fix: Apply quote_spanned selectively in #[program] macro for better error attribution

Signed-off-by: AvhiMaz <avhimazumder5@outlook.com>

Author: AvhiMaz

lang/syn/src/codegen/program/accounts.rs

@@ -1,10 +1,8 @@
 use crate::Program;
 use heck::SnakeCase;
-use quote::quote_spanned;
-use syn::spanned::Spanned;
+use quote::quote;
 
 pub fn generate(program: &Program) -> proc_macro2::TokenStream {
-    let program_span = program.program_mod.span();
     let mut accounts = std::collections::HashMap::new();
 
     // Go through instruction accounts.
@@ -23,7 +21,7 @@ pub fn generate(program: &Program) -> proc_macro2::TokenStream {
         .iter()
         .map(|(macro_name, cfgs)| {
             let macro_name: proc_macro2::TokenStream = macro_name.parse().unwrap();
-            quote_spanned! { program_span =>
+            quote! {
                 #(#cfgs)*
                 pub use crate::#macro_name::*;
             }
@@ -33,7 +31,7 @@ pub fn generate(program: &Program) -> proc_macro2::TokenStream {
     // TODO: calculate the account size and add it as a constant field to
     //       each struct here. This is convenient for Rust clients.
 
-    quote_spanned! { program_span =>
+    quote! {
         /// An Anchor generated module, providing a set of structs
         /// mirroring the structs deriving `Accounts`, where each field is
         /// a `Pubkey`. This is useful for specifying accounts for a client.

lang/syn/src/codegen/program/cpi.rs

@@ -3,12 +3,10 @@ use crate::codegen::program::common::{
 };
 use crate::Program;
 use heck::SnakeCase;
-use quote::{quote_spanned, ToTokens};
-#[allow(unused_imports)]
+use quote::{quote, quote_spanned, ToTokens};
 use syn::spanned::Spanned;
 
 pub fn generate(program: &Program) -> proc_macro2::TokenStream {
-    let program_span = program.program_mod.span();
     // Generate cpi methods for global methods.
     let global_cpi_methods: Vec<proc_macro2::TokenStream> = program
         .ixs
@@ -75,7 +73,7 @@ pub fn generate(program: &Program) -> proc_macro2::TokenStream {
 
     let accounts = generate_accounts(program);
 
-    quote_spanned! { program_span =>
+    quote! {
         #[cfg(feature = "cpi")]
         pub mod cpi {
             use super::*;
@@ -101,7 +99,6 @@ pub fn generate(program: &Program) -> proc_macro2::TokenStream {
 }
 
 pub fn generate_accounts(program: &Program) -> proc_macro2::TokenStream {
-    let program_span = program.program_mod.span();
     let mut accounts = std::collections::HashMap::new();
 
     // Go through instruction accounts.
@@ -121,14 +118,14 @@ pub fn generate_accounts(program: &Program) -> proc_macro2::TokenStream {
         .iter()
         .map(|(macro_name, cfgs)| {
             let macro_name: proc_macro2::TokenStream = macro_name.parse().unwrap();
-            quote_spanned! { program_span =>
+            quote! {
                 #(#cfgs)*
                 pub use crate::#macro_name::*;
             }
         })
         .collect();
 
-    quote_spanned! { program_span =>
+    quote! {
         /// An Anchor generated module, providing a set of structs
         /// mirroring the structs deriving `Accounts`, where each field is
         /// an `AccountInfo`. This is useful for CPI.

lang/syn/src/codegen/program/dispatch.rs

@@ -1,6 +1,6 @@
 use crate::Program;
 use heck::CamelCase;
-use quote::quote_spanned;
+use quote::{quote, quote_spanned};
 use syn::spanned::Spanned;
 
 pub fn generate(program: &Program) -> proc_macro2::TokenStream {
@@ -30,10 +30,9 @@ pub fn generate(program: &Program) -> proc_macro2::TokenStream {
     });
 
     // Generate the event-cpi instruction handler based on whether the `event-cpi` feature is enabled.
-    let program_span = program.program_mod.span();
     let event_cpi_handler = {
         #[cfg(feature = "event-cpi")]
-        quote_spanned! { program_span =>
+        quote! {
             // `event-cpi` feature is enabled, dispatch self-cpi instruction
             __private::__events::__event_dispatch(
                 program_id,
@@ -42,7 +41,7 @@ pub fn generate(program: &Program) -> proc_macro2::TokenStream {
             )
         }
         #[cfg(not(feature = "event-cpi"))]
-        quote_spanned! { program_span =>
+        quote! {
             // `event-cpi` feature is not enabled
             Err(anchor_lang::error::ErrorCode::EventInstructionStub.into())
         }
@@ -60,8 +59,7 @@ pub fn generate(program: &Program) -> proc_macro2::TokenStream {
             }
         })
         .unwrap_or_else(|| {
-            let program_span = program.program_mod.span();
-            quote_spanned! { program_span =>
+            quote! {
                 Err(anchor_lang::error::ErrorCode::InstructionFallbackNotFound.into())
             }
         });

lang/syn/src/codegen/program/handlers.rs

@@ -1,7 +1,7 @@
 use crate::codegen::program::common::*;
 use crate::program_codegen::idl::idl_accounts_and_functions;
 use crate::Program;
-use quote::{quote_spanned, ToTokens};
+use quote::{quote, quote_spanned, ToTokens};
 use syn::spanned::Spanned;
 
