Function inline_block_layout

cranelift/codegen/src/inline.rs:1053–1078

Inline the callee's layout into the caller's layout. Returns the last inlined block in the layout.

(
    func: &mut ir::Function,
    call_block: ir::Block,
    callee: &ir::Function,
    entity_map: &EntityMap,
)

///
/// Returns the last inlined block in the layout.
fn inline_block_layout(
    func: &mut ir::Function,
    call_block: ir::Block,
    callee: &ir::Function,
    entity_map: &EntityMap,
) -> ir::Block {
    debug_assert!(func.layout.is_block_inserted(call_block));

    // Iterate over callee blocks in layout order, inserting their associated
    // inlined block into the caller's layout.
    let mut prev_inlined_block = call_block;
    let mut next_callee_block = callee.layout.entry_block();
    while let Some(callee_block) = next_callee_block {
        debug_assert!(func.layout.is_block_inserted(prev_inlined_block));

        let inlined_block = entity_map.inlined_block(callee_block);
        func.layout
            .insert_block_after(inlined_block, prev_inlined_block);

        prev_inlined_block = inlined_block;
        next_callee_block = callee.layout.next_block(callee_block);
    }

    debug_assert!(func.layout.is_block_inserted(prev_inlined_block));
    prev_inlined_block
}

/// Split the call instruction's block just after the call instruction to create
/// the point where control-flow joins after the inlined callee "returns".