stdexcept> // invalid_argument
+
+#include <butl/path>
+#include <butl/fdstream>
+#include <butl/tab-parser>
+
+using namespace std;
+using namespace butl;
+
+namespace bbot
+{
+  LIBBBOT_EXPORT build_configs
+  parse_buildtab (istream& is, const string& name)
+  {
+    build_configs r;
+    tab_parser parser (is, name);
+
+    tab_fields tl;
+    while (!(tl = parser.next ()).empty ())
+    {
+      size_t n (tl.size ()); // Fields count.
+      size_t i (0);          // The field currently being processed.
+
+      // Throw tab_parsing for the field currently being processed. If i == n
+      // then we refer to the end-of-line column (presumably reporting a missed
+      // field).
+      //
+      auto bad_line = [&name, &tl, &i, n] (const string& d, size_t offset = 0)
+      {
+        // Offset beyond the end-of-line is meaningless.
+        //
+        assert (i < n || (i == n && offset == 0));
+
+        throw tab_parsing (name,
+                           tl.line,
+                           i == n
+                           ? tl.end_column
+                           : tl[i].column + offset,
+                           d);
+      };
+
+      build_config config;
+      config.machine_pattern = move (tl[i++].value);
+
+      // Configuration name field is a required one.
+      //
+      if (i == n)
+        bad_line ("no configuration name found");
+
+      config.name = move (tl[i].value);
+
+      // Make sure the name is unique.
+      //
+      for (const auto& c: r)
+        if (c.name == config.name)
+          bad_line ("duplicate configuration name");
+
+      // If there is no target nor configuration variables then save the
+      // configuration and proceed with the next line.
+      //
+      if (++i == n)
+      {
+        r.emplace_back (move (config));
+        continue;
+      }
+
+      // If the third field doesn't contain '=' character, then we will treat
+      // it as a target.
+      //
+      if (tl[i].value.find ('=') == string::npos)
+      {
+        try
+        {
+          config.target = target_triplet (tl[i].value);
+        }
+        catch (const invalid_argument& e)
+        {
+          bad_line (e.what ());
+        }
+
+        ++i;
+      }
+
+      try
+      {
+        for (; i < n; ++i)
+          config.vars.emplace_back (variable (move (tl[i].value)));
+      }
+      catch (const invalid_variable& e)
+      {
+        bad_line (e.what (), e.pos); // Note that tl[i].value is moved from,
+                                     // but happily we don't use it
+      }
+
+      // Save the configuration.
+      //
+      r.emplace_back (move (config));
+    }
+
+    return r;
+  }
+
+  build_configs
+  parse_buildtab (const path& p)
+  {
+    ifdstream ifs (p);
+    build_configs r (parse_buildtab (ifs, p.string ()));
+
+    ifs.close (); // Throws on failure.
+    return r;
+  }
+}
diff --git a/bbot/buildfile b/bbot/buildfile
new file mode 100644
index 0000000..1bb608f
--- /dev/null
+++ b/bbot/buildfile
@@ -0,0 +1,35 @@
+# file      : bbot/buildfile
+# copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+# license   : MIT; see accompanying LICENSE file
+
+import int_libs = libbutl%lib{butl} libbpkg%lib{bpkg}
+
+lib{bbot}:                        \
+{hxx         cxx}{ build-config } \
+{hxx            }{ export       } \
+{hxx         cxx}{ manifest     } \
+{hxx         cxx}{ variable     } \
+{hxx            }{ version      } \
+                   $int_libs
+
+# For pre-releases use the complete version to make sure they cannot be used
+# in place of another pre-release or the final version.
+#
+if $abi_prerelease
+  lib{bbot}: bin.lib.version = @-$version
+else
+  lib{bbot}: bin.lib.version = @-$abi_major.$abi_minor
+
+cxx.poptions =+ "-I$src_root"
+obja{*}: cxx.poptions += -DLIBBBOT_STATIC_BUILD
+objs{*}: cxx.poptions += -DLIBBBOT_SHARED_BUILD
+
+lib{bbot}: cxx.export.poptions = "-I$src_root"
+liba{bbot}: cxx.export.poptions += -DLIBBBOT_STATIC
+libs{bbot}: cxx.export.poptions += -DLIBBBOT_SHARED
+
+lib{bbot}: cxx.export.libs = $int_libs
+
+# Install into the bbot/ subdirectory of, say, /usr/include/.
+#
+install.include = $install.include/bbot/
diff --git a/bbot/export b/bbot/export
new file mode 100644
index 0000000..6947752
--- /dev/null
+++ b/bbot/export
@@ -0,0 +1,41 @@
+// file      : bbot/export -*- C++ -*-
+// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef BBOT_EXPORT
+#define BBOT_EXPORT
+
+// Normally we don't export class templates (but do complete specializations),
+// inline functions, and classes with only inline member functions. Exporting
+// classes that inherit from non-exported/imported bases (e.g., std::string)
+// will end up badly. The only known workarounds are to not inherit or to not
+// export. Also, MinGW GCC doesn't like seeing non-exported function being
+// used before their inline definition. The workaround is to reorder code. In
+// the end it's all trial and error.
+
+#if defined(LIBBBOT_STATIC)         // Using static.
