fix(codegen): allocator not accounting for extra ref in a cell resulting in cell overflows in some cases

CHANGELOG.md

@@ -50,6 +50,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Defining non-existing native FunC functions now throws an understandable compilation error: PR [#585](https://github.com/tact-lang/tact/pull/585)
 - Bump used `@tact-lang/opcode` version to `0.0.16` which fixes the issue with `DIV` instructions: PR [#589](https://github.com/tact-lang/tact/pull/589)
 - Incorrect FunC code generated for `recv_external`: PR [#604](https://github.com/tact-lang/tact/pull/604)
+- Allocator bug resulting in cell overflows for some contract data layouts: PR [#615](https://github.com/tact-lang/tact/pull/615)
 
 ## [1.4.0] - 2024-06-21
 

examples/__snapshots__/increment.spec.ts.snap

@@ -20,14 +20,14 @@ exports[`increment should deploy 1`] = `
           },
           "bounce": true,
           "from": "@treasure(treasure)",
-          "to": "kQCFVwtFcoSZ-muVDfXKSpI0fzDrWMuzTgXqo4_QDKKycmXS",
+          "to": "kQCZq6o-nSHCoxfIzdCAl3fDePr-LEYT-VUlqbQ5prvrJ7Y2",
           "type": "internal",
           "value": "10",
         },
       },
       {
         "$type": "processed",
-        "gasUsed": 8491n,
+        "gasUsed": 8473n,
       },
       {
         "$type": "sent",
@@ -41,10 +41,10 @@ exports[`increment should deploy 1`] = `
               },
             },
             "bounce": false,
-            "from": "kQCFVwtFcoSZ-muVDfXKSpI0fzDrWMuzTgXqo4_QDKKycmXS",
+            "from": "kQCZq6o-nSHCoxfIzdCAl3fDePr-LEYT-VUlqbQ5prvrJ7Y2",
             "to": "@treasure(treasure)",
             "type": "internal",
-            "value": "9.990313",
+            "value": "9.990331",
           },
         ],
       },
@@ -71,14 +71,14 @@ exports[`increment should deploy 2`] = `
           },
           "bounce": true,
           "from": "@treasure(treasure)",
-          "to": "kQCFVwtFcoSZ-muVDfXKSpI0fzDrWMuzTgXqo4_QDKKycmXS",
+          "to": "kQCZq6o-nSHCoxfIzdCAl3fDePr-LEYT-VUlqbQ5prvrJ7Y2",
           "type": "internal",
           "value": "10",
         },
       },
       {
         "$type": "processed",
-        "gasUsed": 6007n,
+        "gasUsed": 5963n,
       },
     ],
   },

src/generator/writers/__snapshots__/writeSerialization.spec.ts.snap

@@ -13007,8 +13007,8 @@ return result;",
       "code": "var (v'a, v'b, v'c, v'd, v'e, v'f, v'g, v'h) = v;
 build_0 = build_0.store_ref(v'a);
 build_0 = ~ null?(v'b) ? build_0.store_int(true, 1).store_ref(v'b) : build_0.store_int(false, 1);
-build_0 = ~ null?(v'c) ? build_0.store_int(true, 1).store_ref(begin_cell().store_slice(v'c).end_cell()) : build_0.store_int(false, 1);
 var build_1 = begin_cell();
+build_1 = ~ null?(v'c) ? build_1.store_int(true, 1).store_ref(begin_cell().store_slice(v'c).end_cell()) : build_1.store_int(false, 1);
 build_1 = ~ null?(v'd) ? build_1.store_int(true, 1).store_ref(begin_cell().store_slice(v'd).end_cell()) : build_1.store_int(false, 1);
 build_1 = build_1.store_int(v'e, 1);
 build_1 = build_1.store_int(v'f, 257);
@@ -13837,8 +13837,8 @@ if (null?(loaded)) {
     "code": {
       "code": "var v'a = sc_0~load_ref();
 var v'b = sc_0~load_int(1) ? sc_0~load_ref() : null();
-var v'c = sc_0~load_int(1) ? sc_0~load_ref().begin_parse() : null();
 slice sc_1 = sc_0~load_ref().begin_parse();
+var v'c = sc_1~load_int(1) ? sc_1~load_ref().begin_parse() : null();
 var v'd = sc_1~load_int(1) ? sc_1~load_ref().begin_parse() : null();
 var v'e = sc_1~load_int(1);
 var v'f = sc_1~load_int(257);

