Add simple validation CI

Author: Erlend E. Aasland

.github/workflows/sqlite.yml

@@ -0,0 +1,65 @@
+name: Check SQLite sources
+
+on:
+  push:
+    branches:
+      - sqlite
+  pull_request:
+    branches:
+      - sqlite
+
+jobs:
+  validate:
+    name: "Validate SQLite sources"
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 1
+
+      - name: "Get SQLite version info"
+        env:
+          # See https://sqlite.org/c3ref/c_source_id.html
+          SQLITE_H: sqlite3.h
+          VERSION_RE: "^#define SQLITE_VERSION\\>.*\\([0-9]\\+.[0-9]\\+.[0-9]\\+\\).*"
+          DATE_RE: "^#define SQLITE_SOURCE_ID.*\\([0-9]\\{4\\}-[0-9]\\{2\\}-[0-9]\\{2\\}\\).*"
+        id: info
+        run: |
+          VERSION=$(sed -n "s/${VERSION_RE}/\\1/p" $SQLITE_H)
+          test -z $VERSION && false
+          echo "::set-output name=version::$VERSION"
+
+          # ISO 8601 date should have 10 characters: YYYY-MM-DD
+          DATE=$(sed -n "s/${DATE_RE}/\\1/p" $SQLITE_H)
+          test ${#DATE} -eq 10 || false
+          echo "::set-output name=date::$DATE"
+
+      - name: "Get URL"
+        id: url
+        env:
+          VERSION: ${{ steps.info.outputs.version }}
+          DATE: ${{ steps.info.outputs.date }}
+        run: |
+          YEAR=$(echo $DATE | cut -d '-' -f 1)
+          MAJOR=$(echo $VERSION | cut -d '.' -f 1)
+          MINOR=$(echo $VERSION | cut -d '.' -f 2)
+          PATCH=$(echo $VERSION | cut -d '.' -f 3)
+
+          # See https://sqlite.org/download.html
+          printf -v ENCODED_VERSION "%d%02d%02d00" $MAJOR $MINOR $PATCH
+          URL="https://sqlite.org/$YEAR/sqlite-amalgamation-${ENCODED_VERSION}.zip"
+          echo "::set-output name=url::$URL"
+
+      - name: "Download and validate SQLite amalgamation sources"
+        env:
+          URL: ${{ steps.url.outputs.url }}
+        run: |
+          curl -sO $URL
+
+          ARCHIVE=$(basename $URL)
+          unzip -o $ARCHIVE
+
+          DIR=$(basename $ARCHIVE .zip)
+          for _F in *.[ch]; do
+            cmp $_F $DIR/$_F && echo "$_F: check"
+          done