Add handling for catching severe errors via libclang

pkgs/ffigen/CHANGELOG.md

@@ -1,3 +1,8 @@
+# 10.1.0
+
+- Add flag and config `ignore-source-errors`. This prevents bindings to be generated
+until source errors are resolved or manually ignore via this flag.
+
 ## 10.0.0
 
 - Stable release targeting Dart 3.2 using new `dart:ffi` features available

pkgs/ffigen/README.md

@@ -452,6 +452,24 @@ use-supported-typedefs: true
 ```yaml
 use-dart-handle: true
 ```
+
+  </td>
+  </tr>
+  <tr>
+    <td>ignore-source-errors</td>
+    <td>Where to ignore compiler warnings/errors in source header files.<br>
+    <b>Default: false</b>
+    </td>
+    <td>
+
+```yaml
+ignore-source-errors: true
+```
+and/or via the command line -
+```bash
+dart run ffigen --ignore-source-errors
+```
+
   </td>
   </tr>
   <tr>

pkgs/ffigen/lib/src/config_provider/config.dart

@@ -176,6 +176,14 @@ class Config {
   FfiNativeConfig get ffiNativeConfig => _ffiNativeConfig;
   late FfiNativeConfig _ffiNativeConfig;
 
+  /// Where to ignore compiler warnings/errors in source header files.
+  bool get ignoreSourceErrors => _ignoreSourceErrors;
+  set ignoreSourceErrors(bool n) {
+    _ignoreSourceErrors = _ignoreSourceErrors || n;
+  }
+
+  bool _ignoreSourceErrors = false;
+
   Config._({required this.filename, required this.packageConfig});
 
   /// Create config from Yaml map.
@@ -285,6 +293,12 @@ class Config {
               transform: (node) => headersExtractor(node.value, filename),
               result: (node) => _headers = node.value,
             )),
+        HeterogeneousMapEntry(
+          key: strings.ignoreSourceErrors,
+          valueConfigSpec: BoolConfigSpec(),
+          defaultValue: (node) => false,
+          resultOrDefault: (node) => ignoreSourceErrors = node.value as bool,
+        ),
         HeterogeneousMapEntry(
           key: strings.compilerOpts,
           valueConfigSpec: OneOfConfigSpec<List<String>, List<String>>(

pkgs/ffigen/lib/src/executables/ffigen.dart

@@ -16,6 +16,7 @@ final _logger = Logger('ffigen.ffigen');
 final _ansi = Ansi(Ansi.terminalSupportsAnsi);
 
 const compilerOpts = 'compiler-opts';
+const ignoreSourceErrors = 'ignore-source-errors';
 const conf = 'config';
 const help = 'help';
 const verbose = 'verbose';
@@ -87,6 +88,10 @@ Config getConfig(ArgResults result, PackageConfig? packageConfig) {
         highPriority: true);
   }
 
+  if (result.wasParsed(ignoreSourceErrors)) {
+    config.ignoreSourceErrors = true;
+  }
+
   return config;
 }
 
@@ -158,6 +163,11 @@ ArgResults getArgResults(List<String> args) {
     compilerOpts,
     help: 'Compiler options for clang. (E.g --$compilerOpts "-I/headers -W")',
   );
+  parser.addFlag(
+    ignoreSourceErrors,
+    help: 'Ignore any compiler warnings/errors in source header files',
+    negatable: false,
+  );
 
   ArgResults results;
   try {

pkgs/ffigen/lib/src/header_parser/clang_bindings/clang_bindings.dart

@@ -316,6 +316,21 @@ class Clang {
   late final _clang_formatDiagnostic = _clang_formatDiagnosticPtr
       .asFunction<CXString Function(CXDiagnostic, int)>();
 
