extend run-make test runner with some helper functions

src/tools/run-make-support/src/rustc.rs

@@ -1,5 +1,5 @@
 use std::env;
-use std::ffi::OsStr;
+use std::ffi::{OsStr, OsString};
 use std::path::Path;
 use std::process::{Command, Output};
 
@@ -86,6 +86,33 @@ impl Rustc {
         self
     }
 
+    /// Specify number of codegen units
+    pub fn codegen_units(&mut self, units: usize) -> &mut Self {
+        self.cmd.arg(format!("-Ccodegen-units={units}"));
+        self
+    }
+
+    /// Specify directory path used for incremental cache
+    pub fn incremental<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
+        let mut arg = OsString::new();
+        arg.push("-Cincremental=");
+        arg.push(path.as_ref());
+        self.cmd.arg(&arg);
+        self
+    }
+
+    /// Specify error format to use
+    pub fn error_format(&mut self, format: &str) -> &mut Self {
+        self.cmd.arg(format!("--error-format={format}"));
+        self
+    }
+
+    /// Specify json messages printed by the compiler
+    pub fn json(&mut self, items: &str) -> &mut Self {
+        self.cmd.arg(format!("--json={items}"));
+        self
+    }
+
     /// Specify target triple.
     pub fn target(&mut self, target: &str) -> &mut Self {
         assert!(!target.contains(char::is_whitespace), "target triple cannot contain spaces");
@@ -94,13 +121,7 @@ impl Rustc {
     }
 
     /// Generic command argument provider. Use `.arg("-Zname")` over `.arg("-Z").arg("arg")`.
-    /// This method will panic if a plain `-Z` or `-C` is passed, or if `-Z <name>` or `-C <name>`
+    pub fn arg<S: AsRef<OsStr>>(&mut self, arg: S) -> &mut Self {
-    /// is passed (note the space).
-    pub fn arg(&mut self, arg: &str) -> &mut Self {
-        assert!(
-            !(["-Z", "-C"].contains(&arg) || arg.starts_with("-Z ") || arg.starts_with("-C ")),
-            "use `-Zarg` or `-Carg` over split `-Z` `arg` or `-C` `arg`"
-        );
         self.cmd.arg(arg);
         self
     }
@@ -120,16 +141,7 @@ impl Rustc {
     }
 
     /// Generic command arguments provider. Use `.arg("-Zname")` over `.arg("-Z").arg("arg")`.
-    /// This method will panic if a plain `-Z` or `-C` is passed, or if `-Z <name>` or `-C <name>`
+    pub fn args<S: AsRef<OsStr>>(&mut self, args: &[S]) -> &mut Self {
-    /// is passed (note the space).
-    pub fn args(&mut self, args: &[&str]) -> &mut Self {
-        for arg in args {
-            assert!(
-                !(["-Z", "-C"].contains(&arg) || arg.starts_with("-Z ") || arg.starts_with("-C ")),
-                "use `-Zarg` or `-Carg` over split `-Z` `arg` or `-C` `arg`"
-            );
-        }
-
         self.cmd.args(args);
         self
     }