Add benchmarking CI that generates graphs on updates to master (#544)

This PR adds a CI workflow that generates performance graphs on every update to master. It stores the data as json in the `gh-pages` branch and renders the graphs on a Github Page. Here's [an example](https://galoisinc.github.io/cerberus/dev/bench/) of what this looks like with [dummy data](https://github.com/GaloisInc/cerberus/blob/gh-pages/dev/bench/data.js). 

This currently runs `cn` on all the .c files in the test suite. Eventually, we probably want to make a proper benchmark suite using something like [Core_bench](https://blog.janestreet.com/core_bench-micro-benchmarking-for-ocaml/).

It relies upon the existence of the (currently empty) `gh-pages` branch.

Implements part of rems-project/cn-tutorial/issues/54.

.github/workflows/ci-bench.yml

@@ -0,0 +1,113 @@
+name: CI Benchmarks
+
+on:
+  push:
+    branches:
+      - master
+
+env:
+  CERBERUS_IMAGE_ID: ghcr.io/rems-project/cerberus/cn:release
+
+permissions:
+  # deployments permission to deploy GitHub pages website
+  deployments: write
+  # contents permission to update benchmark contents in gh-pages branch
+  contents: write
+
+# cancel in-progress job when a new push is performed
+concurrency:
+  group: ci-bench-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  benchmark:
+    name: Performance benchmarks
+    strategy:
+      matrix:
+        # version: [4.12.0, 4.14.1]
+        version: [4.14.1]
+
+
+    runs-on: ubuntu-22.04
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: System dependencies (ubuntu)
+      run: |
+        sudo apt install build-essential libgmp-dev z3 opam cmake jq
+
+    - name: Restore cached opam
+      id: cache-opam-restore
+      uses: actions/cache/restore@v4
+      with:
+        path: ~/.opam
+        key: ${{ matrix.version }}
+
+    - name: Setup opam
+      if: steps.cache-opam-restore.outputs.cache-hit != 'true'
+      run: |
+        opam init --yes --no-setup --shell=sh --compiler=${{ matrix.version }}
+        opam install --deps-only --yes ./cerberus-lib.opam
+        opam switch create with_coq ${{ matrix.version }}
+        eval $(opam env --switch=with_coq)
+        opam repo add --yes --this-switch coq-released https://coq.inria.fr/opam/released
+        opam pin --yes -n coq-struct-tact https://github.com/uwplse/StructTact.git
+        opam repo add --yes --this-switch iris-dev https://gitlab.mpi-sws.org/iris/opam.git
+        opam pin --yes -n coq-sail-stdpp https://github.com/rems-project/coq-sail.git#f319aad
+        opam pin --yes -n coq-cheri-capabilities https://github.com/rems-project/coq-cheri-capabilities.git
+        opam install --deps-only --yes ./cerberus-lib.opam ./cerberus-cheri.opam
+
+    - name: Save cached opam
+      if: steps.cache-opam-restore.outputs.cache-hit != 'true'
+      id: cache-opam-save
+      uses: actions/cache/save@v4
+      with:
+        path: ~/.opam
+        key: ${{ steps.cache-opam-restore.outputs.cache-primary-key }}
+
+    - name: Install Cerberus
+      run: |
+        opam switch ${{ matrix.version }}
+        eval $(opam env --switch=${{ matrix.version }})
+        opam pin --yes --no-action add cerberus-lib .
+        opam pin --yes --no-action add cerberus .
+        opam install --yes cerberus
+
+    - name: Download cvc5 release
+      uses: robinraju/release-downloader@v1
+      with:
+        repository: cvc5/cvc5
+        tag: cvc5-1.1.2
+        fileName: cvc5-Linux-static.zip
+
+    - name: Unzip and install cvc5
+      run: |
+        unzip cvc5-Linux-static.zip
+        chmod +x cvc5-Linux-static/bin/cvc5
+        sudo cp cvc5-Linux-static/bin/cvc5 /usr/local/bin/
+
+    - name: Install CN
+      run: |
+        opam switch ${{ matrix.version }}
+        eval $(opam env --switch=${{ matrix.version }})
+        opam pin --yes --no-action add cn .
+        opam install --yes cn ocamlformat.0.26.2
+
+    - name: Run benchmark
+      run: |
+        opam switch ${{ matrix.version }}
+        eval $(opam env --switch=${{ matrix.version }})
+        cd tests; USE_OPAM='' ./run-ci-benchmarks.sh
+        cd ..
+
+    - name: Store benchmark result
+      uses: benchmark-action/github-action-benchmark@v1
+      with:
+        name: CN Benchmarks
+        tool: 'customSmallerIsBetter'
+        output-file-path: tests/benchmark-data.json
+        # Access token to deploy GitHub Pages branch
+        github-token: ${{ secrets.GITHUB_TOKEN }}
+        # Push and deploy GitHub pages branch automatically
+        auto-push: true

tests/run-ci-benchmarks.sh

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+#!/usr/bin/env bash
+set -euo pipefail -o noclobber
+# set -xv # uncomment to debug variables
+
+JSON_FILE="benchmark-data.json"
+
+echo "[" >> "${JSON_FILE}"
+
+DIRNAME=$(dirname "$0")
+
+TESTS=$(find "${DIRNAME}"/cn -name '*.c')
+
+COUNT=0
+for TEST in ${TESTS}; do
+  let COUNT=${COUNT}+1
+done
+
+INDEX=0
+for TEST in ${TESTS}; do
+
+  # Record wall clock time in seconds
+  /usr/bin/time --quiet -f "%e" -o /tmp/time cn verify "${TEST}" || true
+  TIME=$(cat /tmp/time)
+
+  # If we're last, don't print a trailing comma.
+  if [[ ${INDEX} -eq ${COUNT}-1 ]]; then
+    # Hack to output JSON.
+    cat << EOF >> ${JSON_FILE}
+    {
+	"name": "${TEST}",
+        "unit": "Seconds",
+	"value": ${TIME}
+    }
+EOF
+  else
+    cat << EOF >> ${JSON_FILE}
+    {
+	"name": "${TEST}",
+        "unit": "Seconds",
+	"value": ${TIME}
+    },
+EOF
+  fi
+
+  let INDEX=${INDEX}+1
+done
+
+echo "]" >> "${JSON_FILE}"
+
+jq . "${JSON_FILE}"