pina_lints

pina_lints is Pina's self-contained replacement for the previous Dylint setup: every security, performance, and IDL lint that Pina ships lives in this one importable crate, so the lints are built into Pina instead of being distributed as separate Dylint libraries. They turn repository security conventions into compiler diagnostics and are intended to run during normal development and CI.

The crate keeps the Dylint authoring shape — each lint lives in its own module under lints and declares itself with declare_late_lint! or declare_pre_expansion_lint! — but no lint registers itself; registration is centralized in register_all_lints. The crate builds as both a library and a cdylib that exports the Dylint-compatible register_lints symbol, so a Dylint driver can still load it as a single library. It also ships the bundled pina_lint_driver binary, a rustc wrapper with every lint statically linked; pina lint runs it as RUSTC_WRAPPER, so it needs no external lint tooling.

The lints complement tests and audits; they do not prove that a program's economic design is safe. Every path-sensitive lint documents the approximation it uses so findings can be reviewed with the right expectations.

Installation and execution

Run the catalog shipped with your installed Pina CLI:

pina lint
# Apply machine-applicable suggestions, then inspect the diff.
pina lint --fix

pina lint builds and manages the bundled pina_lint_driver under Cargo home, then invokes cargo with the driver as RUSTC_WRAPPER. Cargo calls the driver with the arguments it would have passed to rustc; the driver registers every lint compiled into this crate, and compilation continues normally. Because the lints are statically linked into the driver, no external lint tooling is downloaded or installed. The driver reads a few environment variables: PINA_LINT_NO_DEPS skips dependency crates, PINA_LINT_LEVELS forwards configured lint levels to rustc (see Configuring lint levels), PINA_LINT_ONLY restricts linting to a single lint, and PINA_LINT_LIST prints the lint catalog instead of compiling. PINA_LINT_NO_DEPS, PINA_LINT_LEVELS, and PINA_LINT_ONLY are recorded in dep-info, so changing them invalidates cargo's cached check results.

The crate itself is nightly-only: the lint passes and the driver link against the Rust compiler's unstable rustc_private crates. It is published to crates.io, but consuming projects never build it — the CLI builds and manages the driver for the active toolchain.

Pina contributors still run the in-workspace driver when changing a lint:

devenv shell -- security:pina-lint

security:pina-lint is the authoritative gate. It builds the workspace's pina_lint_driver binary and runs cargo with RUSTC_WRAPPER pointing at it, discovering every package under examples/ and every security/*/secure fixture, then checks each one in the driver's no-deps mode with --locked. Insecure fixtures are intentionally excluded because they demonstrate rejected patterns.

Importing the lints

Every lint constant and pass is public:

use pina_lints::lints::require_owner_before_token_cast::REQUIRE_OWNER_BEFORE_TOKEN_CAST;
use pina_lints::lints::require_owner_before_token_cast::RequireOwnerBeforeTokenCast;

Tooling that needs to validate lint names or enumerate the catalog can read pina_lints::LINT_NAMES, which lists every lint in the crate in catalog (alphabetical) order.

Configuring lint levels

Lint levels are configured in the project's pina.toml under the [lints] table. Each entry maps a lint name to allow, warn, or deny; lints that are not listed use their built-in default level (the "Level" column in the catalog below). The Pina CLI reads the table and passes the result to pina_lint_driver through the PINA_LINT_LEVELS environment variable; the driver forwards each level to rustc as an --allow, --warn, or --deny argument.

[lints]
deny_heap_allocations_in_onchain_instruction_handlers = "deny"
require_explicit_discriminators_and_seed_namespaces = "allow"

Deny-level security lints should not be disabled at crate scope; see the suppression policy below.

Complete lint catalog

Security and correctness reference

require_owner_before_token_cast

Detects calls to the unchecked as_token_mint(), as_token_account(), as_token_2022_mint(), and as_token_2022_account() loaders without an earlier assert_owner() or assert_owners() on the same account.