src/storage/__snapshots__/resolveAllocation.spec.ts.snap

@@ -465,12 +465,12 @@ exports[`resolveAllocation should write program 1`] = `
         ],
         "size": {
           "bits": 514,
-          "refs": 0,
+          "refs": 1,
         },
       },
       "size": {
         "bits": 514,
-        "refs": 0,
+        "refs": 1,
       },
     },
     "type": {
@@ -867,7 +867,7 @@ exports[`resolveAllocation should write program 1`] = `
             ],
             "size": {
               "bits": 771,
-              "refs": 0,
+              "refs": 1,
             },
           },
           "ops": [
@@ -916,7 +916,7 @@ exports[`resolveAllocation should write program 1`] = `
           ],
           "size": {
             "bits": 771,
-            "refs": 0,
+            "refs": 1,
           },
         },
         "ops": [
@@ -965,12 +965,12 @@ exports[`resolveAllocation should write program 1`] = `
         ],
         "size": {
           "bits": 771,
-          "refs": 0,
+          "refs": 1,
         },
       },
       "size": {
         "bits": 771,
-        "refs": 0,
+        "refs": 1,
       },
     },
     "type": {
@@ -1667,7 +1667,7 @@ exports[`resolveAllocation should write program 1`] = `
             "ref": false,
             "size": {
               "bits": 771,
-              "refs": 0,
+              "refs": 1,
             },
             "type": "Deep",
           },
@@ -1685,7 +1685,7 @@ exports[`resolveAllocation should write program 1`] = `
             "ref": false,
             "size": {
               "bits": 771,
-              "refs": 0,
+              "refs": 1,
             },
             "type": "Deep",
           },
@@ -1703,7 +1703,7 @@ exports[`resolveAllocation should write program 1`] = `
             "ref": false,
             "size": {
               "bits": 771,
-              "refs": 0,
+              "refs": 1,
             },
             "type": "Deep",
           },
@@ -1727,7 +1727,7 @@ exports[`resolveAllocation should write program 1`] = `
                   "ref": false,
                   "size": {
                     "bits": 771,
-                    "refs": 0,
+                    "refs": 1,
                   },
                   "type": "Deep",
                 },
@@ -1740,7 +1740,7 @@ exports[`resolveAllocation should write program 1`] = `
             ],
             "size": {
               "bits": 771,
-              "refs": 0,
+              "refs": 1,
             },
           },
           "ops": [
@@ -1752,7 +1752,7 @@ exports[`resolveAllocation should write program 1`] = `
                 "ref": false,
                 "size": {
                   "bits": 771,
-                  "refs": 0,
+                  "refs": 1,
                 },
                 "type": "Deep",
               },
@@ -1765,7 +1765,7 @@ exports[`resolveAllocation should write program 1`] = `
           ],
           "size": {
             "bits": 771,
-            "refs": 0,
+            "refs": 2,
           },
         },
         "ops": [
@@ -1777,7 +1777,7 @@ exports[`resolveAllocation should write program 1`] = `
               "ref": false,
               "size": {
                 "bits": 771,
-                "refs": 0,
+                "refs": 1,
               },
               "type": "Deep",
             },
@@ -1790,12 +1790,12 @@ exports[`resolveAllocation should write program 1`] = `
         ],
         "size": {
           "bits": 771,
-          "refs": 0,
+          "refs": 2,
         },
       },
       "size": {
         "bits": 771,
-        "refs": 0,
+        "refs": 2,
       },
     },
     "type": {

src/storage/allocator.ts

@@ -301,16 +301,27 @@ function allocateSegment(
     let next: AllocationCell | null = null;
     const used: { bits: number; refs: number } = { bits: 0, refs: 0 };
 
+    const [totalBits, totalRefs] = ops.reduce(
+        ([sumBits, sumRefs], op) => {
+            const opSize = getOperationSize(op.op);
+            return [sumBits + opSize.bits, sumRefs + opSize.refs];
+        },
+        [0, 0],
+    );
+    // check if there will be a new allocation segment,
+    // meaning we need to have a spare ref to link it
+    // from the current segment
+    if (totalBits > bits || totalRefs > refs) {
+        refs -= 1;
+    }
+
     for (const [i, op] of ops.entries()) {
         const size = getOperationSize(op.op);
 
