forked from M-Labs/nac3
core/stmt: Add gen_if* functions
For generating if-constructs in IR.
This commit is contained in:
parent
e7fca67786
commit
f0715e2b6d
|
@ -29,6 +29,7 @@ use nac3parser::ast::{
|
|||
Constant, ExcepthandlerKind, Expr, ExprKind, Location, Stmt, StmtKind, StrRef,
|
||||
};
|
||||
use std::convert::TryFrom;
|
||||
use itertools::Itertools;
|
||||
|
||||
/// See [`CodeGenerator::gen_var_alloc`].
|
||||
pub fn gen_var<'ctx>(
|
||||
|
@ -694,6 +695,243 @@ pub fn gen_while<G: CodeGenerator>(
|
|||
Ok(())
|
||||
}
|
||||
|
||||
/// Generates a C-style chained-`if` construct using lambdas, similar to the following C code:
|
||||
///
|
||||
/// ```c
|
||||
/// T val;
|
||||
/// if (ifts[0].cond()) {
|
||||
/// val = ifts[0].then();
|
||||
/// } else if (ifts[1].cond()) {
|
||||
/// val = ifts[1].then();
|
||||
/// } else if /* ... */
|
||||
/// else {
|
||||
/// if (else_fn) {
|
||||
/// val = else_fn();
|
||||
/// } else {
|
||||
/// __builtin_unreachable();
|
||||
/// }
|
||||
/// }
|
||||
/// ```
|
||||
///
|
||||
/// - `ifts` - A slice of tuples containing the condition and body of a branch respectively. The
|
||||
/// branches will be generated in the order as appears in the slice.
|
||||
/// - `else_fn` - The body to generate if no other branches evaluates to `true`. If [`None`], a call
|
||||
/// to `__builtin_unreachable` will be generated instead.
|
||||
pub fn gen_chained_if_expr_callback<'ctx, 'a, G, CondFn, ThenFn, ElseFn, R>(
|
||||
generator: &mut G,
|
||||
ctx: &mut CodeGenContext<'ctx, 'a>,
|
||||
ifts: &[(CondFn, ThenFn)],
|
||||
else_fn: Option<ElseFn>,
|
||||
) -> Result<Option<BasicValueEnum<'ctx>>, String>
|
||||
where
|
||||
G: CodeGenerator + ?Sized,
|
||||
CondFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<IntValue<'ctx>, String>,
|
||||
ThenFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<Option<R>, String>,
|
||||
ElseFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<Option<R>, String>,
|
||||
R: BasicValue<'ctx>,
|
||||
{
|
||||
assert!(!ifts.is_empty());
|
||||
|
||||
let current_bb = ctx.builder.get_insert_block().unwrap();
|
||||
let current_fn = current_bb.get_parent().unwrap();
|
||||
|
||||
let end_bb = ctx.ctx.append_basic_block(current_fn, "if.end");
|
||||
|
||||
let vals = {
|
||||
let mut vals = ifts.iter()
|
||||
.map(|(cond, then)| -> Result<_, String> {
|
||||
let then_bb = ctx.ctx.insert_basic_block_after(current_bb, "if.then");
|
||||
let else_bb = ctx.ctx.insert_basic_block_after(current_bb, "if.else");
|
||||
|
||||
let cond = cond(generator, ctx)?;
|
||||
assert_eq!(cond.get_type().get_bit_width(), ctx.ctx.bool_type().get_bit_width());
|
||||
ctx.builder.build_conditional_branch(cond, then_bb, else_bb).unwrap();
|
||||
|
||||
ctx.builder.position_at_end(then_bb);
|
||||
let val = then(generator, ctx)?;
|
||||
|
||||
if !ctx.is_terminated() {
|
||||
ctx.builder.build_unconditional_branch(end_bb).unwrap();
|
||||
}
|
||||
|
||||
ctx.builder.position_at_end(else_bb);
|
||||
|
||||
Ok((val, then_bb))
|
||||
})
|
||||
.collect::<Result<Vec<_>, _>>()?;
|
||||
|
||||
if let Some(else_fn) = else_fn {
|
||||
let else_bb = ctx.builder.get_insert_block().unwrap();
|
||||
let else_val = else_fn(generator, ctx)?;
|
||||
vals.push((else_val, else_bb));
|
||||
|
||||
if !ctx.is_terminated() {
|
||||
ctx.builder.build_unconditional_branch(end_bb).unwrap();
|
||||
}
|
||||
} else {
|
||||
ctx.builder.build_unreachable().unwrap();
|
||||
}
|
||||
|
||||
vals
|
||||
};
|
||||
|
||||
ctx.builder.position_at_end(end_bb);
|
||||
let phi = if vals.is_empty() {
|
||||
None
|
||||
} else {
|
||||
let llvm_val_ty = vals.iter()
|
||||
.filter_map(|(val, _)| val.as_ref().map(|v| v.as_basic_value_enum().get_type()))
|
||||
.reduce(|acc, ty| {
|
||||
assert_eq!(acc, ty);
|
||||
acc
|
||||
})
|
||||
.unwrap();
|
||||
|
||||
let phi = ctx.builder.build_phi(llvm_val_ty, "").unwrap();
|
||||
vals.into_iter()
|
||||
.filter_map(|(val, bb)| val.map(|v| (v, bb)))
|
||||
.for_each(|(val, bb)| phi.add_incoming(&[(&val.as_basic_value_enum(), bb)]));
|
||||
|
||||
Some(phi.as_basic_value())
|
||||
};
|
||||
|
||||
Ok(phi)
|
||||
}
|
||||
|
||||
/// Generates a C-style chained-`if` construct using lambdas, similar to the following C code:
|
||||
///
|
||||
/// ```c
|
||||
/// if (ifts[0].cond()) {
|
||||
/// ifts[0].then();
|
||||
/// } else if (ifts[1].cond()) {
|
||||
/// ifts[1].then();
|
||||
/// } else if /* ... */
|
||||
/// else {
|
||||
/// if (else_fn) {
|
||||
/// else_fn();
|
||||
/// } else {
|
||||
/// __builtin_unreachable();
|
||||
/// }
|
||||
/// }
|
||||
/// ```
|
||||
///
|
||||
/// This function mainly serves as an abstraction over [`gen_chained_if_expr_callback`] when a value
|
||||
/// does not need to be returned from the `if` construct.
|
||||
///
|
||||
/// - `ifts` - A slice of tuples containing the condition and body of a branch respectively. The
|
||||
/// branches will be generated in the order as appears in the slice.
|
||||
/// - `else_fn` - The body to generate if no other branches evaluates to `true`. If [`None`], a call
|
||||
/// to `__builtin_unreachable` will be generated instead.
