feat(missing_account_reload): LazyAccount support

meumar-osec · meumar-osec · commit b63fcbe69a11 · 2026-03-11T16:46:37.000+05:30
diff --git a/anchor-lints-utils/src/diag_items.rs b/anchor-lints-utils/src/diag_items.rs
@@ -78,6 +78,8 @@ pub enum DiagnoticItem {
     SplTokenAccount,
     /// `spl_token::state::Mint`
     SplTokenMint,
+    /// `anchor_lang::prelude::LazyAccount`
+    AnchorLazyAccount,
 }
 
 impl DiagnoticItem {
@@ -149,6 +151,9 @@ impl DiagnoticItem {
             DiagnoticItem::SplTokenMint => {
                 return None;
             }
+            DiagnoticItem::AnchorLazyAccount => {
+                return None;
+            }
         })
     }
 
@@ -255,6 +260,7 @@ impl DiagnoticItem {
             }
             DiagnoticItem::SplTokenAccount => &["spl_token::state::Account"],
             DiagnoticItem::SplTokenMint => &["spl_token::state::Mint"],
+            DiagnoticItem::AnchorLazyAccount => &["anchor_lang::prelude::LazyAccount"],
         }
     }
 
@@ -463,10 +469,10 @@ pub fn is_solana_instruction_type(tcx: TyCtxt, ty: Ty) -> bool {
 
 pub fn is_box_type(tcx: TyCtxt, ty: Ty) -> bool {
     let ty = ty.peel_refs();
-    if let ty::Adt(adt_def, _) = ty.kind() {
-        if let Some(box_def_id) = tcx.lang_items().owned_box() {
-            return adt_def.did() == box_def_id;
-        }
+    if let ty::Adt(adt_def, _) = ty.kind()
+        && let Some(box_def_id) = tcx.lang_items().owned_box()
+    {
+        return adt_def.did() == box_def_id;
     }
     false
 }
@@ -492,3 +498,8 @@ pub fn is_cpi_builder_constructor_fn(tcx: TyCtxt, def_id: DefId) -> bool {
         || path.contains("UnlockV1")
         || path.contains("RevokeStaking")
 }
+
+pub fn is_anchor_lazy_account_type(tcx: TyCtxt, ty: Ty) -> bool {
+    let ty = ty.peel_refs();
+    DiagnoticItem::AnchorLazyAccount.defid_is_type(tcx, ty)
+}
diff --git a/lints/missing_account_reload/src/lib.rs b/lints/missing_account_reload/src/lib.rs
@@ -10,7 +10,7 @@ use std::collections::{HashMap, HashSet};
 
