[ffigen] Fix macro file parser (#524)

diff --git a/pkgs/ffigen/CHANGELOG.md b/pkgs/ffigen/CHANGELOG.md
index 2861c65..5144ff0 100644
--- a/pkgs/ffigen/CHANGELOG.md
+++ b/pkgs/ffigen/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 7.2.7
+
+- Fix some macros not being generated in some cases due to relative header paths.
+
 # 7.2.6
 
 - Fix path normalization behaviour for absolute paths and globs starting with `**`.

diff --git a/pkgs/ffigen/lib/src/header_parser/sub_parsers/macro_parser.dart b/pkgs/ffigen/lib/src/header_parser/sub_parsers/macro_parser.dart
index 7478ea8..535e46d 100644
--- a/pkgs/ffigen/lib/src/header_parser/sub_parsers/macro_parser.dart
+++ b/pkgs/ffigen/lib/src/header_parser/sub_parsers/macro_parser.dart

@@ -68,9 +68,6 @@
   var cmdLen = 0;
 
   final compilerOpts = config.compilerOpts;
-  config.headers.entryPoints.followedBy([file.path]).forEach((entryFile) {
-    compilerOpts.add("-imacros$entryFile");
-  });
   clangCmdArgs = createDynamicStringArray(compilerOpts);
 
   cmdLen = config.compilerOpts.length;
@@ -87,6 +84,7 @@
   if (tu == nullptr) {
     _logger.severe('Unable to parse Macros.');
   } else {
+    logTuDiagnostics(tu, _logger, file.path, logLevel: Level.FINEST);
     final rootCursor = clang.clang_getTranslationUnitCursor(tu);
 
     final resultCode = clang.clang_visitChildren(
@@ -205,7 +203,8 @@
   // Write file contents.
   final sb = StringBuffer();
   for (final h in config.headers.entryPoints) {
-    sb.writeln('#include "$h"');
+    final fullHeaderPath = File(h).absolute.path;
+    sb.writeln('#include "$fullHeaderPath"');
   }
 
   _macroVarNames = {};

diff --git a/pkgs/ffigen/lib/src/header_parser/utils.dart b/pkgs/ffigen/lib/src/header_parser/utils.dart
index d53cb8b..355bf3a 100644
--- a/pkgs/ffigen/lib/src/header_parser/utils.dart
+++ b/pkgs/ffigen/lib/src/header_parser/utils.dart

@@ -30,16 +30,13 @@
 
 /// Logs the warnings/errors returned by clang for a translation unit.
 void logTuDiagnostics(
-  Pointer<clang_types.CXTranslationUnitImpl> tu,
-  Logger logger,
-  String header,
-) {
+    Pointer<clang_types.CXTranslationUnitImpl> tu, Logger logger, String header,
+    {Level logLevel = Level.SEVERE}) {
   final total = clang.clang_getNumDiagnostics(tu);
   if (total == 0) {
     return;
   }
-
-  logger.severe('Header $header: Total errors/warnings: $total.');
+  logger.log(logLevel, 'Header $header: Total errors/warnings: $total.');
   for (var i = 0; i < total; i++) {
     final diag = clang.clang_getDiagnostic(tu, i);
     final cxstring = clang.clang_formatDiagnostic(
@@ -50,7 +47,7 @@
           clang_types
               .CXDiagnosticDisplayOptions.CXDiagnostic_DisplayCategoryName,
     );
-    logger.severe('    ' + cxstring.toStringAndDispose());
+    logger.log(logLevel, '    ' + cxstring.toStringAndDispose());
     clang.clang_disposeDiagnostic(diag);
   }
 }

diff --git a/pkgs/ffigen/pubspec.yaml b/pkgs/ffigen/pubspec.yaml
index dbb5194..015c592 100644
--- a/pkgs/ffigen/pubspec.yaml
+++ b/pkgs/ffigen/pubspec.yaml

@@ -3,7 +3,7 @@
 # BSD-style license that can be found in the LICENSE file.
 
 name: ffigen
-version: 7.2.6
+version: 7.2.7
 description: Generator for FFI bindings, using LibClang to parse C header files.
 repository: https://github.com/dart-lang/ffigen
 

diff --git a/pkgs/ffigen/test/header_parser_tests/macros.h b/pkgs/ffigen/test/header_parser_tests/macros.h
index 90bbd45..5cae837 100644
--- a/pkgs/ffigen/test/header_parser_tests/macros.h
+++ b/pkgs/ffigen/test/header_parser_tests/macros.h

@@ -30,3 +30,16 @@
 #define TEST14 INFINITY
 #define TEST15 -INFINITY
 #define TEST16 NAN
+
+
+// Inside include guard.
+#ifndef __TEST_INCLUDE_GUARD_1__
+#define __TEST_INCLUDE_GUARD_1__
+
+#define TEST17 TEST_FUNCTION_MACRO(0)
+#define TEST18 TEST_FUNCTION_MACRO(1)
+#define TEST19 TEST_FUNCTION_MACRO(2)
+
+#define TEST_FUNCTION_MACRO(x) ((unsigned long)((x) << (2)))
+
+#endif /* __TEST_INCLUDE_GUARD_1__ */

diff --git a/pkgs/ffigen/test/header_parser_tests/macros_test.dart b/pkgs/ffigen/test/header_parser_tests/macros_test.dart
index d615b26..689a289 100644
--- a/pkgs/ffigen/test/header_parser_tests/macros_test.dart
+++ b/pkgs/ffigen/test/header_parser_tests/macros_test.dart

@@ -98,6 +98,18 @@
       expect(actual.getBindingAsString('TEST16'),
           expected.getBindingAsString('TEST16'));
     });
+    test('TEST17', () {
+      expect(actual.getBindingAsString('TEST17'),
+          expected.getBindingAsString('TEST17'));
+    });
+    test('TEST18', () {
+      expect(actual.getBindingAsString('TEST18'),
+          expected.getBindingAsString('TEST18'));
+    });
+    test('TEST19', () {
+      expect(actual.getBindingAsString('TEST19'),
+          expected.getBindingAsString('TEST19'));
+    });
   });
 }
 
@@ -125,6 +137,9 @@
           rawType: 'double',
           rawValue: strings.doubleNegativeInfinity),
       Constant(name: 'TEST16', rawType: 'double', rawValue: strings.doubleNaN),
+      Constant(name: 'TEST17', rawType: 'int', rawValue: "0"),
+      Constant(name: 'TEST18', rawType: 'int', rawValue: "4"),
+      Constant(name: 'TEST19', rawType: 'int', rawValue: "8"),
     ],
   );
 }