Auto merge of #14998 - Veykril:eager-mapping, r=Veykril

internal: Lazy eager macros

This PR makes eager macros less eager. We now only eagerly expand the input of them, while the actual expansion of the macro itself now happens like other lazy macros.
This change allows unifying a lot of macro handling between the two now, most of the special casing now happens for `include!` specifically as it is a very unique macro (by having two inputs that come from differing files).
Fixes #14841
Fixes #14996

crates/hir-def/src/expander.rs

@@ -113,10 +113,10 @@ impl Expander {
         call_id: MacroCallId,
         error: Option<ExpandError>,
     ) -> ExpandResult<Option<InFile<Parse<SyntaxNode>>>> {
-        let file_id = call_id.as_file();
-        let ExpandResult { value, err } = db.parse_or_expand_with_err(file_id);
+        let macro_file = call_id.as_macro_file();
+        let ExpandResult { value, err } = db.parse_macro_expansion(macro_file);
 
-        ExpandResult { value: Some(InFile::new(file_id, value)), err: error.or(err) }
+        ExpandResult { value: Some(InFile::new(macro_file.into(), value.0)), err: error.or(err) }
     }
 
     pub fn exit(&mut self, db: &dyn DefDatabase, mut mark: Mark) {
@@ -179,8 +179,8 @@ impl Expander {
         } else if self.recursion_limit.check(self.recursion_depth as usize + 1).is_err() {
             self.recursion_depth = u32::MAX;
             cov_mark::hit!(your_stack_belongs_to_me);
-            return ExpandResult::only_err(ExpandError::Other(
-                "reached recursion limit during macro expansion".into(),
+            return ExpandResult::only_err(ExpandError::other(
+                "reached recursion limit during macro expansion",
             ));
         }
 

crates/hir-def/src/lib.rs

@@ -71,7 +71,7 @@ use hir_expand::{
     builtin_derive_macro::BuiltinDeriveExpander,
     builtin_fn_macro::{BuiltinFnLikeExpander, EagerExpander},
     db::ExpandDatabase,
-    eager::expand_eager_macro,
+    eager::expand_eager_macro_input,
     hygiene::Hygiene,
     proc_macro::ProcMacroExpander,
     AstId, ExpandError, ExpandResult, ExpandTo, HirFileId, InFile, MacroCallId, MacroCallKind,
@@ -865,7 +865,7 @@ impl AsMacroCall for InFile<&ast::MacroCall> {
         let path = self.value.path().and_then(|path| path::ModPath::from_src(db, path, &h));
 
         let Some(path) = path else {
-            return Ok(ExpandResult::only_err(ExpandError::Other("malformed macro invocation".into())));
+            return Ok(ExpandResult::only_err(ExpandError::other("malformed macro invocation")));
         };
 
         macro_call_as_call_id_(
@@ -913,7 +913,7 @@ fn macro_call_as_call_id_(
 
     let res = if let MacroDefKind::BuiltInEager(..) = def.kind {
         let macro_call = InFile::new(call.ast_id.file_id, call.ast_id.to_node(db));
-        expand_eager_macro(db, krate, macro_call, def, &resolver)?
+        expand_eager_macro_input(db, krate, macro_call, def, &resolver)?
     } else {
         ExpandResult {
             value: Some(def.as_lazy_macro(

crates/hir-def/src/macro_expansion_tests/builtin_fn_macro.rs

@@ -79,7 +79,7 @@ fn main() { env!("TEST_ENV_VAR"); }
 #[rustc_builtin_macro]
 macro_rules! env {() => {}}
 
-fn main() { "__RA_UNIMPLEMENTED__"; }
+fn main() { "UNRESOLVED_ENV_VAR"; }
 "##]],
     );
 }
@@ -442,10 +442,6 @@ macro_rules! surprise {
     () => { "s" };
 }
 
-macro_rules! stuff {
-    ($string:expr) => { concat!($string) };
-}
-
 fn main() { concat!(surprise!()); }
 "##,
         expect![[r##"
@@ -456,10 +452,6 @@ macro_rules! surprise {
     () => { "s" };
 }
 
-macro_rules! stuff {
-    ($string:expr) => { concat!($string) };
-}
-
 fn main() { "s"; }
 "##]],
     );

crates/hir-expand/src/builtin_derive_macro.rs

@@ -194,15 +194,15 @@ fn parse_adt(tt: &tt::Subtree) -> Result<BasicAdtInfo, ExpandError> {
     let (parsed, token_map) = mbe::token_tree_to_syntax_node(tt, mbe::TopEntryPoint::MacroItems);
     let macro_items = ast::MacroItems::cast(parsed.syntax_node()).ok_or_else(|| {
         debug!("derive node didn't parse");
-        ExpandError::Other("invalid item definition".into())
+        ExpandError::other("invalid item definition")
     })?;
     let item = macro_items.items().next().ok_or_else(|| {
         debug!("no module item parsed");
-        ExpandError::Other("no item found".into())
+        ExpandError::other("no item found")
     })?;
     let adt = ast::Adt::cast(item.syntax().clone()).ok_or_else(|| {
         debug!("expected adt, found: {:?}", item);
-        ExpandError::Other("expected struct, enum or union".into())
+        ExpandError::other("expected struct, enum or union")
     })?;
     let (name, generic_param_list, shape) = match &adt {
         ast::Adt::Struct(it) => (
@@ -305,7 +305,7 @@ fn parse_adt(tt: &tt::Subtree) -> Result<BasicAdtInfo, ExpandError> {
 fn name_to_token(token_map: &TokenMap, name: Option<ast::Name>) -> Result<tt::Ident, ExpandError> {
     let name = name.ok_or_else(|| {
         debug!("parsed item has no name");
-        ExpandError::Other("missing name".into())
+        ExpandError::other("missing name")
     })?;
     let name_token_id =
         token_map.token_by_range(name.syntax().text_range()).unwrap_or_else(TokenId::unspecified);