bump msrv to 1.56

.cargo/config

@@ -3,10 +3,6 @@ xtask = "run --package xtask --"
 
 [target.'cfg(feature = "cargo-clippy")']
 rustflags = [
-    # TODO: remove these allows once msrv increased from 1.48
-    "-Aclippy::iter_kv_map",
-    "-Aclippy::needless_borrow",
-    "-Aclippy::uninlined_format_args",
     # Lints to enforce in CI
     "-Dclippy::checked_conversions",
     "-Dclippy::dbg_macro",
@@ -15,7 +11,6 @@ rustflags = [
     "-Dclippy::filter_map_next",
     "-Dclippy::flat_map_option",
     "-Dclippy::let_unit_value",
-    "-Dclippy::manual_assert",
     "-Dclippy::manual_ok_or",
     "-Dclippy::todo",
     "-Dclippy::unnecessary_wraps",

.github/workflows/build.yml

@@ -201,7 +201,3 @@ jobs:
       # TODO: this is a hack to workaround compile_error! warnings about auto-initialize on PyPy
       # Once cargo's `resolver = "2"` is stable (~ MSRV Rust 1.52), remove this.
       PYO3_CI: 1
-      # This is a hack to make CARGO_PRIMARY_PACKAGE always set even for the
-      # msrv job. MSRV is currently 1.48, but CARGO_PRIMARY_PACKAGE only came in
-      # 1.49.
-      CARGO_PRIMARY_PACKAGE: 1

.github/workflows/ci.yml

@@ -34,6 +34,32 @@ jobs:
       - name: Check rust formatting (rustfmt)
         run: nox -s fmt-rust
 
+  check-msrv:
+    needs: [fmt]
+    runs-on: ubuntu-latest
+    if: github.ref != 'refs/heads/main'
+    steps:
+      - uses: actions/checkout@v3
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: 1.56.0
+          targets: x86_64-unknown-linux-gnu
+          components: clippy,rust-src
+      - uses: actions/setup-python@v4
+        with:
+          architecture: "x64"
+      - uses: Swatinem/rust-cache@v2
+        with:
+          key: check-msrv-1.56.0
+        continue-on-error: true
+      - run: python -m pip install --upgrade pip && pip install nox
+      - name: Prepare minimal package versions
+        run: nox -s set-minimal-package-versions
+      - run: nox -s check-all
+
+    env:
+      CARGO_BUILD_TARGET: x86_64-unknown-linux-gnu
+
   clippy:
     needs: [fmt]
     runs-on: ${{ matrix.platform.os }}
@@ -80,16 +106,6 @@ jobs:
             rust-target: "i686-pc-windows-msvc",
           },
         ]
-        include:
-          - rust: 1.48.0
-            python-version: "3.11"
-            platform:
-              {
-                os: "ubuntu-latest",
-                python-architecture: "x64",
-                rust-target: "x86_64-unknown-linux-gnu",
-              }
-            msrv: "MSRV"
     name: clippy/${{ matrix.platform.rust-target }}/${{ matrix.rust }}
     steps:
       - uses: actions/checkout@v3
@@ -106,9 +122,6 @@ jobs:
           key: clippy-${{ matrix.platform.rust-target }}-${{ matrix.platform.os }}-${{ matrix.rust }}
         continue-on-error: true
       - run: python -m pip install --upgrade pip && pip install nox
-      - if: matrix.msrv == 'MSRV'
-        name: Prepare minimal package versions (MSRV only)
-        run: nox -s set-minimal-package-versions
       - run: nox -s clippy-all
     env:
       CARGO_BUILD_TARGET: ${{ matrix.platform.rust-target }}
@@ -207,7 +220,7 @@ jobs:
           ]
         include:
           # Test minimal supported Rust version
-          - rust: 1.48.0
+          - rust: 1.56.0
             python-version: "3.11"
             platform:
               {
@@ -353,6 +366,7 @@ jobs:
   conclusion:
     needs:
       - fmt
+      - check-msrv
       - clippy
       - build-pr
       - build-full