+#  define LIBBBOT_EXPORT
+#elif defined(LIBBBOT_STATIC_BUILD) // Building static.
+#  define LIBBBOT_EXPORT
+#elif defined(LIBBBOT_SHARED)       // Using shared.
+#  ifdef _WIN32
+#    define LIBBBOT_EXPORT __declspec(dllimport)
+#  else
+#    define LIBBBOT_EXPORT
+#  endif
+#elif defined(LIBBBOT_SHARED_BUILD) // Building shared.
+#  ifdef _WIN32
+#    define LIBBBOT_EXPORT __declspec(dllexport)
+#  else
+#    define LIBBBOT_EXPORT
+#  endif
+#else
+// If none of the above macros are defined, then we assume we are being used
+// by some third-party build system that cannot/doesn't signal the library
+// type. Note that this fallback works for both static and shared but in case
+// of shared will be sub-optimal compared to having dllimport.
+//
+#  define LIBBBOT_EXPORT            // Using static or shared.
+#endif
+
+#endif // BBOT_EXPORT
diff --git a/bbot/manifest b/bbot/manifest
new file mode 100644
index 0000000..5122dc6
--- /dev/null
+++ b/bbot/manifest
@@ -0,0 +1,215 @@
+// file      : bbot/manifest -*- C++ -*-
+// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef BBOT_MANIFEST
+#define BBOT_MANIFEST
+
+#include <string>
+#include <vector>
+#include <iosfwd>
+
+#include <butl/optional>
+#include <butl/small-vector>
+#include <butl/target-triplet>
+#include <butl/manifest-forward>
+
+#include <bpkg/manifest> // version, repository_location
+
+#include <bbot/export>
+
+#include <bbot/variable>
+
+namespace bbot
+{
+  enum class machine_type {vm, container};
+
+  class LIBBBOT_EXPORT machine_manifest
+  {
+  public:
+    std::string id;
+    std::string name;
+
+    // Absent if inside task_request_manifest.
+    //
+    butl::optional<machine_type> type;
+
+    std::string summary;
+
+  public:
+    machine_manifest () = default; // VC export.
+    machine_manifest (butl::manifest_parser&, bool ignore_unknown = false);
+    machine_manifest (butl::manifest_parser&,
+                      butl::manifest_name_value start,
+                      bool ignore_unknown = false);
+
+    void
+    serialize (butl::manifest_serializer&) const;
+
+  private:
+    machine_manifest (butl::manifest_parser&,
+                      butl::manifest_name_value start,
+                      bool in_list,
+                      bool ignore_unknown);
+  };
+
+  class LIBBBOT_EXPORT task_request_manifest
+  {
+  public:
+    std::string agent;
+
+    // Agent's public key SHA256 fingerprint.
+    //
+    // @@ How the fingerpring for openssl public key will be produced? Seems
+    //    there is no "standard" for it. Possibly we will use the following
+    //    command result (plain SHA256).
+    //
+    //    $ cat key.pub | openssl sha256
+    //
+    std::string fingerprint;
+
+    std::vector<machine_manifest> machines;
+
+  public:
+    task_request_manifest () = default; // VC export.
+    task_request_manifest (butl::manifest_parser&,
+                           bool ignore_unknown = false);
+
+    void
+    serialize (butl::manifest_serializer&) const;
+  };
+
+  class LIBBBOT_EXPORT task_manifest
+  {
+  public:
+    // Package to build.
+    //
+    std::string name;
+    bpkg::version version;
+    bpkg::repository_location repository; // Remote or absolute.
+
+    // Build machine to use for building the package.
+    //
+    std::string machine;
+
+    // Default for the machine if absent.
+    //
+    butl::optional<butl::target_triplet> target;
+
+    // Build system configuration variables (in addition to build environment
+    // configuration variables).
+    //
+    variables config;
+
+  public:
+    task_manifest () = default; // VC export.
+    task_manifest (butl::manifest_parser&, bool ignore_unknown = false);
+    task_manifest (butl::manifest_parser&,
+                   butl::manifest_name_value start,
+                   bool ignore_unknown = false);
+
+    void
+    serialize (butl::manifest_serializer&) const;
+  };
+
+  class LIBBBOT_EXPORT task_response_manifest
+  {
+  public:
+    // If empty then no task available.
+    //
+    std::string session;
+
+    // Challenge and task are absent if session is empty.
+    //
+    butl::optional<std::string> challenge;
+    butl::optional<task_manifest> task;
+
+  public:
+    task_response_manifest () = default; // VC export.
+    task_response_manifest (butl::manifest_parser&,
+                            bool ignore_unknown = false);
+
+    void
+    serialize (butl::manifest_serializer&) const;
+  };
+
+  // Build task or operation result status.
+  //
+  enum class result_status: std::uint8_t
+  {
+    // The order of the enumerators is arranged so that their integral values
+    // indicate whether one "overrides" the other in the "merge" operator|
+    // (see below).
+    //
+    success,
+    warning,
+    error,
+    abort,
+    abnormal
+  };
+
+  std::ostream&
+  operator<< (std::ostream&, result_status);
+
+  inline result_status&
+  operator |= (result_status& l, result_status r)
+  {
+    if (static_cast<std::uint8_t> (r) > static_cast<std::uint8_t> (l))
+      l = r;
+    return l;
+  }
+
+  struct operation_result
+  {
+    std::string operation; // "configure", "update", "test", etc.