An account can contain bytes shaped like token state while being owned by an attacker-controlled program. Parsing those bytes before checking ownership lets spoofed balances or authorities enter trusted logic.

mint.assert_owners(&[token::ID, token_2022::ID])?;
let mint = mint.as_token_mint()?;

The lint tracks the root receiver identifier and lexical call order within one function. Prefer the checked loaders or *_for_program() APIs when possible.

require_empty_before_init

Detects CreateProgramAccount, CreateProgramAccountWithBump, and the matching creation functions when the target account has not first passed assert_empty(). It recognizes inline builders and builders stored in local variables.

state.assert_empty()?;
CreateProgramAccount { account: state, payer, owner: &ID, seeds }.invoke::<State>()?;

The analysis tracks concrete local/field places and builder bindings within one function. Validation hidden behind a helper is not treated as proof at the call site.

require_program_check_before_cpi

Detects unchecked invoke*() calls. Dynamic CPI program arguments must be dominated by assert_address(), assert_addresses(), or assert_program(). Pina CPI builders whose program identity is fixed by their concrete type are recognized as trusted.

token_program.assert_address(&token::ID)?;
transfer.invoke_with_program(token_program.address())?;

The analyzer intersects validation state across if and match branches and invalidates proof after assignment or mutable aliasing. A check performed on only one branch is therefore insufficient.

require_program_owned_before_lamport_mutation

Detects direct send() calls without an earlier ownership or typed-account check on the debited account.

vault.assert_owner(&ID)?;
vault.send(amount, recipient)?;

Direct lamport mutation is not a system-program transfer: the executing program must own the debited account. The lint uses lexical receiver matching, so keep the validation close to the mutation.

require_writable_before_account_resize

Detects resize() without a preceding assert_writable() on the same account.

state.assert_writable()?;
state.resize(new_len)?;

The lint tracks lexical call order and receiver identity. It does not infer writability from comments, IDL metadata, or helper functions.

require_zeroed_before_close

Detects close() or close_with_recipient() without an earlier zeroed() on the same account. Prefer close_account_zeroed() when the combined helper fits.

state.zeroed()?;
state.close_with_recipient(recipient)?;

This protects against stale bytes remaining observable during the transaction. The lint intentionally does not flag the combined zeroing close helper.

require_sysvar_assert_before_sysvar_use

Detects reads from accounts whose names identify known sysvars without a matching assert_sysvar() and expected sysvar ID.

clock.assert_sysvar(&sysvar::clock::ID)?;
let data = clock.try_borrow()?;

The lint recognizes standard Solana sysvar names and instruction-sysvar loader functions. Unusually named sysvar wrappers may require an explicit, local code shape for the heuristic to recognize them.

require_type_assert_before_zero_copy_cast

Detects raw zero-copy cast methods and known bytemuck cast functions when no prior assert_type::<T>(), as_account::<T>(), or as_account_mut::<T>() establishes the account layout.

account.assert_type::<Vault>(&ID)?;
let vault = account.as_account::<Vault>(&ID)?;

Pina instruction and account try_from_bytes() associated functions are safe framework conversions and are not treated as raw casts. The analysis correlates the nearest account borrow and validation within one function.

require_associated_token_address_before_ata_cast

Detects as_associated_token_account() without a prior assert_associated_token_address() on the same account.

vault.assert_associated_token_address(wallet, mint, token_program)?;
let vault = vault.as_associated_token_account(wallet, mint, token_program)?;

Prefer as_associated_token_account_checked(), which performs owner and ATA derivation validation in one operation. The lint uses lexical receiver matching.

require_reason_for_duplicate_remaining_accounts

Detects #[pina(remaining, distinct = false)] on mutable remaining accounts unless the field has a doc-comment explanation of at least five words.

/// Duplicate entries represent votes and are deduplicated before mutation.
#[pina(remaining, distinct = false)]
pub votes: &'a mut [AccountView],

#[pina(remaining)] is distinct by default. The word threshold only rejects missing or placeholder explanations; reviewers must still verify the stated invariant.

require_canonical_bump_before_pda_write

Detects assert_seeds_with_bump() in instruction paths unless the same account has already passed assert_canonical_bump() or assert_seeds().

let canonical = state.assert_canonical_bump(&seeds, &ID)?;
if canonical != supplied_bump {
	return Err(ProgramError::InvalidSeeds);
}
state.assert_seeds_with_bump(&seeds_with_bump, &ID)?;

Multiple valid bump values can otherwise create multiple addresses for one logical namespace. See Solana's PDA documentation. The lint tracks lexical receiver identity; it cannot inspect opaque validation helpers.

deny_account_borrows_across_cpi

Detects CPI while a local returned by try_borrow_mut() or as_account_mut() is still alive.

let amount = {
	let state = account.as_account_mut::<State>(&ID)?;
	state.amount.get()
};
transfer.invoke()?;

