Cpp To Dafny Translator

C/C++ Input → Analyze Structure → Map Types & Memory → Translate → Add Specifications → Verify
    ├─ Identify types, pointers, memory patterns
    ├─ Map C/C++ constructs to Dafny equivalents
    ├─ Handle memory safety and ownership
    ├─ Add preconditions, postconditions, invariants
    └─ Validate executability and verification

int add(int a, int b) {
    return a + b;
}

function add(a: int, b: int): int
{
    a + b
}

void increment(int* x) {
    (*x)++;
}

method increment(x: array<int>, index: nat)
    requires index < x.Length
    modifies x
    ensures x[index] == old(x[index]) + 1
{
    x[index] := x[index] + 1;
}

int sum_array(int* arr, int n) {
    int sum = 0;
    for (int i = 0; i < n; i++) {
        sum += arr[i];
    }
    return sum;
}

method sumArray(arr: array<int>) returns (sum: int)
    ensures sum == arraySum(arr[..])
{
    sum := 0;
    var i := 0;
    while i < arr.Length
        invariant 0 <= i <= arr.Length
        invariant sum == arraySum(arr[..i])
    {
        sum := sum + arr[i];
        i := i + 1;
    }
}

function arraySum(s: seq<int>): int
{
    if |s| == 0 then 0 else s[0] + arraySum(s[1..])
}

struct Point {
    int x;
    int y;
};

int distance_squared(struct Point* p) {
    return p->x * p->x + p->y * p->y;
}

class Point {
    var x: int
    var y: int

    constructor(x0: int, y0: int)
        ensures x == x0 && y == y0
    {
        x := x0;
        y := y0;
    }
}

function distanceSquared(p: Point): int
    reads p
{
    p.x * p.x + p.y * p.y
}

int max(int a, int b) {
    if (a > b) return a;
    else return b;
}

function max(a: int, b: int): int
{
    if a > b then a else b
}

int factorial(int n) {
    int result = 1;
    for (int i = 1; i <= n; i++) {
        result *= i;
    }
    return result;
}

method factorial(n: nat) returns (result: nat)
    ensures result == fact(n)
{
    result := 1;
    var i := 1;
    while i <= n
        invariant 1 <= i <= n + 1
        invariant result == fact(i - 1)
    {
        result := result * i;
        i := i + 1;
    }
}

function fact(n: nat): nat
{
    if n == 0 then 1 else n * fact(n - 1)
}

// C
int* ptr = arr + 5;
*ptr = 10;

// Dafny
arr[5] := 10;

// C
int* arr = (int*)malloc(n * sizeof(int));
// ... use arr ...
free(arr);

// Dafny
var arr := new int[n];
// ... use arr ...
// No explicit free needed

// C
int* find(int* arr, int n, int target) {
    for (int i = 0; i < n; i++) {
        if (arr[i] == target) return &arr[i];
    }
    return NULL;
}

// Dafny
method find(arr: array<int>, target: int) returns (index: int)
    ensures index == -1 || (0 <= index < arr.Length && arr[index] == target)
{
    var i := 0;
    while i < arr.Length
        invariant 0 <= i <= arr.Length
    {
        if arr[i] == target {
            return i;
        }
        i := i + 1;
    }
    return -1;
}

method binarySearch(arr: array<int>, target: int) returns (index: int)
    requires forall i, j :: 0 <= i < j < arr.Length ==> arr[i] <= arr[j]  // sorted
    ensures index == -1 || (0 <= index < arr.Length && arr[index] == target)
{
    var low := 0;
    var high := arr.Length;
    while low < high
        invariant 0 <= low <= high <= arr.Length
        invariant forall i :: 0 <= i < low ==> arr[i] < target
        invariant forall i :: high <= i < arr.Length ==> arr[i] > target
    {
        var mid := (low + high) / 2;
        if arr[mid] < target {
            low := mid + 1;
        } else if arr[mid] > target {
            high := mid;
        } else {
            return mid;
        }
    }
    return -1;
}