chore(users): grfn -> aspen r/7511

Change-Id: I6c6847fac56f0a9a1a2209792e00a3aec5e672b9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10809
Autosubmit: aspen <root@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: lukegb <lukegb@tvl.fyi>

1 files changed, 486 insertions, 0 deletions

diff --git a/users/aspen/achilles/src/codegen/llvm.rs b/users/aspen/achilles/src/codegen/llvm.rs
new file mode 100644
index 000000000000..9a71ac954e00
--- /dev/null
+++ b/users/aspen/achilles/src/codegen/llvm.rs
@@ -0,0 +1,486 @@
+use std::convert::{TryFrom, TryInto};
+use std::path::Path;
+use std::result;
+
+use inkwell::basic_block::BasicBlock;
+use inkwell::builder::Builder;
+pub use inkwell::context::Context;
+use inkwell::module::Module;
+use inkwell::support::LLVMString;
+use inkwell::types::{BasicType, BasicTypeEnum, FunctionType, IntType, StructType};
+use inkwell::values::{AnyValueEnum, BasicValueEnum, FunctionValue, StructValue};
+use inkwell::{AddressSpace, IntPredicate};
+use itertools::Itertools;
+use thiserror::Error;
+
+use crate::ast::hir::{Binding, Decl, Expr, Pattern};
+use crate::ast::{BinaryOperator, Ident, Literal, Type, UnaryOperator};
+use crate::common::env::Env;
+
+#[derive(Debug, PartialEq, Eq, Error)]
+pub enum Error {
+    #[error("Undefined variable {0}")]
+    UndefinedVariable(Ident<'static>),
+
+    #[error("LLVM Error: {0}")]
+    LLVMError(String),
+}
+
+impl From<LLVMString> for Error {
+    fn from(s: LLVMString) -> Self {
+        Self::LLVMError(s.to_string())
+    }
+}
+
+pub type Result<T> = result::Result<T, Error>;
+
+pub struct Codegen<'ctx, 'ast> {
+    context: &'ctx Context,
+    pub module: Module<'ctx>,
+    builder: Builder<'ctx>,
+    env: Env<&'ast Ident<'ast>, AnyValueEnum<'ctx>>,
+    function_stack: Vec<FunctionValue<'ctx>>,
+    identifier_counter: u32,
+}
+
+impl<'ctx, 'ast> Codegen<'ctx, 'ast> {
+    pub fn new(context: &'ctx Context, module_name: &str) -> Self {
+        let module = context.create_module(module_name);
+        let builder = context.create_builder();
+        Self {
+            context,
+            module,
+            builder,
+            env: Default::default(),
+            function_stack: Default::default(),
+            identifier_counter: 0,
+        }
+    }
+
+    pub fn new_function<'a>(
+        &'a mut self,
+        name: &str,
+        ty: FunctionType<'ctx>,
+    ) -> &'a FunctionValue<'ctx> {
+        self.function_stack
+            .push(self.module.add_function(name, ty, None));
+        let basic_block = self.append_basic_block("entry");
+        self.builder.position_at_end(basic_block);
+        self.function_stack.last().unwrap()
+    }
+
+    pub fn finish_function(&mut self, res: Option<&BasicValueEnum<'ctx>>) -> FunctionValue<'ctx> {
+        self.builder.build_return(match res {
+            // lol
+            Some(val) => Some(val),
+            None => None,
+        });
+        self.function_stack.pop().unwrap()
+    }
+
+    pub fn append_basic_block(&self, name: &str) -> BasicBlock<'ctx> {
+        self.context
+            .append_basic_block(*self.function_stack.last().unwrap(), name)
+    }
+
+    fn bind_pattern(&mut self, pat: &'ast Pattern<'ast, Type>, val: AnyValueEnum<'ctx>) {
+        match pat {
+            Pattern::Id(id, _) => self.env.set(id, val),
+            Pattern::Tuple(pats) => {
+                for (i, pat) in pats.iter().enumerate() {
+                    let member = self
+                        .builder
+                        .build_extract_value(
+                            StructValue::try_from(val).unwrap(),
+                            i as _,
+                            "pat_bind",
+                        )
+                        .unwrap();
+                    self.bind_pattern(pat, member.into());
+                }
+            }
+        }
+    }
+
+    pub fn codegen_expr(
+        &mut self,
+        expr: &'ast Expr<'ast, Type>,
+    ) -> Result<Option<AnyValueEnum<'ctx>>> {
+        match expr {
+            Expr::Ident(id, _) => self
+                .env
+                .resolve(id)
+                .cloned()
+                .ok_or_else(|| Error::UndefinedVariable(id.to_owned()))
+                .map(Some),
+            Expr::Literal(lit, ty) => {
+                let ty = self.codegen_int_type(ty);
+                match lit {
+                    Literal::Int(i) => Ok(Some(AnyValueEnum::IntValue(ty.const_int(*i, false)))),