An explicit drop(guard) or the end of a nested block releases the guard. The analysis follows block scope and explicit drops. It resolves method definitions before classifying a borrow or CPI, so an unrelated type that happens to define try_borrow_mut() or invoke() does not trigger the lint. Account borrows hidden inside custom wrapper constructors and CPIs hidden behind opaque helpers are outside its current model.

require_consistent_token_program

Detects token parsing, ATA derivation, and dynamic token CPI calls that use different program identities within one instruction function.

token_program.assert_addresses(&SPL_PROGRAM_IDS)?;
let program_id = *token_program.address();
let mint = mint.as_token_mint_for_program(&program_id)?;
transfer.invoke_with_program(&program_id)?;

The lint compares resolved identifier paths, including module-qualified constants, so token::ID and token_2022::ID cannot collapse to the same terminal name. Immutable local aliases are traced back to their original identity, allowing clear names for parsing and CPI without reporting a mismatch. It still rejects reassignment of a program binding between token operations, because the same lexical name would otherwise hide a changed value. Copy and reuse a single immutable, validated address instead of independently deriving, mutating, or hard-coding program IDs.

require_explicit_token_2022_extension_policy

Detects Token-2022-capable mint loads without an explicit call to assert_no_extensions() or assert_extensions_allowed() in the instruction function.

let mint = mint_account
	.as_token_mint_for_program(&program_id)?
	.assert_extensions_allowed(&[
		token_2022::state::ExtensionType::ImmutableOwner,
	])?;

Extensions can alter transfer, fee, hook, freeze, and authority semantics. Pina therefore requires an allow-list instead of treating the legacy base layout as a complete policy. The analysis pairs a policy with the concrete mint-view binding or with the same direct method chain; a policy asserted on a different mint does not satisfy the rule. Keep each policy adjacent to its mint load so the pairing also remains obvious to reviewers.

An as_token_mint_for_program(&token::ID) call with the canonical legacy SPL Token ID is exempt because Token-2022 extensions cannot be present. Dynamic program identities and the explicit Token-2022 loaders still require a policy.

Both policies are inherent, chainable methods on TokenMintRef and TokenAccountRef; they return the validated view rather than wrapping it in a separate free-function API.

as_token_mint_for_program() and as_token_account_for_program() only accept the canonical SPL Token and Token-2022 program IDs, require the account owner to match the selected ID, and parse the corresponding concrete layout. The caller therefore cannot make a legacy account appear to be Token-2022 (or vice versa) by supplying an arbitrary address. Extension assertions are a no-op on the validated legacy variant and inspect the actual TLV extension data on the validated Token-2022 variant.

require_post_cpi_balance_reload

Detects token transfers into accounts whose names indicate protocol custody (vault, custody, reserve, or pool) unless the destination amount is read before and after CPI.

let before = vault.as_token_account_for_program(&program_id)?.amount();
transfer.invoke_with_program(&program_id)?;
let after = vault.as_token_account_for_program(&program_id)?.amount();
let received = after.checked_sub(before).ok_or(ProgramError::ArithmeticOverflow)?;

Token-2022 transfer fees can make received differ from the requested amount; Solana's on-chain Token-2022 guide describes this accounting requirement. The lint pairs each source-visible Transfer::new or TransferChecked::new constructor with the direct invocation of that exact builder. It requires the closest destination reads on each side of the transfer to have no intervening CPI, then applies a custody-name heuristic and tracks direct receiver expressions. A static invoke() is exempt only when the resolved constructor belongs to the canonical pinocchio_token crate, including Pina's token re-export; local look-alikes and Token-2022 builders remain covered. Opaque builder wrappers are not diagnosed because the analysis cannot associate them with a particular invocation; audit such wrappers manually or keep the transfer direct in the instruction handler.

require_checked_asset_arithmetic

Detects raw +, -, *, and /, plus saturating or wrapping arithmetic, when an operand has an economic identifier component such as amount, balance, lamport, price, reward, stake, or supply.

let next_balance = balance
	.checked_sub(amount)
	.ok_or(ProgramError::ArithmeticOverflow)?;

Saturating arithmetic is rejected because silently clamping economic state can violate conservation just as surely as wrapping. Components are split at Rust identifier separators, so vault_balance is covered while an unrelated name such as rebalance_attempts is not. The naming heuristic favors clear domain names and may not recognize opaque abbreviations.

