Evaluate Comparison Expressions with Constant Operands during Compila…

…tion

This patch supports evaluation of comparison expressions with
constants as operands during compile time.

src/sema/eval.rs

@@ -729,6 +729,150 @@ pub(crate) fn eval_constants_in_expression(
  (None, true)
  }
  }
+ Expression::More {
+ loc,
+ left,
+ right,
+ } => {
+ let left = eval_constants_in_expression(left, diagnostics).0;
+ let right = eval_constants_in_expression(right, diagnostics).0;
+
+ if let (
+ Some(Expression::NumberLiteral { value: left, .. }),
+ Some(Expression::NumberLiteral { value: right, .. }),
+ ) = (&left, &right)
+ {
+ (
+ Some(Expression::BoolLiteral { 
+ loc: *loc,
+ value: left > right
+ }),
+ true,
+ )
+ } else {
+ (None, true)
+ }
+ }
+ Expression::Less {
+ loc,
+ left,
+ right,
+ } => {
+ let left = eval_constants_in_expression(left, diagnostics).0;
+ let right = eval_constants_in_expression(right, diagnostics).0;
+
+ if let (
+ Some(Expression::NumberLiteral { value: left, .. }),
+ Some(Expression::NumberLiteral { value: right, .. }),
+ ) = (&left, &right)
+ {
+ (
+ Some(Expression::BoolLiteral { 
+ loc: *loc,
+ value: left < right
+ }),
+ true,
+ )
+ } else {
+ (None, true)
+ }
+ }
+ Expression::Equal {
+ loc,
+ left,
+ right,
+ } => {
+ let left = eval_constants_in_expression(left, diagnostics).0;
+ let right = eval_constants_in_expression(right, diagnostics).0;
+
+ if let (
+ Some(Expression::NumberLiteral { value: left, .. }),
+ Some(Expression::NumberLiteral { value: right, .. }),
+ ) = (&left, &right)
+ {
+ (
+ Some(Expression::BoolLiteral { 
+ loc: *loc,
+ value: left == right
+ }),
+ true,
+ )
+ } else {
+ (None, true)
+ }
+ }
+ Expression::NotEqual {
+ loc,
+ left,
+ right,
+ } => {
+ let left = eval_constants_in_expression(left, diagnostics).0;
+ let right = eval_constants_in_expression(right, diagnostics).0;
+
+ if let (
+ Some(Expression::NumberLiteral { value: left, .. }),
+ Some(Expression::NumberLiteral { value: right, .. }),
+ ) = (&left, &right)
+ {
+ (
+ Some(Expression::BoolLiteral { 
+ loc: *loc,
+ value: left != right
+ }),
+ true,
+ )
+ } else {
+ (None, true)
+ }
+ }
+ Expression::MoreEqual {
+ loc,
+ left,
+ right,
+ } => {
+ let left = eval_constants_in_expression(left, diagnostics).0;
+ let right = eval_constants_in_expression(right, diagnostics).0;
+
+ if let (
+ Some(Expression::NumberLiteral { value: left, .. }),
+ Some(Expression::NumberLiteral { value: right, .. }),
+ ) = (&left, &right)
+ {
+ (
+ Some(Expression::BoolLiteral { 
+ loc: *loc,
+ value: left >= right 
+ }),
+ true,
+ )
+ } else {
+ (None, true)
+ }
+ }
+ Expression::LessEqual {
+ loc,
+ left,
+ right,
+ } => {
+ let left = eval_constants_in_expression(left, diagnostics).0;
+ let right = eval_constants_in_expression(right, diagnostics).0;
+
+ if let (
+ Some(Expression::NumberLiteral { value: left, .. }),
+ Some(Expression::NumberLiteral { value: right, .. }),
+ ) = (&left, &right)
+ {
+ (
+ Some(Expression::BoolLiteral { 
+ loc: *loc,
+ value: left <= right 
+ }),
+ true,
+ )
+ } else {
+ (None, true)
+ }
+ }
  Expression::ZeroExt { loc, to, expr } => {
  let expr = eval_constants_in_expression(expr, diagnostics).0;
  if let Some(Expression::NumberLiteral { value, .. }) = expr {

tests/codegen_testcases/solidity/const_expr_eval.sol

@@ -0,0 +1,11 @@
+// RUN: --target polkadot --emit cfg
+contract ConstExprEvaluate {
+ // BEGIN-CHECK: ConstExprEvaluate::ConstExprEvaluate::function::less
+ function less() public pure returns (bool r) {
+ int a = 100;
+ int b = 200;
+
+ // CHECK: return true
+ r = a < b;
+ }
+}