feat: optimize context access for internal receivers

dev-docs/CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Code generation
+
+- Optimized context field access in internal receivers: PR [#3329](https://github.com/tact-lang/tact/pull/3329)
+
 ### Docs
 
 - Described off-chain calls and mention exit code 11 for getters: PR [#3314](https://github.com/tact-lang/tact/pull/3314)

src/benchmarks/notcoin/gas.json

@@ -98,6 +98,15 @@
         "burn": "11739",
         "discovery": "5818"
       }
+    },
+    {
+      "label": "1.6.13 with optimized context access",
+      "pr": "https://github.com/tact-lang/tact/pull/3329",
+      "gas": {
+        "transfer": "15139",
+        "burn": "11413",
+        "discovery": "5818"
+      }
     }
   ]
 }

src/benchmarks/notcoin/size.json

@@ -119,6 +119,16 @@
         "wallet cells": "13",
         "wallet bits": "7708"
       }
+    },
+    {
+      "label": "1.6.13 with optimized context access",
+      "pr": "https://github.com/tact-lang/tact/pull/3329",
+      "size": {
+        "minter cells": "29",
+        "minter bits": "15423",
+        "wallet cells": "13",
+        "wallet bits": "7628"
+      }
     }
   ]
 }

src/benchmarks/wallet-v4/gas.json

@@ -125,6 +125,15 @@
         "addPlugin": "7399",
         "pluginTransfer": "3709"
       }
+    },
+    {
+      "label": "1.6.13 with optimized context access",
+      "pr": "https://github.com/tact-lang/tact/pull/3329",
+      "gas": {
+        "externalTransfer": "3625",
+        "addPlugin": "7399",
+        "pluginTransfer": "3619"
+      }
     }
   ]
 }

src/generator/Writer.ts

@@ -47,6 +47,11 @@ export class WriterContext {
     #nextId = 0;
     // #headers: string[] = [];
     #rendered: Set<string> = new Set();
+    private _currentReceiverType:
+        | "internal"
+        | "external"
+        | "bounced"
+        | undefined = undefined;
 
     constructor(ctx: CompilerContext, name: string) {
         this.ctx = ctx;
@@ -287,8 +292,18 @@ export class WriterContext {
         }
     }
 
-    currentContext() {
-        return this.#pendingName;
+    currentContext(): string {
+        return this.#pendingName ?? "";
+    }
+
+    currentReceiverType(): "internal" | "external" | "bounced" | undefined {
+        return this._currentReceiverType;
+    }
+
+    setReceiverType(
+        receiverType: "internal" | "external" | "bounced" | undefined,
+    ) {
+        this._currentReceiverType = receiverType;
     }
 
     //

src/generator/writers/writeContract.ts

@@ -405,6 +405,8 @@ export function writeMainContract(
         wCtx.inBlock(
             "() recv_internal(int msg_value, cell in_msg_cell, slice in_msg) impure",
             () => {
+                wCtx.setReceiverType("internal");
+                wCtx.context("internal-receiver");
                 wCtx.append();
                 wCtx.append(`;; Context`);
                 wCtx.append(`var cs = in_msg_cell.begin_parse();`);
@@ -435,6 +437,7 @@ export function writeMainContract(
                     contractReceivers.internal,
                     contract,
                     wCtx,
+                    "internal",
                 );
             },
         );
@@ -453,6 +456,8 @@ export function writeMainContract(
             wCtx.append();
 
             wCtx.inBlock("() recv_external(slice in_msg) impure", () => {
+                wCtx.setReceiverType("external");
+                wCtx.context("external-receiver");
                 if (contract.globalVariables.has("inMsg")) {
                     wCtx.append(`__tact_in_msg = in_msg;`);
                 }
@@ -463,6 +468,7 @@ export function writeMainContract(
                     contractReceivers.external,
                     contract,
                     wCtx,
+                    "external",
                 );
             });
         }

src/generator/writers/writeExpression.ts

@@ -470,19 +470,44 @@ const writeUnaryExpr =
  * NOTE: this branch resolves "a.b", where "a" is an expression and "b" is a field name
  */
 const writeFieldExpr =
-    (f: Ast.FieldAccess) =>
+    (f: Ast.FieldAccess, receiverType?: "internal" | "external" | "bounced") =>
     (wCtx: WriterContext): string => {
-        // Optimize Context().sender to sender()
-        // This is a special case to improve gas efficiency
+        // Optimize context() field accesses inside receivers
+        // Use local variables where possible for better efficiency
         if (
             f.aggregate.kind === "static_call" &&
             f.aggregate.function.text === "context" &&
-            f.aggregate.args.length === 0 &&
-            f.field.text === "sender"
+            f.aggregate.args.length === 0
         ) {
-            // Use sender() directly instead of context().sender
-            wCtx.used("__tact_context_get_sender");
-            return `__tact_context_get_sender()`;
+            const field = f.field.text;
+
+            // Check if we're in an internal receiver context
+            const currentContext = wCtx.currentContext();
+            const writerReceiverType = wCtx.currentReceiverType();
+            const isInternalReceiver =
+                currentContext === "internal-receiver" ||
+                receiverType === "internal" ||
+                writerReceiverType === "internal";
+
+            // Only use direct variable access inside internal receivers where variables exist
+            if (isInternalReceiver) {
+                if (field === "sender") {
+                    return "msg_sender_addr";
+                } else if (field === "value") {
+                    return "msg_value";
+                } else if (field === "bounceable") {
+                    return "msg_bounceable";
+                } else if (field === "raw") {
+                    return "cs";
+                }
+            } else {
+                // For external receivers, getters, and other contexts, use function calls
+                if (field === "sender") {
+                    wCtx.used("__tact_context_get_sender");
+                    return `__tact_context_get_sender()`;
+                }
+                // Other fields (value, bounceable, raw) fall through to default field access logic
+            }
         }
 
         // Resolve the type of the expression
@@ -931,6 +956,7 @@ const writeExpressionAux: (
 export function writeExpression(
     f: Ast.Expression,
     wCtx: WriterContext,
+    receiverType?: "internal" | "external" | "bounced",
 ): string {
     // literals and constant expressions are covered here
 
@@ -953,6 +979,10 @@ export function writeExpression(
         if (!(error instanceof TactConstEvalError) || error.fatal) throw error;
     }
 
+    if (f.kind === "field_access") {
+        return writeFieldExpr(f, receiverType)(wCtx);
+    }
+
     return writeExpressionAux(f)(wCtx);
 }