[ffigen] Handled proper conversion of macro doubles. (#113) * Fixed issues with macros with value double.infinity and double.NaN

diff --git a/pkgs/ffigen/CHANGELOG.md b/pkgs/ffigen/CHANGELOG.md
index 7b452c5..b452cb9 100644
--- a/pkgs/ffigen/CHANGELOG.md
+++ b/pkgs/ffigen/CHANGELOG.md

@@ -1,3 +1,6 @@
+# 1.0.5
+- Fixed issues with generating macros of type `double.Infinity` and `double.NaN`.
+
 # 1.0.4
 - Updated code to use `dart format` instead of `dartfmt` for sdk version `>= 2.10.0`.
 

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 16cf4a1..6c13ada 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

@@ -6,6 +6,7 @@
 import 'dart:io';
 import 'dart:typed_data';
 
+import 'package:ffigen/src/strings.dart' as strings;
 import 'package:path/path.dart' as p;
 import 'package:ffi/ffi.dart';
 import 'package:ffigen/src/code_generator.dart';
@@ -128,7 +129,8 @@
             originalName: savedMacros[macroName].originalName,
             name: macroName,
             rawType: 'double',
-            rawValue: clang.clang_EvalResult_getAsDouble(e).toString(),
+            rawValue:
+                _writeDoubleAsString(clang.clang_EvalResult_getAsDouble(e)),
           );
           break;
         case clang_types.CXEvalResultKind.CXEval_StrLiteral:
@@ -322,3 +324,18 @@
   /// In all other cases, simply convert to string.
   return String.fromCharCode(char);
 }
+
+/// Converts a double to a string, handling cases like Infinity and NaN.
+String _writeDoubleAsString(double d) {
+  if (d.isFinite) {
+    return d.toString();
+  } else {
+    // The only Non-Finite numbers are Infinity, NegativeInfinity and NaN.
+    if (d.isInfinite) {
+      return d.isNegative
+          ? strings.doubleNegativeInfinity
+          : strings.doubleInfinity;
+    }
+    return strings.doubleNaN;
+  }
+}

diff --git a/pkgs/ffigen/lib/src/strings.dart b/pkgs/ffigen/lib/src/strings.dart
index 2cd2697..5a81450 100644
--- a/pkgs/ffigen/lib/src/strings.dart
+++ b/pkgs/ffigen/lib/src/strings.dart

@@ -108,3 +108,8 @@
 const libclang_dylib_linux = 'libwrapped_clang.so';
 const libclang_dylib_macos = 'libwrapped_clang.dylib';
 const libclang_dylib_windows = 'wrapped_clang.dll';
+
+// Writen doubles
+const doubleInfinity = 'double.infinity';
+const doubleNegativeInfinity = 'double.negativeInfinity';
+const doubleNaN = 'double.nan';

diff --git a/pkgs/ffigen/pubspec.yaml b/pkgs/ffigen/pubspec.yaml
index a03c62e..7b1185b 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: 1.0.4
+version: 1.0.5
 homepage: https://github.com/dart-lang/ffigen
 description: Experimental generator for FFI bindings, using LibClang to parse C header files.
 

diff --git a/pkgs/ffigen/test/header_parser_tests/macros.h b/pkgs/ffigen/test/header_parser_tests/macros.h
index e58d4ac..90bbd45 100644
--- a/pkgs/ffigen/test/header_parser_tests/macros.h
+++ b/pkgs/ffigen/test/header_parser_tests/macros.h

@@ -1,3 +1,5 @@
+#include<math.h>
+
 #define TEST1 1.1
 #define TEST2 10
 #define TEST3 (TEST1 + TEST2)
@@ -23,3 +25,8 @@
 #define TEST11 "\x80"
 #define TEST12 "hello\n\t\r\v\b"
 #define TEST13 "test\\"
+
+// Infinity, NaN and Negative Infinity.
+#define TEST14 INFINITY
+#define TEST15 -INFINITY
+#define TEST16 NAN

diff --git a/pkgs/ffigen/test/header_parser_tests/macros_test.dart b/pkgs/ffigen/test/header_parser_tests/macros_test.dart
index 9b279e7..6ad5090 100644
--- a/pkgs/ffigen/test/header_parser_tests/macros_test.dart
+++ b/pkgs/ffigen/test/header_parser_tests/macros_test.dart

@@ -27,6 +27,8 @@
 ${strings.headers}:
   ${strings.entryPoints}:
     - 'test/header_parser_tests/macros.h'
+  ${strings.includeDirectives}:
+    - '**macros.h'
         ''') as yaml.YamlMap),
       );
     });
@@ -84,6 +86,18 @@
       expect(actual.getBindingAsString('TEST13'),
           expected.getBindingAsString('TEST13'));
     });
+    test('TEST14', () {
+      expect(actual.getBindingAsString('TEST14'),
+          expected.getBindingAsString('TEST14'));
+    });
+    test('TEST15', () {
+      expect(actual.getBindingAsString('TEST15'),
+          expected.getBindingAsString('TEST15'));
+    });
+    test('TEST16', () {
+      expect(actual.getBindingAsString('TEST16'),
+          expected.getBindingAsString('TEST16'));
+    });
   });
 }
 
@@ -104,6 +118,13 @@
       Constant(
           name: 'TEST12', rawType: 'String', rawValue: r"'hello\n\t\r\v\b'"),
       Constant(name: 'TEST13', rawType: 'String', rawValue: r"'test\\'"),
+      Constant(
+          name: 'TEST14', rawType: 'double', rawValue: strings.doubleInfinity),
+      Constant(
+          name: 'TEST15',
+          rawType: 'double',
+          rawValue: strings.doubleNegativeInfinity),
+      Constant(name: 'TEST16', rawType: 'double', rawValue: strings.doubleNaN),
     ],
   );
 }