Add first proof

.github/TOOL_REQUEST_TEMPLATE.md

@@ -0,0 +1,31 @@
+_The following form is designed to provide information for your tool that should be included in the effort to verify the Rust standard library. Please note that the tool will need to be **supported** if it is to be included._
+
+## Tool Name
+_Please enter your tool name here._
+
+## Description
+_Please enter a description for your tool and any information you deem relevant._
+
+## Tool Information
+
+* [ ] Does the tool perform Rust verification? 
+* [ ] Does the tool deal with *unsafe* Rust code? 
+* [ ] Does the tool run independently in CI? 
+* [ ] Is the tool open source?
+* [ ] Is the tool under development? 
+* [ ] Will you or your team be able to provide support for the tool?
+
+## Licenses
+_Please list the license(s) that are used by your tool, and if to your knowledge they conflict with the Rust standard library license(s)._
+
+## Steps to Use the Tool
+
+1. [First Step]
+2. [Second Step]
+3. [and so on...]
+
+## Artifacts
+_If there are noteworthy examples of using the tool to perform verificaiton, please include them in this section.Links, papers, etc._
+
+## CI & Versioning
+_Please describe how you version the tool and how it will be supported in CI pipelines._

.github/pull_requests.toml

@@ -9,5 +9,8 @@ members = [
     "remi-delmas-3000",
     "qinheping",
     "tautschnig",
-    "jaisnan"
+    "jaisnan",
+    "patricklam",
+    "ranjitjhala",
+    "carolynzech"
 ]

.github/workflows/kani.yml

@@ -9,6 +9,7 @@ on:
     paths:
       - 'library/**'
       - '.github/workflows/kani.yml'
+      - 'scripts/check_kani.sh'
 
 defaults:
   run:
@@ -30,32 +31,8 @@ jobs:
       - name: Checkout Library
         uses: actions/checkout@v4
         with:
-          path: verify-rust-std
+          path: head
           submodules: true
 
-      # We currently build Kani from a branch that tracks a rustc version compatible with this library version.
-      - name: Checkout `Kani`
-        uses: actions/checkout@v4
-        with:
-          repository: model-checking/kani
-          path: kani
-          ref: features/verify-rust-std
-
-      - name: Setup Dependencies
-        working-directory: kani
-        run: |
-          ./scripts/setup/${{ matrix.base }}/install_deps.sh
-
-      - name: Build `Kani`
-        working-directory: kani
-        run: |
-          cargo build-dev --release
-          echo "$(pwd)/scripts" >> $GITHUB_PATH
-
-      - name: Run tests
-        working-directory: verify-rust-std
-        env:
-          RUST_BACKTRACE: 1
-        run: |
-          kani verify-std -Z unstable-options ./library --target-dir ${{ runner.temp }} -Z function-contracts \
-            -Z mem-predicates -Z ptr-to-ref-cast-checks
+      - name: Run Kani Script
+        run: bash ./head/scripts/check_kani.sh ${{github.workspace}}/head

.github/workflows/pr_approval.yml

@@ -7,12 +7,6 @@ name: Check PR Approvals
 on:
   pull_request_review:
     types: [submitted]
-  workflow_dispatch:
-
-# Without these permissions, we get a 403 error from github
-# for trying to modify the pull request for newer project.
-# Source: https://stackoverflow.com/a/76994510
-permissions: write-all
 
 jobs:
   check-approvals:
@@ -51,22 +45,6 @@ jobs:
               pull_number = context.issue.number;
             }
 
-            // Get PR files
-            const files = await github.rest.pulls.listFiles({
-              owner,
-              repo,
-              pull_number
-            });
-
-            const relevantPaths = ['library/', 'doc/src/challenges/'];
-            const isRelevantPR = files.data.some(file =>
-              relevantPaths.some(path => file.filename.startsWith(path))
-            );
-
-            if (!isRelevantPR) {
-              console.log('PR does not touch relevant paths. Exiting workflow.');
-              return;
-            }
 
