Get rustdoc flags from Cargo.toml.

.github/workflows/build.yml

@@ -9,7 +9,7 @@ on:
 
 env:
   CARGO_TERM_COLOR: always
-  RUSTFLAGS: '-D warnings'
+  RUSTFLAGS: "-D warnings"
 
 jobs:
   # Run MIRI tests on nightly
@@ -182,11 +182,6 @@ jobs:
   doc:
     name: doc
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        target:
-          - x86_64-unknown-linux-gnu
-          - thumbv7m-none-eabi
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -213,14 +208,40 @@ jobs:
             ${{ runner.OS }}-build-${{ hashFiles('**/Cargo.lock') }}
             ${{ runner.OS }}-build-
 
-      - name: Install nightly Rust with target (${{ matrix.target }})
+      - name: Get metadata
+        id: metadata
+        run: |
+          set -euo pipefail
+
+          docsrs_metadata="$(cargo metadata --format-version 1 | jq '.packages[] | select(.name == "heapless") | .metadata.docs.rs')"
+          features=($(jq --raw-output '.features[]' <<< "${docsrs_metadata}"))
+          rustdocflags=(-D warnings --cfg docsrs $(jq --raw-output '.["rustdoc-args"][]' <<< "${docsrs_metadata}"))
+          targets=($(jq --raw-output '.targets[]' <<< "${docsrs_metadata}"))
+
+          echo "features=${features[*]}" >> "${GITHUB_OUTPUT}"
+          echo "rustdocflags=${rustdocflags[*]}" >> "${GITHUB_OUTPUT}"
+          echo "targets=${targets[*]}" >> "${GITHUB_OUTPUT}"
+
+      - name: Install nightly Rust with targets (${{ steps.metadata.outputs.targets }})
         uses: dtolnay/rust-toolchain@nightly
         with:
-          targets: ${{ matrix.target }}
+          targets: ${{ steps.metadata.outputs.targets }}
 
       - name: cargo rustdoc
-        env: {"RUSTDOCFLAGS": "-D warnings --cfg docsrs"}
-        run: cargo rustdoc --target=${{ matrix.target }} --features="alloc bytes defmt mpmc_large portable-atomic-critical-section serde ufmt"
+        run: |
+          set -euo pipefail
+
+          targets=(${targets})
+
+          for target in "${targets[@]}"; do
+            set -x
+            cargo rustdoc --target "${target}" --features "${features}"
+            set +x
+          done
+        env:
+          features: ${{ steps.metadata.outputs.features }}
+          RUSTDOCFLAGS: ${{ steps.metadata.outputs.rustdocflags }}
+          targets: ${{ steps.metadata.outputs.targets }}
 
   # Run cpass tests
   testcpass: