doc declarations for macro

Summary:
Currently glean supports showing comments from declarations on xref hover.
The problem is for the macro it works poorly, since we need data from the calling part.
This diff makes the same trick with macro like previous with vars: create a definition right on the xref location and add relevant comment there. As arity macro xref location is used. This way we can have ODS links, macro expansion and macro definition on hover. Drawbacks is that we miss go-to-def and find references for macros

Reviewed By: alanz

Differential Revision: D55916496

fbshipit-source-id: 29fa4d399516792172d592faf8dcd4699bb3265a

crates/elp/src/bin/glean.rs

@@ -57,6 +57,7 @@ use hir::ExprId;
 use hir::ExprSource;
 use hir::InFile;
 use hir::Literal;
+use hir::MacroName;
 use hir::Name;
 use hir::NameArity;
 use hir::PPDirective;
@@ -79,15 +80,15 @@ const HEADER_ARITY: u32 = 100;
 #[derive(Serialize, Debug, Eq, Hash, PartialEq, Clone)]
 struct GleanFileId(u32);
 
-impl GleanFileId {
-    fn new(file_id: FileId) -> Self {
-        Self(file_id.0 + 1)
+impl Into<FileId> for GleanFileId {
+    fn into(self) -> FileId {
+        FileId(self.0 - 1)
     }
 }
 
 impl From<FileId> for GleanFileId {
     fn from(value: FileId) -> Self {
-        GleanFileId::new(value)
+        GleanFileId(value.0 + 1)
     }
 }
 
@@ -808,9 +809,9 @@ impl GleanIndexer {
     )> {
         let file_fact = Self::file_fact(db, file_id, path, project_id)?;
         let line_fact = Self::line_fact(db, file_id);
-        let xref_v2 = Self::xrefs_v2(db, file_id, file_ids);
+        let mut xref_v2 = Self::xrefs_v2(db, file_id, file_ids);
         let mut file_decl = Self::declarations_v2(db, file_id, path)?;
-        Self::add_xref_based_declarations(db, project_id, file_id, &xref_v2, &mut file_decl);
+        Self::add_xref_based_declarations(db, project_id, file_id, &mut xref_v2, &mut file_decl);
 
         let module_index = db.module_index(project_id);
         if let Some(module) = module_index.module_for_file(file_id) {
@@ -825,17 +826,55 @@ impl GleanIndexer {
         db: &RootDatabase,
         project_id: ProjectId,
         file_id: FileId,
-        xrefs: &XRefFile,
+        xrefs: &mut XRefFile,
         file_decl: &mut FileDeclaration,
     ) {
-        let vars: FxHashMap<&Location, &String> = xrefs
-            .xrefs
-            .iter()
-            .filter_map(|x| match &x.target {
-                XRefTarget::Var(v) => Some((&x.source, &v.key.name)),
-                _ => None,
-            })
-            .collect();
+        let mut vars = FxHashMap::default();
+        for xref in &mut xrefs.xrefs {
+            match &mut xref.target {
+                XRefTarget::Var(x) => {
+                    vars.insert(&xref.source, &x.key.name);
+                }
+                XRefTarget::Macro(x) => {
+                    let id: FileId = x.key.file_id.clone().into();
+                    let def_map = db.def_map(id);
+                    let name = Name::from_erlang_service(&x.key.name);
+                    let def = def_map.get_macros().get(&MacroName::new(name, x.key.arity));
+                    if let Some(def) = def {
+                        let range = def.source(db).syntax().text_range();
+                        let text = &db.file_text(id)[range];
+                        let text = format!("```erlang\n{}\n```", text);
+                        let doc = match (&x.key.expansion, &x.key.ods_url) {
+                            (None, None) => text,
+                            (None, Some(o)) => format!("[ODS]({})\n{}", o, text),
+                            (Some(e), None) => format!("{}\n---\n\n{}", text, e),
+                            (Some(e), Some(o)) => format!("[ODS]({})\n{}\n---\n\n{}", o, text, e),
+                        };
+                        let decl = Declaration::MacroDeclaration(
+                            MacroDecl {
+                                name: x.key.name.clone(),
+                                arity: Some(xref.source.start),
+                                span: xref.source.clone(),
+                            }
+                            .into(),
+                        );
+                        let doc_decl = Declaration::DocDeclaration(
+                            DocDecl {
+                                target: Box::new(decl.clone()),
+                                span: xref.source.clone(),
+                                text: doc,
+                            }
+                            .into(),
+                        );
+                        file_decl.declarations.push(decl);
+                        file_decl.declarations.push(doc_decl);
+                        x.key.file_id = file_id.into();
+                        x.key.arity = Some(xref.source.start);
+                    }
+                }
+                _ => (),
+            }
+        }
         let var_decls = Self::types(db, project_id, file_id, vars);
         for var in var_decls {
             let doc = var.doc.clone();
@@ -2179,9 +2218,9 @@ mod tests {
             -define(MAX(X, Y), if X > Y -> X; true -> Y end).
 
             baz(1) -> ?TAU;
-        %%             ^^^ macro.hrl/macro/TAU/no_arity/no_ods/6.28
+        %%             ^^^ macro.erl/macro/TAU/161/no_ods/6.28
             baz(N) -> ?MAX(N, 200).
-        %%             ^^^ macro.erl/macro/MAX/2/no_ods/if (N > 200) -> N; 'true' -> 200 end
+        %%             ^^^ macro.erl/macro/MAX/236/no_ods/if (N > 200) -> N; 'true' -> 200 end
 
         "#;
         xref_v2_check(&spec);
@@ -2194,7 +2233,7 @@ mod tests {
             -module(macro).
             -define(COUNT_INFRA(X), X).
             baz(atom) -> ?COUNT_INFRA(atom),
-        %%                ^^^^^^^^^^^ macro.erl/macro/COUNT_INFRA/1/has_ods/'atom'
+        %%                ^^^^^^^^^^^ macro.erl/macro/COUNT_INFRA/70/has_ods/'atom'
 
         "#;
         // @fb-only: xref_v2_check(&spec);
@@ -2208,7 +2247,7 @@ mod tests {
             -define(TAU, 6.28).
 
             baz(?TAU) -> 1.
-        %%       ^^^ macro.erl/macro/TAU/no_arity/no_ods/6.28
+        %%       ^^^ macro.erl/macro/TAU/54/no_ods/6.28
 
         "#;
         xref_v2_check(&spec);
@@ -2222,7 +2261,7 @@ mod tests {
             -define(TYPE, integer()).
 
             -spec baz(ok) -> ?TYPE.
-        %%                    ^^^^ macro.erl/macro/TYPE/no_arity/no_ods/'integer'()
+        %%                    ^^^^ macro.erl/macro/TYPE/73/no_ods/'integer'()
             baz(ok) -> 1.
 
         "#;
@@ -2236,7 +2275,7 @@ mod tests {
             -module(macro).
            -define(FOO(X), X).
            -wild(?FOO(atom)).
-        %%        ^^^ macro.erl/macro/FOO/1/no_ods/'atom'
+        %%        ^^^ macro.erl/macro/FOO/53/no_ods/'atom'
 
         "#;
         xref_v2_check(&spec);