feat(ENG-288): Add field attributes to #[frame] for declarative constant generation

build/src/inject.rs

@@ -65,11 +65,20 @@ impl Constant {
             }
         };
 
+        let comment_line = format!("# {}", comment);
+        assert!(
+            comment_line.len() <= max_width,
+            "comment exceeds {} chars ({} chars): {}",
+            max_width,
+            comment_line.len(),
+            comment_line,
+        );
+
         let inline = format!(".equ {}, {} # {}", name, value_str, comment);
         if inline.len() <= max_width {
             inline
         } else {
-            format!("# {}\n.equ {}, {}", comment, name, value_str)
+            format!("{}\n.equ {}, {}", comment_line, name, value_str)
         }
     }
 }
@@ -148,9 +157,17 @@ fn render_group(group: &ConstantGroup) -> String {
     if group.comment.is_empty() {
         directives.join("\n")
     } else {
+        let comment_line = format!("# {}", group.comment);
+        assert!(
+            comment_line.len() <= MAX_LINE_WIDTH,
+            "group comment exceeds {} chars ({} chars): {}",
+            MAX_LINE_WIDTH,
+            comment_line.len(),
+            comment_line,
+        );
         format!(
-            "# {}\n{}\n{}\n{}",
-            group.comment,
+            "{}\n{}\n{}\n{}",
+            comment_line,
             SEPARATOR,
             directives.join("\n"),
             SEPARATOR,

docs/src/development/build-scaffolding.md

@@ -89,6 +89,13 @@ In frame-relative mode, generated constant names include a `_FM_` infix after
 the prefix (e.g. `RM_FM_PDA_OFF` instead of `RM_PDA_OFF`) to distinguish
 frame-relative constants from other offset constants.
 
+::: tip
+For frame structs, [`#[frame("mod")]`](#frame) with field attributes can
+generate the constant group directly, making a separate `constant_group!`
+invocation unnecessary. The `constant_group!` macro remains available for
+non-frame groups (e.g. input buffer offsets, standalone immediates).
+:::
+
 <Include rs="interface::market#register_market_stack" collapsible/>
 
 Each group generates:
@@ -152,6 +159,28 @@ mappings and the struct's doc comment in proc-macro shared state so that
 [`constant_group!`](#constant_group) can auto-discover frame fields and
 derive its header comment.
 
+When called as `#[frame("module_name")]` with `#[inject("target")]` and
+`#[prefix("PREFIX")]` on the struct, it also generates a constant group
+module directly from field-level attributes, eliminating the need for a
+separate `constant_group!` invocation. Supported field attributes:
+
+- `#[offset]`: aligned frame-relative offset (`_OFF` suffix). Name is
+  auto-inferred from the field name via `SCREAMING_SNAKE_CASE`, or
+  overridden with `#[offset(CUSTOM_NAME)]`
+- `#[unaligned_offset]`: frame-relative offset without alignment (`_UOFF`)
+- `#[pubkey_offsets]`: base offset + four chunk offsets
+- `#[signer_seeds]`: auto-expands seed offsets from
+  [`signer_seeds!`](#signer_seeds) shared state
+- `#[cpi_accounts]`: auto-expands CPI account offsets from
+  [`cpi_accounts!`](#cpi_accounts) shared state
+- `#[sol_instruction]`: base offset + per-field `SolInstruction` offsets
+
+Sub-field access uses comma-separated form:
+`#[unaligned_offset(NAME, subfield, "doc")]`.
+
+Struct-level `#[relative_offset(NAME, from, to, "doc")]` attributes compute
+the difference between two field offsets.
+
 <Include rs="interface::market#frame_example" collapsible/>
 
 ### `#[svm_data]`
@@ -168,8 +197,9 @@ input buffer segments, tree nodes).
 Function-like macro that defines a `#[repr(C)]` struct where every field is
 typed as `SolSignerSeed`. Field names are registered in proc-macro shared
 state so that `signer_seeds!(field)` inside a
-[`constant_group!`](#constant_group) can auto-discover all seed fields by
-looking up the parent field's type on the frame struct.
+[`constant_group!`](#constant_group), or an `#[signer_seeds]` field attribute
+on a [`#[frame]`](#frame) struct, can auto-discover all seed fields by
+looking up the parent field's type.
 
