15 files changed, 175 insertions, 71 deletions

diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index 2707e422d..0b477f0e9 100644
--- a/crates/ra_hir/src/semantics.rs
+++ b/crates/ra_hir/src/semantics.rs
@@ -20,6 +20,7 @@ use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::{
     db::HirDatabase,
+    diagnostics::Diagnostic,
     semantics::source_to_def::{ChildContainer, SourceToDefCache, SourceToDefCtx},
     source_analyzer::{resolve_hir_path, SourceAnalyzer},
     AssocItem, Function, HirFileId, ImplDef, InFile, Local, MacroDef, Module, ModuleDef, Name,
@@ -126,6 +127,13 @@ impl<'db, DB: HirDatabase> Semantics<'db, DB> {
         original_range(self.db, node.as_ref())
     }
 
+    pub fn diagnostics_range(&self, diagnostics: &dyn Diagnostic) -> FileRange {
+        let src = diagnostics.source();
+        let root = self.db.parse_or_expand(src.file_id).unwrap();
+        let node = src.value.to_node(&root);
+        original_range(self.db, src.with_value(&node))
+    }
+
     pub fn ancestors_with_macros(&self, node: SyntaxNode) -> impl Iterator<Item = SyntaxNode> + '_ {
         let node = self.find_file(node);
         node.ancestors_with_macros(self.db).map(|it| it.value)
diff --git a/crates/ra_hir_def/src/body.rs b/crates/ra_hir_def/src/body.rs
index eafaf48c1..3b169440a 100644
--- a/crates/ra_hir_def/src/body.rs
+++ b/crates/ra_hir_def/src/body.rs
@@ -210,7 +210,7 @@ pub struct BodySourceMap {
     expr_map_back: ArenaMap<ExprId, Result<ExprSource, SyntheticSyntax>>,
     pat_map: FxHashMap<PatSource, PatId>,
     pat_map_back: ArenaMap<PatId, Result<PatSource, SyntheticSyntax>>,
-    field_map: FxHashMap<(ExprId, usize), AstPtr<ast::RecordField>>,
+    field_map: FxHashMap<(ExprId, usize), InFile<AstPtr<ast::RecordField>>>,
     expansions: FxHashMap<InFile<AstPtr<ast::MacroCall>>, HirFileId>,
 }
 
@@ -303,7 +303,7 @@ impl BodySourceMap {
         self.pat_map.get(&src).cloned()
     }
 
-    pub fn field_syntax(&self, expr: ExprId, field: usize) -> AstPtr<ast::RecordField> {
+    pub fn field_syntax(&self, expr: ExprId, field: usize) -> InFile<AstPtr<ast::RecordField>> {
         self.field_map[&(expr, field)].clone()
     }
 }
diff --git a/crates/ra_hir_def/src/body/lower.rs b/crates/ra_hir_def/src/body/lower.rs
index 0679ffa1e..82a52804d 100644
--- a/crates/ra_hir_def/src/body/lower.rs
+++ b/crates/ra_hir_def/src/body/lower.rs
@@ -320,7 +320,8 @@ impl ExprCollector<'_> {
 
                 let res = self.alloc_expr(record_lit, syntax_ptr);
                 for (i, ptr) in field_ptrs.into_iter().enumerate() {
-                    self.source_map.field_map.insert((res, i), ptr);
+                    let src = self.expander.to_source(ptr);
+                    self.source_map.field_map.insert((res, i), src);
                 }
                 res
             }
diff --git a/crates/ra_hir_def/src/diagnostics.rs b/crates/ra_hir_def/src/diagnostics.rs
index cfa0f2f76..510c5e064 100644
--- a/crates/ra_hir_def/src/diagnostics.rs
+++ b/crates/ra_hir_def/src/diagnostics.rs
@@ -20,7 +20,7 @@ impl Diagnostic for UnresolvedModule {
         "unresolved module".to_string()
     }
     fn source(&self) -> InFile<SyntaxNodePtr> {
-        InFile { file_id: self.file, value: self.decl.clone().into() }
+        InFile::new(self.file, self.decl.clone().into())
     }
     fn as_any(&self) -> &(dyn Any + Send + 'static) {
         self
diff --git a/crates/ra_hir_expand/src/diagnostics.rs b/crates/ra_hir_expand/src/diagnostics.rs
index 108c1e38c..99209c6e8 100644
--- a/crates/ra_hir_expand/src/diagnostics.rs
+++ b/crates/ra_hir_expand/src/diagnostics.rs
@@ -16,16 +16,13 @@
 
 use std::{any::Any, fmt};
 