Cargo.toml

@@ -12,6 +12,7 @@ categories = ["api-bindings", "development-tools::ffi"]
 license = "Apache-2.0"
 exclude = ["/.gitignore", ".cargo/config", "/codecov.yml", "/Makefile", "/pyproject.toml", "/noxfile.py", "/.github", "/tests/test_compile_error.rs", "/tests/ui"]
 edition = "2018"
+rust-version = "1.56"
 
 [dependencies]
 cfg-if = "1.0"

README.md

@@ -4,7 +4,7 @@
 [![benchmark](https://github.com/PyO3/pyo3/actions/workflows/bench.yml/badge.svg)](https://pyo3.rs/dev/bench/)
 [![codecov](https://codecov.io/gh/PyO3/pyo3/branch/main/graph/badge.svg)](https://codecov.io/gh/PyO3/pyo3)
 [![crates.io](https://img.shields.io/crates/v/pyo3)](https://crates.io/crates/pyo3)
-[![minimum rustc 1.48](https://img.shields.io/badge/rustc-1.48+-blue.svg)](https://rust-lang.github.io/rfcs/2495-min-rust-version.html)
+[![minimum rustc 1.56](https://img.shields.io/badge/rustc-1.56+-blue.svg)](https://rust-lang.github.io/rfcs/2495-min-rust-version.html)
 [![dev chat](https://img.shields.io/gitter/room/nwjs/nw.js.svg)](https://gitter.im/PyO3/Lobby)
 [![contributing notes](https://img.shields.io/badge/contribute-on%20github-Green)](https://github.com/PyO3/pyo3/blob/main/Contributing.md)
 
@@ -18,7 +18,7 @@
 
 PyO3 supports the following software versions:
   - Python 3.7 and up (CPython and PyPy)
-  - Rust 1.48 and up
+  - Rust 1.56 and up
 
 You can use PyO3 to write a native Python module in Rust, or to embed Python in a Rust binary. The following sections explain each of these in turn.
 

examples/plugin/plugin_api/pyproject.toml

@@ -10,5 +10,3 @@ classifiers = [
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Python :: Implementation :: PyPy",
 ]
-
-

guide/src/getting_started.md

@@ -4,7 +4,7 @@ To get started using PyO3 you will need three things: a Rust toolchain, a Python
 
 ## Rust
 
-First, make sure you have Rust installed on your system. If you haven't already done so, try following the instructions [here](https://www.rust-lang.org/tools/install). PyO3 runs on both the `stable` and `nightly` versions so you can choose whichever one fits you best. The minimum required Rust version is 1.48.
+First, make sure you have Rust installed on your system. If you haven't already done so, try following the instructions [here](https://www.rust-lang.org/tools/install). PyO3 runs on both the `stable` and `nightly` versions so you can choose whichever one fits you best. The minimum required Rust version is 1.56.
 
 If you can run `rustc --version` and the version is new enough you're good to go!
 

guide/src/migration.md

@@ -3,6 +3,12 @@
 This guide can help you upgrade code through breaking changes from one PyO3 version to the next.
 For a detailed list of all changes, see the [CHANGELOG](changelog.md).
 
+## from 0.19.* to 0.20
+
+### Drop support for older technologies
+
+PyO3 0.20 has increased minimum Rust version to 1.56. This enables use of newer language features and simplifies maintenance of the project.
+
 ## from 0.18.* to 0.19
 
 ### Access to `Python` inside `__traverse__` implementations are now forbidden

newsfragments/3208.packaging.md

@@ -0,0 +1 @@
+Update MSRV to Rust 1.56.