 use anchor_lints_utils::utils::should_skip_function;
 use anchor_lints_utils::{
-    diag_items::{DiagnoticItem, is_cpi_invoke_fn},
+    diag_items::{DiagnoticItem, is_anchor_lazy_account_type, is_cpi_invoke_fn},
     mir_analyzer::{AnchorContextInfo, MirAnalyzer},
     utils::get_hir_body_from_local_def_id,
 };
@@ -124,6 +124,25 @@ impl<'tcx> LateLintPass<'tcx> for MissingAccountReload {
                         }
                     }
                 }
+                // Check for LazyAccount::load/LazyAccount::load_mut (reloads for LazyAccount)
+                else if let Some(name) = cx.tcx.opt_item_name(*fn_def_id)
+                    && (name.as_str() == "load" || name.as_str() == "load_mut")
+                    && let Some(receiver) = args.first()
+                    && let Operand::Move(place) | Operand::Copy(place) = &receiver.node
+                    && let Some(local) = place.as_local()
+                    && let Some(decl) = mir.local_decls.get(local)
+                {
+                    let receiver_ty = decl.ty.peel_refs();
+                    if is_anchor_lazy_account_type(cx.tcx, receiver_ty)
+                        && let Some(account_name_and_local) =
+                            mir_analyzer.extract_account_name_from_local(&local, false)
+                    {
+                        account_reloads
+                            .entry(account_name_and_local.account_name)
+                            .or_default()
+                            .insert(bb);
+                    }
+                }
                 // Or a CPI invoke function
                 else if is_cpi_invoke_fn(cx.tcx, *fn_def_id)
                     || mir_analyzer.takes_cpi_context(args)
@@ -375,6 +394,27 @@ pub fn analyze_nested_function_operations<'tcx>(
                     nested_function_blocks.push(block);
                 }
             }
+            // Check for LazyAccount::load/LazyAccount::load_mut (reloads for LazyAccount)
+            else if let Some(name) = cx.tcx.opt_item_name(*def_id)
+                && (name.as_str() == "load" || name.as_str() == "load_mut")
+                && let Some(receiver) = args.first()
+                && let Operand::Move(place) | Operand::Copy(place) = &receiver.node
+                && let Some(local) = place.as_local()
+                && let Some(decl) = mir_body.local_decls.get(local)
+            {
+                let receiver_ty = decl.ty.peel_refs();
+                if is_anchor_lazy_account_type(cx.tcx, receiver_ty)
+                    && let Some(block) = handle_account_reload_in_nested_function(
+                        &mir_analyzer,
+                        mir_body,
+                        args,
+                        *fn_span,
+                        bb,
+                    )
+                {
+                    nested_function_blocks.push(block);
+                }
+            }
             // Handle account access (deref) in nested function
             else if cx
                 .tcx
diff --git a/lints/missing_account_reload/src/utils/paths.rs b/lints/missing_account_reload/src/utils/paths.rs
@@ -1,8 +1,8 @@
 use anchor_lints_utils::{
     diag_items::{
         is_account_info_type, is_anchor_account_loader_type, is_anchor_account_type,
-        is_anchor_interface_account_type, is_anchor_signer_type, is_anchor_system_account_type,
-        is_anchor_unchecked_account_type, is_box_type,
+        is_anchor_interface_account_type, is_anchor_lazy_account_type, is_anchor_signer_type,
+        is_anchor_system_account_type, is_anchor_unchecked_account_type, is_box_type,
     },
     mir_analyzer::AnchorContextInfo,
 };
@@ -58,7 +58,9 @@ pub fn contains_deserialized_data<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) ->
         if is_anchor_account_loader_type(cx.tcx, ty) {
             return false;
         }
-        if is_anchor_interface_account_type(cx.tcx, ty) || is_anchor_system_account_type(cx.tcx, ty)
+        if is_anchor_interface_account_type(cx.tcx, ty)
+            || is_anchor_system_account_type(cx.tcx, ty)
+            || is_anchor_lazy_account_type(cx.tcx, ty)
         {
             return true;
         }
diff --git a/lints/missing_account_reload/tests/test_program/src/lib.rs b/lints/missing_account_reload/tests/test_program/src/lib.rs
@@ -4,7 +4,7 @@ use anchor_lang::solana_program::{
     system_instruction,
 };
 
-use anchor_lang::system_program::{transfer, Transfer};
+use anchor_lang::system_program::{Transfer, transfer};
 
 declare_id!("11111111111111111111111111111111");
 
@@ -319,18 +319,56 @@ pub mod missing_account_reload_tests {
     }
 
     // Pattern 17: CPI call with self implementation - safe
-    pub fn invoke_with_self_implementation_safe(ctx: Context<SolTransfer3>, amount: u64) -> Result<()> {
+    pub fn invoke_with_self_implementation_safe(
+        ctx: Context<SolTransfer3>,
+        amount: u64,
+    ) -> Result<()> {
         ctx.accounts.cpi_call_safe(amount)?;
         let _final_data = ctx.accounts.pda_account.data; // [safe_account_accessed]
         Ok(())
     }
 
     // Pattern 18: CPI call with self implementation - unsafe
-    pub fn invoke_with_self_implementation_unsafe(ctx: Context<SolTransfer3>, amount: u64) -> Result<()> {
+    pub fn invoke_with_self_implementation_unsafe(
+        ctx: Context<SolTransfer3>,
+        amount: u64,
+    ) -> Result<()> {
         ctx.accounts.cpi_call_unsafe(amount)?;
         let _final_data = ctx.accounts.pda_account.data; // [unsafe_account_accessed]
         Ok(())
     }
+
+    /// Patten 19: load_mut() then CPI — unsafe.
+    pub fn test_lazy_account_unsafe(
+        ctx: Context<LazyAccountCpiAccounts>,
+        amount: u64,
+    ) -> Result<()> {
+        let data = ctx.accounts.lazy_acc.load_mut()?; // ref held across CPI
+        let _ = data.value;
+        let new_space = ctx.accounts.lazy_acc.to_account_info().data_len() as u64 + amount;
+        let ix = system_instruction::allocate(&ctx.accounts.lazy_acc.key(), new_space);
+        let account_infos = vec![
+            ctx.accounts.lazy_acc.to_account_info(),
+            ctx.accounts.system_program.to_account_info(),
+        ];
+        invoke(&ix, &account_infos)?; // [cpi_call]
+        let _ = data.value; // [unsafe_account_accessed]
+        Ok(())
+    }
+
+    // Pattern 20: load_mut() then CPI with load_mut() — safe
+    pub fn test_lazy_account_safe(ctx: Context<LazyAccountCpiAccounts>, amount: u64) -> Result<()> {
+        let new_space = ctx.accounts.lazy_acc.to_account_info().data_len() as u64 + amount;
+        let ix = system_instruction::allocate(&ctx.accounts.lazy_acc.key(), new_space);
+        let account_infos = vec![
+            ctx.accounts.lazy_acc.to_account_info(),
+            ctx.accounts.system_program.to_account_info(),
+        ];
+        invoke(&ix, &account_infos)?;
+        let data = ctx.accounts.lazy_acc.load_mut()?;
+        let _ = data.value; // [safe_account_accessed]
+        Ok(())
+    }
 }
 pub fn cpi_call_safe(ctx_a: &mut Context<SolTransfer3>, amount: u64) -> Result<()> {
     let from_pubkey = ctx_a.accounts.pda_account.to_account_info();
@@ -614,6 +652,18 @@ pub struct UserState {
     pub data: u64,
 }
 
