build: run clippy for powerset of features (#4077)

This will catch compiler & clippy warnings in all feature combinations.

We should probably use cargo hack for build and test as well, but,
that's quite expensive and would add to overall CI wait times.

obsoletes https://github.com/neondatabase/neon/pull/4073
refs https://github.com/neondatabase/neon/pull/4070

.github/workflows/build_and_test.yml

@@ -111,8 +111,21 @@ jobs:
       - name: Get postgres headers
         run: make postgres-headers -j$(nproc)
 
-      - name: Run cargo clippy
-        run: ./run_clippy.sh
+      # cargo hack runs the given cargo subcommand (clippy in this case) for all feature combinations.
+      # This will catch compiler & clippy warnings in all feature combinations.
+      # TODO: use cargo hack for build and test as well, but, that's quite expensive.
+      # NB: keep clippy args in sync with ./run_clippy.sh
+      - run: |
+          CLIPPY_COMMON_ARGS="$( source .neon_clippy_args; echo "$CLIPPY_COMMON_ARGS")"
+          if [ "$CLIPPY_COMMON_ARGS" = "" ]; then
+            echo "No clippy args found in .neon_clippy_args"
+            exit 1
+          fi
+          echo "CLIPPY_COMMON_ARGS=${CLIPPY_COMMON_ARGS}" >> $GITHUB_ENV
+      - name: Run cargo clippy (debug)
+        run: cargo hack --feature-powerset clippy $CLIPPY_COMMON_ARGS
+      - name: Run cargo clippy (release)
+        run: cargo hack --feature-powerset clippy --release $CLIPPY_COMMON_ARGS
 
       # Use `${{ !cancelled() }}` to run quck tests after the longer clippy run
       - name: Check formatting

.neon_clippy_args

@@ -0,0 +1,4 @@
+# * `-A unknown_lints` – do not warn about unknown lint suppressions
+#                        that people with newer toolchains might use
+# * `-D warnings`      - fail on any warnings (`cargo` returns non-zero exit status)
+export CLIPPY_COMMON_ARGS="--locked --workspace --all-targets -- -A unknown_lints -D warnings"

run_clippy.sh

@@ -1,4 +1,5 @@
-#!/bin/bash
+#!/usr/bin/env bash
+set -euo pipefail
 
 # If you save this in your path under the name "cargo-zclippy" (or whatever
 # name you like), then you can run it as "cargo zclippy" from the shell prompt.
@@ -8,7 +9,11 @@
 # warnings and errors right in the editor.
 # In vscode, this setting is Rust-analyzer>Check On Save:Command
 
-# * `-A unknown_lints` – do not warn about unknown lint suppressions
-#                        that people with newer toolchains might use
-# * `-D warnings`      - fail on any warnings (`cargo` returns non-zero exit status)
-cargo clippy --locked --all --all-targets --all-features -- -A unknown_lints -D warnings
+# NB: the CI runs the full feature powerset, so, it catches slightly more errors
+# at the expense of longer runtime. This script is used by developers, so, don't
+# do that here.
+
+thisscript="${BASH_SOURCE[0]}"
+thisscript_dir="$(dirname "$thisscript")"
+CLIPPY_COMMON_ARGS="$( source .neon_clippy_args; echo "$CLIPPY_COMMON_ARGS")"
+exec cargo clippy --all-features $CLIPPY_COMMON_ARGS