noxfile.py

@@ -8,7 +8,7 @@
 from functools import lru_cache
 from glob import glob
 from pathlib import Path
-from typing import Any, Dict, List, Optional, Tuple
+from typing import Any, Callable, Dict, List, Optional, Tuple
 
 import nox
 
@@ -96,25 +96,19 @@ def _clippy(session: nox.Session, *, env: Dict[str, str] = None) -> bool:
     success = True
     env = env or os.environ
     for feature_set in _get_feature_sets():
-        command = "clippy"
-        extra = ("--", "--deny=warnings")
-        if _get_rust_version()[:2] == (1, 48):
-            # 1.48 crashes during clippy because of lints requested
-            # in .cargo/config
-            command = "check"
-            extra = ()
         try:
             _run(
                 session,
                 "cargo",
-                command,
+                "clippy",
                 *feature_set,
                 "--all-targets",
                 "--workspace",
                 # linting pyo3-ffi-check requires docs to have been built or
                 # the macros will error; doesn't seem worth it on CI
                 "--exclude=pyo3-ffi-check",
-                *extra,
+                "--",
+                "--deny=warnings",
                 external=True,
                 env=env,
             )
@@ -126,31 +120,43 @@ def _clippy(session: nox.Session, *, env: Dict[str, str] = None) -> bool:
 @nox.session(name="clippy-all", venv_backend="none")
 def clippy_all(session: nox.Session) -> None:
     success = True
-    with tempfile.NamedTemporaryFile("r+") as config:
-        env = os.environ.copy()
-        env["PYO3_CONFIG_FILE"] = config.name
-        env["PYO3_CI"] = "1"
 
-        def _clippy_with_config(implementation, version) -> bool:
-            config.seek(0)
-            config.truncate(0)
-            config.write(
-                f"""\
-implementation={implementation}
-version={version}
-suppress_build_script_link_lines=true
-"""
-            )
-            config.flush()
+    def _clippy_with_config(env: Dict[str, str]) -> None:
+        nonlocal success
+        success &= _clippy(session, env=env)
 
-            session.log(f"{implementation} {version}")
-            return _clippy(session, env=env)
+    _for_all_version_configs(session, _clippy_with_config)
 
-        for version in PY_VERSIONS:
-            success &= _clippy_with_config("CPython", version)
+    if not success:
+        session.error("one or more jobs failed")
 
-        for version in PYPY_VERSIONS:
-            success &= _clippy_with_config("PyPy", version)
+
+@nox.session(name="check-all", venv_backend="none")
+def check_all(session: nox.Session) -> None:
+    success = True
+
+    def _check(env: Dict[str, str]) -> None:
+        nonlocal success
+        env = env or os.environ
+        for feature_set in _get_feature_sets():
+            try:
+                _run(
+                    session,
+                    "cargo",
+                    "check",
+                    *feature_set,
+                    "--all-targets",
+                    "--workspace",
+                    # linting pyo3-ffi-check requires docs to have been built or
+                    # the macros will error; doesn't seem worth it on CI
+                    "--exclude=pyo3-ffi-check",
+                    external=True,
+                    env=env,
+                )
+            except Exception:
+                success = False
+
+    _for_all_version_configs(session, _check)
 
     if not success:
         session.error("one or more jobs failed")
@@ -422,42 +428,13 @@ def set_minimal_package_versions(session: nox.Session):
         "examples/word-count",
     )
     min_pkg_versions = {
-        # newer versions of rust_decimal want newer arrayvec
-        "rust_decimal": "1.18.0",
-        # newer versions of arrayvec use const generics (Rust 1.51+)
-        "arrayvec": "0.5.2",
+        "rust_decimal": "1.26.1",
         "csv": "1.1.6",
-        # newer versions of chrono use i32::rem_euclid as a const fn
-        "chrono": "0.4.24",
-        "indexmap": "1.6.2",
-        "inventory": "0.3.4",
-        "hashbrown": "0.9.1",
-        "plotters": "0.3.1",
-        "plotters-svg": "0.3.1",
-        "plotters-backend": "0.3.2",
-        "bumpalo": "3.10.0",
-        "once_cell": "1.14.0",
-        "rayon": "1.5.3",
-        "rayon-core": "1.9.3",
+        "hashbrown": "0.12.3",
+        "once_cell": "1.17.2",
+        "rayon": "1.6.1",
+        "rayon-core": "1.10.2",
         "regex": "1.7.3",
-        # string_cache 0.8.4 depends on parking_lot 0.12
-        "string_cache": "0.8.3",
-        # 1.15.0 depends on hermit-abi 0.2.6 which has edition 2021 and breaks 1.48.0
-        "num_cpus": "1.14.0",
-        "parking_lot": "0.11.0",
-        # 1.0.77 needs basic-toml which has edition 2021
-        "trybuild": "1.0.76",
-        # pins to avoid syn 2.0 (which requires Rust 1.56)
-        "ghost": "0.1.8",
-        "serde": "1.0.156",
-        "serde_derive": "1.0.156",
-        "cxx": "1.0.92",
-        "cxxbridge-macro": "1.0.92",
-        "cxx-build": "1.0.92",
-        "web-sys": "0.3.61",
-        "js-sys": "0.3.61",
-        "wasm-bindgen": "0.2.84",
-        "syn": "1.0.109",
     }
 