 <Include rs="interface::market#signer_seeds_example" collapsible/>
 
@@ -178,9 +208,9 @@ looking up the parent field's type on the frame struct.
 Function-like macro that defines a `#[repr(C)]` struct with `SolAccountInfo`
 fields first (contiguous), then `SolAccountMeta` fields (contiguous), for each
 named account. Field names are registered in proc-macro shared state so that
-`cpi_accounts!(field)` inside a [`constant_group!`](#constant_group) can
-auto-discover all account fields by looking up the parent field's type on the
-frame struct.
+`cpi_accounts!(field)` inside a [`constant_group!`](#constant_group), or a
+`#[cpi_accounts]` field attribute on a [`#[frame]`](#frame) struct, can
+auto-discover all account fields by looking up the parent field's type.
 
 ### `size_of_group!`
 

interface/src/market.rs

@@ -107,6 +107,7 @@ pub enum RegisterMarketAccounts {
 }
 // endregion: register_market_accounts
 
+// region: register_market_stack
 #[svm_data]
 /// CPI instruction data for CreateAccount.
 pub struct CreateAccountData {
@@ -116,8 +117,6 @@ pub struct CreateAccountData {
     pub space: u64,
     /// Zero-initialized on stack.
     pub owner: Address,
-    /// Included for alignment on stack.
-    _pad: u32,
 }
 
 cpi_accounts! {
@@ -131,10 +130,9 @@ cpi_accounts! {
     }
 }
 
-// region: register_market_stack
 // region: signer_seeds_example
 signer_seeds! {
-    PDASignerSeeds {
+    SignerSeeds {
         /// Market PDA: base mint address. Vault: market PDA address.
         idx_0,
         /// Market PDA: quote mint address. Vault: vault index (0 = base, 1 = quote).
@@ -146,126 +144,140 @@ signer_seeds! {
 // endregion: signer_seeds_example
 
