Merge #1147

1147: Handle macros in type checking / HIR r=matklad a=Lapz

An other attempt at  #1102. I will need to flatten the nested if statements and im also not sure if the way that i get the resolver and module will always work

Co-authored-by: Lenard Pratt <l3np27@gmail.com>

crates/ra_hir/src/expr.rs

@@ -5,13 +5,14 @@ use rustc_hash::FxHashMap;
 
 use ra_arena::{Arena, RawId, impl_arena_id, map::ArenaMap};
 use ra_syntax::{
-    SyntaxNodePtr, AstPtr, AstNode,
+    SyntaxNodePtr, AstPtr, AstNode,TreeArc,
     ast::{self, LoopBodyOwner, ArgListOwner, NameOwner, LiteralKind,ArrayExprKind, TypeAscriptionOwner}
 };
 
 use crate::{
     Path, Name, HirDatabase, Resolver,DefWithBody, Either,
     name::AsName,
+    ids::{MacroCallId},
     type_ref::{Mutability, TypeRef},
 };
 use crate::{path::GenericArgs, ty::primitive::{IntTy, UncertainIntTy, FloatTy, UncertainFloatTy}};
@@ -478,38 +479,54 @@ impl Pat {
 
 // Queries
 
-pub(crate) struct ExprCollector {
+pub(crate) struct ExprCollector<DB> {
+    db: DB,
     owner: DefWithBody,
     exprs: Arena<ExprId, Expr>,
     pats: Arena<PatId, Pat>,
     source_map: BodySourceMap,
     params: Vec<PatId>,
     body_expr: Option<ExprId>,
+    resolver: Resolver,
+    // FIXEME: Its a quick hack,see issue #1196
+    is_in_macro: bool,
 }
 
-impl ExprCollector {
-    fn new(owner: DefWithBody) -> Self {
+impl<'a, DB> ExprCollector<&'a DB>
+where
+    DB: HirDatabase,
+{
+    fn new(owner: DefWithBody, resolver: Resolver, db: &'a DB) -> Self {
         ExprCollector {
             owner,
+            resolver,
+            db,
             exprs: Arena::default(),
             pats: Arena::default(),
             source_map: BodySourceMap::default(),
             params: Vec::new(),
             body_expr: None,
+            is_in_macro: false,
         }
     }
-
     fn alloc_expr(&mut self, expr: Expr, syntax_ptr: SyntaxNodePtr) -> ExprId {
         let id = self.exprs.alloc(expr);
-        self.source_map.expr_map.insert(syntax_ptr, id);
-        self.source_map.expr_map_back.insert(id, syntax_ptr);
+        if !self.is_in_macro {
+            self.source_map.expr_map.insert(syntax_ptr, id);
+            self.source_map.expr_map_back.insert(id, syntax_ptr);
+        }
+
         id
     }
 
     fn alloc_pat(&mut self, pat: Pat, ptr: PatPtr) -> PatId {
         let id = self.pats.alloc(pat);
-        self.source_map.pat_map.insert(ptr, id);
-        self.source_map.pat_map_back.insert(id, ptr);
+
+        if !self.is_in_macro {
+            self.source_map.pat_map.insert(ptr, id);
+            self.source_map.pat_map_back.insert(id, ptr);
+        }
+
         id
     }
 
@@ -794,7 +811,26 @@ impl ExprCollector {
             ast::ExprKind::Label(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
             ast::ExprKind::IndexExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
             ast::ExprKind::RangeExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
-            ast::ExprKind::MacroCall(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
+            ast::ExprKind::MacroCall(e) => {
+                // very hacky.FIXME change to use the macro resolution
+                let path = e.path().and_then(Path::from_ast);
+
+                if let Some(call_id) = self.resolver.resolve_macro_call(self.db, path, e) {
+                    if let Some(expr) = expand_macro_to_expr(self.db, call_id, e.token_tree()) {
+                        log::debug!("macro expansion {}", expr.syntax().debug_dump());
+                        let old = std::mem::replace(&mut self.is_in_macro, true);
+                        let id = self.collect_expr(&expr);
+                        self.is_in_macro = old;
+                        id
+                    } else {
+                        // FIXME: Instead of just dropping the error from expansion
+                        // report it
+                        self.alloc_expr(Expr::Missing, syntax_ptr)
+                    }
+                } else {
+                    self.alloc_expr(Expr::Missing, syntax_ptr)
+                }
+            }
         }
     }
 
