Merge #3920

3920: Implement expand_task and list_macros in proc_macro_srv r=matklad a=edwin0cheng

This PR finish up the remain `proc_macro_srv` implementation :

1. Added dylib loading code for proc-macro crate dylib. Note that we have to add some special flags for unix loading because of a bug in old version of glibc, see https://github.com/fedochet/rust-proc-macro-panic-inside-panic-expample/issues/1 and https://github.com/rust-lang/rust/issues/60593 for details.

2. Added tests for proc-macro expansion: We use a trick here by adding `serde_derive` to dev-dependencies and calling `cargo-metadata` for searching its dylib path, and expand it in our tests. 

[EDIT]
Note that this PR **DO NOT** implement the final glue code with rust-analzyer and proc-macro-srv yet.
 

Co-authored-by: Edwin Cheng <[email protected]>

1 files changed, 4 insertions, 1 deletions

diff --git a/crates/ra_proc_macro_srv/Cargo.toml b/crates/ra_proc_macro_srv/Cargo.toml
index f08de5fc7..1e0f50339 100644
--- a/crates/ra_proc_macro_srv/Cargo.toml
+++ b/crates/ra_proc_macro_srv/Cargo.toml
@@ -12,9 +12,12 @@ doctest = false
 ra_tt = { path = "../ra_tt" }
 ra_mbe = { path = "../ra_mbe" }
 ra_proc_macro = { path = "../ra_proc_macro" }
+goblin = "0.2.1"
+libloading = "0.6.0"
+test_utils = { path = "../test_utils" }
 
 [dev-dependencies]
 cargo_metadata = "0.9.1"
 difference = "2.0.0"
 # used as proc macro test target
-serde_derive = "=1.0.104"
\ No newline at end of file
+serde_derive = "=1.0.104"