-use ra_syntax::{SyntaxNode, SyntaxNodePtr, TextRange};
+use ra_syntax::{SyntaxNode, SyntaxNodePtr};
 
 use crate::{db::AstDatabase, InFile};
 
 pub trait Diagnostic: Any + Send + Sync + fmt::Debug + 'static {
     fn message(&self) -> String;
     fn source(&self) -> InFile<SyntaxNodePtr>;
-    fn highlight_range(&self) -> TextRange {
-        self.source().value.range()
-    }
     fn as_any(&self) -> &(dyn Any + Send + 'static);
 }
 
diff --git a/crates/ra_hir_ty/src/diagnostics.rs b/crates/ra_hir_ty/src/diagnostics.rs
index 927896d6f..c8fd54861 100644
--- a/crates/ra_hir_ty/src/diagnostics.rs
+++ b/crates/ra_hir_ty/src/diagnostics.rs
@@ -21,7 +21,7 @@ impl Diagnostic for NoSuchField {
     }
 
     fn source(&self) -> InFile<SyntaxNodePtr> {
-        InFile { file_id: self.file, value: self.field.clone().into() }
+        InFile::new(self.file, self.field.clone().into())
     }
 
     fn as_any(&self) -> &(dyn Any + Send + 'static) {
diff --git a/crates/ra_hir_ty/src/infer.rs b/crates/ra_hir_ty/src/infer.rs
index 246b0e9be..b6d9b3438 100644
--- a/crates/ra_hir_ty/src/infer.rs
+++ b/crates/ra_hir_ty/src/infer.rs
@@ -682,10 +682,10 @@ mod diagnostics {
         ) {
             match self {
                 InferenceDiagnostic::NoSuchField { expr, field } => {
-                    let file = owner.lookup(db.upcast()).source(db.upcast()).file_id;
+                    let source = owner.lookup(db.upcast()).source(db.upcast());
                     let (_, source_map) = db.body_with_source_map(owner.into());
                     let field = source_map.field_syntax(*expr, *field);
-                    sink.push(NoSuchField { file, field })
+                    sink.push(NoSuchField { file: source.file_id, field: field.value })
                 }
             }
         }
diff --git a/crates/ra_ide/src/completion/complete_trait_impl.rs b/crates/ra_ide/src/completion/complete_trait_impl.rs
index fab02945c..2ec0e7ce9 100644
--- a/crates/ra_ide/src/completion/complete_trait_impl.rs
+++ b/crates/ra_ide/src/completion/complete_trait_impl.rs
@@ -142,11 +142,11 @@ fn add_function_impl(
         CompletionItemKind::Function
     };
 
-    let snippet = format!("{} {{}}", display);
+    let snippet = format!("{} {{\n    $0\n}}", display);
 
     let range = TextRange::from_to(fn_def_node.text_range().start(), ctx.source_range().end());
 
-    builder.text_edit(TextEdit::replace(range, snippet)).kind(completion_kind).add_to(acc);
+    builder.snippet_edit(TextEdit::replace(range, snippet)).kind(completion_kind).add_to(acc);
 }
 
 fn add_type_alias_impl(
@@ -217,9 +217,10 @@ fn make_const_compl_syntax(const_: &ast::ConstDef) -> String {
 
 #[cfg(test)]
 mod tests {
-    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
     use insta::assert_debug_snapshot;
 
+    use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
+
     fn complete(code: &str) -> Vec<CompletionItem> {
         do_completion(code, CompletionKind::Magic)
     }
@@ -255,7 +256,7 @@ mod tests {
                 label: "fn test()",
                 source_range: [209; 210),
                 delete: [209; 210),
-                insert: "fn test() {}",
+                insert: "fn test() {\n    $0\n}",
                 kind: Function,
                 lookup: "test",
             },
@@ -313,7 +314,7 @@ mod tests {
                 label: "fn test()",
                 source_range: [139; 140),
                 delete: [139; 140),
-                insert: "fn test() {}",
+                insert: "fn test() {\n    $0\n}",
                 kind: Function,
                 lookup: "test",
             },
@@ -342,7 +343,7 @@ mod tests {
                 label: "fn foo()",
                 source_range: [141; 142),
                 delete: [138; 142),
-                insert: "fn foo() {}",
+                insert: "fn foo() {\n    $0\n}",
                 kind: Function,
                 lookup: "foo",
             },
@@ -374,7 +375,7 @@ mod tests {
                 label: "fn foo_bar()",
                 source_range: [200; 201),
                 delete: [197; 201),
-                insert: "fn foo_bar() {}",
+                insert: "fn foo_bar() {\n    $0\n}",
                 kind: Function,
                 lookup: "foo_bar",
             },
@@ -425,7 +426,7 @@ mod tests {
                 label: "fn foo()",
                 source_range: [144; 145),
                 delete: [141; 145),
-                insert: "fn foo<T>() {}",
+                insert: "fn foo<T>() {\n    $0\n}",
                 kind: Function,
                 lookup: "foo",
             },
@@ -454,7 +455,7 @@ mod tests {
                 label: "fn foo()",
                 source_range: [166; 167),
                 delete: [163; 167),
-                insert: "fn foo<T>()\nwhere T: Into<String> {}",
+                insert: "fn foo<T>()\nwhere T: Into<String> {\n    $0\n}",
                 kind: Function,
                 lookup: "foo",
             },
diff --git a/crates/ra_ide/src/completion/complete_unqualified_path.rs b/crates/ra_ide/src/completion/complete_unqualified_path.rs
index 2d8e0776c..ad5fdcc4e 100644
--- a/crates/ra_ide/src/completion/complete_unqualified_path.rs
+++ b/crates/ra_ide/src/completion/complete_unqualified_path.rs
@@ -1,6 +1,10 @@
 //! Completion of names from the current scope, e.g. locals and imported items.
 
