Misc. improvements

• Emit non-zero array constants properly
• Emit only actually used array constants per runtime wrapper
• Juno CLI
• Use repr(C) structs for product types
• Minimal implementation of SROA
• TODO: inlining, codegen cast, intrinsics, dynamic constant math

hercules_rt_proc/src/lib.rs

@@ -40,13 +40,9 @@ fn generate_type_string(ty: &Type, rust_types: &Vec<String>) -> String {
         Type::UnsignedInteger64 => "u64".to_string(),
         Type::Float32 => "f32".to_string(),
         Type::Float64 => "f64".to_string(),
-        Type::Product(fields) => {
-            fields
-                .iter()
-                .map(|field_id| &rust_types[field_id.idx()] as &str)
-                .fold("(".to_string(), |acc, field| acc + field + ",")
-                + ")"
-        }
+        Type::Product(fields) => fields.iter().fold("Prod".to_string(), |acc, field| {
+            format!("{}_{}", acc, field.idx())
+        }),
         Type::Summation(_) => todo!(),
         Type::Array(elem, _) => format!("*mut {}", &rust_types[elem.idx()]),
     }
@@ -135,6 +131,25 @@ fn codegen(manifest: &ModuleManifest, elf: &[u8]) -> Result<String, anyhow::Erro
             }
         )?;
 
+        // In order to get repr(C), we need to define named structs to attach
+        // that attribute to. This unfortunately means we can't use anonymous
+        // products, which would be much nicer than this nonsense.
+        for id in types_bottom_up(&manifest.types) {
+            match manifest.types[id.idx()] {
+                Type::Product(ref fields) => {
+                    write!(
+                        rust_code,
+                        "#[repr(C)] struct {}({});",
+                        rust_types[id.idx()],
+                        fields.iter().fold("".to_string(), |acc, field| {
+                            acc + "," + &rust_types[field.idx()]
+                        })
+                    )?;
+                }
+                _ => {}
+            }
+        }
+
         // Load the ELF object, and cast the appropriate pointers.
         write!(
             rust_code,