1 files changed, 24 insertions, 0 deletions
diff --git a/packages/sol-cov/src/instructions.ts b/packages/sol-cov/src/instructions.ts
new file mode 100644
index 000000000..c6506e58d
--- /dev/null
+++ b/packages/sol-cov/src/instructions.ts
@@ -0,0 +1,24 @@
+// tslint:disable:number-literal-format
+const PUSH1 = 0x60;
+const PUSH32 = 0x7f;
+const isPush = (inst: number) => inst >= PUSH1 && inst <= PUSH32;
+
+const pushDataLength = (inst: number) => inst - PUSH1 + 1;
+
+const instructionLength = (inst: number) => (isPush(inst) ? pushDataLength(inst) + 1 : 1);
+
+export const getPcToInstructionIndexMapping = (bytecode: Uint8Array) => {
+    const result: {
+        [programCounter: number]: number;
+    } = {};
+    let byteIndex = 0;
+    let instructionIndex = 0;
+    while (byteIndex < bytecode.length) {
+        const instruction = bytecode[byteIndex];
+        const length = instructionLength(instruction);
+        result[byteIndex] = instructionIndex;
+        byteIndex += length;
+        instructionIndex += 1;
+    }
+    return result;
+};