[move][move-linter] implement public mut context rules

external-crates/move/crates/move-compiler/src/linters/public_mut_tx_context.rs

@@ -0,0 +1,88 @@
+// Copyright (c) The Move Contributors
+// SPDX-License-Identifier: Apache-2.0
+
+//! Enforces that public functions use `&mut TxContext` instead of `&TxContext` to ensure upgradability.
+//! Detects and reports instances where a non-mutable reference to `TxContext` is used in public function signatures.
+//! Promotes best practices for future-proofing smart contract code by allowing mutation of the transaction context.
+use crate::{
+    diag,
+    diagnostics::{
+        codes::{custom, DiagnosticInfo, Severity},
+        WarningFilters,
+    },
+    expansion::ast::{ModuleIdent, Visibility},
+    naming::ast::{TypeName_, Type_},
+    parser::ast::{DatatypeName, FunctionName},
+    shared::CompilationEnv,
+    typing::{
+        ast as T,
+        visitor::{TypingVisitorConstructor, TypingVisitorContext},
+    },
+};
+use move_ir_types::location::Loc;
+
+use super::{LinterDiagnosticCategory, LINT_WARNING_PREFIX, REQUIRE_MUTABLE_TX_CONTEXT_DIAG_CODE};
+
+const REQUIRE_MUTABLE_TX_CONTEXT_DIAG: DiagnosticInfo = custom(
+    LINT_WARNING_PREFIX,
+    Severity::Warning,
+    LinterDiagnosticCategory::Suspicious as u8,
+    REQUIRE_MUTABLE_TX_CONTEXT_DIAG_CODE,
+    "",
+);
+
+pub struct RequireMutableTxContext;
+
+pub struct Context<'a> {
+    env: &'a mut CompilationEnv,
+}
+
+impl TypingVisitorConstructor for RequireMutableTxContext {
+    type Context<'a> = Context<'a>;
+
+    fn context<'a>(env: &'a mut CompilationEnv, _program: &T::Program) -> Self::Context<'a> {
+        Context { env }
+    }
+}
+
+impl TypingVisitorContext for Context<'_> {
+    fn visit_function_custom(
+        &mut self,
+        _module: ModuleIdent,
+        _function_name: FunctionName,
+        fdef: &mut T::Function,
+    ) -> bool {
+        if let Visibility::Public(_) = fdef.visibility {
+            for param in &fdef.signature.parameters {
+                if let Type_::Ref(false, var_type) = &param.2.value {
+                    if let Type_::Apply(_, type_name, _) = &var_type.value {
+                        if let TypeName_::ModuleType(_, DatatypeName(sp!(_, struct_name))) =
+                            &type_name.value
+                        {
+                            if struct_name.to_string() == "TxContext" {
+                                report_non_mutable_tx_context(self.env, type_name.loc);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        false
+    }
+    fn add_warning_filter_scope(&mut self, filter: WarningFilters) {
+        self.env.add_warning_filter_scope(filter)
+    }
+
+    fn pop_warning_filter_scope(&mut self) {
+        self.env.pop_warning_filter_scope()
+    }
+}
+
+fn report_non_mutable_tx_context(env: &mut CompilationEnv, loc: Loc) {
+    let diag = diag!(
+        REQUIRE_MUTABLE_TX_CONTEXT_DIAG,
+        (loc, "Public functions should take `&mut TxContext` instead of `&TxContext` for better upgradability.")
+    );
+    env.add_diag(diag);
+}

external-crates/move/crates/move-compiler/tests/linter/correct_public_mut_tx_context.move

@@ -0,0 +1,10 @@
+module 0x42::M {
+    use sui::tx_context::TxContext;
+    public fun mint(_ctx: &mut TxContext) {
+
+    }
+}
+
+module sui::tx_context {
+    struct TxContext has drop {}
+}

external-crates/move/crates/move-compiler/tests/linter/incorrect_public_mut_tx_context.exp

@@ -0,0 +1,8 @@
+warning[Lint W02014]: 
+  ┌─ tests/linter/incorrect_public_mut_tx_context.move:3:28
+  │
+3 │     public fun mint(_ctx: &TxContext) {
+  │                            ^^^^^^^^^ Public functions should take `&mut TxContext` instead of `&TxContext` for better upgradability.
+  │
+  = This warning can be suppressed with '#[allow(lint(public_mut_tx_context))]' applied to the 'module' or module member ('const', 'fun', or 'struct')
+

external-crates/move/crates/move-compiler/tests/linter/incorrect_public_mut_tx_context.move

@@ -0,0 +1,10 @@
+module 0x42::M {
+    use sui::tx_context::TxContext;
+    public fun mint(_ctx: &TxContext) {
+
+    }
+}
+
+module sui::tx_context {
+    struct TxContext has drop {}
+}

external-crates/move/crates/move-compiler/tests/linter/suppressed_lints.move

@@ -1,5 +1,16 @@
 module 0x42::M {
+    use sui::tx_context::TxContext;
 
     #[allow(lint(constant_naming))]
     const Another_BadName: u64 = 42; // Should trigger a warning
+
+    #[allow(lint(public_mut_tx_context))]
+    public fun mint(_ctx: &TxContext) {
+
+    }
+}
+
+
+module sui::tx_context {
+    struct TxContext has drop {}
 }