reuse fetching target data layout from rustc function

Cargo.lock

@@ -583,6 +583,7 @@ dependencies = [
  "limit",
  "once_cell",
  "profile",
+ "project-model",
  "rustc-hash",
  "scoped-tls",
  "smallvec",

crates/hir-ty/Cargo.toml

@@ -48,6 +48,7 @@ tracing-subscriber = { version = "0.3.16", default-features = false, features =
     "registry",
 ] }
 tracing-tree = "0.2.1"
+project-model = { path = "../project-model" }
 
 # local deps
 test-utils.workspace = true

crates/hir-ty/src/layout/tests.rs

@@ -1,3 +1,5 @@
+use std::collections::HashMap;
+
 use base_db::fixture::WithFixture;
 use chalk_ir::{AdtId, TyKind};
 use hir_def::{
@@ -9,16 +11,12 @@
 
 use super::layout_of_ty;
 
-fn eval_goal(ra_fixture: &str, minicore: &str) -> Result<Layout, LayoutError> {
-    // using unstable cargo features failed, fall back to using plain rustc
-    let mut cmd = std::process::Command::new("rustc");
-    cmd.args(["-Z", "unstable-options", "--print", "target-spec-json"]).env("RUSTC_BOOTSTRAP", "1");
-    let output = cmd.output().unwrap();
-    assert!(output.status.success(), "{}", output.status);
-    let stdout = String::from_utf8(output.stdout).unwrap();
-    let target_data_layout =
-        stdout.split_once(r#""data-layout": ""#).unwrap().1.split_once('"').unwrap().0.to_owned();
+fn current_machine_data_layout() -> String {
+    project_model::target_data_layout::get(None, None, &HashMap::default()).unwrap()
+}
 
+fn eval_goal(ra_fixture: &str, minicore: &str) -> Result<Layout, LayoutError> {
+    let target_data_layout = current_machine_data_layout();
     let ra_fixture = format!(
         "{minicore}//- /main.rs crate:test target_data_layout:{target_data_layout}\n{ra_fixture}",
     );
@@ -47,15 +45,7 @@ fn eval_goal(ra_fixture: &str, minicore: &str) -> Result<Layout, LayoutError> {
 
 /// A version of `eval_goal` for types that can not be expressed in ADTs, like closures and `impl Trait`
 fn eval_expr(ra_fixture: &str, minicore: &str) -> Result<Layout, LayoutError> {
-    // using unstable cargo features failed, fall back to using plain rustc
-    let mut cmd = std::process::Command::new("rustc");
-    cmd.args(["-Z", "unstable-options", "--print", "target-spec-json"]).env("RUSTC_BOOTSTRAP", "1");
-    let output = cmd.output().unwrap();
-    assert!(output.status.success(), "{}", output.status);
-    let stdout = String::from_utf8(output.stdout).unwrap();
-    let target_data_layout =
-        stdout.split_once(r#""data-layout": ""#).unwrap().1.split_once('"').unwrap().0.to_owned();
-
+    let target_data_layout = current_machine_data_layout();
     let ra_fixture = format!(
         "{minicore}//- /main.rs crate:test target_data_layout:{target_data_layout}\nfn main(){{let goal = {{{ra_fixture}}};}}",
     );

crates/project-model/src/lib.rs

@@ -25,7 +25,7 @@
 mod workspace;
 mod rustc_cfg;
 mod build_scripts;
-mod target_data_layout;
+pub mod target_data_layout;
 
 #[cfg(test)]
 mod tests;

crates/project-model/src/target_data_layout.rs

@@ -6,7 +6,7 @@
 
 use crate::{utf8_stdout, ManifestPath};
 
-pub(super) fn get(
+pub fn get(
     cargo_toml: Option<&ManifestPath>,
     target: Option<&str>,
     extra_env: &FxHashMap<String, String>,