Add support for additional *-build package manifest values and alternative buildfile naming

2 files changed, 117 insertions, 6 deletions

diff --git a/libbpkg/manifest.cxx b/libbpkg/manifest.cxx
index 9578977..4555bbc 100644
--- a/libbpkg/manifest.cxx
+++ b/libbpkg/manifest.cxx
@@ -3367,6 +3367,20 @@ namespace bpkg
       return (fl & f) != package_manifest_flags::none;
     };
 
+    // Based on the `*-build[2]` value name set the manifest's alt_naming flag
+    // if absent and verify that it doesn't change otherwise.
+    //
+    auto alt_naming = [&m, &bad_name] (const string& n)
+    {
+      bool v (n.size () > 7 && n.compare (n.size () - 7, 7, "-build2") == 0);
+
+      if (!m.alt_naming)
+        m.alt_naming = v;
+      else if (*m.alt_naming != v)
+        bad_name (string (*m.alt_naming ? "alternative" : "standard") +
+                  " buildfile naming scheme is already used");
+    };
+
     // Cache the upstream version manifest value and validate whether it's
     // allowed later, after the version value is parsed.
     //
@@ -3701,20 +3715,77 @@ namespace bpkg
 
         tests.push_back (move (nv));
       }
-      else if (n == "bootstrap-build")
+      else if (n == "bootstrap-build" || n == "bootstrap-build2")
       {
+        alt_naming (n);
+
         if (m.bootstrap_build)
-          bad_name ("package bootstrap-build redefinition");
+          bad_name ("package " + n + " redefinition");
 
         m.bootstrap_build = move (v);
       }
-      else if (n == "root-build")
+      else if (n == "root-build" || n == "root-build2")
       {
+        alt_naming (n);
+
         if (m.root_build)
-          bad_name ("package root-build redefinition");
+          bad_name ("package " + n + " redefinition");
 
         m.root_build = move (v);
       }
+      else if ((n.size () > 6 && n.compare (n.size () - 6, 6, "-build") == 0) ||
+               (n.size () > 7 && n.compare (n.size () - 7, 7, "-build2") == 0))
+      {
+        alt_naming (n);
+
+        // Verify that the path doesn't contain backslashes which would be
+        // interpreted differently on Windows and POSIX.
+        //
+        if (n.find ('\\') != string::npos)
+          bad_name ("backslash in package buildfile path");
+
+        // Strip the '-build' suffix.
+        //
+        n.resize (n.size () - (*m.alt_naming ? 7 : 6));
+
+        try
+        {
+          path f (move (n)); // Note: not empty.
+
+          // Fail if the value name is something like `config/-build`.
+          //
+          if (f.to_directory ())
+            bad_name ("empty package buildfile name");
+
+          if (f.absolute ())
+            bad_name ("absolute package buildfile path");
+
+          // Verify that the path refers inside the package's build/
+          // subdirectory.
+          //
+          f.normalize (); // Note: can't throw since the path is relative.
+
+          if (dir_path::traits_type::parent (*f.begin ()))
+            bad_name ("package buildfile path refers outside build/ "
+                      "subdirectory");
+
+          // Check for duplicates.
+          //
+          vector<buildfile>& bs (m.buildfiles);
+          if (find_if (bs.begin (), bs.end (),
+                       [&f] (const auto& v) {return v.path == f;}) !=
+              bs.end ())
+          {
+            bad_name ("package buildfile redefinition");
+          }
+
+          bs.push_back (buildfile (move (f), move (v)));
+        }
+        catch (const invalid_path&)
+        {
+          bad_name ("invalid package buildfile path");
+        }
+      }
       else if (n == "location")
       {
         if (flag (package_manifest_flags::forbid_location))
@@ -4446,11 +4517,18 @@ namespace bpkg
                                            : c.config + "/" + *c.target,
                                            c.comment));
 
+      bool an (m.alt_naming && *m.alt_naming);
+
       if (m.bootstrap_build)
-        s.next ("bootstrap-build", *m.bootstrap_build);
+        s.next (an ? "bootstrap-build2" : "bootstrap-build",
+                *m.bootstrap_build);
 
       if (m.root_build)
-        s.next ("root-build", *m.root_build);
+        s.next (an ? "root-build2" : "root-build", *m.root_build);
+
+      for (const auto& bf: m.buildfiles)
+        s.next (bf.path.posix_string () + (an ? "-build2" : "-build"),
+                bf.content);
 
       if (m.location)
         s.next ("location", m.location->posix_string ());
diff --git a/libbpkg/manifest.hxx b/libbpkg/manifest.hxx
index 09d64d1..a3415cc 100644
--- a/libbpkg/manifest.hxx
+++ b/libbpkg/manifest.hxx
@@ -1054,6 +1054,29 @@ namespace bpkg
     string () const;
   };
 
+  // Package's buildfile path and content.
+  //
+  struct buildfile
+  {
+    // The path is relative to the package's build/ subdirectory with the
+    // extension stripped.
+    //
+    // For example, for the build/config/common.build file the path will be
+    // config/common.
+    //
+    // Note that the actual file path depends on the project's buildfile
+    // naming scheme and for the config/common example above the actual path
+    // can also be build2/config/common.build2.
+    //
+    butl::path path;
+    std::string content;
+
+    buildfile () = default;
+    buildfile (butl::path p, std::string c)
+        : path (std::move (p)),
+          content (std::move (c)) {}
+  };
+
   class LIBBPKG_EXPORT package_manifest
   {
   public:
@@ -1090,9 +1113,19 @@ namespace bpkg
     butl::small_vector<build_class_expr, 1> builds;
     std::vector<build_constraint> build_constraints;
 
+    // If true, then this package use the alternative buildfile naming scheme
+    // (build2/, .build2). In the manifest serialization this is encoded as
+    // either *-build or *-build2 value names.
+    //
+    butl::optional<bool> alt_naming;
+
     butl::optional<std::string> bootstrap_build;
     butl::optional<std::string> root_build;
 
+    // Additional buildfiles which are potentially included by root.build.
+    //
+    std::vector<buildfile> buildfiles;
+
     // The following values are only valid in the manifest list (and only for
     // certain repository types).
     //