@@ -952,11 +988,25 @@ impl ExprCollector {
     }
 }
 
+fn expand_macro_to_expr(
+    db: &impl HirDatabase,
+    macro_call: MacroCallId,
+    args: Option<&ast::TokenTree>,
+) -> Option<TreeArc<ast::Expr>> {
+    let rules = db.macro_def(macro_call.loc(db).def)?;
+
+    let args = mbe::ast_to_token_tree(args?)?.0;
+
+    let expanded = rules.expand(&args).ok()?;
+
+    mbe::token_tree_to_expr(&expanded).ok()
+}
+
 pub(crate) fn body_with_source_map_query(
     db: &impl HirDatabase,
     def: DefWithBody,
 ) -> (Arc<Body>, Arc<BodySourceMap>) {
-    let mut collector = ExprCollector::new(def);
+    let mut collector = ExprCollector::new(def, def.resolver(db), db);
 
     match def {
         DefWithBody::Const(ref c) => collector.collect_const_body(&c.source(db).1),

crates/ra_hir/src/nameres.rs

@@ -104,6 +104,7 @@ pub struct CrateDefMap {
     /// However, do we want to put it as a global variable?
     poison_macros: FxHashSet<MacroDefId>,
 
+    local_macros: FxHashMap<Name, MacroDefId>,
     diagnostics: Vec<DefDiagnostic>,
 }
 
@@ -209,6 +210,7 @@ impl CrateDefMap {
                 modules,
                 public_macros: FxHashMap::default(),
                 poison_macros: FxHashSet::default(),
+                local_macros: FxHashMap::default(),
                 diagnostics: Vec::new(),
             }
         };
@@ -270,6 +272,10 @@ impl CrateDefMap {
         (res.resolved_def, res.segment_index)
     }
 
+    pub(crate) fn find_macro(&self, name: &Name) -> Option<&MacroDefId> {
+        self.public_macros.get(name).or(self.local_macros.get(name))
+    }
+
     // Returns Yes if we are sure that additions to `ItemMap` wouldn't change
     // the result.
     fn resolve_path_fp(

crates/ra_hir/src/nameres/collector.rs

@@ -131,6 +131,8 @@ where
     fn define_macro(&mut self, name: Name, macro_id: MacroDefId, export: bool) {
         if export {
             self.def_map.public_macros.insert(name.clone(), macro_id);
+        } else {
+            self.def_map.local_macros.insert(name.clone(), macro_id);
         }
         self.global_macro_scope.insert(name, macro_id);
     }
@@ -517,12 +519,12 @@ where
 
         // Case 2: try to expand macro_rules from this crate, triggering
         // recursive item collection.
-        if let Some(&macro_id) =
-            mac.path.as_ident().and_then(|name| self.def_collector.global_macro_scope.get(name))
+        if let Some(macro_id) =
+            mac.path.as_ident().and_then(|name| self.def_collector.global_macro_scope.get(&name))
         {
-            let macro_call_id = MacroCallLoc { def: macro_id, ast_id }.id(self.def_collector.db);
+            let macro_call_id = MacroCallLoc { def: *macro_id, ast_id }.id(self.def_collector.db);
 
-            self.def_collector.collect_macro_expansion(self.module_id, macro_call_id, macro_id);
+            self.def_collector.collect_macro_expansion(self.module_id, macro_call_id, *macro_id);
             return;
         }
 
