pub struct Compiler<'a> { /* private fields */ }Implementations§
source§impl<'a> Compiler<'a>
impl<'a> Compiler<'a>
sourcepub fn label(&mut self, l: &str) -> usize
pub fn label(&mut self, l: &str) -> usize
Get the underlying bytecode label for a given label
identifier. If necessary, this allocates that label in the
Bytecode object.
Examples found in repository?
src/compiler.rs (line 155)
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fn translate_goto(&mut self, label: &str) -> Result {
// Allocate labels branch target
let lab = self.label(label);
// Translate unconditional branch
self.bytecode.push(Instruction::PUSHL(lab));
self.bytecode.push(Instruction::JUMP);
//
Ok(())
}
fn translate_ifgoto(&mut self, expr: &Term, label: &str) -> Result {
// Allocate labels for true/false outcomes
let lab = self.label(label);
// Translate conditional branch
self.translate_conditional(expr,Some(lab),None)
}
fn translate_label(&mut self, label: &str) -> Result {
// Determine underlying index of label
let lab = self.label(label);
// Construct corresponding JumpDest
self.bytecode.push(Instruction::JUMPDEST(lab));
// Done
Ok(())
}sourcepub fn translate(&mut self, term: &Term) -> Result<(), Error>
pub fn translate(&mut self, term: &Term) -> Result<(), Error>
Examples found in repository?
More examples
src/compiler.rs (line 108)
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fn translate_assignment(&mut self, lhs: &Term, rhs: &Term) -> Result {
// Translate value being assigned
self.translate(rhs)?;
// Translate assignent itself
match lhs {
Term::ArrayAccess(src,idx) => {
self.translate_assignment_array(&src,&idx)?;
}
_ => {
return Err(Error::InvalidLVal);
}
}
//
Ok(())
}
fn translate_assignment_array(&mut self, src: &Term, index: &Term) -> Result {
match src {
Term::MemoryAccess(r) => {
self.translate_assignment_memory(*r,index)
}
_ => {
Err(Error::InvalidMemoryAccess)
}
}
}
fn translate_assignment_memory(&mut self, region: Region, address: &Term) -> Result {
// Translate index expression
self.translate(address)?;
// Dispatch based on region
match region {
Region::Memory => self.bytecode.push(Instruction::MSTORE),
Region::Storage => self.bytecode.push(Instruction::SSTORE),
_ => {
return Err(Error::InvalidMemoryAccess);
}
};
//
Ok(())
}
fn translate_fail(&mut self) -> Result {
self.bytecode.push(Instruction::INVALID);
Ok(())
}
fn translate_goto(&mut self, label: &str) -> Result {
// Allocate labels branch target
let lab = self.label(label);
// Translate unconditional branch
self.bytecode.push(Instruction::PUSHL(lab));
self.bytecode.push(Instruction::JUMP);
//
Ok(())
}
fn translate_ifgoto(&mut self, expr: &Term, label: &str) -> Result {
// Allocate labels for true/false outcomes
let lab = self.label(label);
// Translate conditional branch
self.translate_conditional(expr,Some(lab),None)
}
fn translate_label(&mut self, label: &str) -> Result {
// Determine underlying index of label
let lab = self.label(label);
// Construct corresponding JumpDest
self.bytecode.push(Instruction::JUMPDEST(lab));
// Done
Ok(())
}
fn translate_revert(&mut self, exprs: &[Term]) -> Result {
self.translate_succeed_revert(Instruction::REVERT,exprs)
}
fn translate_succeed(&mut self, exprs: &[Term]) -> Result {
if exprs.len() == 0 {
self.bytecode.push(Instruction::STOP);
Ok(())
} else {
self.translate_succeed_revert(Instruction::RETURN,exprs)
}
}
fn translate_succeed_revert(&mut self, insn: Instruction, exprs: &[Term]) -> Result {
if exprs.len() == 0 {
self.bytecode.push(Instruction::PUSH(vec![0]));
self.bytecode.push(Instruction::PUSH(vec![0]));
} else {
for i in 0 .. exprs.len() {
let addr = (i * 0x20) as u128;
self.translate(&exprs[i])?;
self.bytecode.push(make_push(addr)?);
self.bytecode.push(Instruction::MSTORE);
}
let len = (exprs.len() * 0x20) as u128;
self.bytecode.push(Instruction::PUSH(vec![0]));
self.bytecode.push(make_push(len)?);
}
self.bytecode.push(insn);
Ok(())
}
fn translate_stop(&mut self) -> Result {
self.bytecode.push(Instruction::STOP);
Ok(())
}
// ============================================================================
// Conditional Expressions
// ============================================================================
/// Translate a conditional expression using _short circuiting_
/// semantics. Since implementing short circuiting requires
/// branching, we can exploit this to optimise other translations
/// and reduce the number of branches required. To do that, this
/// method requires either a `true` target or a `false` target.
