From d1c0f4b4f13653b48b35a0d6bdca211ec03acb8f Mon Sep 17 00:00:00 2001 From: "mergify[bot]" <37929162+mergify[bot]@users.noreply.github.com> Date: Wed, 15 Jul 2020 02:40:36 +0000 Subject: [PATCH] Fix hygiene issues in `declare_program!` and `declare_loader!` (bp #10905) (#11073) * Fix hygiene issues in `declare_program!` and `declare_loader!` The `declare_program!` and `declare_loader!` macros both expand to new macro definitions (based on the `$name` argument). These 'inner' macros make use of the special `$crate` metavariable to access items in the crate where the 'inner' macros is defined. However, this only works due to a bug in rustc. When a macro is expanded, all `$crate` tokens in its output are 'marked' as being resolved in the defining crate of that macro. An inner macro (including the body of its arms) is 'just' another set of tokens that appears in the body of the outer macro, so any `$crate` identifiers used there are resolved relative to the 'outer' macro. For example, consider the following code: ```rust macro_rules! outer { () => { macro_rules! inner { () => { $crate::Foo } } } } ``` The path `$crate::Foo` will be resolved relative to the crate that defines `outer`, **not** the crate which defines `inner`. However, rustc currently loses this extra resolution information (referred to as 'hygiene' information) when a crate is serialized. In the above example, this means that the macro `inner` (which gets defined in whatever crate invokes `outer!`) will behave differently depending on which crate it is invoked from: When `inner` is invoked from the same crate in which it is defined, the hygiene information will still be available, which will cause `$crate::Foo` to be resolved in the crate which defines 'outer'. When `inner` is invoked from a different crate, it will be loaded from the metadata of the crate which defines 'inner'. Since the hygiene information is currently lost, rust will 'forget' that `$crate::Foo` is supposed to be resolved in the context of 'outer'. Instead, it will be resolved relative to the crate which defines 'inner', which can cause incorrect code to compile. This bug will soon be fixed in rust (see https://github.com/rust-lang/rust/pull/72121), which will break `declare_program!` and `declare_loader!`. Fortunately, it's possible to obtain the desired behavior (`$crate` resolving in the context of the 'inner' macro) by use of a procedural macro. This commit adds a `respan!` proc-macro to the `sdk/macro` crate. Using the newly-stabilized (on Nightly) `Span::resolved_at` method, the `$crate` identifier can be made to be resolved in the context of the proper crate. Since `Span::resolved_at` is only stable on the latest nightly, referencing it on an earlier version of Rust will cause a compilation error. This requires the `rustversion` crate to be used, which allows conditionally compiling code epending on the Rust compiler version in use. Since this method is already stabilized in the latest nightly, there will never be a situation where the hygiene bug is fixed (e.g. https://github.com/rust-lang/rust/pull/72121) is merged but we are unable to call `Span::resolved_at`. (cherry picked from commit 05445c718e6dda2f166a0ce1d2c7e1f85eddd83b) # Conflicts: # Cargo.lock # sdk/Cargo.toml * Replace FIXME with an issue link (cherry picked from commit b0cb2b01065e5c4b349941264f606074ba1c4be8) * Update lock files (cherry picked from commit 42f88484f43564ebcf22bfd84554b28b8c9d1b6c) # Conflicts: # programs/bpf/Cargo.lock # programs/librapay/Cargo.lock # programs/move_loader/Cargo.lock * Split comment over multiple lines Due to https://github.com/rust-lang/rustfmt/issues/4325, leaving this as one line causes rustfmt to add extra indentation to the surrounding code. (cherry picked from commit fed69e96a96485d1eda68c82f5c6085b0e4feae2) * Fix clippy lints (cherry picked from commit e7387f60a7cf68e1d630d3e96dbe7ff8606a4ac6) * Apply #![feature(proc_macro_hygiene)] when needed This allows the rust-bpf-builder toolchain to build the sdk (cherry picked from commit 95490ff56eb274f8dea58c79a2d33e4f2713d8c8) # Conflicts: # sdk/build.rs # sdk/src/lib.rs * Update Cargo.toml * Update lib.rs * Add rustc_version * lock file updates Co-authored-by: