add needs_rebuild, should probably be moved to somewhere else

toolsrc/include/vcpkg/statusparagraphs.h

@@ -62,6 +62,8 @@ namespace vcpkg
         /// <returns>`true` if installed, `false` if not or not found.</returns>
         bool is_installed(const FeatureSpec& spec) const;
 
+        bool needs_rebuild(const PackageSpec& spec);
+
         iterator insert(std::unique_ptr<StatusParagraph>);
 
         friend void serialize(const StatusParagraphs& pgh, std::string& out_str);

toolsrc/src/vcpkg/statusparagraphs.cpp

@@ -118,6 +118,31 @@ namespace vcpkg
         return it != end() && (*it)->is_installed();
     }
 
+    bool vcpkg::StatusParagraphs::needs_rebuild(const PackageSpec& spec)
+    {
+        auto it = find(spec);
+        if (it != end())
+        {
+            for (const std::string& dep : (*it)->package.depends)
+            {
+                PackageSpec dep_spec =
+                    PackageSpec::from_name_and_triplet(
+                            dep,
+                            spec.triplet()).value_or_exit(VCPKG_LINE_INFO);
+
+                if (needs_rebuild(dep_spec))
+                {
+                    (*it)->state = InstallState::NEEDS_REBUILD;
+                    return true;
+                }
+            }
+
+            return (*it)->needs_rebuild();
+        }
+
+        return false;
+    }
+
     StatusParagraphs::iterator StatusParagraphs::insert(std::unique_ptr<StatusParagraph> pgh)
     {
         Checks::check_exit(VCPKG_LINE_INFO, pgh != nullptr, "Inserted null paragraph");