+    result_status status;
+    std::string log;
+  };
+
+  using operation_results = butl::small_vector<operation_result, 3>;
+
+  class LIBBBOT_EXPORT result_manifest
+  {
+  public:
+    // Built package.
+    //
+    std::string name;
+    bpkg::version version;
+
+    result_status status;
+
+    // Ordered (ascending) by operation value. May not contain all the
+    // operations if the task failed in the middle, but should have no gaps
+    // (operation can not start unless all previous ones succeeded).
+    //
+    operation_results results;
+
+    result_manifest () = default; // VC export.
+    result_manifest (butl::manifest_parser&, bool ignore_unknown = false);
+    result_manifest (butl::manifest_parser&,
+                     butl::manifest_name_value start,
+                     bool ignore_unknown = false);
+
+    void
+    serialize (butl::manifest_serializer&) const;
+  };
+
+  class LIBBBOT_EXPORT result_request_manifest
+  {
+  public:
+    std::string session;   // The task response session.
+    std::string challenge; // The answer to challenge in the task response.
+
+    result_manifest result;
+
+  public:
+    result_request_manifest () = default; // VC export.
+    result_request_manifest (butl::manifest_parser&,
+                             bool ignore_unknown = false);
+
+    void
+    serialize (butl::manifest_serializer&) const;
+  };
+}
+
+#endif // BBOT_MANIFEST
diff --git a/bbot/manifest.cxx b/bbot/manifest.cxx
new file mode 100644
index 0000000..6c9fe4d
--- /dev/null
+++ b/bbot/manifest.cxx
@@ -0,0 +1,931 @@
+// file      : bbot/manifest.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <bbot/manifest>
+
+#include <vector>
+#include <string>
+#include <cassert>
+#include <sstream>
+#include <cstddef>   // size_t
+#include <utility>   // move()
+#include <cstdint>   // uint64_t
+#include <algorithm> // find()
+
+#include <butl/utility>             // digit()
+#include <butl/tab-parser>
+#include <butl/manifest-parser>
+#include <butl/manifest-serializer>
+
+using namespace std;
+using namespace butl;
+using namespace bpkg;
+
+namespace bbot
+{
+  using parser = manifest_parser;
+  using parsing = manifest_parsing;
+  using serializer = manifest_serializer;
+  using serialization = manifest_serialization;
+  using name_value = manifest_name_value;
+
+  using strings = vector<string>;
+
+  static const strings machine_type_names ({"vm", "container"});
+
+  static const strings result_status_names ({
+    "success",
+    "warning",
+    "error",
+    "abort",
+    "abnormal"});
+
+  ostream&
+  operator<< (ostream& o, result_status s)
+  {
+    size_t i (static_cast<size_t> (s));
+    assert (i < result_status_names.size ());
+    o << result_status_names[i];
+    return o;
+  }
+
+  inline static bool
+  valid_sha256 (const string& s) noexcept
+  {
+    if (s.size () != 64)
+      return false;
+
+    for (const auto& c: s)
+    {
+      if ((c < 'a' || c > 'f' ) && !digit (c))
+        return false;
+    }
+
+    return true;
+  }
+
+  // machine_manifest
+  //
+  machine_manifest::
+  machine_manifest (parser& p, bool iu)
+      : machine_manifest (p, p.next (), false, iu)
+  {
+    // Make sure this is the end.
+    //
+    name_value nv (p.next ());
+    if (!nv.empty ())
+      throw parsing (p.name (), nv.name_line, nv.name_column,
+                     "single machine manifest expected");
+  }
+
+  machine_manifest::
+  machine_manifest (parser& p, name_value nv, bool iu)
+      : machine_manifest (p, nv, true, iu)
+  {
+  }
+
+  machine_manifest::
+  machine_manifest (parser& p, name_value nv, bool il, bool iu)
+  {
+    auto bad_name = [&p, &nv] (const string& d)
+    {
+      throw parsing (p.name (), nv.name_line, nv.name_column, d);
+    };
+
+    auto bad_value = [&p, &nv] (const string& d)
+    {
+      throw parsing (p.name (), nv.value_line, nv.value_column, d);
+    };
+
+    // Make sure this is the start and we support the version.
+    //
+    if (!nv.name.empty ())
+      bad_name ("start of machine manifest expected");
+
+    if (nv.value != "1")
+      bad_value ("unsupported format version");
+
+    for (nv = p.next (); !nv.empty (); nv = p.next ())
+    {
+      string& n (nv.name);
+      string& v (nv.value);
+
+      if (n == "id")
+      {
+        if (!id.empty ())
+          bad_name ("machine id redefinition");
+
+        if (v.empty ())
+          bad_value ("empty machine id");
+
+        id = move (v);
+      }
+      else if (n == "name")
+      {
+        if (!name.empty ())
+          bad_name ("machine name redefinition");
+
+        if (v.empty ())
+          bad_value ("empty machine name");
+
+        name = move (v);
+      }
+      else if (n == "type")
+      {
+        if (il)
+          bad_name ("machine type not allowed");
+
+        if (type)
+          bad_name ("machine type redefinition");
+
+        auto b (machine_type_names.cbegin ());
+        auto e (machine_type_names.cend ());
+        auto i (find (b, e, v));
+
+        if (i == e)
+          bad_value ("invalid machine type");
+
+        type = static_cast<machine_type> (i - b);
+      }
+      else if (n == "summary")
+      {
+        if (!summary.empty ())
+          bad_name ("machine summary redefinition");
+
+        if (v.empty ())
+          bad_value ("empty machine summary");
+
+        summary = move (v);
+      }
+      else if (!iu)
+        bad_name ("unknown name '" + n + "' in machine manifest");
+    }
+
+    // Verify all non-optional values were specified.