Aaron Hill Co-authored-by: Jack May Co-authored-by: Michael Vines --- Cargo.lock | 15 +++++++ programs/bpf/Cargo.lock | 14 +++++++ programs/bpf_loader/Cargo.toml | 1 + programs/bpf_loader/src/lib.rs | 8 ++++ programs/librapay/Cargo.lock | 14 +++++++ programs/move_loader/Cargo.lock | 14 +++++++ sdk/Cargo.toml | 4 ++ sdk/build.rs | 27 ++++++++++++ sdk/macro/Cargo.toml | 1 + sdk/macro/src/lib.rs | 73 ++++++++++++++++++++++++++++++++- sdk/src/entrypoint_native.rs | 73 +++++++++++++++++++++++++++------ sdk/src/lib.rs | 4 ++ 12 files changed, 233 insertions(+), 15 deletions(-) create mode 100644 sdk/build.rs diff --git a/Cargo.lock b/Cargo.lock index ce72a8bf02..dc2fbb0c8a 100644 --- a/Cargo.lock +++ b/Cargo.lock @@ -3295,6 +3295,17 @@ dependencies = [ "webpki", ] +[[package]] +name = "rustversion" +version = "1.0.3" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "b9bdc5e856e51e685846fb6c13a1f5e5432946c2c90501bdc76a1319f19e29da" +dependencies = [ + "proc-macro2 1.0.18", + "quote 1.0.7", + "syn 1.0.33", +] + [[package]] name = "rusty-fork" version = "0.2.2" @@ -3824,6 +3835,7 @@ dependencies = [ "num-derive 0.3.0", "num-traits", "rand 0.7.3", + "rustversion", "solana-logger", "solana-runtime", "solana-sdk 1.2.11", @@ -4667,6 +4679,8 @@ dependencies = [ "pbkdf2", "rand 0.7.3", "rand_chacha 0.2.2", + "rustc_version", + "rustversion", "serde", "serde_bytes", "serde_derive", @@ -4704,6 +4718,7 @@ dependencies = [ "bs58 0.3.1", "proc-macro2 1.0.18", "quote 1.0.7", + "rustversion", "syn 1.0.33", ] diff --git a/programs/bpf/Cargo.lock b/programs/bpf/Cargo.lock index 56151ae013..aa6c724aa2 100644 --- a/programs/bpf/Cargo.lock +++ b/programs/bpf/Cargo.lock @@ -1235,6 +1235,16 @@ dependencies = [ "webpki 0.21.2 (registry+https://github.com/rust-lang/crates.io-index)", ] +[[package]] +name = "rustversion" +version = "1.0.3" +source = "registry+https://github.com/rust-lang/crates.io-index" +dependencies = [ + "proc-macro2 1.0.17 (registry+https://github.com/rust-lang/crates.io-index)", + "quote 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)", + "syn 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)", +] + [[package]] name = "ryu" version = "1.0.5" @@ -1670,6 +1680,8 @@ dependencies = [ "pbkdf2 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)", "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)", "rand_chacha 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)", + "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)", + "rustversion 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)", "serde 1.0.114 (registry+https://github.com/rust-lang/crates.io-index)", "serde_bytes 0.11.5 (registry+https://github.com/rust-lang/crates.io-index)", "serde_derive 1.0.114 (registry+https://github.com/rust-lang/crates.io-index)", @@ -1688,6 +1700,7 @@ dependencies = [ "bs58 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)", "proc-macro2 1.0.18 (registry+https://github.com/rust-lang/crates.io-index)", "quote 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)", + "rustversion 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)", "syn 1.0.33 (registry+https://github.com/rust-lang/crates.io-index)", ] @@ -2445,6 +2458,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index" "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a" "checksum rustls 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c0d4a31f5d68413404705d6982529b0e11a9aacd4839d1d6222ee3b8cb4015e1" "checksum ryu 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e" +"checksum rustversion 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "b9bdc5e856e51e685846fb6c13a1f5e5432946c2c90501bdc76a1319f19e29da" "checksum same-file 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502" "checksum scoped-tls 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "332ffa32bf586782a3efaeb58f127980944bbc8c4d6913a86107ac2a5ab24b28" "checksum scopeguard 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd" diff --git a/programs/bpf_loader/Cargo.toml b/programs/bpf_loader/Cargo.toml index bf3d65e7f2..31d5c937a6 100644 --- a/programs/bpf_loader/Cargo.toml +++ b/programs/bpf_loader/Cargo.toml @@ -23,6 +23,7 @@ thiserror = "1.0" [dev-dependencies] rand = "0.7.3" +rustversion = "1.0.3" [lib] crate-type = ["lib", "cdylib"] diff --git a/programs/bpf_loader/src/lib.rs b/programs/bpf_loader/src/lib.rs index 905abf0a41..3f445b7f5c 100644 --- a/programs/bpf_loader/src/lib.rs +++ b/programs/bpf_loader/src/lib.rs @@ -297,6 +297,14 @@ mod tests { } } + #[rustversion::since(1.46.0)] + #[test] + fn test_bpf_loader_same_crate() { + // Ensure that we can invoke this macro from the same crate + // where it is defined. + solana_bpf_loader_program!