annotation: add lookup_annotation_on_modules and related methods

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/src/annotation.nit b/src/annotation.nit
index 36fef4c..8d9ca25 100644 (file)
--- a/src/annotation.nit
+++ b/src/annotation.nit
@@ -18,6 +18,7 @@ module annotation
 import parser
 import modelbuilder
 import literal
+import model::mmodule_data
 
 redef class Prod
        super ANode
@@ -150,4 +151,54 @@ redef class ModelBuilder
                end
                return annotations
        end
+
+       # Return the single annotation `name` locally assocated to `mmodule`, if any.
+       # Obviously, if there is no ast associated to `mmodule`, then nothing is returned.
+       fun get_mmodule_annotation(name: String, mmodule: MModule): nullable AAnnotation
+       do
+               if not mmodule2nmodule.keys.has(mmodule) then return null
+               var amod = mmodule2nmodule[mmodule]
+               var module_decl = amod.n_moduledecl
+               if module_decl == null then return null
+               var res = module_decl.get_single_annotation(name, self)
+               return res
+       end
+
+       private var collect_annotations_data_cache = new HashMap[String, MModuleData[AAnnotation]]
+
+       # Collect all annotations by `name` in `mmodule` and its importations (direct and indirect)
+       # Note that visibility is not considered.
+       fun collect_annotations_data(name: String, mmodule: MModule): MModuleData[AAnnotation]
+       do
+               var res = collect_annotations_data_cache.get_or_null(name)
+               if res == null then
+                       res = new MModuleData[AAnnotation](model)
+                       collect_annotations_data_cache[name] = res
+               end
+
+               for mmod in mmodule.in_importation.greaters do
+                       if res.has_mmodule(mmod) then continue
+                       var ass = get_mmodule_annotation(name, mmod)
+                       if ass == null then continue
+                       res[mmod] = ass
+               end
+               return res
+       end
+
+       # Get an annotation by name from `mmodule` and its super modules. Will recursively search
+       # in imported module to find the "latest" declaration and detects priority conflicts.
+       fun lookup_annotation_on_modules(name: String, mmodule: MModule): nullable AAnnotation
+       do
+               var data = collect_annotations_data(name, mmodule)
+               var annotations = data.lookup_values(mmodule, none_visibility)
+               if annotations.is_empty then return null
+               if annotations.length > 1 then
+                       var locs = new Array[Location]
+                       for annot in annotations do locs.add(annot.location)
+
+                       toolcontext.error(mmodule.location,
+                               "Priority conflict on annotation {name}, it has been defined in: {locs.join(", ")}")
+               end
+               return annotations.first
+       end
 end