Struct Function

pub struct Function<'a> {
    pub linkage: Linkage,
    pub name: String,
    pub arguments: Vec<(Type<'a>, Value)>,
    pub return_ty: Option<Type<'a>>,
    pub blocks: Vec<Block<'a>>,
}

A QBE function definition.

A function consists of a name, linkage information, arguments, return type, and a collection of blocks containing the function’s implementation.

Examples

use qbe::{Function, Linkage, Type, Value, Instr, Cmp};

// Create a function that checks if a number is even
let mut is_even = Function::new(
    Linkage::public(),
    "is_even",
    vec![(Type::Word, Value::Temporary("n".to_string()))],
    Some(Type::Word), // Returns 1 if even, 0 if odd
);

// Add the start block
let mut start = is_even.add_block("start");

// Calculate n % 2 (by using n & 1)
start.assign_instr(
    Value::Temporary("remainder".to_string()),
    Type::Word,
    Instr::And(
        Value::Temporary("n".to_string()),
        Value::Const(1),
    ),
);

// Check if remainder is 0 (even number)
start.assign_instr(
    Value::Temporary("is_zero".to_string()),
    Type::Word,
    Instr::Cmp(
        Type::Word,
        Cmp::Eq,
        Value::Temporary("remainder".to_string()),
        Value::Const(0),
    ),
);

// Return the result
start.add_instr(Instr::Ret(Some(Value::Temporary("is_zero".to_string()))));

Fields

linkage: Linkage

Function’s linkage

name: String

Function name

arguments: Vec<(Type<'a>, Value)>

Function arguments

return_ty: Option<Type<'a>>

Return type

blocks: Vec<Block<'a>>

Labelled blocks

Implementations

impl<'a> Function<'a>

pub fn new( linkage: Linkage, name: impl Into<String>, arguments: Vec<(Type<'a>, Value)>, return_ty: Option<Type<'a>>, ) -> Self

Instantiates an empty function and returns it

Examples found in repository

examples/hello_world.rs (lines 6-14)

fn generate_add_func(module: &mut Module) {
    let mut func = Function::new(
        Linkage::private(),
        "add",
        vec![
            (Type::Word, Value::Temporary("a".into())),
            (Type::Word, Value::Temporary("b".into())),
        ],
        Some(Type::Word),
    );

    func.add_block("start");
    func.assign_instr(
        Value::Temporary("c".into()),
        Type::Word,
        Instr::Add(Value::Temporary("a".into()), Value::Temporary("b".into())),
    );
    func.add_instr(Instr::Ret(Some(Value::Temporary("c".into()))));

    module.add_function(func);
}

fn generate_main_func(module: &mut Module) {
    let mut func = Function::new(Linkage::public(), "main", Vec::new(), Some(Type::Word));

    func.add_block("start");
    func.assign_instr(
        Value::Temporary("r".into()),
        Type::Word,
        Instr::Call(
            "add".into(),
            vec![(Type::Word, Value::Const(1)), (Type::Word, Value::Const(1))],
            None,
        ),
    );
    func.add_instr(Instr::Call(
        "printf".into(),
        vec![
            (Type::Long, Value::Global("fmt".into())),
            (Type::Word, Value::Temporary("r".into())),
        ],
        Some(1),
    ));
    func.add_instr(Instr::Ret(Some(Value::Const(0))));

    module.add_function(func);
}

pub fn add_block(&mut self, label: impl Into<String>) -> &mut Block<'a>

Adds a new empty block with a specified label and returns a reference to it

Examples found in repository

examples/hello_world.rs (line 16)

fn generate_add_func(module: &mut Module) {
    let mut func = Function::new(
        Linkage::private(),
        "add",
        vec![
            (Type::Word, Value::Temporary("a".into())),
            (Type::Word, Value::Temporary("b".into())),
        ],
        Some(Type::Word),
    );

    func.add_block("start");
    func.assign_instr(
        Value::Temporary("c".into()),
        Type::Word,
        Instr::Add(Value::Temporary("a".into()), Value::Temporary("b".into())),
    );
    func.add_instr(Instr::Ret(Some(Value::Temporary("c".into()))));

    module.add_function(func);
}

fn generate_main_func(module: &mut Module) {
    let mut func = Function::new(Linkage::public(), "main", Vec::new(), Some(Type::Word));