+    //
+    if (id.empty ())
+      bad_value ("no machine id specified");
+
+    if (name.empty ())
+      bad_value ("no machine name specified");
+
+    if (!il && !type)
+      bad_value ("no machine type specified");
+
+    if (summary.empty ())
+      bad_value ("no machine summary specified");
+  }
+
+  void machine_manifest::
+  serialize (serializer& s) const
+  {
+    // @@ Should we check that all non-optional values are specified and all
+    //    values are valid?
+    //
+    s.next ("", "1"); // Start of manifest.
+    s.next ("id", id);
+    s.next ("name", name);
+
+    if (type)
+    {
+      size_t v (static_cast<size_t> (*type));
+      assert (v < machine_type_names.size ());
+      s.next ("type", machine_type_names[v]);
+    }
+
+    s.next ("summary", summary);
+    s.next ("", ""); // End of manifest.
+  }
+
+  // task_request_manifest
+  //
+  task_request_manifest::
+  task_request_manifest (parser& p, bool iu)
+  {
+    name_value nv (p.next ());
+
+    auto bad_name = [&p, &nv] (const string& d)
+    {
+      throw parsing (p.name (), nv.name_line, nv.name_column, d);
+    };
+
+    auto bad_value = [&p, &nv] (const string& d)
+    {
+      throw parsing (p.name (), nv.value_line, nv.value_column, d);
+    };
+
+    // Make sure this is the start and we support the version.
+    //
+    if (!nv.name.empty ())
+      bad_name ("start of task request manifest expected");
+
+    if (nv.value != "1")
+      bad_value ("unsupported format version");
+
+    // Parse the task request manifest.
+    //
+    for (nv = p.next (); !nv.empty (); nv = p.next ())
+    {
+      string& n (nv.name);
+      string& v (nv.value);
+
+      if (n == "agent")
+      {
+        if (!agent.empty ())
+          bad_name ("task request agent redefinition");
+
+        if (v.empty ())
+          bad_value ("empty task request agent");
+
+        agent = move (v);
+      }
+      else if (n == "fingerprint")
+      {
+        if (!fingerprint.empty ())
+          bad_name ("task request fingerprint redefinition");
+
+        if (!valid_sha256 (v))
+          bad_value ("invalid task request fingerprint");
+
+        fingerprint = move (v);
+      }
+      else if (!iu)
+        bad_name ("unknown name '" + n + "' in task request manifest");
+    }
+
+    // Verify all non-optional values were specified.
+    //
+    if (agent.empty ())
+      bad_value ("no task request agent specified");
+
+    if (fingerprint.empty ())
+      bad_value ("no task request fingerprint specified");
+
+    // Parse machine manifests.
+    //
+    for (nv = p.next (); !nv.empty (); nv = p.next ())
+      machines.emplace_back (machine_manifest (p, nv, iu));
+
+    if (machines.empty ())
+      bad_value ("no task request machines specified");
+  }
+
+  void task_request_manifest::
+  serialize (serializer& s) const
+  {
+    // @@ Should we check that all non-optional values are specified and all
+    //    values are valid?
+    //
+    s.next ("", "1"); // Start of manifest.
+    s.next ("agent", agent);
+    s.next ("fingerprint", fingerprint);
+    s.next ("", "");  // End of manifest.
+
+    for (const machine_manifest& m: machines)
+    {
+      if (m.type)
+        throw serialization (s.name (), "machine type is forbidden");
+
+      m.serialize (s);
+    }
+
+    s.next ("", ""); // End of stream.
+  }
+
+  // task_manifest
+  //
+  task_manifest::
+  task_manifest (parser& p, bool iu)
+      : task_manifest (p, p.next (), iu)
+  {
+    // Make sure this is the end.
+    //
+    name_value nv (p.next ());
+    if (!nv.empty ())
+      throw parsing (p.name (), nv.name_line, nv.name_column,
+                     "single task manifest expected");
+  }
+
+  task_manifest::
+  task_manifest (parser& p, name_value nv, bool iu)
+  {
+    auto bad_name = [&p, &nv] (const string& d)
+    {
+      throw parsing (p.name (), nv.name_line, nv.name_column, d);
+    };
+
+    // Offsets are used to tie an error to the specific position inside a
+    // manifest value (possibly a multiline one).
+    //
+    auto bad_value = [&p, &nv] (
+      const string& d, uint64_t column_offset = 0, uint64_t line_offset = 0)
+    {
+      throw parsing (p.name (),
+                     nv.value_line + line_offset,
+                     (line_offset == 0 ? nv.value_column : 1) + column_offset,
+                     d);
+    };
+
+    // Make sure this is the start and we support the version.
