transpile: In Case translation, do not skip over initial cast

Author: Rua

c2rust-transpile/src/cfg/mod.rs

@@ -1857,23 +1857,16 @@ impl CfgBuilder {
                 self.add_wip_block(wip, Jump(this_label.clone()));
 
                 // Case
-                let resolved = translator.ast_context.unwrap_cast_expr(case_expr);
-                let branch = match translator.ast_context.index(resolved).kind {
-                    CExprKind::Literal(..) | CExprKind::ConstantExpr(_, _, Some(_)) => translator
-                        .convert_expr(ctx.const_().pattern().used(), resolved, None)
-                        .ok()
-                        .and_then(WithStmts::to_pure_expr)
-                        .and_then(|expr| expr_to_pat(*expr)),
-                    _ => None,
-                };
-
-                let pat = match branch {
-                    Some(pat) => pat,
-                    None => match cie {
+                let expr = translator
+                    .convert_expr(ctx.const_().pattern().used(), case_expr, None)
+                    .ok()
+                    .and_then(WithStmts::to_pure_expr);
+                let pat = expr
+                    .and_then(|expr| expr_to_pat(*expr))
+                    .unwrap_or_else(|| match cie {
                         ConstIntExpr::U(n) => mk().lit_pat(mk().int_unsuffixed_lit(n)),
                         ConstIntExpr::I(n) => mk().lit_pat(mk().int_unsuffixed_lit(n)),
-                    },
-                };
+                    });
 
                 self.switch_expr_cases
                     .last_mut()

c2rust-transpile/tests/snapshots/snapshots__transpile@enums.c.2021.clang15.snap

@@ -50,7 +50,7 @@ pub unsafe extern "C" fn test_enums() {
     let mut wrong_enum_constant: ::core::ffi::c_int =
         (e.0 == Bar0.0 as ::core::ffi::c_uint) as ::core::ffi::c_int;
     match foo.0 {
-        0 | 1 | 2 | 3 | 42 | 4294967254 | _ => {}
+        0 | FOO1_MACRO | 2 | 3 | 42 | 4294967254 | _ => {}
     }
     match bar.0 {
         0 | BAR1_MACRO | 2 | 3 | -1 | 42 | -42 | _ => {}

c2rust-transpile/tests/snapshots/snapshots__transpile@enums.c.2024.clang15.snap

@@ -51,7 +51,7 @@ pub unsafe extern "C" fn test_enums() {
     let mut wrong_enum_constant: ::core::ffi::c_int =
         (e.0 == Bar0.0 as ::core::ffi::c_uint) as ::core::ffi::c_int;
     match foo.0 {
-        0 | 1 | 2 | 3 | 42 | 4294967254 | _ => {}
+        0 | FOO1_MACRO | 2 | 3 | 42 | 4294967254 | _ => {}
     }
     match bar.0 {
         0 | BAR1_MACRO | 2 | 3 | -1 | 42 | -42 | _ => {}

c2rust-transpile/tests/snapshots/snapshots__transpile@macrocase.c.2021.clang15.snap

@@ -25,7 +25,7 @@ pub unsafe extern "C" fn ZSTD_dParam_getBounds(mut dParam: ZSTD_dParameter) -> :
             bounds = 1 as ::core::ffi::c_int;
             return bounds;
         }
-        1000 => {
+        ZSTD_d_format => {
             bounds = 5 as ::core::ffi::c_int;
             return bounds;
         }

c2rust-transpile/tests/snapshots/snapshots__transpile@macrocase.c.2024.clang15.snap

@@ -26,7 +26,7 @@ pub unsafe extern "C" fn ZSTD_dParam_getBounds(mut dParam: ZSTD_dParameter) -> :
             bounds = 1 as ::core::ffi::c_int;
             return bounds;
         }
-        1000 => {
+        ZSTD_d_format => {
             bounds = 5 as ::core::ffi::c_int;
             return bounds;
         }