 // Generate non-inlined wrappers for each instruction handler, since Solana's
@@ -12,9 +12,8 @@ pub fn generate(program: &Program) -> proc_macro2::TokenStream {
     // A constant token stream that stores the accounts and functions, required to live
     // inside the target program in order to get the program ID.
     let idl_accounts_and_functions = idl_accounts_and_functions();
-    let program_span = program.program_mod.span();
     let non_inlined_idl: proc_macro2::TokenStream = {
-        quote_spanned! { program_span =>
+        quote! {
             // Entry for all IDL related instructions. Use the "no-idl" feature
             // to eliminate this code, for example, if one wants to make the
             // IDL no longer mutable or if one doesn't want to store the IDL
@@ -169,7 +168,7 @@ pub fn generate(program: &Program) -> proc_macro2::TokenStream {
         })
         .collect();
 
-    quote_spanned! { program_span =>
+    quote! {
         /// Create a private module to not clutter the program's namespace.
         /// Defines an entrypoint for each individual instruction handler
         /// wrapper.
@@ -201,9 +200,8 @@ fn generate_event_cpi_mod() -> proc_macro2::TokenStream {
     {
         let authority = crate::parser::accounts::event_cpi::EventAuthority::get();
         let authority_name = authority.name;
-        let span = proc_macro2::Span::call_site();
 
-        quote_spanned! { span =>
+        quote! {
             /// __events mod defines handler for self-cpi based event logging
             pub mod __events {
                 use super::*;
@@ -237,7 +235,6 @@ fn generate_event_cpi_mod() -> proc_macro2::TokenStream {
     }
     #[cfg(not(feature = "event-cpi"))]
     {
-        let span = proc_macro2::Span::call_site();
-        quote_spanned! { span => }
+        quote! { }
     }
 }

lang/syn/src/codegen/program/idl.rs

@@ -1,8 +1,7 @@
-use quote::quote_spanned;
+use quote::quote;
 
 pub fn idl_accounts_and_functions() -> proc_macro2::TokenStream {
-    let span = proc_macro2::Span::call_site();
-    quote_spanned! { span =>
+    quote! {
         use anchor_lang::idl::ERASED_AUTHORITY;
 
         #[account("internal")]

lang/syn/src/codegen/program/instruction.rs

@@ -2,11 +2,10 @@ use crate::codegen::program::common::*;
 use crate::parser;
 use crate::Program;
 use heck::CamelCase;
-use quote::quote_spanned;
+use quote::{quote, quote_spanned};
 use syn::spanned::Spanned;
 
 pub fn generate(program: &Program) -> proc_macro2::TokenStream {
-    let program_span = program.program_mod.span();
     let variants: Vec<proc_macro2::TokenStream> = program
         .ixs
         .iter()
@@ -78,7 +77,7 @@ pub fn generate(program: &Program) -> proc_macro2::TokenStream {
         })
         .collect();
 
-    quote_spanned! { program_span =>
+    quote! {
         /// An Anchor generated module containing the program's set of
         /// instructions, where each method handler in the `#[program]` mod is
         /// associated with a struct defining the input arguments to the

lang/syn/src/codegen/program/mod.rs

@@ -1,6 +1,5 @@
 use crate::Program;
-use quote::quote_spanned;
-use syn::spanned::Spanned;
+use quote::quote;
 
 mod accounts;
 pub mod common;
@@ -13,7 +12,6 @@ mod instruction;
 
 pub fn generate(program: &Program) -> proc_macro2::TokenStream {
     let mod_name = &program.name;
-    let program_span = program.program_mod.span();
 
     let entry = entry::generate(program);
     let dispatch = dispatch::generate(program);
@@ -25,7 +23,7 @@ pub fn generate(program: &Program) -> proc_macro2::TokenStream {
 
     #[allow(clippy::let_and_return)]
     let ret = {
-        quote_spanned! { program_span =>
+        quote! {
             // TODO: remove once we allow segmented paths in `Accounts` structs.
             use self::#mod_name::*;
 
@@ -42,7 +40,7 @@ pub fn generate(program: &Program) -> proc_macro2::TokenStream {
     #[cfg(feature = "idl-build")]
     {
         let idl_build_impl = crate::idl::gen_idl_print_fn_program(program);
-        return quote_spanned! { program_span =>
+        return quote! {
             #ret
             #idl_build_impl
         };