assembler: parse negative values in Offset properly

Fixes #186
NethermindEth · Jan 24, 2024 · 6b2ed03 · 6b2ed03
1 parent 06dca18
commit 6b2ed03
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diff --git a/pkg/assembler/assembler_test.go b/pkg/assembler/assembler_test.go
@@ -8,6 +8,25 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func TestCondJumpNegativeImmediate(t *testing.T) {
+	// See #186
+	instrList := parseSingleInstructionToInstrList("jmp rel [ap+5] if [fp + -3] != 0;")
+
+	expected := Instruction{
+		OffDest:     -3,
+		OffOp0:      -1,
+		OffOp1:      5,
+		DstRegister: Fp,
+		Op0Register: Fp,
+		Op1Source:   ApPlusOffOp1,
+		Res:         Op1,
+		PcUpdate:    PcUpdateJnz,
+		ApUpdate:    SameAp,
+		Opcode:      OpCodeNop,
+	}
+	assert.Equal(t, expected, instrList[0])
+}
+
 func TestAssertEqRegisterToInstrList(t *testing.T) {
 	instrList := parseSingleInstructionToInstrList("[ap] = [fp], ap++;")
 

diff --git a/pkg/assembler/grammar.go b/pkg/assembler/grammar.go
@@ -68,7 +68,7 @@ type DoubleDeref struct {
 
 type Offset struct {
 	Sign  string `@("+" | "-")`
-	Value *int   `@Int`
+	Value *int   `@('-'? Int)`
 }
 
 type MathOperation struct {