|
||||
pub fn gen_chained_if_callback<'ctx, 'a, G, CondFn, ThenFn, ElseFn>(
|
||||
generator: &mut G,
|
||||
ctx: &mut CodeGenContext<'ctx, 'a>,
|
||||
ifts: &[(CondFn, ThenFn)],
|
||||
else_fn: &Option<ElseFn>,
|
||||
) -> Result<(), String>
|
||||
where
|
||||
G: CodeGenerator + ?Sized,
|
||||
CondFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<IntValue<'ctx>, String>,
|
||||
ThenFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<(), String>,
|
||||
ElseFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<(), String>,
|
||||
{
|
||||
let res = gen_chained_if_expr_callback(
|
||||
generator,
|
||||
ctx,
|
||||
ifts.iter()
|
||||
.map(|(cond, then)| {
|
||||
(
|
||||
cond,
|
||||
|generator: &mut G, ctx: &mut CodeGenContext<'ctx, 'a>| {
|
||||
then(generator, ctx)?;
|
||||
Ok(None::<BasicValueEnum<'ctx>>)
|
||||
},
|
||||
)
|
||||
})
|
||||
.collect_vec()
|
||||
.as_slice(),
|
||||
else_fn
|
||||
.as_ref()
|
||||
.map(|else_fn| |generator: &mut G, ctx: &mut CodeGenContext<'ctx, 'a>| {
|
||||
else_fn(generator, ctx)?;
|
||||
Ok(None)
|
||||
}),
|
||||
)?;
|
||||
|
||||
assert!(res.is_none());
|
||||
|
||||
Ok(())
|
||||
}
|
||||
|
||||
/// Generates a C-style chained-`if` construct using lambdas, similar to the following C code:
|
||||
///
|
||||
/// ```c
|
||||
/// T val;
|
||||
/// if (cond_fn()) {
|
||||
/// val = then_fn();
|
||||
/// } else {
|
||||
/// val = else_fn();
|
||||
/// }
|
||||
/// ```
|
||||
///
|
||||
/// This function mainly serves as an abstraction over [`gen_chained_if_expr_callback`] for a basic
|
||||
/// `if`-`else` construct that returns a value.
|
||||
pub fn gen_if_else_expr_callback<'ctx, 'a, G, CondFn, ThenFn, ElseFn, R>(
|
||||
generator: &mut G,
|
||||
ctx: &mut CodeGenContext<'ctx, 'a>,
|
||||
cond_fn: CondFn,
|
||||
then_fn: ThenFn,
|
||||
else_fn: ElseFn,
|
||||
) -> Result<Option<BasicValueEnum<'ctx>>, String>
|
||||
where
|
||||
G: CodeGenerator + ?Sized,
|
||||
CondFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<IntValue<'ctx>, String>,
|
||||
ThenFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<Option<R>, String>,
|
||||
ElseFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<Option<R>, String>,
|
||||
R: BasicValue<'ctx>,
|
||||
{
|
||||
gen_chained_if_expr_callback(
|
||||
generator,
|
||||
ctx,
|
||||
&[(cond_fn, then_fn)],
|
||||
Some(else_fn),
|
||||
)
|
||||
}
|
||||
|
||||
/// Generates a C-style chained-`if` construct using lambdas, similar to the following C code:
|
||||
///
|
||||
/// ```c
|
||||
/// if (cond_fn()) {
|
||||
/// then_fn();
|
||||
/// } else {
|
||||
/// if (else_fn) {
|
||||
/// else_fn();
|
||||
/// }
|
||||
/// }
|
||||
/// ```
|
||||
///
|
||||
/// This function mainly serves as an abstraction over [`gen_chained_if_expr_callback`] for a basic
|
||||
/// `if`-`else` construct that does not return a value.
|
||||
pub fn gen_if_callback<'ctx, 'a, G, CondFn, ThenFn, ElseFn>(
|
||||
generator: &mut G,
|
||||
ctx: &mut CodeGenContext<'ctx, 'a>,
|
||||
cond_fn: CondFn,
|
||||
then_fn: ThenFn,
|
||||
else_fn: &Option<ElseFn>,
|
||||
) -> Result<(), String>
|
||||
where
|
||||
G: CodeGenerator + ?Sized,
|
||||
CondFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<IntValue<'ctx>, String>,
|
||||
ThenFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<(), String>,
|
||||
ElseFn: Fn(&mut G, &mut CodeGenContext<'ctx, 'a>) -> Result<(), String>,
|
||||
{
|
||||
gen_chained_if_callback(
|
||||
generator,
|
||||
ctx,
|
||||
&[(cond_fn, then_fn)],
|
||||
else_fn,
|
||||
)
|
||||
}
|
||||
|
||||
/// See [`CodeGenerator::gen_if`].
|
||||
pub fn gen_if<G: CodeGenerator>(
|
||||
generator: &mut G,
|
||||
|
|
Loading…
Reference in New Issue