error redesign (#1462)

.github/workflows/tests.yaml

@@ -121,6 +121,7 @@ jobs:
     name: Setup Client Example Test
     runs-on: ubuntu-18.04
     strategy:
+      fail-fast: false
       matrix:
         node:
           - path: tests/events/
@@ -232,6 +233,7 @@ jobs:
     name: Test ${{ matrix.node.path }}
     runs-on: ubuntu-18.04
     strategy:
+      fail-fast: false
       matrix:
         node:
           - cmd: cd tests/sysvars && anchor test

CHANGELOG.md

@@ -25,6 +25,11 @@ incremented for features.
 * lang: Enforce that the payer for an init-ed account be marked `mut` ([#1271](https://github.com/project-serum/anchor/pull/1271)).
 * lang: All error-related code is now in the error module ([#1426](https://github.com/project-serum/anchor/pull/1426)).
 * lang: Require doc comments when using AccountInfo or UncheckedAccount types ([#1452](https://github.com/project-serum/anchor/pull/1452)).
+* lang: add [`error!`](https://docs.rs/anchor-lang/latest/anchor_lang/prelude/macro.error.html) and [`err!`](https://docs.rs/anchor-lang/latest/anchor_lang/prelude/macro.err.html) macro and `Result` type ([#1462](https://github.com/project-serum/anchor/pull/1462)).
+This change will break most programs. Do the following to upgrade:
+     * change all `ProgramResult`'s to `Result<()>` 
+     * change `#[error]` to `#[error_code]`
+     * change all `Err(MyError::SomeError.into())` to `Err(error!(MyError::SomeError))` and all `Err(ProgramError::SomeProgramError)` to `Err(ProgramError::SomeProgramError.into())` or `Err(Error::from(ProgramError::SomeProgramError).with_source(source!()))` to provide file and line source of the error (`with_source` is most useful with `ProgramError`s. `error!` already adds source information for custom and anchor internal errors).
 
 ## [0.21.0] - 2022-02-07
 

client/src/lib.rs

@@ -376,6 +376,8 @@ pub enum ClientError {
     #[error("Account not found")]
     AccountNotFound,
     #[error("{0}")]
+    AnchorError(#[from] anchor_lang::error::Error),
+    #[error("{0}")]
     ProgramError(#[from] ProgramError),
     #[error("{0}")]
     SolanaClientError(#[from] SolanaClientError),

docs/src/tutorials/tutorial-4.md

@@ -1,8 +1,8 @@
 # Errors
 
 If you've ever programmed on a blockchain, you've probably been frustrated by
-either non existant or opaque error codes. Anchor attempts to address this by
-providing the `#[error]` attribute, which can be used to create typed Errors with
+either non existent or opaque error codes. Anchor attempts to address this by
+providing the `#[error_code]` attribute, which can be used to create typed Errors with
 descriptive messages that automatically propagate to the client.
 
 ## Defining a Program
@@ -16,31 +16,26 @@ use anchor_lang::prelude::*;
 mod errors {
     use super::*;
     pub fn hello(_ctx: Context<Hello>) -> Result<()> {
-        Err(ErrorCode::Hello.into())
+        Err(error!(ErrorCode::Hello))
     }
 }
 
