Merge pull request #99 from Ralith/display

impl Display for constants

ash/tests/display.rs

@@ -0,0 +1,12 @@
+extern crate ash;
+use ash::vk;
+
+#[test]
+fn display_flags() {
+    assert_eq!((vk::AccessFlags::INDIRECT_COMMAND_READ | vk::AccessFlags::VERTEX_ATTRIBUTE_READ).to_string(), "INDIRECT_COMMAND_READ | VERTEX_ATTRIBUTE_READ");
+}
+
+#[test]
+fn display_enum() {
+    assert_eq!(vk::ChromaLocation::MIDPOINT.to_string(), "MIDPOINT");
+}

generator/src/lib.rs

@@ -786,6 +786,7 @@ pub fn generate_extension_constants<'a>(
     extension_number: i64,
     extension_items: &'a [vk_parse::ExtensionItem],
     const_cache: &mut HashSet<&'a str>,
+    const_values: &mut HashMap<Ident, Vec<Ident>>,
 ) -> quote::Tokens {
     let items = extension_items
         .iter()
@@ -819,13 +820,14 @@ pub fn generate_extension_constants<'a>(
                 }
                 _ => None,
             }?;
-
             let extends = extends?;
             let ext_constant = ExtensionConstant {
                 name: &_enum.name,
                 constant,
             };
             let ident = name_to_tokens(&extends);
+            const_values.entry(ident.clone()).or_insert_with(Vec::new)
+                .push(ext_constant.variant_ident(&extends));
             let impl_block = bitflags_impl_block(ident, &extends, &[&ext_constant]);
             let doc_string = format!("Generated from '{}'", extension_name);
             let q = quote!{
@@ -867,6 +869,7 @@ pub fn generate_extension<'a>(
     extension: &'a vk_parse::Extension,
     cmd_map: &CommandMap,
     const_cache: &mut HashSet<&'a str>,
+    const_values: &mut HashMap<Ident, Vec<Ident>>
 ) -> Option<quote::Tokens> {
     // Okay this is a little bit odd. We need to generate all extensions, even disabled ones,
     // because otherwise some StructureTypes won't get generated. But we don't generate extensions
@@ -879,6 +882,7 @@ pub fn generate_extension<'a>(
         extension.number.unwrap_or(0),
         &extension.items,
         const_cache,
+        const_values,
     );
     let fp = generate_extension_commands(&extension.name, &extension.items, cmd_map);
     let q = quote!{
@@ -991,6 +995,7 @@ pub fn bitflags_impl_block(
 pub fn generate_enum<'a>(
     _enum: &'a vkxml::Enumeration,
     const_cache: &mut HashSet<&'a str>,
+    const_values: &mut HashMap<Ident, Vec<Ident>>
 ) -> EnumType {
     let name = &_enum.name[2..];
     let _name = name.replace("FlagBits", "Flags");
@@ -1002,8 +1007,10 @@ pub fn generate_enum<'a>(
             vkxml::EnumerationElement::Enum(ref constant) => Some(constant),
             _ => None,
         }).collect_vec();
+    let values = const_values.entry(ident.clone()).or_insert_with(Vec::new);
     for constant in &constants {
         const_cache.insert(constant.name.as_str());
+        values.push(constant.variant_ident(&_enum.name));
     }
 
     if name.contains("Bit") {
@@ -1061,22 +1068,31 @@ pub fn generate_result(ident: Ident, _enum: &vkxml::Enumeration) -> Tokens {
 
         let variant_ident = variant_ident(&_enum.name, variant_name);
         Some(quote!{
-            #ident::#variant_ident => write!(fmt, #notation)
+            #ident::#variant_ident => Some(#notation)
         })
     });
 
+    let notation2 = notation.clone();
     quote!{
         impl ::std::error::Error for #ident {
             fn description(&self) -> &str {
-                "vk::Result"
-            }
-        }
-        impl ::std::fmt::Display for #ident {
-            fn fmt(&self, fmt: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
-                writeln!(fmt, "vk::Result::{:?}", self)?;
-                match *self {
+                let name = match *self {
                     #(#notation),*,
-                    _ => write!(fmt, "Unknown variant")
+                    _ => None,
+                };
+                name.unwrap_or("unknown error")
+            }
+        }
+        impl fmt::Display for #ident {
+            fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+                let name = match *self {
+                    #(#notation2),*,
+                    _ => None,
+                };
+                if let Some(x) = name {
+                    fmt.write_str(x)
+                } else {
+                    write!(fmt, "{}", self.0)
                 }
             }
         }
@@ -1447,10 +1463,11 @@ pub fn generate_constant<'a>(
 pub fn generate_feature_extension<'a>(
     registry: &'a vk_parse::Registry,
     const_cache: &mut HashSet<&'a str>,
+    const_values: &mut HashMap<Ident, Vec<Ident>>
 ) -> Tokens {
     let constants = registry.0.iter().filter_map(|item| match item {
         vk_parse::RegistryItem::Feature { name, items, .. } => {
-            Some(generate_extension_constants(name, 0, items, const_cache))
+            Some(generate_extension_constants(name, 0, items, const_cache, const_values))
         }
         _ => None,
     });
@@ -1459,6 +1476,68 @@ pub fn generate_feature_extension<'a>(
     }
 }
 
