From e8c3962ba3a955b4dea5329faae2b6241607318f Mon Sep 17 00:00:00 2001
From: Aaron Hill <aa1ronham@gmail.com>
Date: Sat, 20 Jun 2020 01:42:11 -0400
Subject: [PATCH 1/6] 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`.
---
 Cargo.lock                     | 14 +++++++
 programs/bpf_loader/Cargo.toml |  1 +
 programs/bpf_loader/src/lib.rs |  8 ++++
 sdk/Cargo.toml                 |  1 +
 sdk/macro/Cargo.toml           |  1 +
 sdk/macro/src/lib.rs           | 73 +++++++++++++++++++++++++++++++++-
 sdk/src/entrypoint_native.rs   | 70 ++++++++++++++++++++++++++------
 sdk/src/lib.rs                 |  2 +
 8 files changed, 155 insertions(+), 15 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 5933b08b76b932..89088220dfc61b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3250,6 +3250,17 @@ 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"
@@ -3772,6 +3783,7 @@ dependencies = [
  "num-derive 0.3.0",
  "num-traits",
  "rand 0.7.3",
+ "rustversion",
  "solana-runtime",
  "solana-sdk 1.3.0",
  "solana_rbpf",
@@ -4639,6 +4651,7 @@ dependencies = [
  "rand 0.7.3",
  "rand_chacha 0.2.2",
  "rustc_version",
+ "rustversion",
  "serde",
  "serde_bytes",
  "serde_derive",
@@ -4671,6 +4684,7 @@ dependencies = [
  "bs58 0.3.1",
  "proc-macro2 1.0.17",
  "quote 1.0.6",
+ "rustversion",
  "syn 1.0.27",
 ]
 
diff --git a/programs/bpf_loader/Cargo.toml b/programs/bpf_loader/Cargo.toml
index b31039a9146fea..74eb549e991856 100644
--- a/programs/bpf_loader/Cargo.toml
+++ b/programs/bpf_loader/Cargo.toml
@@ -21,6 +21,7 @@ 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 456f516db04170..41d48d0c02ce5d 100644
--- a/programs/bpf_loader/src/lib.rs
+++ b/programs/bpf_loader/src/lib.rs
@@ -340,6 +340,14 @@ 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/sdk/Cargo.toml b/sdk/Cargo.toml
index f17dc4de4a030f..cb1dc7dfe91308 100644
--- a/sdk/Cargo.toml
+++ b/sdk/Cargo.toml
@@ -55,6 +55,7 @@ solana-crate-features = { path = "../crate-features", version = "1.3.0", optiona
 solana-logger = { path = "../logger", version = "1.3.0", optional = true }
 solana-sdk-macro = { path = "macro", version = "1.3.0" }
 solana-sdk-macro-frozen-abi = { path = "macro-frozen-abi", version = "1.3.0" }
+rustversion = "1.0.3"
 
 [dev-dependencies]
 tiny-bip39 = "0.7.0"
diff --git a/sdk/macro/Cargo.toml b/sdk/macro/Cargo.toml
index 50c8234974f0d2..839e88f842db7e 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 e58d9b4319f679..f130a53055c76b 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<Self> {
+        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();
+    return 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 04ecd3b0d64fdb..24822d798601d0 100644
--- a/sdk/src/entrypoint_native.rs
+++ b/sdk/src/entrypoint_native.rs
@@ -30,6 +30,60 @@ 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 `$name` value passed
+                // to `declare_name!` (e.g. the 'foo' in
+                // `declare_name(foo)`
+                //
+                // See the `respan!` macro for more details.
+                // FIXME: Use `crate::respan!` once https://github.com/rust-lang/rust/pull/72121
+                // is merged.
+                // `respan!` respans the path `$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(), $crate::id())
+            };
+        }
+    };
+}
+
 /// Convenience macro to declare a native program
 ///
 /// bs58_string: bs58 string representation the program's id
@@ -102,13 +156,7 @@ pub type LoaderEntrypoint = unsafe extern "C" fn(
 macro_rules! declare_program(
     ($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 $name(
@@ -126,13 +174,9 @@ macro_rules! declare_program(
 macro_rules! declare_loader(
     ($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 99c3b7098f9e21..0268e705ce3f59 100644
--- a/sdk/src/lib.rs
+++ b/sdk/src/lib.rs
@@ -67,6 +67,8 @@ 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;

From 4a5ca256e60b74385103fbe03fe2f370d2d13be5 Mon Sep 17 00:00:00 2001
From: Aaron Hill <aa1ronham@gmail.com>
Date: Mon, 6 Jul 2020 19:19:48 -0400
Subject: [PATCH 2/6] Replace FIXME with an issue link

---
 sdk/src/entrypoint_native.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sdk/src/entrypoint_native.rs b/sdk/src/entrypoint_native.rs
index 24822d798601d0..f60e11344afd41 100644
--- a/sdk/src/entrypoint_native.rs
+++ b/sdk/src/entrypoint_native.rs
@@ -58,8 +58,10 @@ macro_rules! declare_name {
                 // `declare_name(foo)`
                 //
                 // See the `respan!` macro for more details.
-                // FIXME: Use `crate::respan!` once https://github.com/rust-lang/rust/pull/72121
-                // is merged.
+                // 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)
                 (

From d2b0df2eea24125e23d07e0ab7ee1f1de9c52d92 Mon Sep 17 00:00:00 2001
From: Jack May <jack@solana.com>
Date: Tue, 7 Jul 2020 09:42:26 -0700
Subject: [PATCH 3/6] Update lock files