+                    Literal::Bool(b) => Ok(Some(AnyValueEnum::IntValue(
+                        ty.const_int(if *b { 1 } else { 0 }, false),
+                    ))),
+                    Literal::String(s) => Ok(Some(
+                        self.builder
+                            .build_global_string_ptr(s, "s")
+                            .as_pointer_value()
+                            .into(),
+                    )),
+                    Literal::Unit => Ok(None),
+                }
+            }
+            Expr::UnaryOp { op, rhs, .. } => {
+                let rhs = self.codegen_expr(rhs)?.unwrap();
+                match op {
+                    UnaryOperator::Not => unimplemented!(),
+                    UnaryOperator::Neg => Ok(Some(AnyValueEnum::IntValue(
+                        self.builder.build_int_neg(rhs.into_int_value(), "neg"),
+                    ))),
+                }
+            }
+            Expr::BinaryOp { lhs, op, rhs, .. } => {
+                let lhs = self.codegen_expr(lhs)?.unwrap();
+                let rhs = self.codegen_expr(rhs)?.unwrap();
+                match op {
+                    BinaryOperator::Add => {
+                        Ok(Some(AnyValueEnum::IntValue(self.builder.build_int_add(
+                            lhs.into_int_value(),
+                            rhs.into_int_value(),
+                            "add",
+                        ))))
+                    }
+                    BinaryOperator::Sub => {
+                        Ok(Some(AnyValueEnum::IntValue(self.builder.build_int_sub(
+                            lhs.into_int_value(),
+                            rhs.into_int_value(),
+                            "add",
+                        ))))
+                    }
+                    BinaryOperator::Mul => {
+                        Ok(Some(AnyValueEnum::IntValue(self.builder.build_int_sub(
+                            lhs.into_int_value(),
+                            rhs.into_int_value(),
+                            "add",
+                        ))))
+                    }
+                    BinaryOperator::Div => Ok(Some(AnyValueEnum::IntValue(
+                        self.builder.build_int_signed_div(
+                            lhs.into_int_value(),
+                            rhs.into_int_value(),
+                            "add",
+                        ),
+                    ))),
+                    BinaryOperator::Pow => unimplemented!(),
+                    BinaryOperator::Equ => Ok(Some(AnyValueEnum::IntValue(
+                        self.builder.build_int_compare(
+                            IntPredicate::EQ,
+                            lhs.into_int_value(),
+                            rhs.into_int_value(),
+                            "eq",
+                        ),
+                    ))),
+                    BinaryOperator::Neq => todo!(),
+                }
+            }
+            Expr::Let { bindings, body, .. } => {
+                self.env.push();
+                for Binding { pat, body, .. } in bindings {
+                    if let Some(val) = self.codegen_expr(body)? {
+                        self.bind_pattern(pat, val);
+                    }
+                }
+                let res = self.codegen_expr(body);
+                self.env.pop();
+                res
+            }
+            Expr::If {
+                condition,
+                then,
+                else_,
+                type_,
+            } => {
+                let then_block = self.append_basic_block("then");
+                let else_block = self.append_basic_block("else");
+                let join_block = self.append_basic_block("join");
+                let condition = self.codegen_expr(condition)?.unwrap();
+                self.builder.build_conditional_branch(
+                    condition.into_int_value(),
+                    then_block,
+                    else_block,
+                );
+                self.builder.position_at_end(then_block);
+                let then_res = self.codegen_expr(then)?;
+                self.builder.build_unconditional_branch(join_block);
+
+                self.builder.position_at_end(else_block);
+                let else_res = self.codegen_expr(else_)?;
+                self.builder.build_unconditional_branch(join_block);
+
+                self.builder.position_at_end(join_block);
+                if let Some(phi_type) = self.codegen_type(type_) {
