Declare Anchor cfg values explicitly

Author: sls_0x

Cargo.toml

@@ -16,6 +16,12 @@ cpi = ["no-entrypoint"]
 default = []
 idl-build = ["anchor-lang/idl-build", "anchor-spl/idl-build"]
 
+[lints.rust]
+unexpected_cfgs = { level = "warn", check-cfg = [
+    'cfg(target_os, values("solana"))',
+    'cfg(feature, values("anchor-debug", "custom-heap", "custom-panic", "no-idl", "no-log-ix-name"))',
+] }
+
 [dependencies]
 anchor-lang = "0.30.1"
 anchor-spl = "0.30.1"

src/lib.rs

@@ -1,8 +1,3 @@
-#![allow(unexpected_cfgs)]
-// Anchor and Solana macros emit cfg values such as `custom-heap`, `custom-panic`,
-// `solana`, and `anchor-debug` during host builds. They are valid for the macro
-// expansion path but trigger noisy `unexpected_cfgs` warnings in normal local tests.
-
 use anchor_lang::prelude::*;
 use anchor_spl::token::{self, Burn, Mint, Token, TokenAccount, Transfer};
 use base64::{Engine as _, engine::general_purpose};