/// If a `true` target is provided then, if the condition
/// evaluates to something other than `0` (i.e. is `true`),
/// control is transfered to this target. Likewise, if the
/// condition evaluates to `0` (i.e. `false`) the control is
/// transfered to the `false` target.
fn translate_conditional(&mut self, expr: &Term, true_lab: Option<usize>, false_lab: Option<usize>) -> Result {
match expr {
Term::Binary(BinOp::LogicalAnd,l,r) => self.translate_conditional_conjunct(l,r,true_lab,false_lab),
Term::Binary(BinOp::LogicalOr,l,r) => self.translate_conditional_disjunct(l,r,true_lab,false_lab), _ => {
self.translate_conditional_other(expr,true_lab,false_lab)
}
}
}
/// Translate a logical conjunction as a conditional. Since
/// such connectives require short circuiting, these must be
/// implementing using branches.
fn translate_conditional_conjunct(&mut self, lhs: &Term, rhs: &Term, true_lab: Option<usize>, false_lab: Option<usize>) -> Result {
match (true_lab,false_lab) {
(Some(_),None) => {
// Harder case
let lab = self.bytecode.fresh_label();
self.translate_conditional(lhs, None, Some(lab))?;
self.translate_conditional(rhs, true_lab, None)?;
self.bytecode.push(Instruction::JUMPDEST(lab));
}
(None,Some(_)) => {
// Easy case
self.translate_conditional(lhs, None, false_lab)?;
self.translate_conditional(rhs, true_lab, false_lab)?;
}
(_,_) => unreachable!()
}
// Done
Ok(())
}
/// Translate a logical disjunction as a conditional. Since
/// such connectives require short circuiting, these must be
/// implementing using branches.
fn translate_conditional_disjunct(&mut self, lhs: &Term, rhs: &Term, true_lab: Option<usize>, false_lab: Option<usize>) -> Result {
match (true_lab,false_lab) {
(None,Some(_)) => {
// Harder case
let lab = self.bytecode.fresh_label();
self.translate_conditional(lhs, Some(lab), None)?;
self.translate_conditional(rhs, None, false_lab)?;
self.bytecode.push(Instruction::JUMPDEST(lab));
}
(Some(_),None) => {
// Easy case
self.translate_conditional(lhs, true_lab, None)?;
self.translate_conditional(rhs, true_lab, false_lab)?;
}
(_,_) => unreachable!()
}
// Done
Ok(())
}
/// Translate a conditional expression which cannot be translated
/// by exploiting branches. In such case, we have to generate the
/// boolean value and dispatch based on that.
fn translate_conditional_other(&mut self, expr: &Term, true_lab: Option<usize>, false_lab: Option<usize>) -> Result {
// Translate conditional expression
self.translate(expr)?;
//
match (true_lab,false_lab) {
(Some(lab),None) => {
self.bytecode.push(Instruction::PUSHL(lab));
self.bytecode.push(Instruction::JUMPI);
}
(None,Some(lab)) => {
self.bytecode.push(Instruction::ISZERO);
self.bytecode.push(Instruction::PUSHL(lab));
self.bytecode.push(Instruction::JUMPI);
}
(_,_) => {
unreachable!("")
}
}
//
Ok(())
}
// ============================================================================
// Binary Expressions
// ============================================================================
/// Translate a binary operation. Observe that logical operations
/// exhibit _short-circuit behaviour_.