+  /// Determine the severity of the given diagnostic.
+  int clang_getDiagnosticSeverity(
+    CXDiagnostic arg0,
+  ) {
+    return _clang_getDiagnosticSeverity(
+      arg0,
+    );
+  }
+
+  late final _clang_getDiagnosticSeverityPtr =
+      _lookup<ffi.NativeFunction<ffi.Int32 Function(CXDiagnostic)>>(
+          'clang_getDiagnosticSeverity');
+  late final _clang_getDiagnosticSeverity =
+      _clang_getDiagnosticSeverityPtr.asFunction<int Function(CXDiagnostic)>();
+
   /// Same as \c clang_parseTranslationUnit2, but returns
   /// the \c CXTranslationUnit instead of an error code.  In case of an error this
   /// routine returns a \c NULL \c CXTranslationUnit, without further detailed
@@ -1484,6 +1499,29 @@ abstract class CXDiagnosticDisplayOptions {
   static const int CXDiagnostic_DisplayCategoryName = 32;
 }
 
+/// Describes the severity of a particular diagnostic.
+abstract class CXDiagnosticSeverity {
+  /// A diagnostic that has been suppressed, e.g., by a command-line
+  /// option.
+  static const int CXDiagnostic_Ignored = 0;
+
+  /// This diagnostic is a note that should be attached to the
+  /// previous (non-note) diagnostic.
+  static const int CXDiagnostic_Note = 1;
+
+  /// This diagnostic indicates suspicious code that may not be
+  /// wrong.
+  static const int CXDiagnostic_Warning = 2;
+
+  /// This diagnostic indicates that the code is ill-formed.
+  static const int CXDiagnostic_Error = 3;
+
+  /// This diagnostic indicates that the code is ill-formed such
+  /// that future parser recovery is unlikely to produce useful
+  /// results.
+  static const int CXDiagnostic_Fatal = 4;
+}
+
 /// Flags that control the creation of translation units.
 ///
 /// The enumerators in this enumeration type are meant to be bitwise
@@ -2641,8 +2679,10 @@ abstract class CXChildVisitResult {
 /// The visitor should return one of the \c CXChildVisitResult values
 /// to direct clang_visitCursorChildren().
 typedef CXCursorVisitor
-    = ffi.Pointer<ffi.NativeFunction<CXCursorVisitor_function>>;
-typedef CXCursorVisitor_function = ffi.Int32 Function(
+    = ffi.Pointer<ffi.NativeFunction<CXCursorVisitorFunction>>;
+typedef CXCursorVisitorFunction = ffi.Int32 Function(
+    CXCursor cursor, CXCursor parent, CXClientData client_data);
+typedef DartCXCursorVisitorFunction = int Function(
     CXCursor cursor, CXCursor parent, CXClientData client_data);
 
 /// Opaque pointer representing client data that will be passed through

pkgs/ffigen/lib/src/header_parser/parser.dart

@@ -4,6 +4,7 @@
 
 import 'dart:ffi';
 import 'dart:io';
+import 'dart:math' show max;
 
 import 'package:ffi/ffi.dart';
 import 'package:ffigen/src/code_generator.dart';
@@ -22,7 +23,7 @@ import 'utils.dart';
 Library parse(Config c) {
   initParser(c);
 
-  final bindings = parseToBindings();
+  final bindings = parseToBindings(c);
 
   final library = Library(
     bindings: bindings,
@@ -52,7 +53,7 @@ void initParser(Config c) {
 }
 
 /// Parses source files and adds generated bindings to [bindings].
-List<Binding> parseToBindings() {
+List<Binding> parseToBindings(Config c) {
   final index = clang.clang_createIndex(0, 0);
 
   Pointer<Pointer<Utf8>> clangCmdArgs = nullptr;
@@ -84,6 +85,8 @@ List<Binding> parseToBindings() {
 
   final tuList = <Pointer<clang_types.CXTranslationUnitImpl>>[];
 