(); + } + #[test] #[should_panic(expected = "ExceededMaxInstructions(10)")] fn test_bpf_loader_non_terminating_program() { diff --git a/programs/librapay/Cargo.lock b/programs/librapay/Cargo.lock index d9f35a7b48..fb77f118a4 100644 --- a/programs/librapay/Cargo.lock +++ b/programs/librapay/Cargo.lock @@ -2095,6 +2095,16 @@ dependencies = [ "webpki 0.21.2 (registry+https://github.com/rust-lang/crates.io-index)", ] +[[package]] +name = "rustversion" +version = "1.0.3" +source = "registry+https://github.com/rust-lang/crates.io-index" +dependencies = [ + "proc-macro2 1.0.17 (registry+https://github.com/rust-lang/crates.io-index)", + "quote 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)", + "syn 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)", +] + [[package]] name = "rusty-fork" version = "0.2.2" @@ -2489,6 +2499,8 @@ dependencies = [ "pbkdf2 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)", "rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)", "rand_chacha 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)", + "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)", + "rustversion 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)", "serde 1.0.114 (registry+https://github.com/rust-lang/crates.io-index)", "serde_bytes 0.11.5 (registry+https://github.com/rust-lang/crates.io-index)", "serde_derive 1.0.114 (registry+https://github.com/rust-lang/crates.io-index)", @@ -2507,6 +2519,7 @@ dependencies = [ "bs58 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)", "proc-macro2 1.0.18 (registry+https://github.com/rust-lang/crates.io-index)", "quote 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)", + "rustversion 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)", "syn 1.0.33 (registry+https://github.com/rust-lang/crates.io-index)", ] @@ -3909,6 +3922,7 @@ dependencies = [ "checksum rustc-demangle 0.1.16 (registry+https://github.com/rust-lang/crates.io-index)" = "4c691c0e608126e00913e33f0ccf3727d5fc84573623b8d65b2df340b5201783" "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a" "checksum rustls 0.17.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c0d4a31f5d68413404705d6982529b0e11a9aacd4839d1d6222ee3b8cb4015e1" +"checksum rustversion 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "b9bdc5e856e51e685846fb6c13a1f5e5432946c2c90501bdc76a1319f19e29da" "checksum rusty-fork 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "3dd93264e10c577503e926bd1430193eeb5d21b059148910082245309b424fae" "checksum ryu 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "71d301d4193d031abdd79ff7e3dd721168a9572ef3fe51a1517aba235bd8f86e" "checksum scoped-tls 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "332ffa32bf586782a3efaeb58f127980944bbc8c4d6913a86107ac2a5ab24b28" diff --git a/programs/move_loader/Cargo.lock b/programs/move_loader/Cargo.lock index 2b28fb6b2d..e795a2983e 100644 --- a/programs/move_loader/Cargo.lock +++ b/programs/move_loader/Cargo.lock @@ -2257,6 +2257,17 @@ dependencies = [ "webpki", ] +[[package]] +name = "rustversion" +version = "1.0.3" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "b9bdc5e856e51e685846fb6c13a1f5e5432946c2c90501bdc76a1319f19e29da" +dependencies = [ + "proc-macro2 1.0.17", + "quote 1.0.6", + "syn 1.0.27", +] + [[package]] name = "rusty-fork" version = "0.2.2" @@ -2586,6 +2597,8 @@ dependencies = [ "pbkdf2", "rand 0.7.3", "rand_chacha 0.2.2", + "rustc_version", + "rustversion", "serde", "serde_bytes", "serde_derive", @@ -2604,6 +2617,7 @@ dependencies = [ "bs58 0.3.1", "proc-macro2 1.0.18", "quote 1.0.7", + "rustversion", "syn 1.0.33", ] diff --git a/sdk/Cargo.toml b/sdk/Cargo.toml index 2d91e808f5..7b8622145c 100644 --- a/sdk/Cargo.toml +++ b/sdk/Cargo.toml @@ -54,9 +54,13 @@ ed25519-dalek = { version = "=1.0.0-pre.3", optional = true } solana-crate-features = { path = "../crate-features", version = "1.2.11", optional = true } solana-logger = { path = "../logger", version = "1.2.11", optional = true } solana-sdk-macro = { path = "macro", version = "1.2.11" } +rustversion = "1.0.3" [dev-dependencies] tiny-bip39 = "0.7.0" [package.metadata.docs.rs] targets = ["x86_64-unknown-linux-gnu"] + +[build-dependencies] +rustc_version = "0.2" diff --git a/sdk/build.rs b/sdk/build.rs new file mode 100644 index 0000000000..c9550c1c5c --- /dev/null +++ b/sdk/build.rs @@ -0,0 +1,27 @@ +extern crate rustc_version; +use rustc_version::{version_meta, Channel}; + +fn main() { + // Copied and adapted from + // https://github.com/Kimundi/rustc-version-rs/blob/1d692a965f4e48a8cb72e82cda953107c0d22f47/README.md#example + // Licensed under Apache-2.0 + MIT + match version_meta().unwrap().channel { + Channel::Stable => { + println!("cargo:rustc-cfg=RUSTC_WITHOUT_SPECIALIZATION"); + } + Channel::Beta => { + println!("cargo:rustc-cfg=RUSTC_WITHOUT_SPECIALIZATION"); + } + Channel::Nightly => { + println!("cargo:rustc-cfg=RUSTC_WITH_SPECIALIZATION"); + } + Channel::Dev => { + println!("cargo:rustc-cfg=RUSTC_WITH_SPECIALIZATION"); + // See https://github.com/solana-labs/solana/issues/11055 + // We may be running the custom `rust-bpf-builder` toolchain, + // which currently needs `#![feature(proc_macro_hygiene)]` to + // be applied. + println!("cargo:rustc-cfg=RUSTC_NEEDS_PROC_MACRO_HYGIENE"); + } + } +} diff --git a/sdk/macro/Cargo.toml b/sdk/macro/Cargo.toml index 036c653e3a..15d6419dc2 100644 --- a/sdk/macro/Cargo.toml +++ b/sdk/macro/Cargo.toml @@ -16,6 +16,7 @@ bs58 = "0.3.0" proc-macro2 = "1.0" quote = "1.0" syn = { version = "1.0", features = ["full", "extra-traits"] } +rustversion = "1.0.3" [package.metadata.docs.rs] targets = ["x86_64-unknown-linux-gnu"] diff --git a/sdk/macro/src/lib.rs b/sdk/macro/src/lib.rs index e58d9b4319..5146f3ed30 100644 --- a/sdk/macro/src/lib.rs +++ b/sdk/macro/src/lib.rs @@ -5,7 +5,7 @@ extern crate proc_macro; use proc_macro::TokenStream; -use proc_macro2::Span; +use proc_macro2::{Delimiter, Span, TokenTree}; use quote::{quote, ToTokens}; use std::convert::TryFrom; use syn::{ @@ -14,7 +14,7 @@ use syn::{ parse_macro_input, punctuated::Punctuated, token::Bracket, - Expr, Ident, LitByte, LitStr, Token, + Expr, Ident, LitByte, LitStr, Path, Token, }; struct Id(proc_macro2::TokenStream); @@ -63,6 +63,75 @@ impl ToTokens for Id { } } +#[allow(dead_code)] // `respan` may be compiled out +struct RespanInput { + to_respan: Path, + respan_using: Span, +} + +impl Parse for RespanInput { + fn parse(input: ParseStream) -> Result { + let to_respan: Path = input.parse()?; + let _comma: Token![,] = input.parse()?; + let respan_tree: TokenTree = input.parse()?; + match respan_tree { + TokenTree::Group(g) if g.delimiter() == Delimiter::None => { + let ident: Ident = syn::parse2(g.stream())?; + Ok(RespanInput { + to_respan, + respan_using: ident.span(), + }) + } + val => Err(syn::Error::new_spanned( + val, + "expected None-delimited group", + )), + } + } +} + +/// A proc-macro which respans the tokens in its first argument (a `Path`) +/// to be resolved at the tokens of its second argument. +/// For internal use only. +/// +/// There must be exactly one comma in the input, +/// which is used to separate the two arguments. +/// The second argument should be exactly one token. +/// +/// For example, `respan!($crate::foo, with_span)` +/// produces the tokens `$crate::foo`, but resolved +/// at the span of `with_span`. +/// +/// The input to this function should be very short - +/// its only purpose is to override the span of a token +/// sequence containing `$crate`. For all other purposes, +/// a more general proc-macro should be used. +#[rustversion::since(1.46.0)] // `Span::resolved_at` is stable in 1.46.0 and above +#[proc_macro] +pub fn respan(input: TokenStream) -> TokenStream { + // Obtain the `Path` we are going to respan, and the ident + // whose span we will be using. + let RespanInput { + to_respan, + respan_using, + } = parse_macro_input!