             // Get parsed data
             try {
@@ -117,45 +95,6 @@ jobs:
               text: `Approvers: ${Array.from(approvers).join(', ')}\nRequired Approvers: ${requiredApprovers.join(', ')}`
             };
 
-            // Get PR details
-            const pr = await github.rest.pulls.get({
-              owner,
-              repo,
-              pull_number
-            });
-
-            // Create or update check run
-            const checkRuns = await github.rest.checks.listForRef({
-              owner,
-              repo,
-              ref: pr.data.head.sha,
-              check_name: checkName
-            });
-
-            // Reuse the same workflow everytime there's a new review submitted
-            // instead of creating new workflows. Better efficiency and readability
-            // as the number of workflows is kept to a minimal number
-            if (checkRuns.data.total_count > 0) {
-              await github.rest.checks.update({
-                owner,
-                repo,
-                check_run_id: checkRuns.data.check_runs[0].id,
-                status: 'completed',
-                conclusion,
-                output
-              });
-            } else {
-              await github.rest.checks.create({
-                owner,
-                repo,
-                name: checkName,
-                head_sha: pr.data.head.sha,
-                status: 'completed',
-                conclusion,
-                output
-              });
-            }
-
             if (conclusion === 'failure') {
               core.setFailed(`PR needs at least ${requiredApprovals} total approvals and 2 required approvals. Current approvals: ${approvers.size}, Required approvals: ${requiredApprovals}`);
             }

.github/workflows/rustc.yml

@@ -11,6 +11,7 @@ on:
       - 'library/**'
       - 'rust-toolchain.toml'
       - '.github/workflows/rustc.yml'
+      - 'scripts/check_rustc.sh'
 
 defaults:
   run:
@@ -29,35 +30,5 @@ jobs:
         with:
           path: head
 
-      - name: Checkout `upstream/master`
-        uses: actions/checkout@v4
-        with:
-          repository: rust-lang/rust
-          path: upstream
-          fetch-depth: 0
-          submodules: true
-
-      # Run rustc twice in case the toolchain needs to be installed.
-      # Retrieve the commit id from the `rustc --version`. Output looks like:
-      # `rustc 1.80.0-nightly (84b40fc90 2024-05-27)`
-      - name: Checkout matching commit
-        run: |
-          cd head
-          rustc --version
-          COMMIT_ID=$(rustc --version | sed -e "s/.*(\(.*\) .*/\1/")
-          cd ../upstream
-          git checkout ${COMMIT_ID}
-
-      - name: Copy Library
-        run: |
-          rm -rf upstream/library
-          cp -r head/library upstream
-
-      - name: Run tests
-        working-directory: upstream
-        env:
-          # Avoid error due to unexpected `cfg`.
-          RUSTFLAGS: "--check-cfg cfg(kani) --check-cfg cfg(feature,values(any()))"
-        run: |
-          ./configure --set=llvm.download-ci-llvm=true
-          ./x test --stage 0 library/std
+      - name: Run rustc script
+        run: bash ./head/scripts/check_rustc.sh ${{github.workspace}}/head

README.md

@@ -7,7 +7,8 @@
 This repository is a fork of the official Rust programming
 language repository, created solely to verify the Rust standard
 library. It should not be used as an alternative to the official
-Rust releases.
+Rust releases. The repository is tool agnostic and welcomes the addition of 
+new tools.
 
 The goal is to have a verified [Rust standard library](https://doc.rust-lang.org/std/) and prove that it is safe.
 1. Contributing to the core mechanism of verifying the rust standard library
@@ -36,12 +37,14 @@ See [SECURITY](https://github.com/model-checking/kani/security/policy) for more
 ## License
 
 ### Kani
-
 Kani is distributed under the terms of both the MIT license and the Apache License (Version 2.0).
 See [LICENSE-APACHE](https://github.com/model-checking/kani/blob/main/LICENSE-APACHE) and [LICENSE-MIT](https://github.com/model-checking/kani/blob/main/LICENSE-MIT) for details.
 
 ## Rust
-
 Rust is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0), with portions covered by various BSD-like licenses.
 