fn translate_binary(&mut self, bop: BinOp, lhs: &Term, rhs: &Term) -> Result {
match bop {
BinOp::LogicalAnd | BinOp::LogicalOr => {
self.translate_logical_connective(bop,lhs,rhs)
}
_ => {
self.translate_binary_arithmetic(bop,lhs,rhs)
}
}
}
/// Translate one of the logical connectives (e.g. `&&` or `||`).
/// These are more challenging than standard binary operators because
/// they exhibit _short circuiting behaviour_.
fn translate_logical_connective(&mut self, bop: BinOp, lhs: &Term, rhs: &Term) -> Result {
self.translate(lhs)?;
self.bytecode.push(Instruction::DUP(1));
if bop == BinOp::LogicalAnd {
self.bytecode.push(Instruction::ISZERO);
}
// Allocate fresh label
let lab = self.bytecode.fresh_label();
self.bytecode.push(Instruction::PUSHL(lab));
self.bytecode.push(Instruction::JUMPI);
self.bytecode.push(Instruction::POP);
self.translate(rhs)?;
self.bytecode.push(Instruction::JUMPDEST(lab));
// Done
Ok(())
}
/// Translate a binary arithmetic operation or comparison. This is
/// pretty straightforward, as we just load items on the stack and
/// perform the op. Observe that the right-hand side is loaded onto
/// the stack first.
fn translate_binary_arithmetic(&mut self, bop: BinOp, lhs: &Term, rhs: &Term) -> Result {
self.translate(rhs)?;
self.translate(lhs)?;
//
match bop {
// standard
BinOp::Add => self.bytecode.push(Instruction::ADD),
BinOp::Subtract => self.bytecode.push(Instruction::SUB),
BinOp::Divide => self.bytecode.push(Instruction::DIV),
BinOp::Multiply => self.bytecode.push(Instruction::MUL),
BinOp::Remainder => self.bytecode.push(Instruction::MOD),
BinOp::Equals => self.bytecode.push(Instruction::EQ),
BinOp::LessThan => self.bytecode.push(Instruction::LT),
BinOp::GreaterThan => self.bytecode.push(Instruction::GT),
// non-standard
BinOp::NotEquals => {
self.bytecode.push(Instruction::EQ);
self.bytecode.push(Instruction::ISZERO);
}
BinOp::LessThanOrEquals => {
self.bytecode.push(Instruction::GT);
self.bytecode.push(Instruction::ISZERO);
}
BinOp::GreaterThanOrEquals => {
self.bytecode.push(Instruction::LT);
self.bytecode.push(Instruction::ISZERO);
}
_ => {
unreachable!();
}
}
//
Ok(())
}
// ============================================================================
// Array Access Expressions
// ============================================================================
/// Translate an array access of the form `src[index]`. The actual
/// form of the translation depends on whether its a direct access
/// (e.g. to storage or memory), or indirect (e.g. via a pointer to
/// memory).
fn translate_array_access(&mut self, src: &Term, index: &Term) -> Result {
match src {
Term::MemoryAccess(r) => {
self.translate_memory_access(*r,index)
}
_ => {
Err(Error::InvalidMemoryAccess)
}
}
}
fn translate_memory_access(&mut self, region: Region, index: &Term) -> Result {
// Translate index expression
self.translate(index)?;
// Dispatch based on region
match region {
Region::Memory => {
self.bytecode.push(Instruction::MLOAD);
}
Region::Storage => {
self.bytecode.push(Instruction::SLOAD);
}
Region::CallData => {
self.bytecode.push(Instruction::CALLDATALOAD);
}
}
//
Ok(())
}