+                    let phi = self.builder.build_phi(phi_type, "join");
+                    phi.add_incoming(&[
+                        (
+                            &BasicValueEnum::try_from(then_res.unwrap()).unwrap(),
+                            then_block,
+                        ),
+                        (
+                            &BasicValueEnum::try_from(else_res.unwrap()).unwrap(),
+                            else_block,
+                        ),
+                    ]);
+                    Ok(Some(phi.as_basic_value().into()))
+                } else {
+                    Ok(None)
+                }
+            }
+            Expr::Call { fun, args, .. } => {
+                if let Expr::Ident(id, _) = &**fun {
+                    let function = self
+                        .module
+                        .get_function(id.into())
+                        .or_else(|| self.env.resolve(id)?.clone().try_into().ok())
+                        .ok_or_else(|| Error::UndefinedVariable(id.to_owned()))?;
+                    let args = args
+                        .iter()
+                        .map(|arg| Ok(self.codegen_expr(arg)?.unwrap().try_into().unwrap()))
+                        .collect::<Result<Vec<_>>>()?;
+                    Ok(self
+                        .builder
+                        .build_call(function, &args, "call")
+                        .try_as_basic_value()
+                        .left()
+                        .map(|val| val.into()))
+                } else {
+                    todo!()
+                }
+            }
+            Expr::Fun { args, body, .. } => {
+                let fname = self.fresh_ident("f");
+                let cur_block = self.builder.get_insert_block().unwrap();
+                let env = self.env.save(); // TODO: closures
+                let function = self.codegen_function(&fname, args, body)?;
+                self.builder.position_at_end(cur_block);
+                self.env.restore(env);
+                Ok(Some(function.into()))
+            }
+            Expr::Tuple(members, ty) => {
+                let values = members
+                    .into_iter()
+                    .map(|expr| self.codegen_expr(expr))
+                    .collect::<Result<Vec<_>>>()?
+                    .into_iter()
+                    .filter_map(|x| x)
+                    .map(|x| x.try_into().unwrap())
+                    .collect_vec();
+                let field_types = ty.as_tuple().unwrap();
+                let tuple_type = self.codegen_tuple_type(field_types);
+                Ok(Some(tuple_type.const_named_struct(&values).into()))
+            }
+        }
+    }
+
+    pub fn codegen_function(
+        &mut self,
+        name: &str,
+        args: &'ast [(Ident<'ast>, Type)],
+        body: &'ast Expr<'ast, Type>,
+    ) -> Result<FunctionValue<'ctx>> {
+        let arg_types = args
+            .iter()
+            .filter_map(|(_, at)| self.codegen_type(at))
+            .collect::<Vec<_>>();
+
+        self.new_function(
+            name,
+            match self.codegen_type(body.type_()) {
+                Some(ret_ty) => ret_ty.fn_type(&arg_types, false),
+                None => self.context.void_type().fn_type(&arg_types, false),
+            },
+        );
+        self.env.push();
+        for (i, (arg, _)) in args.iter().enumerate() {
+            self.env.set(
+                arg,
+                self.cur_function().get_nth_param(i as u32).unwrap().into(),
+            );
+        }
+        let res = self.codegen_expr(body)?;
+        self.env.pop();
+        Ok(self.finish_function(res.map(|av| av.try_into().unwrap()).as_ref()))
+    }
+
+    pub fn codegen_extern(
+        &mut self,
+        name: &str,
+        args: &'ast [Type],
+        ret: &'ast Type,
+    ) -> Result<()> {
+        let arg_types = args
+            .iter()
+            .map(|t| self.codegen_type(t).unwrap())
+            .collect::<Vec<_>>();
+        self.module.add_function(
+            name,
+            match self.codegen_type(ret) {
+                Some(ret_ty) => ret_ty.fn_type(&arg_types, false),
+                None => self.context.void_type().fn_type(&arg_types, false),
+            },
+            None,
+        );
+        Ok(())
+    }
+
+    pub fn codegen_decl(&mut self, decl: &'ast Decl<'ast, Type>) -> Result<()> {
+        match decl {
+            Decl::Fun {
+                name, args, body, ..
