Add CI to check ir module versioning (#7821)

4 files changed, 289 insertions, 0 deletions

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1f831415f..c3444f1b7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -145,6 +145,24 @@ jobs:
         if: ${{ matrix.os == 'linux' && matrix.config == 'debug' }}
         run: ./extras/check-ir-stable-names-gh-actions.sh
 
+      - name: Check Version Constants
+        id: check-ir-versions
+        if: ${{ matrix.os == 'linux' && matrix.config == 'debug' && github.event_name == 'pull_request' }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_EVENT_NAME: ${{ github.event_name }}
+          GITHUB_EVENT_PULL_REQUEST_NUMBER: ${{ github.event.pull_request.number }}
+          GITHUB_BASE_REF: ${{ github.base_ref }}
+        run: ./extras/check-inst-version-changes.sh
+
+      - name: Upload IR version check results
+        if: ${{ steps.check-versions.outputs.artifact_created == 'true' }}
+        uses: actions/upload-artifact@v4
+        with:
+          name: ir-version-check-results
+          path: ir-version-check-artifact/
+          retention-days: 1
+
       - name: Build Slang
         if: steps.filter.outputs.should-run == 'true'
         run: |
diff --git a/.github/workflows/comment-ir-version-check.yml b/.github/workflows/comment-ir-version-check.yml
new file mode 100644
index 000000000..462e2ec9c
--- /dev/null
+++ b/.github/workflows/comment-ir-version-check.yml
@@ -0,0 +1,73 @@
+name: Comment IR Version Check Results
+
+on:
+  workflow_run:
+    workflows: ["CI"]
+    types:
+      - completed
+
+jobs:
+  comment:
+    runs-on: ubuntu-latest
+    if: github.event.workflow_run.event == 'pull_request'
+
+    steps:
+      - name: Download artifacts
+        id: download
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const artifacts = await github.rest.actions.listWorkflowRunArtifacts({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              run_id: ${{ github.event.workflow_run.id }},
+            });
+
+            const matchArtifact = artifacts.data.artifacts.filter((artifact) => {
+              return artifact.name == "ir-version-check-results"
+            })[0];
+
+            if (!matchArtifact) {
+              console.log('No IR version check artifacts found - nothing to comment');
+              return false;
+            }
+
+            const download = await github.rest.actions.downloadArtifact({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              artifact_id: matchArtifact.id,
+              archive_format: 'zip',
+            });
+
+            const fs = require('fs');
+            fs.writeFileSync('${{github.workspace}}/ir-version-check-results.zip', Buffer.from(download.data));
+            return true;
+
+      - name: Extract artifacts
+        if: steps.download.outputs.result == 'true'
+        run: unzip ir-version-check-results.zip
+
+      - name: Read PR number
+        if: steps.download.outputs.result == 'true'
+        id: pr
+        run: |
+          echo "number=$(cat pr-number.txt)" >> $GITHUB_OUTPUT
+
+      - name: Find existing comment
+        if: steps.download.outputs.result == 'true'
+        id: find-comment
+        uses: peter-evans/find-comment@v3
+        with:
+          token: ${{ secrets.SLANGBOT_PAT }}
+          issue-number: ${{ steps.pr.outputs.number }}
+          body-includes: "<!-- slang-ir-version-check -->"
+
+      - name: Create or update comment
+        if: steps.download.outputs.result == 'true'
+        uses: peter-evans/create-or-update-comment@v4
+        with:
+          token: ${{ secrets.SLANGBOT_PAT }}
+          issue-number: ${{ steps.pr.outputs.number }}
+          comment-id: ${{ steps.find-comment.outputs.comment-id }}
+          body-path: comment-body.txt
+          edit-mode: replace
diff --git a/extras/check-inst-version-changes.sh b/extras/check-inst-version-changes.sh
new file mode 100755
index 000000000..74b851796
--- /dev/null
+++ b/extras/check-inst-version-changes.sh
@@ -0,0 +1,197 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+# Enable debug mode if DEBUG env var is set
+DEBUG="${DEBUG:-false}"
+
+debug_log() {