+pub fn generate_const_displays<'a>(const_values: &HashMap<Ident, Vec<Ident>>) -> Tokens {
+    let impls = const_values.iter()
+        .filter(|(ty, _)| *ty != "Result")
+        .map(|(ty, values)| {
+            if ty.to_string().contains("Flags") {
+                let cases = values.iter().map(|value| {
+                    let name = value.to_string();
+                    quote!{ (#ty::#value.0, #name) }
+                });
+                quote!{
+                    impl fmt::Display for #ty {
+                        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                            const KNOWN: &[(Flags, &str)] = &[#(#cases),*];
+                            display_flags(f, KNOWN, self.0)
+                        }
+                    }
+                }
+            } else {
+                let cases = values.iter().map(|value| {
+                    let name = value.to_string();
+                    quote!{ Self::#value => Some(#name), }
+                });
+                quote!{
+                    impl fmt::Display for #ty {
+                        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                            let name = match *self {
+                                #(#cases)*
+                                _ => None,
+                            };
+                            if let Some(x) = name {
+                                f.write_str(x)
+                            } else {
+                                write!(f, "{}", self.0)
+                            }
+                        }
+                    }
+                }
+            }
+        });
+    quote!{
+        fn display_flags(f: &mut fmt::Formatter, known: &[(Flags, &'static str)], value: Flags) -> fmt::Result {
+            let mut first = true;
+            let mut accum = value;
+            for (bit, name) in known {
+                if accum & bit != 0 {
+                    if !first { f.write_str(" | ")?; }
+                    f.write_str(name)?;
+                    first = false;
+                    accum &= !bit;
+                }
+            }
+            if accum != 0 {
+                if !first { f.write_str(" | ")?; }
+                write!(f, "{:b}", accum)?;
+            }
+            Ok(())
+        }
+
+        #(#impls)*
+    }
+}
+
 pub fn write_source_code(path: &Path) {
     use std::fs::File;
     use std::io::Write;
@@ -1523,9 +1602,12 @@ pub fn write_source_code(path: &Path) {
         .collect();
 
     let mut const_cache = HashSet::new();
+
+    let mut const_values: HashMap<Ident, Vec<Ident>> = HashMap::new();
+
     let (enum_code, bitflags_code) = enums
         .into_iter()
-        .map(|e| generate_enum(e, &mut const_cache))
+        .map(|e| generate_enum(e, &mut const_cache, &mut const_values))
         .fold((Vec::new(), Vec::new()), |mut acc, elem| {
             match elem {
                 EnumType::Enum(token) => acc.0.push(token),
@@ -1533,13 +1615,14 @@ pub fn write_source_code(path: &Path) {
             };
             acc
         });
+    
     let constants_code: Vec<_> = constants
         .iter()
         .map(|constant| generate_constant(constant, &mut const_cache))
         .collect();
     let extension_code = extensions
         .iter()
-        .filter_map(|ext| generate_extension(ext, &commands, &mut const_cache))
+        .filter_map(|ext| generate_extension(ext, &commands, &mut const_cache, &mut const_values))
         .collect_vec();
 
     let union_types = definitions
@@ -1558,7 +1641,9 @@ pub fn write_source_code(path: &Path) {
         .iter()
         .map(|feature| generate_feature(feature, &commands))
         .collect();
-    let feature_extensions_code = generate_feature_extension(&spec2, &mut const_cache);
+    let feature_extensions_code = generate_feature_extension(&spec2, &mut const_cache, &mut const_values);
+
+    let const_displays = generate_const_displays(&const_values);
 
     let mut file = File::create("../ash/src/vk.rs").expect("vk");
     let bitflags_macro = vk_bitflags_wrapped_macro();
@@ -1567,6 +1652,7 @@ pub fn write_source_code(path: &Path) {
     let version_macros = vk_version_macros();
     let platform_specific_types = platform_specific_types();
     let source_code = quote!{
+        use std::fmt;
         #[doc(hidden)]
         pub use libc::*;
         #[doc(hidden)]
@@ -1598,6 +1684,7 @@ pub fn write_source_code(path: &Path) {
             #(#extension_code)*
             #feature_extensions_code
         }
+        #const_displays
     };
     write!(&mut file, "{}", source_code).expect("Unable to write to file");
 }