@@ -614,6 +616,7 @@ mod tests {
                 modules,
                 public_macros: FxHashMap::default(),
                 poison_macros: FxHashSet::default(),
+                local_macros: FxHashMap::default(),
                 diagnostics: Vec::new(),
             }
         };

crates/ra_hir/src/path.rs

@@ -126,6 +126,10 @@ impl Path {
         }
         self.segments.first().map(|s| &s.name)
     }
+
+    pub fn expand_macro_expr(&self) -> Option<Name> {
+        self.as_ident().and_then(|name| Some(name.clone()))
+    }
 }
 
 impl GenericArgs {

crates/ra_hir/src/resolve.rs

@@ -1,11 +1,15 @@
 //! Name resolution.
 use std::sync::Arc;
 
+use ra_syntax::ast;
+
 use rustc_hash::FxHashMap;
 
 use crate::{
     ModuleDef,
     code_model_api::Crate,
+    MacroCallId,
+    MacroCallLoc,
     db::HirDatabase,
     name::{Name, KnownName},
     nameres::{PerNs, CrateDefMap, CrateModuleId},
@@ -130,6 +134,31 @@ impl Resolver {
         resolution
     }
 
+    pub fn resolve_macro_call(
+        &self,
+        db: &impl HirDatabase,
+        path: Option<Path>,
+        call: &ast::MacroCall,
+    ) -> Option<MacroCallId> {
+        let name = path.and_then(|path| path.expand_macro_expr()).unwrap_or_else(Name::missing);
+        let macro_def_id = self.module().and_then(|(module, _)| module.find_macro(&name));
+        if let Some(def_id) = macro_def_id {
+            self.module().and_then(|(module, _)| {
+                // we do this to get the ast_id for the macro call
+                // if we used the ast_id from the def_id variable
+                // it gives us the ast_id of the defenition site
+                let module = module.mk_module(module.root());
+                let hir_file_id = module.definition_source(db).0;
+                let ast_id = db.ast_id_map(hir_file_id).ast_id(call).with_file_id(hir_file_id);
+                let call_loc = MacroCallLoc { def: *def_id, ast_id }.id(db);
+
+                Some(call_loc)
+            })
+        } else {
+            None
+        }
+    }
+
     /// Returns the resolved path segments
     /// Which may be fully resolved, empty or partially resolved.
     pub(crate) fn resolve_path_segments(&self, db: &impl HirDatabase, path: &Path) -> PathResult {

crates/ra_hir/src/ty/tests.rs

@@ -2417,6 +2417,30 @@ fn test() -> u64 {
     );
 }
 
+#[test]
+fn infer_macros_expanded() {
+    assert_snapshot_matches!(
+        infer(r#"
+struct Foo(Vec<i32>);
+
+macro_rules! foo {
+    ($($item:expr),*) => {
+            {
+                Foo(vec![$($item,)*])
+            }
+    };
+}
+
+fn main() {
+    let x = foo!(1,2);
+}
+"#),
+        @r###"
+[156; 182) '{     ...,2); }': ()
+[166; 167) 'x': Foo"###
+    );
+}
+
 #[ignore]
 #[test]
 fn method_resolution_trait_before_autoref() {
@@ -2510,6 +2534,7 @@ fn type_at(content: &str) -> String {
 fn infer(content: &str) -> String {
     let (db, _, file_id) = MockDatabase::with_single_file(content);
     let source_file = db.parse(file_id);
+
     let mut acc = String::new();
     acc.push_str("\n");
 
@@ -2532,6 +2557,7 @@ fn infer(content: &str) -> String {
             };
             types.push((syntax_ptr, ty));
         }
+
         // sort ranges for consistency
         types.sort_by_key(|(ptr, _)| (ptr.range().start(), ptr.range().end()));
         for (syntax_ptr, ty) in &types {