(input as RespanInput); + // Respan all of the tokens in the `Path` + let to_respan: proc_macro2::TokenStream = to_respan + .into_token_stream() + .into_iter() + .map(|mut t| { + // Combine the location of the token with the resolution behavior of `respan_using` + // Note: `proc_macro2::Span::resolved_at` is currently gated with cfg(procmacro2_semver_exempt) + // Once this gate is removed, we will no longer need to use 'unwrap()' to call + // the underling `proc_macro::Span::resolved_at` method. + let new_span: Span = t.span().unwrap().resolved_at(respan_using.unwrap()).into(); + t.set_span(new_span); + t + }) + .collect(); + TokenStream::from(to_respan) +} + #[proc_macro] pub fn declare_id(input: TokenStream) -> TokenStream { let id = parse_macro_input!(input as Id); diff --git a/sdk/src/entrypoint_native.rs b/sdk/src/entrypoint_native.rs index 278a5214f8..4e0c63e722 100644 --- a/sdk/src/entrypoint_native.rs +++ b/sdk/src/entrypoint_native.rs @@ -30,6 +30,63 @@ pub type LoaderEntrypoint = unsafe extern "C" fn( invoke_context: &dyn InvokeContext, ) -> Result<(), InstructionError>; +#[rustversion::since(1.46.0)] +#[macro_export] +macro_rules! declare_name { + ($name:ident) => { + #[macro_export] + macro_rules! $name { + () => { + // Subtle: + // The outer `declare_name!` macro may be expanded in another + // crate, causing the macro `$name!` to be defined in that + // crate. We want to emit a call to `$crate::id()`, and have + // `$crate` be resolved in the crate where `$name!` gets defined, + // *not* in this crate (where `declare_name! is defined). + // + // When a macro_rules! macro gets expanded, any $crate tokens + // in its output will be 'marked' with the crate they were expanded + // from. This includes nested macros like our macro `$name` - even + // though it looks like a separate macro, Rust considers it to be + // just another part of the output of `declare_program!`. + // + // We pass `$name` as the second argument to tell `respan!` to + // apply use the `Span` of `$name` when resolving `$crate::id`. + // This causes `$crate` to behave as though it was written + // at the same location as the `$name` value passed + // to `declare_name!` (e.g. the 'foo' in + // `declare_name(foo)` + // + // See the `respan!` macro for more details. + // This should use `crate::respan!` once + // https://github.com/rust-lang/rust/pull/72121 is merged: + // see https://github.com/solana-labs/solana/issues/10933. + // For now, we need to use `::solana_sdk` + // + // `respan!` respans the path `$crate::id`, which we then call (hence the extra + // parens) + ( + stringify!($name).to_string(), + ::solana_sdk::respan!($crate::id, $name)(), + ) + }; + } + }; +} + +#[rustversion::not(since(1.46.0))] +#[macro_export] +macro_rules! declare_name { + ($name:ident) => { + #[macro_export] + macro_rules! $name { + () => { + (stringify!($name).to_string(), $crate::id()) + }; + } + }; +} + /// Convenience macro to declare a native program /// /// bs58_string: bs58 string representation the program's id @@ -102,13 +159,7 @@ pub type LoaderEntrypoint = unsafe extern "C" fn( macro_rules! declare_program( ($bs58_string:expr, $name:ident, $entrypoint:expr) => ( $crate::declare_id!($bs58_string); - - #[macro_export] - macro_rules! $name { - () => { - (stringify!($name).to_string(), $crate::id()) - }; - } + $crate::declare_name!($name); #[no_mangle] pub extern "C" fn $name( @@ -126,13 +177,9 @@ macro_rules! declare_program( macro_rules! declare_loader( ($bs58_string:expr, $name:ident, $entrypoint:expr) => ( $crate::declare_id!($bs58_string); + $crate::declare_name!($name); + - #[macro_export] - macro_rules! $name { - () => { - (stringify!($name).to_string(), $crate::id()) - }; - } #[no_mangle] pub extern "C" fn $name( diff --git a/sdk/src/lib.rs b/sdk/src/lib.rs index 292ec51092..6b4cbda66d 100644 --- a/sdk/src/lib.rs +++ b/sdk/src/lib.rs @@ -1,3 +1,5 @@ +#![cfg_attr(RUSTC_NEEDS_PROC_MACRO_HYGIENE, feature(proc_macro_hygiene))] + // Allows macro expansion of `use ::solana_sdk::*` to work within this crate extern crate self as solana_sdk; @@ -60,6 +62,8 @@ pub mod timing; /// ``` pub use solana_sdk_macro::declare_id; pub use solana_sdk_macro::pubkeys; +#[rustversion::since(1.46.0)] +pub use solana_sdk_macro::respan; // On-chain program specific modules pub mod account_info;