+  if [[ "$DEBUG" == "true" ]]; then
+    echo "[DEBUG] $*" >&2
+  fi
+}
+
+# Check if running in GitHub Actions
+if [[ -z "${GITHUB_ACTIONS:-}" ]]; then
+  echo "This script is designed to run in GitHub Actions"
+  exit 0
+fi
+
+# Check for required tools
+if ! command -v gh &>/dev/null; then
+  echo "Error: GitHub CLI (gh) is not installed"
+  exit 1
+fi
+
+# Verify GitHub authentication
+if ! gh auth status &>/dev/null; then
+  echo "Error: Not authenticated with GitHub CLI"
+  exit 1
+fi
+
+# Function to check if module ir version constants were modified
+check_module_versions_modified() {
+  local base_ref="$1"
+
+  # Check if slang-ir.h was modified and if the version constants were changed
+  if git diff --name-only "$base_ref...HEAD" | grep -q "^source/slang/slang-ir\.h$"; then
+    # Check if either version constant was modified
+    if git diff "$base_ref...HEAD" -- source/slang/slang-ir.h | grep -E "^\+.*k_(min|max)SupportedModuleVersion\s*="; then
+      debug_log "Module version constants were modified"
+      return 0
+    fi
+  fi
+
+  debug_log "Module version constants were not modified"
+  return 1
+}
+
+# Function to check if serialization version was modified
+check_serialization_version_modified() {
+  local base_ref="$1"
+
+  # Check if the serialization version constant was modified
+  if git diff "$base_ref...HEAD" -- source/slang/slang-serialize-ir.cpp | grep -E "^\+.*kSupportedSerializationVersion\s*="; then
+    debug_log "Serialization version constant was modified"
+    return 0
+  fi
+
+  debug_log "Serialization version constant was not modified"
+  return 1
+}
+
+# Get PR number if this is a pull request
+PR_NUMBER=""
+if [[ "$GITHUB_EVENT_NAME" == "pull_request" ]]; then
+  PR_NUMBER="${GITHUB_EVENT_PULL_REQUEST_NUMBER:-${GITHUB_PULL_REQUEST_NUMBER:-}}"
+  if [[ -z "$PR_NUMBER" ]] && [[ -f "${GITHUB_EVENT_PATH:-}" ]]; then
+    PR_NUMBER=$(jq -r '.pull_request.number // empty' "$GITHUB_EVENT_PATH" 2>/dev/null || echo "")
+  fi
+fi
+
+debug_log "Event name: $GITHUB_EVENT_NAME"
+debug_log "PR number: ${PR_NUMBER:-<none>}"
+
+# Get the base ref for comparison
+if [[ "$GITHUB_EVENT_NAME" == "pull_request" ]]; then
+  BASE_REF="origin/${GITHUB_BASE_REF}"
+  debug_log "Fetching base ref: $GITHUB_BASE_REF"
+  if ! git fetch origin "$GITHUB_BASE_REF" --depth=1; then
+    echo "Warning: Failed to fetch base ref, trying without depth limit"
+    git fetch origin "$GITHUB_BASE_REF"
+  fi
+else
+  BASE_REF="HEAD^1"
+fi
+
+debug_log "Base ref for comparison: $BASE_REF"
+
+# Get list of changed files
+CHANGED_FILES=$(git diff --name-only "$BASE_REF...HEAD" || echo "")
+debug_log "Changed files:"
+debug_log "$CHANGED_FILES"
+
+# Check for changes in IR instruction files
+INST_FILES_CHANGED=false
+if echo "$CHANGED_FILES" | grep -E "^source/slang/slang-ir-insts(-stable-names)?\.lua$"; then
+  INST_FILES_CHANGED=true
+  debug_log "IR instruction files have changed"
+fi
+
+# Check for changes in serialization file
+SERIALIZE_CHANGED=false
+if echo "$CHANGED_FILES" | grep -q "^source/slang/slang-serialize-ir\.cpp$"; then
+  SERIALIZE_CHANGED=true
+  debug_log "Serialization file has changed"
+fi
+
+# Initialize comment body
+COMMENT_BODY=""
+NEEDS_COMMENT=false
+
+# Check if we need to add warnings
+if [[ "$INST_FILES_CHANGED" == "true" ]]; then
+  # Check if the version constants have already been updated
+  if check_module_versions_modified "$BASE_REF"; then
+    echo "::notice::IR instruction files changed but module version constants were already updated"
+  else
+    NEEDS_COMMENT=true
+    if [[ -n "$COMMENT_BODY" ]]; then
+      COMMENT_BODY="${COMMENT_BODY}
+
+"
+    fi
+    COMMENT_BODY="${COMMENT_BODY}⚠️ **IR Instruction Files Changed**
+
+This PR modifies IR instruction definition files. Please review if you need to update the following constants in \`source/slang/slang-ir.h\`:
+
+- \`k_minSupportedModuleVersion\`: Should be incremented if you're removing instructions or making breaking changes
+- \`k_maxSupportedModuleVersion\`: Should be incremented when adding new instructions
+
+These version numbers help ensure compatibility between different versions of compiled modules."