 #[derive(Accounts)]
 pub struct Hello {}
 
-#[error]
+#[error_code]
 pub enum ErrorCode {
     #[msg("This is an error message clients will automatically display")]
     Hello,
 }
 ```
 
-Observe the [#[error]](https://docs.rs/anchor-lang/latest/anchor_lang/attr.error.html) attribute on the `ErrorCode` enum. This macro generates two types: an `Error` and a `Result`, both of which can be used when returning from your program.
+Observe the [#[error_code]](https://docs.rs/anchor-lang/latest/anchor_lang/attr.error_code.html) attribute on the `ErrorCode` enum.
+This macro generates internal anchor code that helps anchor turn the error code into an error and display it properly.
 
-To use the `Error`, you can simply use the user defined `ErrorCode` with Rust's [From](https://doc.rust-lang.org/std/convert/trait.From.html) trait. If you're unfamiliar with `From`, no worries. Just know that you need to either call
-`.into()` when using your `ErrorCode`. Or use Rust's `?` operator, when returning an error.
-Both of these will automatically convert *into* the correct `Error`.
+To create an error, use the [`error!`](https://docs.rs/anchor-lang/latest/anchor_lang/prelude/macro.error.html) macro together with an error code. This macro creates an [`AnchorError`](https://docs.rs/anchor-lang/latest/anchor_lang/error/struct.AnchorError.html) that includes helpful information like the file and line the error was created in.
 
-::: details
-What's the deal with this From stuff? Well, because the Solana runtime expects a [ProgramError](https://docs.rs/solana-program/1.5.5/solana_program/program_error/enum.ProgramError.html) in the return value. The framework needs to wrap the user defined error code into a
-`ProgramError::Code` variant, before returning. The alternative would be to use the
-`ProgramError` directly.
-:::
+To make writing errors even easier, anchor also provides the [`err!`](https://docs.rs/anchor-lang/latest/anchor_lang/prelude/macro.err.html and the [`require!`](https://docs.rs/anchor-lang/latest/anchor_lang/prelude/macro.require.html macros.
 
 ## Using the Client
 

examples/tutorial/basic-0/programs/basic-0/src/lib.rs

@@ -5,7 +5,7 @@ declare_id!("Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS");
 #[program]
 mod basic_0 {
     use super::*;
-    pub fn initialize(_ctx: Context<Initialize>) -> ProgramResult {
+    pub fn initialize(_ctx: Context<Initialize>) -> Result<()> {
         Ok(())
     }
 }

examples/tutorial/basic-1/programs/basic-1/src/lib.rs

@@ -6,13 +6,13 @@ declare_id!("Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS");
 mod basic_1 {
     use super::*;
 
-    pub fn initialize(ctx: Context<Initialize>, data: u64) -> ProgramResult {
+    pub fn initialize(ctx: Context<Initialize>, data: u64) -> Result<()> {
         let my_account = &mut ctx.accounts.my_account;
         my_account.data = data;
         Ok(())
     }
 
-    pub fn update(ctx: Context<Update>, data: u64) -> ProgramResult {
+    pub fn update(ctx: Context<Update>, data: u64) -> Result<()> {
         let my_account = &mut ctx.accounts.my_account;
         my_account.data = data;
         Ok(())

examples/tutorial/basic-2/programs/basic-2/src/lib.rs

@@ -6,14 +6,14 @@ declare_id!("Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS");
 mod basic_2 {
     use super::*;
 
-    pub fn create(ctx: Context<Create>, authority: Pubkey) -> ProgramResult {
+    pub fn create(ctx: Context<Create>, authority: Pubkey) -> Result<()> {
         let counter = &mut ctx.accounts.counter;
         counter.authority = authority;
         counter.count = 0;
         Ok(())
     }
 
-    pub fn increment(ctx: Context<Increment>) -> ProgramResult {
+    pub fn increment(ctx: Context<Increment>) -> Result<()> {
         let counter = &mut ctx.accounts.counter;
         counter.count += 1;
         Ok(())

examples/tutorial/basic-3/programs/puppet-master/src/lib.rs

@@ -9,7 +9,7 @@ declare_id!("HmbTLCmaGvZhKnn1Zfa1JVnp7vkMV4DYVxPLWBVoN65L");
 #[program]
 mod puppet_master {
     use super::*;
-    pub fn pull_strings(ctx: Context<PullStrings>, data: u64) -> ProgramResult {
+    pub fn pull_strings(ctx: Context<PullStrings>, data: u64) -> anchor_lang::Result<()> {
         let cpi_program = ctx.accounts.puppet_program.to_account_info();
         let cpi_accounts = SetData {
             puppet: ctx.accounts.puppet.to_account_info(),

examples/tutorial/basic-3/programs/puppet/src/lib.rs

@@ -5,11 +5,11 @@ declare_id!("Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS");
 #[program]
 pub mod puppet {
     use super::*;
-    pub fn initialize(_ctx: Context<Initialize>) -> ProgramResult {