+  var highestDiagnosticLevel =
+      clang_types.CXDiagnosticSeverity.CXDiagnostic_Ignored;
   // Parse all translation units from entry points.
   for (final headerLocation in config.headers.entryPoints) {
     _logger.fine('Creating TranslationUnit for header: $headerLocation');
@@ -109,10 +112,19 @@ List<Binding> parseToBindings() {
       continue;
     }
 
-    logTuDiagnostics(tu, _logger, headerLocation);
+    final diagnosticsLevel = logTuDiagnostics(tu, _logger, headerLocation);
+    highestDiagnosticLevel = max(highestDiagnosticLevel, diagnosticsLevel);
     tuList.add(tu);
   }
 
+  if (!config.ignoreSourceErrors &&
+      highestDiagnosticLevel >=
+          clang_types.CXDiagnosticSeverity.CXDiagnostic_Warning) {
+    _logger.severe(
+        "Source headers contains errors. Either resolve them or set flag --ignore-source-errors to generate the bindings.");
+    exit(1);
+  }
+
   final tuCursors =
       tuList.map((tu) => clang.clang_getTranslationUnitCursor(tu));
 

pkgs/ffigen/lib/src/header_parser/utils.dart

@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:ffi';
+import 'dart:math' show max;
 
 import 'package:ffi/ffi.dart';
 import 'package:ffigen/src/code_generator.dart';
@@ -29,16 +30,21 @@ void visitChildrenResultChecker(int resultCode) {
 }
 
 /// Logs the warnings/errors returned by clang for a translation unit.
-void logTuDiagnostics(
+///
+/// Returns the highest [clang_types.CXDiagnosticSeverity] seen, defaults to
+/// [clang_types.CXDiagnosticSeverity.CXDiagnostic_Ignored] if none.
+int logTuDiagnostics(
     Pointer<clang_types.CXTranslationUnitImpl> tu, Logger logger, String header,
     {Level logLevel = Level.SEVERE}) {
+  var result = clang_types.CXDiagnosticSeverity.CXDiagnostic_Ignored;
   final total = clang.clang_getNumDiagnostics(tu);
   if (total == 0) {
-    return;
+    return result;
   }
   logger.log(logLevel, 'Header $header: Total errors/warnings: $total.');
   for (var i = 0; i < total; i++) {
     final diag = clang.clang_getDiagnostic(tu, i);
+    result = max(result, clang.clang_getDiagnosticSeverity(diag));
     final cxstring = clang.clang_formatDiagnostic(
       diag,
       clang_types
@@ -50,6 +56,7 @@ void logTuDiagnostics(
     logger.log(logLevel, '    ${cxstring.toStringAndDispose()}');
     clang.clang_disposeDiagnostic(diag);
   }
+  return result;
 }
 
 extension CXSourceRangeExt on Pointer<clang_types.CXSourceRange> {

pkgs/ffigen/lib/src/strings.dart

@@ -200,6 +200,7 @@ const supportedNativeType_mappings = <String, SupportedNativeType>{
 const sort = 'sort';
 const useSupportedTypedefs = 'use-supported-typedefs';
 const useDartHandle = 'use-dart-handle';
+const ignoreSourceErrors = 'ignore-source-errors';
 
 const comments = 'comments';
 // Sub-fields of comments.

pkgs/ffigen/pubspec.yaml

@@ -3,7 +3,7 @@
 # BSD-style license that can be found in the LICENSE file.
 
 name: ffigen
-version: 10.0.0
+version: 10.1.0
 description: >
   Generator for FFI bindings, using LibClang to parse C, Objective-C, and Swift
   files.

pkgs/ffigen/tool/libclang_config.yaml

@@ -61,6 +61,7 @@ functions:
     - clang_disposeIndex
     - clang_getNumDiagnostics
     - clang_getDiagnostic
+    - clang_getDiagnosticSeverity
     - clang_disposeDiagnostic
     - clang_parseTranslationUnit
     - clang_disposeTranslationUnit