merge(glittershark/achilles): Subtree import at 'b93268085a'

Imported from https://github.com/glittershark/achilles/

git-subtree-dir: users/glittershark/achilles
git-subtree-mainline: 4d193f2395
git-subtree-split: b93268085a
Change-Id: I64a583b454bbe03e20358ad7808939a4cbc212ba

users/glittershark/achilles/src/codegen/mod.rs

@@ -0,0 +1,25 @@
+pub mod llvm;
+
+use inkwell::execution_engine::JitFunction;
+use inkwell::OptimizationLevel;
+pub use llvm::*;
+
+use crate::ast::hir::Expr;
+use crate::ast::Type;
+use crate::common::Result;
+
+pub fn jit_eval<T>(expr: &Expr<Type>) -> Result<T> {
+    let context = Context::create();
+    let mut codegen = Codegen::new(&context, "eval");
+    let execution_engine = codegen
+        .module
+        .create_jit_execution_engine(OptimizationLevel::None)
+        .map_err(Error::from)?;
+    codegen.codegen_function("test", &[], &expr)?;
+
+    unsafe {
+        let fun: JitFunction<unsafe extern "C" fn() -> T> =
+            execution_engine.get_function("eval").unwrap();
+        Ok(fun.call())
+    }
+}