+    //
+    if (!nv.name.empty ())
+      bad_name ("start of task manifest expected");
+
+    if (nv.value != "1")
+      bad_value ("unsupported format version");
+
+    // Parse the task manifest.
+    //
+    for (nv = p.next (); !nv.empty (); nv = p.next ())
+    {
+      string& n (nv.name);
+      string& v (nv.value);
+
+      if (n == "name")
+      {
+        if (!name.empty ())
+          bad_name ("task package name redefinition");
+
+        if (v.empty ())
+          bad_value ("empty task package name");
+
+        name = move (v);
+      }
+      else if (n == "version")
+      {
+        if (!version.empty ())
+          bad_name ("task package version redefinition");
+
+        try
+        {
+          version = bpkg::version (move (v));
+        }
+        catch (const invalid_argument& e)
+        {
+          bad_value (string ("invalid task package version: ") + e.what ());
+        }
+
+        // Versions like 1.2.3- are forbidden in manifest as intended to be
+        // used for version constrains rather than actual releases.
+        //
+        if (version.release && version.release->empty ())
+          bad_value ("invalid task package version release");
+      }
+      else if (n == "repository")
+      {
+        if (!repository.empty ())
+          bad_name ("task repository redefinition");
+
+        if (v.empty ())
+          bad_value ("empty task repository");
+
+        try
+        {
+          // Call remote/absolute repository location constructor (throws
+          // invalid_argument for relative location).
+          //
+          repository = repository_location (move (v));
+        }
+        catch (const invalid_argument& e)
+        {
+          bad_value (string ("invalid task repository: ") + e.what ());
+        }
+      }
+      else if (n == "machine")
+      {
+        if (!machine.empty ())
+          bad_name ("task machine redefinition");
+
+        if (v.empty ())
+          bad_value ("empty task machine");
+
+        machine = move (v);
+      }
+      else if (n == "target")
+      {
+        if (target)
+          bad_name ("task target redefinition");
+
+        try
+        {
+          target = target_triplet (v);
+        }
+        catch (const invalid_argument& e)
+        {
+          bad_value (string ("invalid task target: ") + e.what ());
+        }
+      }
+      else if (n == "config")
+      {
+        if (!config.empty ())
+          bad_name ("task configuration redefinition");
+
+        // Note that when reporting errors we combine the manifest value
+        // position with the respective field and error positions.
+        //
+        try
+        {
+          istringstream is (v);
+          tab_parser parser (is, "");
+
+          // Here we naturally support multiline config manifest.
+          //
+          tab_fields tl;
+          while (!(tl = parser.next ()).empty ())
+          {
+            for (auto& tf: tl)
+            {
+              try
+              {
+                config.emplace_back (variable (move (tf.value)));
+              }
+              catch (const invalid_variable& e)
+              {
+                bad_value (string ("invalid task configuration: ") + e.what (),
+                           tf.column - 1 + e.pos,
+                           tl.line - 1);
+              }
+            }
+          }
+        }
+        catch (const tab_parsing& e)
+        {
+          bad_value ("invalid task configuration: " + e.description,
+                     e.column - 1,
+                     e.line - 1);
+        }
+
+        if (config.empty ())
+          bad_value ("empty task configuration");
+      }
+      else if (!iu)
+        bad_name ("unknown name '" + n + "' in task manifest");
+    }
+
+    // Verify all non-optional values were specified.
+    //
+    if (name.empty ())
+      bad_value ("no task package name specified");
+
+    if (version.empty ())
+      bad_value ("no task package version specified");
+
+    if (repository.empty ())
+      bad_value ("no task repository specified");
+
+    if (machine.empty ())
+      bad_value ("no task machine specified");
+  }
+
+  void task_manifest::
+  serialize (serializer& s) const
+  {
+    // @@ Should we check that all non-optional values are specified and all
+    //    values are valid?
+    //
+    s.next ("", "1"); // Start of manifest.
+    s.next ("name", name);
+    s.next ("version", version.string ());
+    s.next ("repository", repository.string ());
+    s.next ("machine", machine);
+
+    if (target)
+      s.next ("target", target->string ());
+
+    // Recompose config string as a space-separated variable list,
+    //
+    if (!config.empty ())
+    {
+      string v;
+      for (auto b (config.cbegin ()), i (b), e (config.cend ()); i != e; ++i)
+      {
+        if (i != b)
+          v += ' ';
+
+        v += *i;
+      }
+
+      s.next ("config", v);
+    }
+
+    s.next ("", ""); // End of manifest.
+  }
+
+  // task_response_manifest
+  //
+  task_response_manifest::
+  task_response_manifest (parser& p, bool iu)
+  {
+    name_value nv (p.next ());
+
+    auto bad_name = [&p, &nv] (const string& d)
+    {
+      throw parsing (p.name (), nv.name_line, nv.name_column, d);
+    };
+
+    auto bad_value = [&p, &nv] (const string& d)
+    {
+      throw parsing (p.name (), nv.value_line, nv.value_column, d);
+    };
+
+    // Make sure this is the start and we support the version.