+use hir::ScopeDef;
+use test_utils::tested_by;
+
 use crate::completion::{CompletionContext, Completions};
+use ra_syntax::AstNode;
 
 pub(super) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionContext) {
     if !ctx.is_trivial_path {
@@ -14,12 +18,23 @@ pub(super) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
         return;
     }
 
-    ctx.scope().process_all_names(&mut |name, res| acc.add_resolution(ctx, name.to_string(), &res));
+    ctx.scope().process_all_names(&mut |name, res| {
+        if ctx.use_item_syntax.is_some() {
+            if let (ScopeDef::Unknown, Some(name_ref)) = (&res, &ctx.name_ref_syntax) {
+                if name_ref.syntax().text() == name.to_string().as_str() {
+                    tested_by!(self_fulfilling_completion);
+                    return;
+                }
+            }
+        }
+        acc.add_resolution(ctx, name.to_string(), &res)
+    });
 }
 
 #[cfg(test)]
 mod tests {
     use insta::assert_debug_snapshot;
+    use test_utils::covers;
 
     use crate::completion::{test_utils::do_completion, CompletionItem, CompletionKind};
 
@@ -28,6 +43,29 @@ mod tests {
     }
 
     #[test]
+    fn self_fulfilling_completion() {
+        covers!(self_fulfilling_completion);
+        assert_debug_snapshot!(
+            do_reference_completion(
+                r#"
+                use foo<|>
+                use std::collections;
+                "#,
+            ),
+            @r###"
+            [
+                CompletionItem {
+                    label: "collections",
+                    source_range: [21; 24),
+                    delete: [21; 24),
+                    insert: "collections",
+                },
+            ]
+            "###
+        );
+    }
+
+    #[test]
     fn bind_pat_and_path_ignore_at() {
         assert_debug_snapshot!(
             do_reference_completion(
diff --git a/crates/ra_ide/src/diagnostics.rs b/crates/ra_ide/src/diagnostics.rs
index 901ad104c..e7e201709 100644
--- a/crates/ra_ide/src/diagnostics.rs
+++ b/crates/ra_ide/src/diagnostics.rs
@@ -1,4 +1,8 @@
-//! FIXME: write short doc here
+//! Collects diagnostics & fixits  for a single file.
+//!
+//! The tricky bit here is that diagnostics are produced by hir in terms of
+//! macro-expanded files, but we need to present them to the users in terms of
+//! original files. So we need to map the ranges.
 
 use std::cell::RefCell;
 
@@ -46,7 +50,7 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
     let mut sink = DiagnosticSink::new(|d| {
         res.borrow_mut().push(Diagnostic {
             message: d.message(),
-            range: d.highlight_range(),
+            range: sema.diagnostics_range(d).range,
             severity: Severity::Error,
             fix: None,
         })
@@ -62,7 +66,7 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
         let create_file = FileSystemEdit::CreateFile { source_root, path };
         let fix = SourceChange::file_system_edit("create module", create_file);
         res.borrow_mut().push(Diagnostic {
-            range: d.highlight_range(),
+            range: sema.diagnostics_range(d).range,
             message: d.message(),
             severity: Severity::Error,
             fix: Some(fix),
@@ -95,7 +99,7 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
         };
 
