Merge pull request #9 from marc-christian-schulze/default_values

Default values

README.md

@@ -106,6 +106,7 @@ fileHeader.write(buffer);
   * padding
   * bit fields
   * implement Java interfaces
+  * default values
 
 ## Unsupported
 * Unions
@@ -373,7 +374,7 @@ struct AnotherBitset
 {
   // any other fields ...
   bitfield uint8_t {
-    int32_t   number : 4; // 2^7, 2^6, 2^5, 2^4; value range 0 .. 16
+    int32_t   number : 4; // 2^7, 2^6, 2^5, 2^4; value range 0 .. 15
     boolean   flag   : 1; // 2^3
     SomeEnum  myEnum : 3; // 2^2, 2^1, 2^0
   }
@@ -397,14 +398,37 @@ This will automatically transform the endianess of all fields having types that
 ## Implementing Java Interfaces
 
 Although `struct`s can not form any inheritance relationship you can let them implement interfaces from your Java code, e.g.:
-```C++
+```
 import org.myproject.MyJavaInterface;
 
 struct SomeStruct implements MyJavaInterface {
   // ...
 }
 ```
 
+## Default Values
+
+You can assign fields within structures a default value which is taken when the structure is default constructed:
+```
+struct SomeStruct {
+  uint8_t  int8  = 1;
+  uint16_t int16 = 0x45;
+  uint32_t int32 = 7;
+  uint64_t int64 = 0x20;
+  float    f     = 7.534;
+  double   d     = 9.75142476
+  char     str[] = "my default";
+  SomeEnum e     = SomeEnum.B;
+}
+
+enum SomeEnum : uint8_t {
+  A = 0xCAFE,
+  B = 123,
+  C = 42
+}
+```
+You can NOT define default values for fields within a bitfield, though.
+
 ## Plugin configuration
 
 Below is a full example configuration, including the default values, of the plugin:

org.structs4java.parent/org.structs4java/src/org/structs4java/Structs4JavaDsl.xtext

@@ -27,10 +27,6 @@ Import:
 QualifiedNameWithWildcard:
     QualifiedName '.*'?
 ;
-
-ComplexTypeDeclaration:
-	StructDeclaration | EnumDeclaration
-;
 
 StructDeclaration:
 	{StructDeclaration}
@@ -56,6 +52,11 @@ EnumDeclaration:
 	'}'
 ;
 
+Item:
+	(comments += SL_COMMENT)*
+	name=ID '=' value=LONG ','?
+;
+
 BitfieldMember:
 	(comments += SL_COMMENT)*
 	'bitfield' typename=INTEGER_TYPE (array=ArrayDimension)? ('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')? '{'
@@ -69,9 +70,8 @@ BitfieldEntry:
 |   (comments += SL_COMMENT)* type=[EnumDeclaration] name=ID (array=ArrayDimension)? ':' bits=LONG ';'
 ;
 
-Item:
-	(comments += SL_COMMENT)*
-	name=ID '=' value=LONG ','?
+ComplexTypeDeclaration:
+    StructDeclaration | EnumDeclaration
 ;
 
 ComplexTypeMember:
@@ -80,6 +80,13 @@ ComplexTypeMember:
 	(array=ArrayDimension)?
 	('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
 	';'
+	|
+	(comments += SL_COMMENT)*
+    type=[EnumDeclaration|QualifiedName] name=ID
+    (array=ArrayDimension)?
+    ('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
+    '=' defaultValue=[Item|QualifiedName]
+    ';'
 ;
 
 IntegerMember:
@@ -92,6 +99,7 @@ IntegerMember:
 		('countof' '(' countof=[Member] ')')?
 	)
 	('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
+	('=' defaultValue=LONG)?
 	';'
 ;
 
@@ -100,6 +108,7 @@ FloatMember:
 	typename=FLOAT_TYPE name=ID 
 	(array=ArrayDimension)?
 	('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
+	('=' defaultValue=FLOAT)?
 	';'
 ;
 
@@ -111,6 +120,7 @@ StringMember:
 	('padding' '(' padding=LONG ( ',' 'using' '=' using=LONG )? ')')?
 	('filler' '(' filler=LONG ')')?
 	(nullTerminated='null-terminated')?
+	('=' defaultValue=STRING)?
 	';'
 ;
 
@@ -122,6 +132,7 @@ QualifiedName:
     ID ('.' ID)*
 ;
 
+terminal FLOAT returns ecore::EFloat: ('0'..'9')+ '.' ('0'..'9')+;
 terminal LONG returns ecore::ELong: ('0'..'9')+ | '0x' ('0'..'9' | 'A'..'F' | 'a'..'f')+;
 terminal STRING	: 
 			'"' ( '\\' . /* 'b'|'t'|'n'|'f'|'r'|'u'|'"'|"'"|'\\' */ | !('\\'|'"') )* '"' |

org.structs4java.parent/org.structs4java/src/org/structs4java/generator/StructGenerator.xtend