require_bounded_remaining_accounts

Detects loops whose source mentions remaining unless the iterator visibly uses .take(MAX) or a dominating constant-bound length guard rejects oversized input first.

const MAX_REMAINING_ACCOUNTS: usize = 16;
if remaining.len() > MAX_REMAINING_ACCOUNTS {
	return Err(ProgramError::InvalidArgument);
}
for account in remaining {
	process(account)?;
}

Remaining accounts are caller-controlled; an explicit bound keeps worst-case compute auditable. Rejecting an oversized list is preferred when every supplied account must be processed, while .take(MAX) is suitable only when ignoring surplus accounts is intentional. The guard must compare remaining.len() against an integer literal or resolved constant, return early on the oversized path, and dominate the loop. A runtime limit, branch-local check, late check, or opaque helper does not satisfy the rule because it does not establish a source-visible protocol maximum on every path.

Performance reference

deny_heap_allocations_in_onchain_instruction_handlers

Warns on collect, to_vec, to_string, clone, format!, Vec creation, and String creation in functions whose names identify instruction handlers.

let mut bytes = [0u8; MAX_MESSAGE_BYTES];
bytes[..input.len()].copy_from_slice(input);

The lint is a performance warning rather than a correctness denial because some off-chain or bounded on-chain designs may intentionally allocate. It uses method and function-name heuristics and does not estimate actual heap size.

IDL and example-structure reference

require_idl_root_to_define_one_program_id

Warns when an IDL-oriented example or security crate does not expose exactly one crate-root declare_id! expansion.

declare_id!("Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS");

The check is repository-scoped by source file: declare_id! expansions are inspected in crates whose sources live under an examples or security directory. The crate-root program id is the contract, and every additional declaration is reported at its own call site, so module-scoped #[allow(...)] suppresses only the extra declarations (as examples/anchor_declare_program demonstrates). Library crates that intentionally define no program are ignored.

require_canonical_instruction_dispatch_for_idl

Warns when process_instruction or an entrypoint does not directly contain a match over parsed instruction data.

match instruction {
	Instruction::Initialize => InitializeAccounts::try_from((program_id, accounts))?.process(data),
	Instruction::Update => UpdateAccounts::try_from((program_id, accounts))?.process(data),
}

The check keeps dispatch visible to pina idl and reviewers. It verifies the presence of direct match-shaped routing, not semantic exhaustiveness.

require_explicit_discriminators_and_seed_namespaces

Warns when seed assertions in example instruction paths do not visibly use a byte-string namespace, a named SEED/*_SEED constant, or a generated Pina seed helper.

const VAULT_SEED: &[u8] = b"vault";
vault.assert_seeds(&[VAULT_SEED, authority.address().as_ref()], &ID)?;

Associated seed helpers generated from #[pda(...)] are accepted because the macro declaration exposes the namespace at the account type. Receiver-less local functions named like assertion methods are not treated as framework proof. The rule is a reviewability warning and does not replace canonical bump validation.

Suppression policy

Prefer making validation and bounds explicit instead of suppressing a finding. When a false positive cannot be expressed more clearly, scope #[allow(...)] to the smallest item and add a doc comment explaining the invariant. Deny-level security lints should not be disabled at crate or workspace scope.

Testing

UI fixtures live under tests/ui/<lint>/. Each fixture is compiled with the bundled pina_lint_driver — the lints are statically linked into the driver — and the emitted diagnostics are compared with the committed .stderr file next to the fixture. PINA_LINT_ONLY restricts the driver to the lint under test, so each fixture observes the same single-lint behavior the previous one-library-per-lint Dylint setup had.

Fixtures support two directives:

• // aux-build: <name>.rs — compile auxiliary/<name>.rs first and pass it to the fixture through --extern. The auxiliary source chooses its own crate type through #![crate_type] (for example proc-macro fixtures); sources without an inner attribute fall back to a plain library.
• // normalize-stderr-test: "<regex>" -> "<replacement>" — rewrite the actual stderr before comparing it with the expectation. Paths under the fixture directory are replaced with $DIR first, mirroring the convention of the Rust repository's UI tests.

To update a .stderr expectation, run the test, copy the saved actual stderr over the .stderr file, and re-run. On a mismatch the harness saves the actual stderr to a pina-lints-ui directory under the system temp directory and prints the saved path in its failure report.