Try to make go to definition work in format!

SourceAnalyzer didn't work properly within expression macro expansions because
it didn't find the enclosing function. Fix this by going up the expansion chain
to find ancestors. This makes the test work, but apparently in real usage it's
still not working.

1 files changed, 27 insertions, 0 deletions

diff --git a/crates/ra_ide/src/goto_definition.rs b/crates/ra_ide/src/goto_definition.rs
index 76a741207..b1d567ca7 100644
--- a/crates/ra_ide/src/goto_definition.rs
+++ b/crates/ra_ide/src/goto_definition.rs
@@ -693,4 +693,31 @@ mod tests {
             "foo FN_DEF FileId(1) [52; 63) [55; 58)",
         );
     }
+
+    #[test]
+    fn goto_through_format() {
+        check_goto(
+            "
+            //- /lib.rs
+            #[macro_export]
+            macro_rules! format {
+                ($($arg:tt)*) => ($crate::fmt::format($crate::__export::format_args!($($arg)*)))
+            }
+            #[rustc_builtin_macro]
+            #[macro_export]
+            macro_rules! format_args {
+                ($fmt:expr) => ({ /* compiler built-in */ });
+                ($fmt:expr, $($args:tt)*) => ({ /* compiler built-in */ })
+            }
+            pub mod __export {
+                pub use crate::format_args;
+            }
+            fn foo() -> i8 {}
+            fn test() {
+                format!(\"{}\", fo<|>o())
+            }
+            ",
+            "foo FN_DEF FileId(1) [359; 376) [362; 365)",
+        );
+    }
 }