+
+    echo "::warning::IR instruction files changed - please check if module version constants need updating"
+  fi
+fi
+
+if [[ "$SERIALIZE_CHANGED" == "true" ]]; then
+  # Check if the serialization version has already been updated
+  if check_serialization_version_modified "$BASE_REF"; then
+    echo "::notice::Serialization code changed but serialization version was already updated"
+  else
+    NEEDS_COMMENT=true
+    if [[ -n "$COMMENT_BODY" ]]; then
+      COMMENT_BODY="${COMMENT_BODY}
+
+"
+    fi
+    COMMENT_BODY="${COMMENT_BODY}⚠️ **Serialization Code Changed**
+
+This PR modifies \`source/slang/slang-serialize-ir.cpp\`. Please review if you need to update:
+
+- \`kSupportedSerializationVersion\`: Should be incremented if you're making backwards-incompatible changes to the serialization format
+
+This version number helps maintain compatibility when loading serialized IR modules."
+
+    echo "::warning::Serialization code changed - please check if serialization version needs updating"
+  fi
+fi
+
+# Create artifact directory only if we need to comment
+if [[ "$NEEDS_COMMENT" == "true" ]] && [[ -n "$PR_NUMBER" ]]; then
+  ARTIFACT_DIR="${ARTIFACT_DIR:-ir-version-check-artifact}"
+  debug_log "Creating artifact directory: $ARTIFACT_DIR"
+  mkdir -p "$ARTIFACT_DIR"
+
+  # Write artifact files
+  echo "$PR_NUMBER" >"$ARTIFACT_DIR/pr-number.txt"
+
+  # Write comment body with marker
+  {
+    echo "<!-- slang-ir-version-check -->"
+    echo "$COMMENT_BODY"
+  } >"$ARTIFACT_DIR/comment-body.txt"
+
+  debug_log "Artifact files created:"
+  debug_log "  pr-number: $PR_NUMBER"
+  debug_log "  comment-body: $(wc -l <"$ARTIFACT_DIR/comment-body.txt") lines"
+
+  # Set output to indicate artifact was created
+  if [[ -n "${GITHUB_OUTPUT:-}" ]]; then
+    echo "artifact_created=true" >>"$GITHUB_OUTPUT"
+  else
+    echo "::set-output name=artifact_created::true"
+  fi
+else
+  debug_log "No artifact needed (needs_comment=$NEEDS_COMMENT, pr_number=${PR_NUMBER:-<empty>})"
+
+  # Set output to indicate no artifact was created
+  if [[ -n "${GITHUB_OUTPUT:-}" ]]; then
+    echo "artifact_created=false" >>"$GITHUB_OUTPUT"
+  else
+    echo "::set-output name=artifact_created::false"
+  fi
+fi
+
+debug_log "Script completed successfully"
+exit 0
diff --git a/source/slang/slang-ir.h b/source/slang/slang-ir.h
index 0f4da4f0d..1f6418036 100644
--- a/source/slang/slang-ir.h
+++ b/source/slang/slang-ir.h
@@ -2409,6 +2409,7 @@ public:
     //
     const static UInt k_minSupportedModuleVersion = 1;
     const static UInt k_maxSupportedModuleVersion = 1;
+    static_assert(k_minSupportedModuleVersion <= k_maxSupportedModuleVersion);
 
 private:
     friend struct IRSerialReadContext;