transpile: Add EnumMode to select enum output type

Author: Rua

c2rust-transpile/src/lib.rs

@@ -37,7 +37,7 @@ use c2rust_ast_exporter as ast_exporter;
 
 use crate::build_files::{emit_build_files, get_build_dir, CrateConfig};
 use crate::compile_cmds::get_compile_commands;
-pub use crate::translator::ReplaceMode;
+pub use crate::translator::{EnumMode, ReplaceMode};
 use std::prelude::v1::Vec;
 
 type PragmaVec = Vec<(&'static str, Vec<&'static str>)>;
@@ -108,6 +108,7 @@ pub struct TranspilerConfig {
     pub log_level: log::LevelFilter,
     pub edition: RustEdition,
     pub deny_unsafe_op_in_unsafe_fn: bool,
+    pub enum_mode: EnumMode,
 
     /// Run `c2rust-postprocess` after transpiling and potentially refactoring.
     pub postprocess: bool,

c2rust-transpile/src/translator/enums.rs

@@ -5,7 +5,7 @@ use syn::Expr;
 use crate::c_ast::CUnOp;
 use crate::{
     diagnostics::TranslationResult,
-    translator::{signed_int_expr, ConvertedDecl, ExprContext, Translation},
+    translator::{signed_int_expr, ConvertedDecl, EnumMode, ExprContext, Translation},
     with_stmts::WithStmts,
     CDeclKind, CEnumConstantId, CEnumId, CExprId, CExprKind, CLiteral, CQualTypeId, CTypeKind,
     ConstIntExpr,
@@ -23,10 +23,15 @@ impl<'c> Translation<'c> {
             .borrow()
             .resolve_decl_name(enum_id)
             .expect("Enums should already be renamed");
-        let ty = self.convert_type(integral_type.ctype)?;
-        Ok(ConvertedDecl::Item(
-            mk().span(span).pub_().type_item(enum_name, ty),
-        ))
+        let integral_type_rs = self.convert_type(integral_type.ctype)?;
+        let item = match self.tcfg.enum_mode {
+            EnumMode::Consts => mk()
+                .span(span)
+                .pub_()
+                .type_item(enum_name, integral_type_rs),
+        };
+
+        Ok(ConvertedDecl::Item(item))
     }
 
     pub fn convert_enum_constant(
@@ -163,11 +168,17 @@ impl<'c> Translation<'c> {
 
         let enum_integral_type = self.enum_integral_type(enum_id);
         let mut val = WithStmts::new_val(val);
-        let source_type_kind = &self.ast_context.resolve_type(source_cty.ctype).kind;
-        let enum_integral_type_kind = &self.ast_context.resolve_type(enum_integral_type.ctype).kind;
 
-        if source_type_kind != enum_integral_type_kind {
-            val = val.map(|val| self.enum_constructor_expr(enum_id, val));
+        match self.tcfg.enum_mode {
+            EnumMode::Consts => {
+                let source_type_kind = &self.ast_context.resolve_type(source_cty.ctype).kind;
+                let enum_integral_type_kind =
+                    &self.ast_context.resolve_type(enum_integral_type.ctype).kind;
+
+                if source_type_kind != enum_integral_type_kind {
+                    val = val.map(|val| self.enum_constructor_expr(enum_id, val));
+                }
+            }
         }
 
         Ok(val)
@@ -222,7 +233,9 @@ impl<'c> Translation<'c> {
             .unwrap();
         self.add_import(enum_id, &enum_name);
 
-        mk().cast_expr(value, mk().ident_ty(enum_name))
+        match self.tcfg.enum_mode {
+            EnumMode::Consts => mk().cast_expr(value, mk().ident_ty(enum_name)),
+        }
     }
 
     fn is_variant_of_enum(&self, enum_id: CEnumId, enum_constant_id: CEnumConstantId) -> bool {

c2rust-transpile/src/translator/mod.rs

@@ -4447,3 +4447,8 @@ fn neg_expr(arg: Box<Expr>) -> Box<Expr> {
 fn wrapping_neg_expr(arg: Box<Expr>) -> Box<Expr> {
     mk().method_call_expr(arg, "wrapping_neg", vec![])
 }
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum EnumMode {
+    Consts,
+}

c2rust-transpile/tests/snapshots.rs

@@ -10,8 +10,7 @@ use c2rust_rust_tools::RustEdition;
 use c2rust_rust_tools::RustEdition::Edition2021;
 use c2rust_rust_tools::RustEdition::Edition2024;
 use c2rust_transpile::renamer::RUST_KEYWORDS;
-use c2rust_transpile::ReplaceMode;
-use c2rust_transpile::TranspilerConfig;
+use c2rust_transpile::{EnumMode, ReplaceMode, TranspilerConfig};
 use itertools::Itertools;
 
 fn config(edition: RustEdition) -> TranspilerConfig {
@@ -67,6 +66,7 @@ fn config(edition: RustEdition) -> TranspilerConfig {
                 .unwrap()
                 .to_path_buf(),
         ),
+        enum_mode: EnumMode::Consts,
     }
 }
 

c2rust/src/bin/c2rust-transpile.rs

@@ -4,7 +4,7 @@ use regex::Regex;
 use std::{ffi::OsStr, fs, path::PathBuf};
 
 use c2rust_rust_tools::RustEdition;
-use c2rust_transpile::{Diagnostic, ReplaceMode, TranspilerConfig};
+use c2rust_transpile::{Diagnostic, EnumMode, ReplaceMode, TranspilerConfig};
 
 #[derive(Debug, Parser)]
 #[clap(
@@ -326,6 +326,7 @@ fn main() {
         log_level: args.log_level,
         edition: args.edition,
         deny_unsafe_op_in_unsafe_fn: args.deny_unsafe_op_in_unsafe_fn,
+        enum_mode: EnumMode::Consts,
     };
     // binaries imply emit-build-files
     if !tcfg.binaries.is_empty() {