     # run cargo update first to ensure that everything is at highest
@@ -634,11 +611,41 @@ def _run_cargo_set_package_version(
     *,
     project: Optional[str] = None,
 ) -> None:
-    command = ["cargo", "update", "-p", pkg_id, "--precise", version]
+    command = ["cargo", "update", "-p", pkg_id, "--precise", version, "--workspace"]
     if project:
         command.append(f"--manifest-path={project}/Cargo.toml")
     _run(session, *command, external=True)
 
 
 def _get_output(*args: str) -> str:
     return subprocess.run(args, capture_output=True, text=True, check=True).stdout
+
+
+def _for_all_version_configs(
+    session: nox.Session, job: Callable[[Dict[str, str]], None]
+) -> None:
+    with tempfile.NamedTemporaryFile("r+") as config:
+        env = os.environ.copy()
+        env["PYO3_CONFIG_FILE"] = config.name
+        env["PYO3_CI"] = "1"
+
+        def _job_with_config(implementation, version) -> bool:
+            config.seek(0)
+            config.truncate(0)
+            config.write(
+                f"""\
+implementation={implementation}
+version={version}
+suppress_build_script_link_lines=true
+"""
+            )
+            config.flush()
+
+            session.log(f"{implementation} {version}")
+            return job(env)
+
+        for version in PY_VERSIONS:
+            _job_with_config("CPython", version)
+
+        for version in PYPY_VERSIONS:
+            _job_with_config("PyPy", version)

pyo3-build-config/src/lib.rs

@@ -161,6 +161,11 @@ pub fn print_feature_cfgs() {
     if rustc_minor_version >= 59 {
         println!("cargo:rustc-cfg=thread_local_const_init");
     }
+
+    // Enable use of `#[cfg(panic = "...")]` on Rust 1.60 and greater
+    if rustc_minor_version >= 60 {
+        println!("cargo:rustc-cfg=panic_unwind");
+    }
 }
 
 /// Private exports used in PyO3's build.rs

pyo3-ffi/README.md

@@ -14,7 +14,7 @@ Manual][capi] for up-to-date documentation.
 
 PyO3 supports the following software versions:
   - Python 3.7 and up (CPython and PyPy)
-  - Rust 1.48 and up
+  - Rust 1.56 and up
 
 # Example: Building Python Native modules
 

pyo3-ffi/src/lib.rs

@@ -51,7 +51,7 @@
 //!
 //! PyO3 supports the following software versions:
 //!   - Python 3.7 and up (CPython and PyPy)
-//!   - Rust 1.48 and up
+//!   - Rust 1.56 and up
 //!
 //! # Example: Building Python Native modules
 //!

pyo3-macros-backend/src/pyfunction/signature.rs

@@ -27,10 +27,11 @@ pub struct Signature {
 impl Parse for Signature {
     fn parse(input: ParseStream<'_>) -> syn::Result<Self> {
         let content;
-        Ok(Signature {
-            paren_token: syn::parenthesized!(content in input),
-            items: content.parse_terminated(SignatureItem::parse)?,
-        })
+        let paren_token = syn::parenthesized!(content in input);
+
+        let items = content.parse_terminated(SignatureItem::parse)?;
+
+        Ok(Signature { paren_token, items })
     }
 }