nac3/nac3core/src/codegen/stmt.rs

251 lines
9.2 KiB
Rust

use super::{
expr::{assert_int_val, assert_pointer_val},
CodeGenContext, CodeGenerator,
};
use crate::typecheck::typedef::Type;
use inkwell::values::{BasicValue, BasicValueEnum, PointerValue};
use rustpython_parser::ast::{Expr, ExprKind, Stmt, StmtKind};
pub fn gen_var<'ctx, 'a>(ctx: &mut CodeGenContext<'ctx, 'a>, ty: Type) -> PointerValue<'ctx> {
// put the alloca in init block
let current = ctx.builder.get_insert_block().unwrap();
// position before the last branching instruction...
ctx.builder.position_before(&ctx.init_bb.get_last_instruction().unwrap());
let ty = ctx.get_llvm_type(ty);
let ptr = ctx.builder.build_alloca(ty, "tmp");
ctx.builder.position_at_end(current);
ptr
}
pub fn gen_store_target<'ctx, 'a, G: CodeGenerator + ?Sized>(
generator: &mut G,
ctx: &mut CodeGenContext<'ctx, 'a>,
pattern: &Expr<Option<Type>>,
) -> PointerValue<'ctx> {
// very similar to gen_expr, but we don't do an extra load at the end
// and we flatten nested tuples
match &pattern.node {
ExprKind::Name { id, .. } => ctx.var_assignment.get(id).cloned().unwrap_or_else(|| {
let ptr = generator.gen_var_alloc(ctx, pattern.custom.unwrap());
ctx.var_assignment.insert(*id, ptr);
ptr
}),
ExprKind::Attribute { value, attr, .. } => {
let index = ctx.get_attr_index(value.custom.unwrap(), *attr);
let val = generator.gen_expr(ctx, value).unwrap();
let ptr = if let BasicValueEnum::PointerValue(v) = val {
v
} else {
unreachable!();
};
unsafe {
ctx.builder.build_in_bounds_gep(
ptr,
&[
ctx.ctx.i32_type().const_zero(),
ctx.ctx.i32_type().const_int(index as u64, false),
],
"attr",
)
}
}
ExprKind::Subscript { value, slice, .. } => {
let i32_type = ctx.ctx.i32_type();
let v = assert_pointer_val(generator.gen_expr(ctx, value).unwrap());
let index = assert_int_val(generator.gen_expr(ctx, slice).unwrap());
unsafe {
let ptr_to_arr = ctx.builder.build_in_bounds_gep(
v,
&[i32_type.const_zero(), i32_type.const_int(1, false)],
"ptr_to_arr",
);
let arr_ptr = assert_pointer_val(ctx.builder.build_load(ptr_to_arr, "loadptr"));
ctx.builder.build_gep(arr_ptr, &[index], "loadarrgep")
}
}
_ => unreachable!(),
}
}
pub fn gen_assign<'ctx, 'a, G: CodeGenerator + ?Sized>(
generator: &mut G,
ctx: &mut CodeGenContext<'ctx, 'a>,
target: &Expr<Option<Type>>,
value: BasicValueEnum<'ctx>,
) {
let i32_type = ctx.ctx.i32_type();
if let ExprKind::Tuple { elts, .. } = &target.node {
if let BasicValueEnum::PointerValue(ptr) = value {
for (i, elt) in elts.iter().enumerate() {
unsafe {
let t = ctx.builder.build_in_bounds_gep(
ptr,
&[i32_type.const_zero(), i32_type.const_int(i as u64, false)],
"elem",
);
let v = ctx.builder.build_load(t, "tmpload");
generator.gen_assign(ctx, elt, v);
}
}
} else {
unreachable!()
}
} else {
let ptr = generator.gen_store_target(ctx, target);
ctx.builder.build_store(ptr, value);
}
}
pub fn gen_while<'ctx, 'a, G: CodeGenerator + ?Sized>(
generator: &mut G,
ctx: &mut CodeGenContext<'ctx, 'a>,
stmt: &Stmt<Option<Type>>,
) {
if let StmtKind::While { test, body, orelse } = &stmt.node {
let current = ctx.builder.get_insert_block().unwrap().get_parent().unwrap();
let test_bb = ctx.ctx.append_basic_block(current, "test");
let body_bb = ctx.ctx.append_basic_block(current, "body");
let cont_bb = ctx.ctx.append_basic_block(current, "cont");
// if there is no orelse, we just go to cont_bb
let orelse_bb =
if orelse.is_empty() { cont_bb } else { ctx.ctx.append_basic_block(current, "orelse") };
// store loop bb information and restore it later
let loop_bb = ctx.loop_bb.replace((test_bb, cont_bb));
ctx.builder.build_unconditional_branch(test_bb);
