compiler: enforce reserved keywords replacement

* compiler: Enforce reserved keywords replacement on empty value initialization

* compiler: Add test for reserved keywords enforcement

A new struct has been introduced in the tests that contains all C reserved keywords that are not reserved in V. Some read and write are tested too.

compiler/parser.v

@@ -3029,9 +3029,10 @@ fn (p mut Parser) struct_init(typ string) string {
 		}
 		// Zero values: init all fields (ints to 0, strings to '' etc)
 		for i, field in t.fields {
+			sanitized_name := if typ != 'Option' { p.table.var_cgen_name( field.name ) } else { field.name }
 			// println('### field.name')
 			// Skip if this field has already been assigned to
-			if field.name in inited_fields {
+			if sanitized_name in inited_fields {
 				continue
 			}
 			field_typ := field.typ
@@ -3040,9 +3041,9 @@ fn (p mut Parser) struct_init(typ string) string {
 			}
 			// init map fields
 			if field_typ.starts_with('map_') {
-				p.gen_struct_field_init(field.name)
+				p.gen_struct_field_init(sanitized_name)
 				p.gen_empty_map(field_typ.right(4))
-				inited_fields << field.name
+				inited_fields << sanitized_name
 				if i != t.fields.len - 1 {
 					p.gen(',')
 				}
@@ -3051,7 +3052,7 @@ fn (p mut Parser) struct_init(typ string) string {
 			}
 			def_val := type_default(field_typ)
 			if def_val != '' && def_val != '{0}' {
-				p.gen_struct_field_init(field.name)
+				p.gen_struct_field_init(sanitized_name)
 				p.gen(def_val)
 				if i != t.fields.len - 1 {
 					p.gen(',')

compiler/tests/struct_test.v

@@ -26,6 +26,35 @@ struct Foo {
 	@type string
 }
 
+//We need to make sure that this compiles with all the reserved names.
+struct ReservedKeywords {
+	delete   int
+	exit     int
+	unix     int
+	error    int
+	malloc   int
+	calloc   int
+	free     int
+	panic    int
+	auto     int
+	char     int
+	do       int
+	double   int
+	extern   int
+	float    int
+	inline   int
+	long     int
+	register int
+	restrict int
+	short    int
+	signed   int
+	typedef  int
+	unsigned int
+	void     int
+	volatile int
+	while    int
+}
+
 fn test_struct_levels() {
 	mut c := C{}
 	assert c.nums.len == 0
@@ -63,3 +92,18 @@ fn test_at() {
 	foo := Foo{ @type: 'test' }
 	println(foo.@type)
 }
+
+fn test_reserved_keywords() {
+	//Make sure we can initialize them correctly using full syntax.
+	rk_holder := ReservedKeywords{0, 0, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3}
+	//Test a few as it'll take too long to test all. If it's initialized
+	//correctly, other fields are also probably valid.
+	assert rk_holder.unix == 5
+	assert rk_holder.while == 3
+
+	rk_holder2 := ReservedKeywords{inline: 9, volatile: 11}
+	//Make sure partial initialization works too.
+	assert rk_holder2.inline == 9
+	assert rk_holder2.volatile == 11
+	assert rk_holder2.while == 0 //Zero value as not specified.
+}