escape chars (#321)

* escape chars

* heart char constant in tests

* translate Rust unicode representation to C style unicode representation

* apply rustfmt

* check char constant length

* nicer code

Signed-off-by: Axel Nennker <axel.nennker@telekom.de>

src/bindgen/ir/constant.rs

@@ -151,7 +151,10 @@ impl Literal {
             syn::Expr::Lit(syn::ExprLit {
                 lit: syn::Lit::Char(ref value),
                 ..
-            }) => Ok(Literal::Expr(format!("'{}'", value.value()))),
+            }) => Ok(Literal::Expr(match value.value() as u32 {
+                0..=255 => format!("'{}'", value.value().escape_default()),
+                other_code => format!(r"L'\u{:X}'", other_code),
+            })),
             syn::Expr::Lit(syn::ExprLit {
                 lit: syn::Lit::Int(ref value),
                 ..

tests/expectations/both/constant.c

@@ -7,6 +7,16 @@
 
 #define FOO 10
 
+#define HEART L'\u2764'
+
+#define LEFTCURLY '{'
+
+#define NEWLINE '\n'
+
+#define QUOTE '\''
+
+#define TAB '\t'
+
 #define ZOM 3.14
 
 typedef struct Foo {

tests/expectations/constant.c

@@ -7,6 +7,16 @@
 
 #define FOO 10
 
+#define HEART L'\u2764'
+
+#define LEFTCURLY '{'
+
+#define NEWLINE '\n'
+
+#define QUOTE '\''
+
+#define TAB '\t'
+
 #define ZOM 3.14
 
 typedef struct {

tests/expectations/constant.cpp

@@ -6,6 +6,16 @@ static const wchar_t DELIMITER = ':';
 
 static const int32_t FOO = 10;
 
+static const wchar_t HEART = L'\u2764';
+
+static const wchar_t LEFTCURLY = '{';
+
+static const wchar_t NEWLINE = '\n';
+
+static const wchar_t QUOTE = '\'';
+
+static const wchar_t TAB = '\t';
+
 static const float ZOM = 3.14;
 
 struct Foo {

tests/expectations/tag/constant.c

@@ -7,6 +7,16 @@
 
 #define FOO 10
 
+#define HEART L'\u2764'
+
+#define LEFTCURLY '{'
+
+#define NEWLINE '\n'
+
+#define QUOTE '\''
+
+#define TAB '\t'
+
 #define ZOM 3.14
 
 struct Foo {

tests/rust/constant.rs

@@ -1,6 +1,11 @@
 const FOO: i32 = 10;
 const BAR: &'static str = "hello world";
 pub const DELIMITER: char = ':';
+pub const LEFTCURLY: char = '{';
+pub const QUOTE: char = '\'';
+pub const TAB: char = '\t';
+pub const NEWLINE: char = '\n';
+pub const HEART: char = '❤';
 const ZOM: f32 = 3.14;
 
 #[repr(C)]