+    //
+    if (!nv.name.empty ())
+      bad_name ("start of task response manifest expected");
+
+    if (nv.value != "1")
+      bad_value ("unsupported format version");
+
+    // Parse the task response manifest.
+    //
+    // Note that we need to distinguish an empty and absent session.
+    //
+    optional<string> sess;
+    for (nv = p.next (); !nv.empty (); nv = p.next ())
+    {
+      string& n (nv.name);
+      string& v (nv.value);
+
+      if (n == "session")
+      {
+        if (sess)
+          bad_name ("task response session redefinition");
+
+        sess = move (v);
+      }
+      else if (n == "challenge")
+      {
+        if (challenge)
+          bad_name ("task response challenge redefinition");
+
+        if (v.empty ())
+          bad_value ("empty task response challenge");
+
+        challenge = move (v);
+      }
+      else if (!iu)
+        bad_name ("unknown name '" + n + "' in task response manifest");
+    }
+
+    // Verify all non-optional values were specified, and all values are
+    // expected.
+    //
+    if (!sess)
+      bad_value ("no task response session specified");
+
+    session = move (*sess);
+
+    // If session is not empty then the challenge must present, otherwise it
+    // shouldn't.
+    //
+    if (!session.empty ())
+    {
+      if (!challenge)
+        bad_value ("no task response challenge specified");
+    }
+    else if (challenge)
+      bad_value ("unexpected task response challenge");
+
+    // If session is not empty then the task manifest must follow, otherwise it
+    // shouldn't.
+    //
+    nv = p.next ();
+
+    if (!session.empty ())
+    {
+      if (nv.empty ())
+        bad_value ("task manifest expected");
+
+      task = task_manifest (p, nv, iu);
+
+      nv = p.next ();
+    }
+
+    // Make sure this is the end.
+    //
+    if (!nv.empty ())
+      throw parsing (p.name (), nv.name_line, nv.name_column,
+                     "single task response manifest expected");
+  }
+
+  void task_response_manifest::
+  serialize (serializer& s) const
+  {
+    // @@ Should we check that all non-optional values are specified and all
+    //    values are valid?
+    //
+    s.next ("", "1"); // Start of manifest.
+    s.next ("session", session);
+
+    if (challenge)
+      s.next ("challenge", *challenge);
+
+    s.next ("", ""); // End of manifest.
+
+    if (task)
+      task->serialize (s);
+
+    s.next ("", ""); // End of stream.
+  }
+
+  // result_manifest
+  //
+  result_manifest::
+  result_manifest (parser& p, bool iu)
+      : result_manifest (p, p.next (), iu)
+  {
+    // Make sure this is the end.
+    //
+    name_value nv (p.next ());
+    if (!nv.empty ())
+      throw parsing (p.name (), nv.name_line, nv.name_column,
+                     "single result manifest expected");
+  }
+
+  result_manifest::
+  result_manifest (parser& p, name_value nv, bool iu)
+  {
+    auto bad_name = [&p, &nv] (const string& d)
+    {
+      throw parsing (p.name (), nv.name_line, nv.name_column, d);
+    };
+
+    auto bad_value = [&p, &nv] (const string& d, size_t offset = 0)
+    {
+      throw parsing (p.name (), nv.value_line, nv.value_column + offset, d);
+    };
+
+    auto result_stat =
+      [&bad_value] (const string& v, const string& what) -> result_status
+    {
+      auto b (result_status_names.cbegin ());
+      auto e (result_status_names.cend ());
+      auto i (find (b, e, v));
+
+      if (i == e)
+        bad_value ("invalid " + what);
+
+      return static_cast<result_status> (i - b);
+    };
+
+    // Make sure this is the start and we support the version.
+    //
+    if (!nv.name.empty ())
+      bad_name ("start of result manifest expected");
+
+    if (nv.value != "1")
+      bad_value ("unsupported format version");
+
+    // Parse the result manifest.
+    //
+    optional<result_status> stat;
+
+    // Number of parsed *-log values. Also denotes the next expected log type.
+    //
+    size_t nlog (0);
+
+    for (nv = p.next (); !nv.empty (); nv = p.next ())
+    {
+      string& n (nv.name);
+      string& v (nv.value);
+
+      if (n == "name")
+      {
+        if (!name.empty ())
+          bad_name ("result package name redefinition");
+
+        if (v.empty ())
+          bad_value ("empty result package name");
+
+        name = move (v);
+      }
+      else if (n == "version")
+      {
+        if (!version.empty ())
+          bad_name ("result package version redefinition");
+
+        try
+        {
+          version = bpkg::version (move (v));
+        }
+        catch (const invalid_argument& e)
+        {
+          bad_value (string ("invalid result package version: ") + e.what ());
+        }
+
+        // Versions like 1.2.3- are forbidden in manifest as intended to be
+        // used for version constrains rather than actual releases.
+        //
+        if (version.release && version.release->empty ())
+          bad_value ("invalid result package version release");
+      }
+      else if (n == "status")
+      {
+        if (stat)
+          bad_name ("result status redefinition");
+
+        stat = result_stat (v, "result status");
+      }
+      else
+      {
+        size_t nn (n.size ()); // Name length.
+
+        // Note: returns false if nothing preceeds a suffix.