         res.borrow_mut().push(Diagnostic {
-            range: d.highlight_range(),
+            range: sema.diagnostics_range(d).range,
             message: d.message(),
             severity: Severity::Error,
             fix,
@@ -103,7 +107,7 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
     })
     .on::<hir::diagnostics::MissingMatchArms, _>(|d| {
         res.borrow_mut().push(Diagnostic {
-            range: d.highlight_range(),
+            range: sema.diagnostics_range(d).range,
             message: d.message(),
             severity: Severity::Error,
             fix: None,
@@ -115,7 +119,7 @@ pub(crate) fn diagnostics(db: &RootDatabase, file_id: FileId) -> Vec<Diagnostic>
         let edit = TextEdit::replace(node.syntax().text_range(), replacement);
         let fix = SourceChange::source_file_edit_from("wrap with ok", file_id, edit);
         res.borrow_mut().push(Diagnostic {
-            range: d.highlight_range(),
+            range: sema.diagnostics_range(d).range,
             message: d.message(),
             severity: Severity::Error,
             fix: Some(fix),
@@ -622,6 +626,62 @@ mod tests {
     }
 
     #[test]
+    fn range_mapping_out_of_macros() {
+        let (analysis, file_id) = single_file(
+            r"
+            fn some() {}
+            fn items() {}
+            fn here() {}
+
+            macro_rules! id {
+                ($($tt:tt)*) => { $($tt)*};
+            }
+
+            fn main() {
+                let _x = id![Foo { a: 42 }];
+            }
+
+            pub struct Foo {
+                pub a: i32,
+                pub b: i32,
+            }
+        ",
+        );
+        let diagnostics = analysis.diagnostics(file_id).unwrap();
+        assert_debug_snapshot!(diagnostics, @r###"
+        [
+            Diagnostic {
+                message: "Missing structure fields:\n- b",
+                range: [224; 233),
+                fix: Some(
+                    SourceChange {
+                        label: "fill struct fields",
+                        source_file_edits: [
+                            SourceFileEdit {
+                                file_id: FileId(
+                                    1,
+                                ),
+                                edit: TextEdit {
+                                    atoms: [
+                                        AtomTextEdit {
+                                            delete: [3; 9),
+                                            insert: "{a:42, b: ()}",
+                                        },
+                                    ],
+                                },
+                            },
+                        ],
+                        file_system_edits: [],
+                        cursor_position: None,
+                    },
+                ),
+                severity: Error,
+            },
+        ]
+        "###);
+    }
+
+    #[test]
     fn test_check_unnecessary_braces_in_use_statement() {
         check_not_applicable(
             "
diff --git a/crates/ra_ide/src/marks.rs b/crates/ra_ide/src/marks.rs
index 5e1f135c5..eee44e886 100644
--- a/crates/ra_ide/src/marks.rs
+++ b/crates/ra_ide/src/marks.rs
@@ -8,4 +8,5 @@ test_utils::marks!(
     test_resolve_parent_module_on_module_decl
     search_filters_by_range
     dont_insert_macro_call_parens_unncessary
+    self_fulfilling_completion
 );
diff --git a/crates/ra_proc_macro_srv/Cargo.toml b/crates/ra_proc_macro_srv/Cargo.toml
index 1e0f50339..ac2d156dc 100644
--- a/crates/ra_proc_macro_srv/Cargo.toml
+++ b/crates/ra_proc_macro_srv/Cargo.toml
@@ -14,6 +14,7 @@ ra_mbe = { path = "../ra_mbe" }
 ra_proc_macro = { path = "../ra_proc_macro" }
 goblin = "0.2.1"
 libloading = "0.6.0"
+memmap = "0.7"
 test_utils = { path = "../test_utils" }
 
 [dev-dependencies]
diff --git a/crates/ra_proc_macro_srv/src/dylib.rs b/crates/ra_proc_macro_srv/src/dylib.rs
index ec63d587b..16bd7466e 100644
--- a/crates/ra_proc_macro_srv/src/dylib.rs
+++ b/crates/ra_proc_macro_srv/src/dylib.rs
@@ -1,10 +1,12 @@
 //! Handles dynamic library loading for proc macro
 
 use crate::{proc_macro::bridge, rustc_server::TokenStream};
+use std::fs::File;
 use std::path::Path;
 
 use goblin::{mach::Mach, Object};
 use libloading::Library;
+use memmap::Mmap;
 use ra_proc_macro::ProcMacroKind;
 
 use std::io::Error as IoError;
@@ -16,55 +18,54 @@ fn invalid_data_err(e: impl Into<Box<dyn std::error::Error + Send + Sync>>) -> I
     IoError::new(IoErrorKind::InvalidData, e)
 }
 