 // region: frame_example
-#[frame]
+#[frame("frame")]
+#[prefix("RM")]
+#[inject("market/register")]
+#[relative_offset(
+    PDA_SEEDS_TO_SOL_INSN,
+    pda_seeds,
+    sol_instruction,
+    "From pda_seeds to sol_instruction."
+)]
+#[relative_offset(PDA_TO_SIGNERS_SEEDS, pda, signers_seeds, "From pda to signers_seeds.")]
+#[relative_offset(
+    CREATE_ACCT_DATA_TO_CPI_ACCT_METAS,
+    create_account_data, cpi_accounts.idx_0_meta,
+    "From create_account_data to CPI account metas.")
+]
 /// Stack frame for REGISTER-MARKET.
 pub struct RegisterMarketFrame {
     /// Pointer to token program address.
+    #[offset]
     pub token_program_id: *const Address,
+
     /// Pointer to program ID in input buffer.
+    #[offset]
     pub program_id: *const Address,
+
     /// Saved input buffer pointer.
+    #[offset]
     pub input: u64,
+
     /// Saved input_shifted pointer.
+    #[offset]
     pub input_shifted: u64,
+
     /// From Rent sysvar.
+    #[offset]
     pub lamports_per_byte: u64,
-    /// Return value from GetAccountDataSize CPI, to check token account data size at runtime.
+
+    /// Return value from spl_token_2022::GetAccountDataSize.
+    #[offset]
     pub token_account_data_size: u64,
+
     /// Pointer to mint account for vault initialization.
+    #[offset]
     pub mint: *const RuntimeAccount,
+
     /// Pointer to Rent sysvar account.
+    #[offset]
     pub rent: *const RuntimeAccount,
-    /// Signer seeds for PDA derivation and CPI signing.
-    pub pda_seeds: PDASignerSeeds,
-    /// From `sol_try_find_program_address`.
+
+    /// PDA signer seeds.
+    #[signer_seeds]
+    pub pda_seeds: SignerSeeds,
+
+    /// PDA address.
+    #[pubkey_offsets]
     pub pda: Address,
-    /// System Program pubkey, zero-initialized on stack
+
+    /// System Program pubkey.
+    #[pubkey_offsets]
     pub system_program_pubkey: Address,
-    /// Pointer to System Program ID in input buffer.
+
+    /// System Program ID in input buffer.
+    #[offset]
     pub system_program_id: *const Address,
-    /// Get return data program ID for CPI calls, zero-initialized on stack.
+
+    /// Get return data program ID for CPI calls.
+    #[offset]
     pub get_return_data_program_id: Address,
-    /// CPI instruction data for CreateAccount.
+
+    /// CreateAccount instruction data.
+    #[offset(CREATE_ACCT_DATA)]
+    #[unaligned_offset(
+        CREATE_ACCT_LAMPORTS,
+        lamports,
+        "Lamports field within CreateAccount instruction data."
+    )]
+    #[unaligned_offset(
+        CREATE_ACCT_SPACE,
+        space,
+        "Space field within CreateAccount instruction data."
+    )]
+    #[unaligned_pubkey_offsets(
+        CREATE_ACCT_OWNER,
+        owner,
+        "Owner field within CreateAccount instruction data."
+    )]
     pub create_account_data: CreateAccountData,
-    /// CPI instruction data for InitializeAccount2.
-    pub initialize_account_2_data: InitializeAccount2,
+
     /// GetAccountDataSize CPI instruction data.
+    #[unaligned_offset]
     pub get_account_data_size_data: u8,
-    /// CPI accounts for CreateAccount and InitializeAccount2.
+
+    /// Vault index for PDA derivation.
+    #[unaligned_offset]
+    pub vault_index: u8,
+
+    /// Whether the current token program is Token 2022.
+    #[unaligned_offset]
+    pub token_program_is_2022: u8,
+
+    /// Padding for 8-byte alignment after CreateAccountData.
+    _pad: u8,
+
+    /// InitializeAccount2 CPI instruction data.
+    #[offset(INIT_ACCT_2_DATA)]
+    #[unaligned_offset(
+        INIT_ACCT_2_DISC,
+        discriminant,
+        "Discriminant field within InitializeAccount2 instruction data."
+    )]
+    #[unaligned_pubkey_offsets(
+        INIT_ACCT_2_PROPRIETOR,
+        proprietor,
+        "Proprietor field within InitializeAccount2 instruction data."
+    )]
+    pub initialize_account_2_data: InitializeAccount2,
+
+    /// CPI accounts.
+    #[cpi_accounts(CPI)]
     pub cpi_accounts: CPIAccounts,
+
     /// Signers seeds for CPI.
+    #[unaligned_offset(SIGNERS_SEEDS_ADDR, addr, "Signers seeds address.")]
+    #[unaligned_offset(SIGNERS_SEEDS_LEN, len, "Signers seeds length.")]
     pub signers_seeds: SolSignerSeeds,
-    /// Re-used across CPIs, zero-initialized on stack.
+
+    /// Solana instruction.
+    #[sol_instruction(SOL_INSN)]
     pub sol_instruction: SolInstruction,
-    /// From `sol_try_find_program_address`.
+
+    /// Bump seed.
+    #[offset]
     pub bump: u8,
-    /// Vault index for vault PDA derivation.
-    pub vault_index: u8,
-    /// Whether the current token program is Token 2022 (zero-initialized on stack).
-    pub token_program_is_2022: u8,
 }
 // endregion: frame_example
 