+        //
+        auto suffix = [&n, nn] (const char* s, size_t sn) -> bool
+        {
+          return nn > sn && n.compare (nn - sn, sn, s) == 0;
+        };
+
+        size_t sn;
+        if (suffix ("-status", sn = 7))
+        {
+          if (!stat)
+            bad_name ("result status must appear first");
+
+          if (nlog > 0) // Some logs have already been parsed.
+            bad_name (n + " after operations logs");
+
+          string op (n, 0, nn - sn);
+
+          // Make sure the operation result status is not redefined.
+          //
+          for (const auto& r: results)
+          {
+            if (r.operation == op)
+              bad_name ("result " + n + " redefinition");
+          }
+
+          // Add the operation result (log will come later).
+          //
+          results.push_back ({move (op), result_stat (v, n), string ()});
+        }
+        else if (suffix ("-log", sn = 4))
+        {
+          string op (n, 0, nn - sn);
+
+          // Check that specifically this operation log is expected.
+          //
+          if (nlog >= results.size ())
+            bad_name ("unexpected " + n);
+
+          if (results[nlog].operation != op)
+            bad_name (results[nlog].operation + "-log is expected");
+
+          // Save operation log.
+          //
+          results[nlog++].log = move (v);
+        }
+        else if (!iu)
+          bad_name ("unknown name '" + n + "' in result manifest");
+      }
+    }
+
+    // Verify all non-optional values were specified.
+    //
+    if (name.empty ())
+      bad_value ("no result package name specified");
+
+    if (version.empty ())
+      bad_value ("no result package version specified");
+
+    if (!stat)
+      bad_value ("no result status specified");
+
+    // @@ Checking that the result status is consistent with operations
+    //    statuses is a bit hairy, so let's postpone for now.
+    //
+    status = move (*stat);
+
+    // Check that we have log for every operation result status.
+    //
+    if (nlog < results.size ())
+      bad_name ("no result " + results[nlog].operation + "-log specified");
+  }
+
+  void result_manifest::
+  serialize (serializer& s) const
+  {
+    // @@ Should we check that all non-optional values are specified and all
+    //    values are valid?
+    //
+    s.next ("", "1"); // Start of manifest.
+    s.next ("name", name);
+    s.next ("version", version.string ());
+
+    size_t v (static_cast<size_t> (status));
+    assert (v < result_status_names.size ());
+    s.next ("status", result_status_names[v]);
+
+    // Serialize *-status values.
+    //
+    for (const auto& r: results)
+    {
+      size_t rs (static_cast<size_t> (r.status));
+      assert (rs < result_status_names.size ());
+
+      s.next (r.operation + "-status", result_status_names[rs]);
+    }
+
+    // Serialize *-log values.
+    //
+    for (const auto& r: results)
+      s.next (r.operation + "-log", r.log);
+
+    s.next ("", ""); // End of manifest.
+  }
+
+  // result_request_manifest
+  //
+  result_request_manifest::
+  result_request_manifest (parser& p, bool iu)
+  {
+    name_value nv (p.next ());
+
+    auto bad_name = [&p, &nv] (const string& d)
+    {
+      throw parsing (p.name (), nv.name_line, nv.name_column, d);
+    };
+
+    auto bad_value = [&p, &nv] (const string& d)
+    {
+      throw parsing (p.name (), nv.value_line, nv.value_column, d);
+    };
+
+    // Make sure this is the start and we support the version.
+    //
+    if (!nv.name.empty ())
+      bad_name ("start of result request manifest expected");
+
+    if (nv.value != "1")
+      bad_value ("unsupported format version");
+
+    // Parse the result request manifest.
+    //
+    for (nv = p.next (); !nv.empty (); nv = p.next ())
+    {
+      string& n (nv.name);
+      string& v (nv.value);
+
+      if (n == "session")
+      {
+        if (!session.empty ())
+          bad_name ("result request session redefinition");
+
+        if (v.empty ())
+          bad_value ("empty result request session");
+
+        session = move (v);
+      }
+      else if (n == "challenge")
+      {
+        if (!challenge.empty ())
+          bad_name ("result request challenge redefinition");
+
+        if (v.empty ())
+          bad_value ("empty result request challenge");
+
+        challenge = move (v);
+      }
+      else if (!iu)
+        bad_name ("unknown name '" + n + "' in result request manifest");
+    }
+
+    // Verify all non-optional values were specified.
+    //
+    if (session.empty ())
+      bad_value ("no result request session specified");
+
+    if (challenge.empty ())
+      bad_value ("no result request challenge specified");
+
+    nv = p.next ();
+    if (nv.empty ())
+      bad_value ("result manifest expected");
+
+    result = result_manifest (p, nv, iu);
+
+    // Make sure this is the end.
+    //
+    nv = p.next ();
+    if (!nv.empty ())
+      throw parsing (p.name (), nv.name_line, nv.name_column,
+                     "single result request manifest expected");
+  }
+
+  void result_request_manifest::
+  serialize (serializer& s) const
+  {
+    // @@ Should we check that all non-optional values are specified and all
+    //    values are valid?
+    //
+    s.next ("", "1"); // Start of manifest.
