Fix .gitignore: stop tracking ignored files

2026-05-27 03:36:32 +00:00 · 2025-07-27 10:39:02 +05:30
parent b42747e9a3
commit 3a87ef0576
625 changed files with 88566 additions and 63 deletions
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/utils/SafeERC20.sol)
+
+pragma solidity ^0.8.0;
+
+import "../IERC20.sol";
+import "../extensions/IERC20Permit.sol";
+import "../../../utils/Address.sol";
+
+/**
+ * @title SafeERC20
+ * @dev Wrappers around ERC20 operations that throw on failure (when the token
+ * contract returns false). Tokens that return no value (and instead revert or
+ * throw on failure) are also supported, non-reverting calls are assumed to be
+ * successful.
+ * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
+ * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
+ */
+library SafeERC20 {
+    using Address for address;
+
+    /**
+     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
+     * non-reverting calls are assumed to be successful.
+     */
+    function safeTransfer(IERC20 token, address to, uint256 value) internal {
+        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
+    }
+
+    /**
+     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
+     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
+     */
+    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
+        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
+    }
+
+    /**
+     * @dev Deprecated. This function has issues similar to the ones found in
+     * {IERC20-approve}, and its usage is discouraged.
+     *
+     * Whenever possible, use {safeIncreaseAllowance} and
+     * {safeDecreaseAllowance} instead.
+     */
+    function safeApprove(IERC20 token, address spender, uint256 value) internal {
+        // safeApprove should only be called when setting an initial allowance,
+        // or when resetting it to zero. To increase and decrease it, use
+        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
+        require(
+            (value == 0) || (token.allowance(address(this), spender) == 0),
+            "SafeERC20: approve from non-zero to non-zero allowance"
+        );
+        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
+    }
+
+    /**
+     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
+     * non-reverting calls are assumed to be successful.
+     */
+    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
+        uint256 oldAllowance = token.allowance(address(this), spender);
+        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
+    }
+
+    /**
+     * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
+     * non-reverting calls are assumed to be successful.
+     */
+    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
+        unchecked {
+            uint256 oldAllowance = token.allowance(address(this), spender);
+            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
+            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
+        }
+    }
+
+    /**
+     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
+     * non-reverting calls are assumed to be successful. Compatible with tokens that require the approval to be set to
+     * 0 before setting it to a non-zero value.
+     */
+    function forceApprove(IERC20 token, address spender, uint256 value) internal {
+        bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);
+
+        if (!_callOptionalReturnBool(token, approvalCall)) {
+            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
+            _callOptionalReturn(token, approvalCall);
+        }
+    }
+
+    /**
+     * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
+     * Revert on invalid signature.
+     */
+    function safePermit(
+        IERC20Permit token,
+        address owner,
+        address spender,
+        uint256 value,
+        uint256 deadline,
+        uint8 v,
+        bytes32 r,
+        bytes32 s
+    ) internal {
+        uint256 nonceBefore = token.nonces(owner);
+        token.permit(owner, spender, value, deadline, v, r, s);
+        uint256 nonceAfter = token.nonces(owner);
+        require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
+    }
+
+    /**
+     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
+     * on the return value: the return value is optional (but if data is returned, it must not be false).
+     * @param token The token targeted by the call.
+     * @param data The call data (encoded using abi.encode or one of its variants).
+     */
+    function _callOptionalReturn(IERC20 token, bytes memory data) private {
+        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
+        // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
+        // the target address contains contract code and also asserts for success in the low-level call.
+
+        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
+        require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
+    }
+
+    /**
+     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
+     * on the return value: the return value is optional (but if data is returned, it must not be false).
+     * @param token The token targeted by the call.
+     * @param data The call data (encoded using abi.encode or one of its variants).
+     *
+     * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
+     */
+    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
+        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
+        // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
+        // and not revert is the subcall reverts.
+
+        (bool success, bytes memory returndata) = address(token).call(data);
+        return
+            success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));
+    }
+}