ctx.builder.position_at_end(test_bb);
let test = generator.gen_expr(ctx, test).unwrap();
if let BasicValueEnum::IntValue(test) = test {
ctx.builder.build_conditional_branch(test, body_bb, orelse_bb);
} else {
unreachable!()
};
ctx.builder.position_at_end(body_bb);
for stmt in body.iter() {
generator.gen_stmt(ctx, stmt);
}
ctx.builder.build_unconditional_branch(test_bb);
if !orelse.is_empty() {
ctx.builder.position_at_end(orelse_bb);
for stmt in orelse.iter() {
generator.gen_stmt(ctx, stmt);
}
ctx.builder.build_unconditional_branch(cont_bb);
}
ctx.builder.position_at_end(cont_bb);
ctx.loop_bb = loop_bb;
} else {
unreachable!()
}
}
pub fn gen_if<'ctx, 'a, G: CodeGenerator + ?Sized>(
generator: &mut G,
ctx: &mut CodeGenContext<'ctx, 'a>,
stmt: &Stmt<Option<Type>>,
) -> bool {
if let StmtKind::If { test, body, orelse } = &stmt.node {
let current = ctx.builder.get_insert_block().unwrap().get_parent().unwrap();
let test_bb = ctx.ctx.append_basic_block(current, "test");
let body_bb = ctx.ctx.append_basic_block(current, "body");
let mut cont_bb = None;
// if there is no orelse, we just go to cont_bb
let orelse_bb = if orelse.is_empty() {
cont_bb = Some(ctx.ctx.append_basic_block(current, "cont"));
cont_bb.unwrap()
} else {
ctx.ctx.append_basic_block(current, "orelse")
};
ctx.builder.build_unconditional_branch(test_bb);
ctx.builder.position_at_end(test_bb);
let test = generator.gen_expr(ctx, test).unwrap();
if let BasicValueEnum::IntValue(test) = test {
ctx.builder.build_conditional_branch(test, body_bb, orelse_bb);
} else {
unreachable!()
};
ctx.builder.position_at_end(body_bb);
let mut exited = false;
for stmt in body.iter() {
exited = generator.gen_stmt(ctx, stmt);
if exited {
break;
}
}
if !exited {
if cont_bb.is_none() {
cont_bb = Some(ctx.ctx.append_basic_block(current, "cont"));
}
ctx.builder.build_unconditional_branch(cont_bb.unwrap());
}
let then_exited = exited;
let else_exited = if !orelse.is_empty() {
exited = false;
ctx.builder.position_at_end(orelse_bb);
for stmt in orelse.iter() {
exited = generator.gen_stmt(ctx, stmt);
if exited {
break;
}
}
if !exited {
if cont_bb.is_none() {
cont_bb = Some(ctx.ctx.append_basic_block(current, "cont"));
}
ctx.builder.build_unconditional_branch(cont_bb.unwrap());
}
exited
} else {
false
};
if let Some(cont_bb) = cont_bb {
ctx.builder.position_at_end(cont_bb);
}
then_exited && else_exited
} else {
unreachable!()
}
}
pub fn gen_stmt<'ctx, 'a, G: CodeGenerator + ?Sized>(
generator: &mut G,
ctx: &mut CodeGenContext<'ctx, 'a>,
stmt: &Stmt<Option<Type>>,
) -> bool {
match &stmt.node {
StmtKind::Pass => {}
StmtKind::Expr { value } => {
generator.gen_expr(ctx, value);
}
StmtKind::Return { value } => {
let value = value.as_ref().map(|v| generator.gen_expr(ctx, v).unwrap());
let value = value.as_ref().map(|v| v as &dyn BasicValue);
ctx.builder.build_return(value);
return true;
}
StmtKind::AnnAssign { target, value, .. } => {
if let Some(value) = value {
let value = generator.gen_expr(ctx, value).unwrap();
generator.gen_assign(ctx, target, value);
}
}
StmtKind::Assign { targets, value, .. } => {
let value = generator.gen_expr(ctx, value).unwrap();
for target in targets.iter() {
generator.gen_assign(ctx, target, value);
}
}
StmtKind::Continue => {
ctx.builder.build_unconditional_branch(ctx.loop_bb.unwrap().0);
return true;
}
StmtKind::Break => {
ctx.builder.build_unconditional_branch(ctx.loop_bb.unwrap().1);
return true;
}
StmtKind::If { .. } => return generator.gen_if(ctx, stmt),
StmtKind::While { .. } => return generator.gen_while(ctx, stmt),
_ => unimplemented!()
};
false
}