    func.add_block("start");
    func.assign_instr(
        Value::Temporary("r".into()),
        Type::Word,
        Instr::Call(
            "add".into(),
            vec![(Type::Word, Value::Const(1)), (Type::Word, Value::Const(1))],
            None,
        ),
    );
    func.add_instr(Instr::Call(
        "printf".into(),
        vec![
            (Type::Long, Value::Global("fmt".into())),
            (Type::Word, Value::Temporary("r".into())),
        ],
        Some(1),
    ));
    func.add_instr(Instr::Ret(Some(Value::Const(0))));

    module.add_function(func);
}

pub fn last_block(&mut self) -> &Block<'_>

👎Deprecated since 3.0.0: Use self.blocks.last() or self.blocks.last_mut() instead.

Returns a reference to the last block

pub fn add_instr(&mut self, instr: Instr<'a>)

Adds a new instruction to the last block

Examples found in repository

examples/hello_world.rs (line 22)

fn generate_add_func(module: &mut Module) {
    let mut func = Function::new(
        Linkage::private(),
        "add",
        vec![
            (Type::Word, Value::Temporary("a".into())),
            (Type::Word, Value::Temporary("b".into())),
        ],
        Some(Type::Word),
    );

    func.add_block("start");
    func.assign_instr(
        Value::Temporary("c".into()),
        Type::Word,
        Instr::Add(Value::Temporary("a".into()), Value::Temporary("b".into())),
    );
    func.add_instr(Instr::Ret(Some(Value::Temporary("c".into()))));

    module.add_function(func);
}

fn generate_main_func(module: &mut Module) {
    let mut func = Function::new(Linkage::public(), "main", Vec::new(), Some(Type::Word));

    func.add_block("start");
    func.assign_instr(
        Value::Temporary("r".into()),
        Type::Word,
        Instr::Call(
            "add".into(),
            vec![(Type::Word, Value::Const(1)), (Type::Word, Value::Const(1))],
            None,
        ),
    );
    func.add_instr(Instr::Call(
        "printf".into(),
        vec![
            (Type::Long, Value::Global("fmt".into())),
            (Type::Word, Value::Temporary("r".into())),
        ],
        Some(1),
    ));
    func.add_instr(Instr::Ret(Some(Value::Const(0))));

    module.add_function(func);
}

pub fn assign_instr(&mut self, temp: Value, ty: Type<'a>, instr: Instr<'a>)

Adds a new instruction assigned to a temporary

Examples found in repository

examples/hello_world.rs (lines 17-21)

fn generate_add_func(module: &mut Module) {
    let mut func = Function::new(
        Linkage::private(),
        "add",
        vec![
            (Type::Word, Value::Temporary("a".into())),
            (Type::Word, Value::Temporary("b".into())),
        ],
        Some(Type::Word),
    );

    func.add_block("start");
    func.assign_instr(
        Value::Temporary("c".into()),
        Type::Word,
        Instr::Add(Value::Temporary("a".into()), Value::Temporary("b".into())),
    );
    func.add_instr(Instr::Ret(Some(Value::Temporary("c".into()))));

    module.add_function(func);
}

fn generate_main_func(module: &mut Module) {
    let mut func = Function::new(Linkage::public(), "main", Vec::new(), Some(Type::Word));

    func.add_block("start");
    func.assign_instr(
        Value::Temporary("r".into()),
        Type::Word,
        Instr::Call(
            "add".into(),
            vec![(Type::Word, Value::Const(1)), (Type::Word, Value::Const(1))],
            None,
        ),
    );
    func.add_instr(Instr::Call(
        "printf".into(),
        vec![
            (Type::Long, Value::Global("fmt".into())),
            (Type::Word, Value::Temporary("r".into())),
        ],
        Some(1),
    ));
    func.add_instr(Instr::Ret(Some(Value::Const(0))));

    module.add_function(func);
}

Trait Implementations

impl<'a> Clone for Function<'a>

fn clone(&self) -> Function<'a>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Debug for Function<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Default for Function<'a>

fn default() -> Function<'a>

Returns the “default value” for a type.

impl Display for Function<'_>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Hash for Function<'a>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<'a> Ord for Function<'a>

fn cmp(&self, other: &Function<'a>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<'a> PartialEq for Function<'a>

fn eq(&self, other: &Function<'a>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'a> PartialOrd for Function<'a>

fn partial_cmp(&self, other: &Function<'a>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> Eq for Function<'a>

impl<'a> StructuralPartialEq for Function<'a>