cranelift: Generate all() function for all enum flags

This allows a user to iterate all flags that exist.

Author: afonso360

cranelift/codegen/meta/src/gen_settings.rs

@@ -98,6 +98,26 @@ fn gen_iterator(group: &SettingGroup, fmt: &mut Formatter) {
     fmtln!(fmt, "}");
 }
 
+/// Generates a `all()` function with all options for this enum
+fn gen_enum_all(name: &str, values: &[&'static str], fmt: &mut Formatter) {
+    fmtln!(
+        fmt,
+        "/// Returns a slice with all possible [{}] values.",
+        name
+    );
+    fmtln!(fmt, "pub fn all() -> &'static [{}] {{", name);
+    fmt.indent(|fmt| {
+        fmtln!(fmt, "&[");
+        fmt.indent(|fmt| {
+            for v in values.iter() {
+                fmtln!(fmt, "Self::{},", camel_case(v));
+            }
+        });
+        fmtln!(fmt, "]");
+    });
+    fmtln!(fmt, "}");
+}
+
 /// Emit Display and FromStr implementations for enum settings.
 fn gen_to_and_from_str(name: &str, values: &[&'static str], fmt: &mut Formatter) {
     fmtln!(fmt, "impl fmt::Display for {} {{", name);
@@ -158,6 +178,12 @@ fn gen_enum_types(group: &SettingGroup, fmt: &mut Formatter) {
         });
         fmtln!(fmt, "}");
 
+        fmtln!(fmt, "impl {} {{", name);
+        fmt.indent(|fmt| {
+            gen_enum_all(&name, values, fmt);
+        });
+        fmtln!(fmt, "}");
+
         gen_to_and_from_str(&name, values, fmt);
     }
 }

cranelift/fuzzgen/src/lib.rs

@@ -231,8 +231,7 @@ where
     fn generate_flags(&mut self) -> Result<Flags> {
         let mut builder = settings::builder();
 
-        let opt_levels = [OptLevel::None, OptLevel::Speed, OptLevel::SpeedAndSize];
-        let opt = self.u.choose(&opt_levels)?;
+        let opt = self.u.choose(OptLevel::all())?;
         builder.set("opt_level", &format!("{}", opt)[..])?;
 
         // Boolean flags