         // Check if we can fit this operation
         if (size.bits > bits || size.refs > refs) {
-            next = allocateSegment(
-                ops.slice(i),
-                1023 - ALLOCATOR_RESERVE_BIT,
-                4 - ALLOCATOR_RESERVE_REF,
-            );
+            used.refs += 1;
+            next = allocateSegment(ops.slice(i), 1023, 4);
             break;
         }
 

src/test/e2e-emulated/__snapshots__/intrinsics.spec.ts.snap

@@ -25,7 +25,7 @@ exports[`intrinsics should return correct intrinsic results 1`] = `
       },
       {
         "$type": "processed",
-        "gasUsed": 7881n,
+        "gasUsed": 7915n,
       },
       {
         "$type": "sent",

src/test/e2e-emulated/__snapshots__/map.spec.ts.snap

@@ -18,7 +18,7 @@ exports[`map should implement maps correctly 1`] = `
           },
           "bounce": true,
           "from": "@treasure(treasure)",
-          "to": "kQDF6S3qUJdr9fVijosUCNJyi5YNnAe1KvoyKjWqsnky6crw",
+          "to": "kQA9A-B3CjPFrYe-tOHzjlnaFNzrG5eTlY2AmsgtGfkzSLTM",
           "type": "internal",
           "value": "1",
         },
@@ -36,10 +36,10 @@ exports[`map should implement maps correctly 1`] = `
             "type": "cell",
           },
           "bounce": false,
-          "from": "kQDF6S3qUJdr9fVijosUCNJyi5YNnAe1KvoyKjWqsnky6crw",
+          "from": "kQA9A-B3CjPFrYe-tOHzjlnaFNzrG5eTlY2AmsgtGfkzSLTM",
           "to": "@treasure(treasure)",
           "type": "internal",
-          "value": "0.981951",
+          "value": "0.982029",
         },
       },
     ],

src/test/e2e-emulated/allocation.spec.ts

@@ -0,0 +1,32 @@
+import { toNano } from "@ton/core";
+import { ContractSystem } from "@tact-lang/emulator";
+import { Test } from "./contracts/output/allocation_Test";
+
+describe("allocation", () => {
+    it("should deploy correctly and process SetCost message without cell overflow", async () => {
+        const system = await ContractSystem.create();
+        const owner = system.treasure("owner");
+        const contract = system.open(
+            await Test.fromInit(owner.address, {
+                $$type: "Struct2",
+                c: "",
+                d: "",
+                e: "",
+                f: "",
+            }),
+        );
+        system.name(contract.address, "main");
+        await contract.send(
+            owner,
+            { value: toNano(1) },
+            { $$type: "Deploy", queryId: 0n },
+        );
+        await system.run();
+        await contract.send(
+            owner,
+            { value: toNano(1) },
+            { $$type: "SetCost", cost: toNano("0.1") },
+        );
+        await system.run();
+    });
+});

src/test/e2e-emulated/contracts/allocation.tact

@@ -0,0 +1,37 @@
+import "@stdlib/deploy";
+
+message SetCost {
+    cost: Int? as coins;
+}
+
+struct Struct2 {
+    c: String;
+    d: String;
+    e: String;
+    f: String;
+}
+
+contract Test with Deployable {
+    owner: Address;
+    seqno: Int as uint256 = 0;
+    a: Int as uint256 = 0;
+    b: Int as uint256 = 0;
+
+    struct2: Struct2;
+
+    author3: Address?;
+
+    cost: Int? as coins;
+    address: Address?;
+    price: Int? as coins;
+
+    init(owner: Address, struct2: Struct2) {
+        self.owner = owner;
+        self.struct2 = struct2;
+    }
+
+    receive(msg: SetCost) {
+        self.cost = msg.cost;
+        self.reply("Cost is updated".asComment());
+    }
+}

tact.config.json

@@ -370,6 +370,11 @@
       "name": "getter-names-conflict",
       "path": "./src/test/e2e-emulated/contracts/getter-names-conflict.tact",
       "output": "./src/test/e2e-emulated/contracts/output"
+    },
+    {
+      "name": "allocation",
+      "path": "./src/test/e2e-emulated/contracts/allocation.tact",
+      "output": "./src/test/e2e-emulated/contracts/output"
     }
   ]
 }