CI: Setup ABI testing

.github/workflows/ci.yml

@@ -4,6 +4,7 @@ on: [push, pull_request]
 
 jobs:
   build:
+    if: false
     strategy:
       matrix:
         os:
@@ -51,6 +52,7 @@ jobs:
           cd build
           ctest -C Debug --output-on-failure
   fuzzing_build:
+    if: false
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
@@ -68,3 +70,21 @@ jobs:
           cd build
           cmake ..
           cmake --build .
+  abi_check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+      - name: Install dependencies
+        run: |
+          sudo apt update
+          sudo apt install liblzo2-dev libssl-dev gnutls-dev libgcrypt-dev abi-dumper abi-compliance-checker universal-ctags
+      - name: Check ABI
+        run: ./test/abi/abi-check.py
+      - uses: actions/upload-artifact@v3
+        if: always()
+        with:
+          name: abi-check-result
+          path: test/abi/abi-check-result
+

.github/workflows/codeql-analysis.yml

@@ -16,6 +16,7 @@ on:
 
 jobs:
   analyze:
+    if: false
     name: Analyze
     runs-on: ubuntu-latest
 

.gitignore

@@ -40,6 +40,7 @@ test/cargstest
 test/copyrecttest
 test/encodingstest
 test/wstest
+test/abi/abi-check-result
 /test/tjbench
 /test/tjunittest
 vncterm/LinuxVNC

test/abi/abi-check.py

@@ -0,0 +1,126 @@
+#!/usr/bin/python3
+
+import os
+import sys
+import argparse
+import tempfile
+import subprocess
+from pathlib import Path
+
+
+ORIGINAL_DIR = Path(os.getcwd())
+SCRIPT_DIR = Path(__file__).resolve().parent
+REPO_DIR = SCRIPT_DIR.parent.parent  # Assuming this script is in 'test/abi'
+WORK_DIR = tempfile.TemporaryDirectory(prefix='libvnc-abi-check')
+
+DEFAULT_REV_FILE = Path(SCRIPT_DIR, 'published-abi-revision')  # May not exist
+OUTPUT_DIR = Path(SCRIPT_DIR, 'abi-check-result')  # ABI dumps & compliance reports are generated here
+
+LIB_CLIENT = 'vncclient'
+LIB_SERVER = 'vncserver'
+LABEL_OLD = 'old'
+LABEL_NEW = 'new'
+
+
+def run_cmd(cmd: str, check=True):
+    return subprocess.run(cmd, shell=True, check=check)
+
+
+def read_cmd_output(cmd: str):
+    return subprocess.run(cmd, shell=True, check=True, stdout=subprocess.PIPE).stdout
+
+
+def create_dump_file_path(library: str, label: str):
+    return str(Path(OUTPUT_DIR, f"{library}-{label}.dump"))
+
+# Builds given library (vncclient/vncserver), and stores it's ABI dump in output directory.
+# Assumes we are in build directory.
+
+
+def dump_library_abi(library: str, label: str):
+    dump_file = create_dump_file_path(library, label)
+    run_cmd(f"cmake --build . --target {library}")
+    run_cmd(f"abi-dumper -lver {label} lib{library}.so -o {dump_file} -public-headers ../rfb")
+
+# Dumps ABIs for given revision
+
+
+def dump_abi(rev: str, label: str):
+    tree_dir = Path(WORK_DIR.name, label)
+    build_dir = Path(tree_dir, "build")
+    run_cmd(f"git -C {str(REPO_DIR)} worktree add {tree_dir} {rev}")
+    os.mkdir(build_dir)
+    os.chdir(build_dir)
+    run_cmd("env CFLAGS='-gdwarf-4 -Og' cmake ..")
+    dump_library_abi(LIB_CLIENT, label)
+    dump_library_abi(LIB_SERVER, label)
+
+
+def compare_library_abi(library: str):
+    old_abi = create_dump_file_path(library, LABEL_OLD)
+    new_abi = create_dump_file_path(library, LABEL_NEW)
+    report = str(Path(OUTPUT_DIR, f"{library}-report.html"))
+    r = run_cmd(f"abi-compliance-checker -l {library}  -old {old_abi} -new {new_abi} -report-path {report}", False)
+    if r.returncode != 0:
+        print(f"~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~")
+        print(f"~ ERROR: ABI break detected in {library}")
+        print(f"~ Please check the report at file://{report}")
+        print(f"~ On GitHub Actions, this report is also available in workflow artifacts")
+        print(f"~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~")
+        sys.exit(1)
+
+
+def compare(old_rev: str, new_rev: str):
+    dump_abi(old_rev, LABEL_OLD)
+    dump_abi(new_rev, LABEL_NEW)
+    compare_library_abi(LIB_CLIENT)
+    compare_library_abi(LIB_SERVER)
+
+
+def update():
+    head = read_cmd_output(f"git -C {str(REPO_DIR)} rev-list HEAD --max-count=1")
+    DEFAULT_REV_FILE.write_bytes(head)
+
+
+def parse_args():
+    rf_name = DEFAULT_REV_FILE.name
+    parser = argparse.ArgumentParser(description="Check ABI compatibility between two Git revisions")
+    parser.add_argument('-o', dest='old', help=f"Old revision; defaults to reading from '{rf_name}'")
+    parser.add_argument('-n', dest='new', help="New revision; defaults to 'HEAD'")
+    parser.add_argument('-u', dest='update', help=f"Update '{rf_name}' file with current 'HEAD'", action='store_true')
+    args = parser.parse_args()
+
+    if args.update:
+        return args
+
+    if args.old == None:
+        if DEFAULT_REV_FILE.exists():
+            with open(DEFAULT_REV_FILE) as f:
+                args.old = f.readline()
+        else:
+            print(f"ERROR: Cannot detect old revision automatically, '{str(DEFAULT_REV_FILE)}' is missing")
+            sys.exit(1)
+
+    if args.new == None:
+        args.new = read_cmd_output(f"git -C {str(REPO_DIR)} rev-list HEAD --max-count=1").decode().strip()
+        if args.new == None:
+            print("ERROR: Cannot detect new revision automatically from git repo")
+            sys.exit(1)
+
+    return args
+
+
+def main():
+    try:
+        args = parse_args()
+        if args.update:
+            update()
+        else:
+            compare(args.old, args.new)
+    finally:
+        os.chdir(ORIGINAL_DIR)  # Restore
+        WORK_DIR.cleanup()
+        run_cmd(f"git -C {str(REPO_DIR)} worktree prune", check=False)
+
+
+main()

test/abi/published-abi-revision

@@ -0,0 +1 @@
+10e9eb75f73e973725dc75c373de5d89807af028