-constant_group! {
-    #[prefix("RM")]
-    #[inject("market/register")]
-    #[frame(RegisterMarketFrame)]
-    frame {
-        /// Pointer to token program address.
-        TOKEN_PROGRAM_ID = offset!(token_program_id),
-        /// Pointer to program ID in input buffer.
-        PROGRAM_ID = offset!(program_id),
-        /// Saved input buffer pointer.
-        INPUT = offset!(input),
-        /// Saved input_shifted pointer.
-        INPUT_SHIFTED = offset!(input_shifted),
-        /// From Rent sysvar.
-        LAMPORTS_PER_BYTE = offset!(lamports_per_byte),
-        /// Return value from GetAccountDataSize CPI, to check token account data size at runtime.
-        TOKEN_ACCOUNT_DATA_SIZE = offset!(token_account_data_size),
-        /// Pointer to mint account for vault initialization.
-        MINT = offset!(mint),
-        /// Pointer to Rent sysvar account.
-        RENT = offset!(rent),
-        /// PDA signer seeds.
-        PDA_SEEDS = signer_seeds!(pda_seeds),
-        /// PDA address.
-        PDA = pubkey_offsets!(pda),
-        /// System Program pubkey.
-        SYSTEM_PROGRAM_PUBKEY = pubkey_offsets!(system_program_pubkey),
-        /// System Program ID in input buffer.
-        SYSTEM_PROGRAM_ID = offset!(system_program_id),
-        /// Get return data program ID for CPI calls.
-        GET_RETURN_DATA_PROGRAM_ID = offset!(get_return_data_program_id),
-        /// CreateAccount instruction data.
-        CREATE_ACCT_DATA = offset!(create_account_data),
-        /// Lamports field within CreateAccount instruction data.
-        CREATE_ACCT_LAMPORTS = unaligned_offset!(create_account_data.lamports),
-        /// Space field within CreateAccount instruction data.
-        CREATE_ACCT_SPACE = unaligned_offset!(create_account_data.space),
-        /// Owner field within CreateAccount instruction data.
-        CREATE_ACCT_OWNER = unaligned_pubkey_offsets!(create_account_data.owner),
-        /// InitializeAccount2 CPI instruction data.
-        INIT_ACCT_2_DATA = offset!(initialize_account_2_data),
-        /// Discriminant field within InitializeAccount2 instruction data.
-        INIT_ACCT_2_DISC = unaligned_offset!(initialize_account_2_data.discriminant),
-        /// Proprietor field within InitializeAccount2 instruction data.
-        INIT_ACCT_2_PROPRIETOR = unaligned_pubkey_offsets!(initialize_account_2_data.proprietor),
-        /// GetAccountDataSize CPI instruction data.
-        GET_ACCOUNT_DATA_SIZE_DATA = unaligned_offset!(get_account_data_size_data),
-        /// CPI accounts.
-        CPI = cpi_accounts!(cpi_accounts),
-        /// Signers seeds address.
-        SIGNERS_SEEDS_ADDR = unaligned_offset!(signers_seeds.addr),
-        /// Signers seeds length.
-        SIGNERS_SEEDS_LEN = unaligned_offset!(signers_seeds.len),
-        /// Solana instruction.
-        SOL_INSN = sol_instruction!(sol_instruction),
-        /// Bump seed.
-        BUMP = offset!(bump),
-        /// Vault index for PDA derivation.
-        VAULT_INDEX = unaligned_offset!(vault_index),
-        /// Whether the current token program is Token 2022.
-        TOKEN_PROGRAM_IS_2022 = unaligned_offset!(token_program_is_2022),
-        /// From pda_seeds to sol_instruction.
-        PDA_SEEDS_TO_SOL_INSN = relative_offset!(pda_seeds, sol_instruction),
-        /// From pda to signers_seeds.
-        PDA_TO_SIGNERS_SEEDS = relative_offset!(pda, signers_seeds),
-        /// From create_account_data to CPI account metas.
-        CREATE_ACCT_DATA_TO_CPI_ACCT_METAS = relative_offset!(
-            create_account_data, cpi_accounts.idx_0_meta
-        ),
-    }
-}
-
 // endregion: register_market_stack

macros/src/constant_group/mod.rs

@@ -1,5 +1,5 @@
 mod expand;
-mod parse;
+pub(crate) mod parse;
 
 use syn::{Expr, Ident};