+            } => {
+                self.codegen_function(name.into(), args, body)?;
+                Ok(())
+            }
+            Decl::Extern {
+                name,
+                arg_types,
+                ret_type,
+            } => self.codegen_extern(name.into(), arg_types, ret_type),
+        }
+    }
+
+    pub fn codegen_main(&mut self, expr: &'ast Expr<'ast, Type>) -> Result<()> {
+        self.new_function("main", self.context.i64_type().fn_type(&[], false));
+        let res = self.codegen_expr(expr)?;
+        if *expr.type_() != Type::Int {
+            self.builder
+                .build_return(Some(&self.context.i64_type().const_int(0, false)));
+        } else {
+            self.finish_function(res.map(|r| r.try_into().unwrap()).as_ref());
+        }
+        Ok(())
+    }
+
+    fn codegen_type(&self, type_: &'ast Type) -> Option<BasicTypeEnum<'ctx>> {
+        // TODO
+        match type_ {
+            Type::Int => Some(self.context.i64_type().into()),
+            Type::Float => Some(self.context.f64_type().into()),
+            Type::Bool => Some(self.context.bool_type().into()),
+            Type::CString => Some(
+                self.context
+                    .i8_type()
+                    .ptr_type(AddressSpace::Generic)
+                    .into(),
+            ),
+            Type::Function(_) => todo!(),
+            Type::Var(_) => unreachable!(),
+            Type::Unit => None,
+            Type::Tuple(ts) => Some(self.codegen_tuple_type(ts).into()),
+        }
+    }
+
+    fn codegen_tuple_type(&self, ts: &'ast [Type]) -> StructType<'ctx> {
+        self.context.struct_type(
+            ts.iter()
+                .filter_map(|t| self.codegen_type(t))
+                .collect_vec()
+                .as_slice(),
+            false,
+        )
+    }
+
+    fn codegen_int_type(&self, type_: &'ast Type) -> IntType<'ctx> {
+        // TODO
+        self.context.i64_type()
+    }
+
+    pub fn print_to_file<P>(&self, path: P) -> Result<()>
+    where
+        P: AsRef<Path>,
+    {
+        Ok(self.module.print_to_file(path)?)
+    }
+
+    pub fn binary_to_file<P>(&self, path: P) -> Result<()>
+    where
+        P: AsRef<Path>,
+    {
+        if self.module.write_bitcode_to_path(path.as_ref()) {
+            Ok(())
+        } else {
+            Err(Error::LLVMError(
+                "Error writing bitcode to output path".to_owned(),
+            ))
+        }
+    }
+
+    fn fresh_ident(&mut self, prefix: &str) -> String {
+        self.identifier_counter += 1;
+        format!("{}{}", prefix, self.identifier_counter)
+    }
+
+    fn cur_function(&self) -> &FunctionValue<'ctx> {
+        self.function_stack.last().unwrap()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use inkwell::execution_engine::JitFunction;
+    use inkwell::OptimizationLevel;
+
+    use super::*;
+
+    fn jit_eval<T>(expr: &str) -> anyhow::Result<T> {
+        let expr = crate::parser::expr(expr).unwrap().1;
+
+        let expr = crate::tc::typecheck_expr(expr).unwrap();
+
+        let context = Context::create();
+        let mut codegen = Codegen::new(&context, "test");
+        let execution_engine = codegen
+            .module
+            .create_jit_execution_engine(OptimizationLevel::None)
+            .unwrap();
+
+        codegen.codegen_function("test", &[], &expr)?;
+
+        unsafe {
+            let fun: JitFunction<unsafe extern "C" fn() -> T> =
+                execution_engine.get_function("test")?;
+            Ok(fun.call())
+        }
+    }
+
+    #[test]
+    fn add_literals() {
+        assert_eq!(jit_eval::<i64>("1 + 2").unwrap(), 3);
+    }
+
+    #[test]
+    fn variable_shadowing() {
+        assert_eq!(
+            jit_eval::<i64>("let x = 1 in (let x = 2 in x) + x").unwrap(),
+            3
+        );
+    }
+
+    #[test]
+    fn eq() {
+        assert_eq!(
+            jit_eval::<i64>("let x = 1 in if x == 1 then 2 else 4").unwrap(),
+            2
+        );
+    }
+
+    #[test]
+    fn function_call() {
+        let res = jit_eval::<i64>("let id = fn x = x in id 1").unwrap();
+        assert_eq!(res, 1);
+    }
+
+    #[test]
+    fn bind_tuple_pattern() {
+        let res = jit_eval::<i64>("let (x, y) = (1, 2) in x + y").unwrap();
+        assert_eq!(res, 3);
+    }
+}