+    pub fn initialize(_ctx: Context<Initialize>) -> Result<()> {
         Ok(())
     }
 
-    pub fn set_data(ctx: Context<SetData>, data: u64) -> ProgramResult {
+    pub fn set_data(ctx: Context<SetData>, data: u64) -> Result<()> {
         let puppet = &mut ctx.accounts.puppet;
         puppet.data = data;
         Ok(())

examples/tutorial/basic-4/programs/basic-4/src/lib.rs

@@ -14,16 +14,16 @@ pub mod basic_4 {
     }
 
     impl Counter {
-        pub fn new(ctx: Context<Auth>) -> Result<Self> {
+        pub fn new(ctx: Context<Auth>) -> anchor_lang::Result<Self> {
             Ok(Self {
                 authority: *ctx.accounts.authority.key,
                 count: 0,
             })
         }
 
-        pub fn increment(&mut self, ctx: Context<Auth>) -> Result<()> {
+        pub fn increment(&mut self, ctx: Context<Auth>) -> anchor_lang::Result<()> {
             if &self.authority != ctx.accounts.authority.key {
-                return Err(ErrorCode::Unauthorized.into());
+                return Err(error!(ErrorCode::Unauthorized));
             }
             self.count += 1;
             Ok(())
@@ -37,7 +37,7 @@ pub struct Auth<'info> {
 }
 // #endregion code
 
-#[error]
+#[error_code]
 pub enum ErrorCode {
     #[msg("You are not authorized to perform this action.")]
     Unauthorized,

lang/attribute/account/src/lib.rs

@@ -146,7 +146,7 @@ pub fn account(
                 // It's expected on-chain programs deserialize via zero-copy.
                 #[automatically_derived]
                 impl #impl_gen anchor_lang::AccountDeserialize for #account_name #type_gen #where_clause {
-                    fn try_deserialize(buf: &mut &[u8]) -> std::result::Result<Self, ProgramError> {
+                    fn try_deserialize(buf: &mut &[u8]) -> anchor_lang::Result<Self> {
                         if buf.len() < #discriminator.len() {
                             return Err(anchor_lang::error::ErrorCode::AccountDiscriminatorNotFound.into());
                         }
@@ -157,7 +157,7 @@ pub fn account(
                         Self::try_deserialize_unchecked(buf)
                     }
 
-                    fn try_deserialize_unchecked(buf: &mut &[u8]) -> std::result::Result<Self, ProgramError> {
+                    fn try_deserialize_unchecked(buf: &mut &[u8]) -> anchor_lang::Result<Self> {
                         let data: &[u8] = &buf[8..];
                         // Re-interpret raw bytes into the POD data structure.
                         let account = anchor_lang::__private::bytemuck::from_bytes(data);
@@ -175,20 +175,21 @@ pub fn account(
 
                 #[automatically_derived]
                 impl #impl_gen anchor_lang::AccountSerialize for #account_name #type_gen #where_clause {
-                    fn try_serialize<W: std::io::Write>(&self, writer: &mut W) -> std::result::Result<(), ProgramError> {
-                        writer.write_all(&#discriminator).map_err(|_| anchor_lang::error::ErrorCode::AccountDidNotSerialize)?;
-                        AnchorSerialize::serialize(
-                            self,
-                            writer
-                        )
-                            .map_err(|_| anchor_lang::error::ErrorCode::AccountDidNotSerialize)?;
+                    fn try_serialize<W: std::io::Write>(&self, writer: &mut W) -> anchor_lang::Result<()> {
+                        if writer.write_all(&#discriminator).is_err() {
+                            return Err(anchor_lang::error::ErrorCode::AccountDidNotSerialize.into());
+                        }
+
+                        if AnchorSerialize::serialize(self, writer).is_err() {
+                            return Err(anchor_lang::error::ErrorCode::AccountDidNotSerialize.into());
+                        }
                         Ok(())
                     }
                 }
 
                 #[automatically_derived]
                 impl #impl_gen anchor_lang::AccountDeserialize for #account_name #type_gen #where_clause {
-                    fn try_deserialize(buf: &mut &[u8]) -> std::result::Result<Self, ProgramError> {
+                    fn try_deserialize(buf: &mut &[u8]) -> anchor_lang::Result<Self> {
                         if buf.len() < #discriminator.len() {
                             return Err(anchor_lang::error::ErrorCode::AccountDiscriminatorNotFound.into());
                         }
@@ -199,7 +200,7 @@ pub fn account(
                         Self::try_deserialize_unchecked(buf)
                     }
 
-                    fn try_deserialize_unchecked(buf: &mut &[u8]) -> std::result::Result<Self, ProgramError> {
+                    fn try_deserialize_unchecked(buf: &mut &[u8]) -> anchor_lang::Result<Self> {