-fn get_symbols_from_lib(file: &Path) -> Result<Vec<String>, IoError> {
-    let buffer = std::fs::read(file)?;
+fn is_derive_registrar_symbol(symbol: &str) -> bool {
+    symbol.contains(NEW_REGISTRAR_SYMBOL)
+}
+
+fn find_registrar_symbol(file: &Path) -> Result<Option<String>, IoError> {
+    let file = File::open(file)?;
+    let buffer = unsafe { Mmap::map(&file)? };
     let object = Object::parse(&buffer).map_err(invalid_data_err)?;
 
     match object {
         Object::Elf(elf) => {
             let symbols = elf.dynstrtab.to_vec().map_err(invalid_data_err)?;
-            let names = symbols.iter().map(|s| s.to_string()).collect();
-            Ok(names)
+            let name =
+                symbols.iter().find(|s| is_derive_registrar_symbol(s)).map(|s| s.to_string());
+            Ok(name)
         }
         Object::PE(pe) => {
-            let symbol_names =
-                pe.exports.iter().flat_map(|s| s.name).map(|n| n.to_string()).collect();
-            Ok(symbol_names)
+            let name = pe
+                .exports
+                .iter()
+                .flat_map(|s| s.name)
+                .find(|s| is_derive_registrar_symbol(s))
+                .map(|s| s.to_string());
+            Ok(name)
         }
-        Object::Mach(mach) => match mach {
-            Mach::Binary(binary) => {
-                let exports = binary.exports().map_err(invalid_data_err)?;
-                let names = exports
-                    .into_iter()
-                    .map(|s| {
-                        // In macos doc:
-                        // https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man3/dlsym.3.html
-                        // Unlike other dyld API's, the symbol name passed to dlsym() must NOT be
-                        // prepended with an underscore.
-                        if s.name.starts_with("_") {
-                            s.name[1..].to_string()
-                        } else {
-                            s.name
-                        }
-                    })
-                    .collect();
-                Ok(names)
-            }
-            Mach::Fat(_) => Ok(vec![]),
-        },
-        Object::Archive(_) | Object::Unknown(_) => Ok(vec![]),
+        Object::Mach(Mach::Binary(binary)) => {
+            let exports = binary.exports().map_err(invalid_data_err)?;
+            let name = exports
+                .iter()
+                .map(|s| {
+                    // In macos doc:
+                    // https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man3/dlsym.3.html
+                    // Unlike other dyld API's, the symbol name passed to dlsym() must NOT be
+                    // prepended with an underscore.
+                    if s.name.starts_with("_") {
+                        &s.name[1..]
+                    } else {
+                        &s.name
+                    }
+                })
+                .find(|s| is_derive_registrar_symbol(s))
+                .map(|s| s.to_string());
+            Ok(name)
+        }
+        _ => Ok(None),
     }
 }
 
-fn is_derive_registrar_symbol(symbol: &str) -> bool {
-    symbol.contains(NEW_REGISTRAR_SYMBOL)
-}
-
-fn find_registrar_symbol(file: &Path) -> Result<Option<String>, IoError> {
-    let symbols = get_symbols_from_lib(file)?;
-    Ok(symbols.into_iter().find(|s| is_derive_registrar_symbol(s)))
-}
-
 /// Loads dynamic library in platform dependent manner.
 ///
 /// For unix, you have to use RTLD_DEEPBIND flag to escape problems described
diff --git a/crates/rust-analyzer/src/cli/load_cargo.rs b/crates/rust-analyzer/src/cli/load_cargo.rs
index eb9ac32c3..762f776fe 100644
--- a/crates/rust-analyzer/src/cli/load_cargo.rs
+++ b/crates/rust-analyzer/src/cli/load_cargo.rs
@@ -75,9 +75,7 @@ pub(crate) fn load_cargo(
     let proc_macro_client = if !with_proc_macro {
         ProcMacroClient::dummy()
     } else {
-        let mut path = std::env::current_exe()?;
-        path.pop();
-        path.push("rust-analyzer");
+        let path = std::env::current_exe()?;
         ProcMacroClient::extern_process(&path, &["proc-macro"]).unwrap()
     };
     let host = load(&source_roots, ws, &mut vfs, receiver, extern_dirs, &proc_macro_client);
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index 2b45f1310..3597a14e3 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -134,9 +134,7 @@ impl Config {
 
         match get::<bool>(value, "/procMacro/enabled") {
             Some(true) => {
-                if let Ok(mut path) = std::env::current_exe() {
-                    path.pop();
-                    path.push("rust-analyzer");
+                if let Ok(path) = std::env::current_exe() {
                     self.proc_macro_srv = Some((path.to_string_lossy().to_string(), vec!["proc-macro".to_string()]));
                 }
             }