Add test interpret support to filetests

cranelift/filetests/src/test_interpret.rs

@@ -0,0 +1,61 @@
+//! Test command for interpreting CLIF files and verifying their results
+//!
+//! The `interpret` test command interprets each function on the host machine using [RunCommand]s.
+
+use crate::subtest::{Context, SubTest, SubtestResult};
+use cranelift_codegen::{self, ir};
+use cranelift_interpreter::environment::Environment;
+use cranelift_interpreter::interpreter::{ControlFlow, Interpreter};
+use cranelift_reader::{parse_run_command, TestCommand};
+use log::trace;
+use std::borrow::Cow;
+
+struct TestInterpret;
+
+pub fn subtest(parsed: &TestCommand) -> SubtestResult<Box<dyn SubTest>> {
+    assert_eq!(parsed.command, "interpret");
+    if !parsed.options.is_empty() {
+        Err(format!("No options allowed on {}", parsed))
+    } else {
+        Ok(Box::new(TestInterpret))
+    }
+}
+
+impl SubTest for TestInterpret {
+    fn name(&self) -> &'static str {
+        "interpret"
+    }
+
+    fn is_mutating(&self) -> bool {
+        false
+    }
+
+    fn needs_isa(&self) -> bool {
+        false
+    }
+
+    fn run(&self, func: Cow<ir::Function>, context: &Context) -> SubtestResult<()> {
+        for comment in context.details.comments.iter() {
+            if let Some(command) =
+                parse_run_command(comment.text, &func.signature).map_err(|e| e.to_string())?
+            {
+                trace!("Parsed run command: {}", command);
+
+                let mut env = Environment::default();
+                env.add(func.name.to_string(), func.clone().into_owned());
+                let interpreter = Interpreter::new(env);
+
+                command.run(|func_name, args| {
+                    // Because we have stored function names with a leading %, we need to re-add it.
+                    let func_name = &format!("%{}", func_name);
+                    match interpreter.call_by_name(func_name, args) {
+                        Ok(ControlFlow::Return(results)) => Ok(results),
+                        Ok(_) => panic!("Unexpected returned control flow--this is likely a bug."),
+                        Err(t) => Err(t.to_string()),
+                    }
+                })?;
+            }
+        }
+        Ok(())
+    }
+}