+#[account]
+pub struct LazyLoadable {
+    pub value: u64,
+}
+
+#[derive(Accounts)]
+pub struct LazyAccountCpiAccounts<'info> {
+    #[account(mut)]
+    pub lazy_acc: LazyAccount<'info, LazyLoadable>,
+    pub system_program: Program<'info, System>,
+}
+
 #[account]
 pub struct InnerAccount {
     pub data: u64,

Original file line number	Diff line number	Diff line change
`@@ -78,6 +78,8 @@ pub enum DiagnoticItem {`
`78`	`78`	`SplTokenAccount,`
`79`	`79`	/// `spl_token::state::Mint`
`80`	`80`	`SplTokenMint,`
	`81`	+ /// `anchor_lang::prelude::LazyAccount`
	`82`	`+ AnchorLazyAccount,`
`81`	`83`	`}`
`82`	`84`
`83`	`85`	`impl DiagnoticItem {`
`@@ -149,6 +151,9 @@ impl DiagnoticItem {`
`149`	`151`	`DiagnoticItem::SplTokenMint => {`
`150`	`152`	`return None;`
`151`	`153`	`}`
	`154`	`+ DiagnoticItem::AnchorLazyAccount => {`
	`155`	`+ return None;`
	`156`	`+ }`
`152`	`157`	`})`
`153`	`158`	`}`
`154`	`159`
`@@ -255,6 +260,7 @@ impl DiagnoticItem {`
`255`	`260`	`}`
`256`	`261`	`DiagnoticItem::SplTokenAccount => &["spl_token::state::Account"],`
`257`	`262`	`DiagnoticItem::SplTokenMint => &["spl_token::state::Mint"],`
	`263`	`+ DiagnoticItem::AnchorLazyAccount => &["anchor_lang::prelude::LazyAccount"],`
`258`	`264`	`}`
`259`	`265`	`}`
`260`	`266`
`@@ -463,10 +469,10 @@ pub fn is_solana_instruction_type(tcx: TyCtxt, ty: Ty) -> bool {`
`463`	`469`
`464`	`470`	`pub fn is_box_type(tcx: TyCtxt, ty: Ty) -> bool {`
`465`	`471`	`let ty = ty.peel_refs();`
`466`		`- if let ty::Adt(adt_def, _) = ty.kind() {`
`467`		`- if let Some(box_def_id) = tcx.lang_items().owned_box() {`
`468`		`- return adt_def.did() == box_def_id;`
`469`		`- }`
	`472`	`+ if let ty::Adt(adt_def, _) = ty.kind()`
	`473`	`+ && let Some(box_def_id) = tcx.lang_items().owned_box()`
	`474`	`+ {`
	`475`	`+ return adt_def.did() == box_def_id;`
`470`	`476`	`}`
`471`	`477`	`false`
`472`	`478`	`}`
`@@ -492,3 +498,8 @@ pub fn is_cpi_builder_constructor_fn(tcx: TyCtxt, def_id: DefId) -> bool {`
`492`	`498`	`\|\| path.contains("UnlockV1")`
`493`	`499`	`\|\| path.contains("RevokeStaking")`
`494`	`500`	`}`
	`501`	`+`
	`502`	`+pub fn is_anchor_lazy_account_type(tcx: TyCtxt, ty: Ty) -> bool {`
	`503`	`+ let ty = ty.peel_refs();`
	`504`	`+ DiagnoticItem::AnchorLazyAccount.defid_is_type(tcx, ty)`
	`505`	`+}`