translate-c: Correctly translate enum init values, addressing #1360

2 files changed, 36 insertions, 2 deletions

diff --git a/src/translate_c.cpp b/src/translate_c.cpp
index 735a671bcc..da37b907d6 100644
--- a/src/translate_c.cpp
+++ b/src/translate_c.cpp
@@ -458,9 +458,17 @@ static const char *decl_name(const Decl *decl) {
 static AstNode *trans_create_node_apint(Context *c, const llvm::APSInt &aps_int) {
     AstNode *node = trans_create_node(c, NodeTypeIntLiteral);
     node->data.int_literal.bigint = allocate<BigInt>(1);
-    bigint_init_data(node->data.int_literal.bigint, aps_int.getRawData(), aps_int.getNumWords(), aps_int.isNegative());
-    return node;
 
+    llvm::APSInt copy = aps_int;
+    llvm::APSInt positive = (~copy)++;
+
+    if (!aps_int.isNegative()) {
+        bigint_init_data(node->data.int_literal.bigint, aps_int.getRawData(), aps_int.getNumWords(), aps_int.isNegative());
+    } else {
+        bigint_init_data(node->data.int_literal.bigint, positive.getRawData(), positive.getNumWords(), aps_int.isNegative());
+    }
+
+    return node;
 }
 
 static const Type *qual_type_canon(QualType qt) {
diff --git a/test/translate_c.zig b/test/translate_c.zig
index b31e515aa2..a25d4200ce 100644
--- a/test/translate_c.zig
+++ b/test/translate_c.zig
@@ -1358,4 +1358,30 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\    }
         \\}
     );
+
+    cases.add("correctly translate enum init values",
+        \\enum EnumWithInits {
+        \\    VAL1 = 0,
+        \\    VAL2 = 1,
+        \\    VAL3 = 2,
+        \\    VAL4 = 3,
+        \\    VAL5 = -1,
+        \\    VAL6 = -2,
+        \\    VAL7 = -3,
+        \\    VAL8 = -4,
+        \\    VAL9 = VAL2 + VAL8,
+        \\};
+    ,
+        \\pub const enum_EnumWithInits = extern enum {
+        \\    VAL1 = 0,
+        \\    VAL2 = 1,
+        \\    VAL3 = 2,
+        \\    VAL4 = 3,
+        \\    VAL5 = -1,
+        \\    VAL6 = -2,
+        \\    VAL7 = -3,
+        \\    VAL8 = -4,
+        \\    VAL9 = -3,
+        \\};
+    );
 }