@@ -1509,12 +1509,15 @@ class StructGenerator {
 	    switch (m) {
             ComplexTypeMember: {
                 if(m.type instanceof EnumDeclaration) {
-                    return "null"
+                    if(m.defaultValue == null) {
+                        return "null"
+                    }
+                    return attributeJavaType(m) + "." + m.defaultValue.name
                 }
                 "new " + javaType(m.type) + "()"
             }
-            IntegerMember: "0"
-            FloatMember: "0.0f"
+            IntegerMember: "" + m.defaultValue
+            FloatMember: m.defaultValue + "f"
             default: throw new RuntimeException("Unsupported member type: " + m)
         }
 	}
@@ -1527,7 +1530,7 @@ class StructGenerator {
 	        }
 
 	        if(m instanceof StringMember) {
-                return "\"\""
+                return "\"" + m.defaultValue + "\""
             }
 
             val nativeType = nativeTypeName(m)
@@ -1536,11 +1539,11 @@ class StructGenerator {
 	    }
 
 	    if(m instanceof IntegerMember) {
-	        return "0"
+	        return "" + m.defaultValue
 	    }
 
 	    if(m instanceof FloatMember) {
-	        return "0.0f"
+	        return m.defaultValue + "f"
 	    }
 
 	    if(isBooleanType(m)) {
@@ -1549,7 +1552,10 @@ class StructGenerator {
 
         if(m instanceof ComplexTypeMember) {
 	        if(m.type instanceof EnumDeclaration) {
-                return "null"
+	            if(m.defaultValue == null) {
+	                return "null"
+	            }
+                return attributeJavaType(m) + "." + m.defaultValue.name
             }
 	    }
 

structs4java-maven-plugin-test/src/main/structs/default-values.structs

@@ -0,0 +1,38 @@
+package org.structs4java.example.tests.defaultvalues;
+
+struct StructWithIntegerDefaultValue {
+    uint8_t  int8 = 1;
+    uint16_t int16 = 2;
+    uint32_t int32 = 3;
+    uint64_t int64 = 4;
+}
+
+struct StructWithFloatDefaultValue {
+    float  f = 1.0;
+    double d = 2.0;
+}
+
+struct StructWithStringDefaultValue {
+    char str[] = "default";
+}
+
+enum Int8Enum : uint8_t {
+    A = 0x01,
+    B = 0x02,
+    C = 0x03
+}
+
+struct StructWithBitfield {
+    bitfield uint16_t {
+        boolean b : 1;
+        uint8_t int8 : 2;
+        uint16_t int16 : 2;
+        uint32_t int32 : 2;
+        uint64_t int64 : 2;
+        Int8Enum int8Enum : 7;
+    }
+}
+
+struct StructWithEnum {
+    Int8Enum int8Enum = Int8Enum.B;
+}

structs4java-maven-plugin-test/src/test/java/org/structs4java/example/tests/DefaultValueTest.java

@@ -0,0 +1,36 @@
+package org.structs4java.example.tests;
+
+import org.junit.Test;
+import org.structs4java.example.tests.defaultvalues.*;
+
+import static org.junit.Assert.assertEquals;
+
+public class DefaultValueTest {
+    @Test
+    public void testStructWithIntegerDefaultValue() {
+        StructWithIntegerDefaultValue struct = new StructWithIntegerDefaultValue();
+        assertEquals(1, struct.getInt8());
+        assertEquals(2, struct.getInt16());
+        assertEquals(3, struct.getInt32());
+        assertEquals(4, struct.getInt64());
+    }
+
+    @Test
+    public void testStructWithFloatDefaultValue() {
+        StructWithFloatDefaultValue struct = new StructWithFloatDefaultValue();
+        assertEquals(1.0, struct.getF(), 0.001);
+        assertEquals(2.0, struct.getD(), 0.001);
+    }
+
+    @Test
+    public void testStructWithStringDefaultValue() {
+        StructWithStringDefaultValue struct = new StructWithStringDefaultValue();
+        assertEquals("default", struct.getStr());
+    }
+
+    @Test
+    public void testStructWithEnumDefaultValue() {
+        StructWithEnum struct = new StructWithEnum();
+        assertEquals(Int8Enum.B, struct.getInt8Enum());
+    }
+}