---
 programs/bpf/Cargo.lock         | 13 +++++++++++++
 programs/librapay/Cargo.lock    | 13 +++++++++++++
 programs/move_loader/Cargo.lock | 13 +++++++++++++
 3 files changed, 39 insertions(+)

diff --git a/programs/bpf/Cargo.lock b/programs/bpf/Cargo.lock
index 555a93cbe27c3c..253b4470c081c8 100644
--- a/programs/bpf/Cargo.lock
+++ b/programs/bpf/Cargo.lock
@@ -1278,6 +1278,16 @@ 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 = "1.0.4"
@@ -1710,6 +1720,7 @@ dependencies = [
  "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 1.0.112 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_bytes 0.11.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.112 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1729,6 +1740,7 @@ dependencies = [
  "bs58 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "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)",
+ "rustversion 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2554,6 +2566,7 @@ 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 ryu 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "ed3d612bc64430efeb3f7ee6ef26d590dce0c43249217bddc62112540c7941e1"
 "checksum same-file 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
 "checksum scopeguard 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
diff --git a/programs/librapay/Cargo.lock b/programs/librapay/Cargo.lock
index ea54971512251d..4924e39c3c5bf0 100644
--- a/programs/librapay/Cargo.lock
+++ b/programs/librapay/Cargo.lock
@@ -2139,6 +2139,16 @@ 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"
@@ -2540,6 +2550,7 @@ dependencies = [
  "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 1.0.112 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_bytes 0.11.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.112 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2559,6 +2570,7 @@ dependencies = [
  "bs58 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "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)",
+ "rustversion 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 1.0.27 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -4040,6 +4052,7 @@ 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 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)" = "ed3d612bc64430efeb3f7ee6ef26d590dce0c43249217bddc62112540c7941e1"
 "checksum same-file 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
diff --git a/programs/move_loader/Cargo.lock b/programs/move_loader/Cargo.lock
index fa1ed3d20d5060..0368dc0883ba70 100644
--- a/programs/move_loader/Cargo.lock
+++ b/programs/move_loader/Cargo.lock
@@ -2214,6 +2214,17 @@ 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"
@@ -2532,6 +2543,7 @@ dependencies = [
  "rand 0.7.3",
  "rand_chacha 0.2.2",
  "rustc_version",
+ "rustversion",
  "serde",
  "serde_bytes",
  "serde_derive",
@@ -2551,6 +2563,7 @@ dependencies = [
  "bs58 0.3.1",
  "proc-macro2 1.0.17",
  "quote 1.0.6",
+ "rustversion",
  "syn 1.0.27",
 ]
 

From 76418801ede052b51c1c6bb3cc083e8b742aecf5 Mon Sep 17 00:00:00 2001
From: Aaron Hill <aa1ronham@gmail.com>
Date: Mon, 13 Jul 2020 20:55:29 -0400
Subject: [PATCH 4/6] 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.
---
 sdk/src/entrypoint_native.rs | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sdk/src/entrypoint_native.rs b/sdk/src/entrypoint_native.rs
index f60e11344afd41..c0a100aefc10fd 100644
--- a/sdk/src/entrypoint_native.rs
+++ b/sdk/src/entrypoint_native.rs
@@ -58,8 +58,9 @@ macro_rules! declare_name {
                 // `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.
+                // 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

From a9cafa209b5b43c6773068b944efe7a90a6d35f2 Mon Sep 17 00:00:00 2001
From: Aaron Hill <aa1ronham@gmail.com>
Date: Mon, 13 Jul 2020 21:16:57 -0400
Subject: [PATCH 5/6] Fix clippy lints

---
 sdk/macro/src/lib.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sdk/macro/src/lib.rs b/sdk/macro/src/lib.rs
index f130a53055c76b..5146f3ed301484 100644
--- a/sdk/macro/src/lib.rs
+++ b/sdk/macro/src/lib.rs
@@ -82,7 +82,7 @@ impl Parse for RespanInput {
                     respan_using: ident.span(),
                 })
             }
-            val @ _ => Err(syn::Error::new_spanned(
+            val => Err(syn::Error::new_spanned(
                 val,
                 "expected None-delimited group",
             )),
@@ -129,7 +129,7 @@ pub fn respan(input: TokenStream) -> TokenStream {
             t
         })
         .collect();
-    return TokenStream::from(to_respan);
+    TokenStream::from(to_respan)
 }
 
 #[proc_macro]

From 3a4672ff5d71c5d61ed8e1b164d990bbc5e803cf Mon Sep 17 00:00:00 2001
From: Aaron Hill <aa1ronham@gmail.com>
Date: Tue, 14 Jul 2020 14:06:01 -0400
Subject: [PATCH 6/6] Apply #![feature(proc_macro_hygiene)] when needed

This allows the rust-bpf-builder toolchain to build the sdk
---
 sdk/build.rs   | 5 +++++
 sdk/src/lib.rs | 1 +
 2 files changed, 6 insertions(+)

diff --git a/sdk/build.rs b/sdk/build.rs
index e17ca70cb4718b..c9550c1c5c4f22 100644
--- a/sdk/build.rs
+++ b/sdk/build.rs
@@ -17,6 +17,11 @@ fn main() {
         }
         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/src/lib.rs b/sdk/src/lib.rs
index 0268e705ce3f59..12fbe3909aec1c 100644
--- a/sdk/src/lib.rs
+++ b/sdk/src/lib.rs
@@ -1,4 +1,5 @@
 #![cfg_attr(RUSTC_WITH_SPECIALIZATION, feature(specialization))]
+#![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;