                         let mut data: &[u8] = &buf[8..];
                         AnchorDeserialize::deserialize(&mut data)
                             .map_err(|_| anchor_lang::error::ErrorCode::AccountDidNotDeserialize.into())

lang/attribute/error/Cargo.toml

@@ -17,4 +17,4 @@ anchor-debug = ["anchor-syn/anchor-debug"]
 proc-macro2 = "1.0"
 quote = "1.0"
 syn = { version = "1.0.60", features = ["full"] }
-anchor-syn = { path = "../../syn", version = "0.21.0" }
+anchor-syn = { path = "../../syn", version = "0.21.0" }

lang/attribute/error/src/lib.rs

@@ -1,9 +1,12 @@
 extern crate proc_macro;
 
-use anchor_syn::codegen::error as error_codegen;
-use anchor_syn::parser::error as error_parser;
+use proc_macro::TokenStream;
+use quote::quote;
+
+use anchor_syn::parser::error::{self as error_parser, ErrorWithAccountNameInput};
 use anchor_syn::ErrorArgs;
-use syn::parse_macro_input;
+use anchor_syn::{codegen, parser::error::ErrorInput};
+use syn::{parse_macro_input, Expr};
 
 /// Generates `Error` and `type Result<T> = Result<T, Error>` types to be
 /// used as return types from Anchor instruction handlers. Importantly, the
@@ -21,14 +24,14 @@ use syn::parse_macro_input;
 /// mod errors {
 ///     use super::*;
 ///     pub fn hello(_ctx: Context<Hello>) -> Result<()> {
-///         Err(MyError::Hello.into())
+///         Err(error!(MyError::Hello))
 ///     }
 /// }
 ///
 /// #[derive(Accounts)]
 /// pub struct Hello {}
 ///
-/// #[error]
+/// #[error_code]
 /// pub enum MyError {
 ///     #[msg("This is an error message clients will automatically display")]
 ///     Hello,
@@ -40,14 +43,14 @@ use syn::parse_macro_input;
 /// [`ProgramError`](../solana_program/enum.ProgramError.html), which is used
 /// pervasively, throughout solana program crates. The generated `Error` type
 /// should almost never be used directly, as the user defined error is
-/// preferred. In the example above, `MyError::Hello.into()`.
+/// preferred. In the example above, `error!(MyError::Hello)`.
 ///
 /// # Msg
 ///
 /// The `#[msg(..)]` attribute is inert, and is used only as a marker so that
 /// parsers  and IDLs can map error codes to error messages.
 #[proc_macro_attribute]
-pub fn error(
+pub fn error_code(
     args: proc_macro::TokenStream,
     input: proc_macro::TokenStream,
 ) -> proc_macro::TokenStream {
@@ -56,6 +59,69 @@ pub fn error(
         false => Some(parse_macro_input!(args as ErrorArgs)),
     };
     let mut error_enum = parse_macro_input!(input as syn::ItemEnum);
-    let error = error_codegen::generate(error_parser::parse(&mut error_enum, args));
+    let error = codegen::error::generate(error_parser::parse(&mut error_enum, args));
     proc_macro::TokenStream::from(error)
 }
+
+/// Generates an [`Error::AnchorError`](../../anchor_lang/error/enum.Error.html) that includes file and line information.
+///
+/// # Example
+/// ```rust,ignore
+/// #[program]
+/// mod errors {
+///     use super::*;
+///     pub fn example(_ctx: Context<Example>) -> Result<()> {
+///         Err(error!(MyError::Hello))
+///     }
+/// }
+///
+/// #[error_code]
+/// pub enum MyError {
+///     #[msg("This is an error message clients will automatically display")]
+///     Hello,
+/// }
+/// ```
+#[proc_macro]
+pub fn error(ts: proc_macro::TokenStream) -> TokenStream {
+    let input = parse_macro_input!(ts as ErrorInput);
+    let error_code = input.error_code;
+    create_error(error_code, true, None)
+}
+
+#[proc_macro]
+pub fn error_with_account_name(ts: proc_macro::TokenStream) -> TokenStream {
+    let input = parse_macro_input!(ts as ErrorWithAccountNameInput);
+    let error_code = input.error_code;
+    let account_name = input.account_name;
+    create_error(error_code, false, Some(account_name))
+}
+
+fn create_error(error_code: Expr, source: bool, account_name: Option<Expr>) -> TokenStream {
+    let source = if source {
+        quote! {
+            Some(anchor_lang::error::Source {
+                filename: file!(),
+                line: line!()
+            })
+        }
+    } else {
+        quote! {
+            None
+        }
+    };
+    let account_name = match account_name {
+        Some(_) => quote! { Some(#account_name.to_string()) },
+        None => quote! { None },
+    };
+    TokenStream::from(quote! {
+        anchor_lang::error::Error::from(
+            anchor_lang::error::AnchorError {
+                error_name: #error_code.name(),
+                error_code_number: #error_code.into(),
+                error_msg: #error_code.to_string(),
+                source: #source,
+                account_name: #account_name
+            }
+        )
+    })
+}