+    s.next ("session", session);
+    s.next ("challenge", challenge);
+    s.next ("", ""); // End of manifest.
+
+    result.serialize (s);
+    s.next ("", ""); // End of stream.
+  }
+}
diff --git a/bbot/variable b/bbot/variable
new file mode 100644
index 0000000..c210dc0
--- /dev/null
+++ b/bbot/variable
@@ -0,0 +1,49 @@
+// file      : bbot/variable -*- C++ -*-
+// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef BBOT_VARIABLE
+#define BBOT_VARIABLE
+
+#include <string>
+#include <vector>
+#include <cstdint>   // uint64_t
+#include <stdexcept> // invalid_argument
+
+#include <bbot/export>
+
+namespace bbot
+{
+  //@@ invalid_argument
+  //
+  class LIBBBOT_EXPORT invalid_variable: public std::invalid_argument
+  {
+  public:
+    invalid_variable (std::uint64_t p, const std::string& d)
+        : invalid_argument (d), pos (p) {}
+
+    std::uint64_t pos; // Zero-based.
+  };
+
+  // String in the name=value format. Can contain single or double quoted
+  // substrings. No escaping is supported. The name must not contain spaces.
+  // Throw variable_error if the string doesn't conform with the above
+  // constraints.
+  //
+  struct LIBBBOT_EXPORT variable: std::string
+  {
+    variable (std::string);
+
+    // Remove a single level of quotes. Don't validate the format or the
+    // correctness of the quotation. Note that the variable can potentially be
+    // modified through the std::string interface in a way that breaks
+    // format/quoting.
+    //
+    std::string
+    unquoted () const;
+  };
+
+  using variables = std::vector<variable>;
+}
+
+#endif // BBOT_VARIABLE
diff --git a/bbot/variable.cxx b/bbot/variable.cxx
new file mode 100644
index 0000000..a25b007
--- /dev/null
+++ b/bbot/variable.cxx
@@ -0,0 +1,94 @@
+// file      : bbot/variable.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <bbot/variable>
+
+#include <utility> // move()
+
+using namespace std;
+
+namespace bbot
+{
+  variable::
+  variable (string v): string (move (v))
+  {
+    // Scan the string untill the end to check that the quoting is terminated.
+    // We will also make sure that the name doesn't contain spaces and the
+    // value is provided.
+    //
+    char quoting ('\0'); // Current quoting mode, can be used as bool.
+    bool name (true);    // True while we are parsing the variable name.
+
+    auto b (cbegin ());
+    auto i (b);
+
+    auto bad_variable = [&b, &i] (const string& d)
+    {
+      throw invalid_variable (i - b, d);
+    };
+
+    for (auto e (cend ()); i != e; ++i)
+    {
+      char c (*i);
+
+      if (!quoting)
+      {
+        if (c == '"' || c == '\'') // Begin of quoted string,
+        {
+          quoting = c;
+          continue;
+        }
+      }
+      else if (c == quoting)       // End of quoted string,
+      {
+        quoting = '\0';
+        continue;
+      }
+
+      if (name)
+      {
+        if (c == ' ' || c == '\t')
+          bad_variable ("expected variable assignment");
+        else if (c == '=')
+          name = false;
+      }
+    }
+
+    if (quoting)
+      bad_variable ("unterminated quoted string");
+
+    if (name)
+      bad_variable ("no variable value");
+  }
+
+  string variable::
+  unquoted () const
+  {
+    string r;
+    char quoting ('\0');  // Current quoting mode, can be used as bool.
+
+    for (auto i (cbegin ()), e (cend ()); i != e; ++i)
+    {
+      char c (*i);
+
+      if (!quoting)
+      {
+        if (c == '"' || c == '\'') // Begin of quoted string.
+        {
+          quoting = c;
+          continue;
+        }
+      }
+      else if (c == quoting)       // End of quoted string.
+      {
+        quoting = '\0';
+        continue;
+      }
+
+      r += c;
+    }
+
+    return r;
+  }
+}
diff --git a/bbot/version b/bbot/version
new file mode 100644
index 0000000..9454762
--- /dev/null
+++ b/bbot/version
@@ -0,0 +1,37 @@
+// file      : bbot/version -*- C++ -*-
+// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef LIBBBOT_VERSION // Note: using the version macro itself.
+
+#include <butl/version> // LIBBUTL_VERSION
+
+// Version format is AABBCCDD where
+//
+// AA - major version number
+// BB - minor version number
+// CC - bugfix version number
+// DD - alpha / beta (DD + 50) version number
+//
+// When DD is not 00, 1 is subtracted from AABBCC. For example:
+//
+// Version     AABBCCDD
+// 2.0.0       02000000
+// 2.1.0       02010000
+// 2.1.1       02010100
+// 2.2.0-a1    02019901
+// 3.0.0-b2    02999952
+//
+#define LIBBBOT_VERSION 49901
+#define LIBBBOT_VERSION_STR "0.5.0-a1"
+
+// Generally, we expect minor versions to be source code backwards-
+// compatible, thought we might have a minimum version requirement.
+//
+// Note: does not apply during early development.
+//
+#if LIBBUTL_VERSION != 49901
+#  error incompatible libbutl version
+#endif
+
+#endif // LIBBBOT_VERSION