 See [the Rust repository](https://github.com/rust-lang/rust) for details.
+
+## Introducing a New Tool
+
+Please use the [template available in this repository](.github/TOOL_REQUEST_TEMPLATE.md) to introduce a new verification tool.

doc/src/SUMMARY.md

@@ -16,4 +16,11 @@
   - [Core Transmutation](./challenges/0001-core-transmutation.md)
   - [Memory safety of core intrinsics](./challenges/0002-intrinsics-memory.md)
   - [Pointer Arithmetic](./challenges/0003-pointer-arithmentic.md)
+  - [Memory safety of BTreeMap's `btree::node` module](./challenges/0004-btree-node.md)
   - [Inductive data type](./challenges/0005-linked-list.md)
+  - [Safety of NonNull](./challenges/0006-nonnull.md)
+  - [Contracts for SmallSort](./challenges/0008-smallsort.md)
+  - [Safe abstractions for `core::time::Duration`](./challenges/0009-duration.md)
+  - [Memory safety of String](./challenges/0010-string.md)
+  - [Safety of Methods for Numeric Primitive Types](./challenges/0011-floats-ints.md)
+  - [Safety of NonZero](./challenges/0012-nonzero.md)

doc/src/challenges/0004-btree-node.md

@@ -0,0 +1,68 @@
+# Challenge 4: Memory safety of BTreeMap's `btree::node` module
+
+- **Status:** Open
+- **Tracking Issue:** [Link to issue](https://github.com/model-checking/verify-rust-std/issues/25)
+- **Start date:** *2024-07-01*
+- **End date:** *2024-12-10*
+
+-------------------
+
+
+## Goal
+
+Verify the memory safety of the [`alloc::collections::btree::node` module](https://github.com/rust-lang/rust/blob/c290e9de32e8ba6a673ef125fde40eadd395d170/library/alloc/src/collections/btree/node.rs).
+This is one of the main modules used for implementing the `BTreeMap` collection, and it includes a lot of unsafe code.
+
+### Success Criteria
+
+The memory safety of all public functions (especially safe ones) containing unsafe code must be verified, e.g.:
+
+1. `LeafNode::new`
+1. `NodeRef::as_internal_mut`
+1. `NodeRef::len`
+1. `NodeRef::ascend`
+1. `NodeRef::first_edge`
+1. `NodeRef::last_edge`
+1. `NodeRef::first_kv`
+1. `NodeRef::last_kv`
+1. `NodeRef::into_leaf`
+1. `NodeRef::keys`
+1. `NodeRef::as_leaf_mut`
+1. `NodeRef::into_leaf_mut`
+1. `NodeRef::as_leaf_dying`
+1. `NodeRef::pop_internal_level`
+1. `NodeRef::push`
+1. `Handle::left_edge`
+1. `Handle::right_edge`
+1. `Handle::left_kv`
+1. `Handle::right_kv`
+1. `Handle::descend`
+1. `Handle::into_kv`
+1. `Handle::key_mut`
+1. `Handle::into_val_mut`
+1. `Handle::into_kv_mut`
+1. `Handle::into_kv_valmut`
+1. `Handle::kv_mut`
+
+Verification must be unbounded for functions that use recursion or contain loops, e.g.
+
+1. `NodeRef::new_internal`
+1. `Handle::insert_recursing`
+1. `BalancingContext::do_merge`
+1. `BalancingContext::merge_tracking_child_edge`
+1. `BalancingContext::steal_left`
+1. `BalancingContext::steal_right`
+1. `BalancingContext::bulk_steal_left`
+1. `BalancingContext::bulk_steal_right`
+
+### List of UBs
+
+All proofs must automatically ensure the absence of the following [undefined behaviors](https://github.com/rust-lang/reference/blob/142b2ed77d33f37a9973772bd95e6144ed9dce43/src/behavior-considered-undefined.md):
+
+* Accessing (loading from or storing to) a place that is dangling or based on a misaligned pointer.
+* Reading from uninitialized memory.
+* Mutating immutable bytes.
+* Producing an invalid value
+
+Note: All solutions to verification challenges need to satisfy the criteria established in the [challenge book](../general-rules.md)
+in addition to the ones listed above.