From c2684634132c0af6f2bd042280fcf667576fceb5 Mon Sep 17 00:00:00 2001
From: jakubtomsu <66876057+jakubtomsu@users.noreply.github.com>
Date: Sun, 1 Oct 2023 12:21:44 +0200
Subject: [PATCH 1/3] Allow zero-length enumerated arrays

---
 src/check_type.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/check_type.cpp b/src/check_type.cpp
index a43c296a603..3360df040fa 100644
--- a/src/check_type.cpp
+++ b/src/check_type.cpp
@@ -2810,7 +2810,7 @@ gb_internal bool check_type_internal(CheckerContext *ctx, Ast *e, Type **type, T
 					}
 				}
 
-				if (!is_sparse && t->EnumeratedArray.count > bt->Enum.fields.count) {
+				if (!is_sparse && t->EnumeratedArray.count > bt->Enum.fields.count && bt->Enum.fields.count > 0) {
 					error(e, "Non-contiguous enumeration used as an index in an enumerated array");
 					long long ea_count   = cast(long long)t->EnumeratedArray.count;
 					long long enum_count = cast(long long)bt->Enum.fields.count;

From 1a57ad233d06e52e486f717ddea1ce15934657eb Mon Sep 17 00:00:00 2001
From: jakubtomsu <66876057+jakubtomsu@users.noreply.github.com>
Date: Sun, 1 Oct 2023 13:09:08 +0200
Subject: [PATCH 2/3] Fix field count in enumerated array type info

---
 src/check_type.cpp | 2 +-
 src/types.cpp      | 8 ++++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/check_type.cpp b/src/check_type.cpp
index 3360df040fa..ee12b90ca39 100644
--- a/src/check_type.cpp
+++ b/src/check_type.cpp
@@ -2797,7 +2797,7 @@ gb_internal bool check_type_internal(CheckerContext *ctx, Ast *e, Type **type, T
 				Type *bt = base_type(index);
 				GB_ASSERT(bt->kind == Type_Enum);
 
-				Type *t = alloc_type_enumerated_array(elem, index, bt->Enum.min_value, bt->Enum.max_value, Token_Invalid);
+				Type *t = alloc_type_enumerated_array(elem, index, bt->Enum.min_value, bt->Enum.max_value, bt->Enum.fields.count, Token_Invalid);
 
 				bool is_sparse = false;
 				if (at->tag != nullptr) {
diff --git a/src/types.cpp b/src/types.cpp
index f3062365fed..574e628c5c7 100644
--- a/src/types.cpp
+++ b/src/types.cpp
@@ -983,7 +983,7 @@ gb_internal Type *alloc_type_matrix(Type *elem, i64 row_count, i64 column_count,
 }
 
 
-gb_internal Type *alloc_type_enumerated_array(Type *elem, Type *index, ExactValue const *min_value, ExactValue const *max_value, TokenKind op) {
+gb_internal Type *alloc_type_enumerated_array(Type *elem, Type *index, ExactValue const *min_value, ExactValue const *max_value, isize count, TokenKind op) {
 	Type *t = alloc_type(Type_EnumeratedArray);
 	t->EnumeratedArray.elem = elem;
 	t->EnumeratedArray.index = index;
@@ -993,7 +993,11 @@ gb_internal Type *alloc_type_enumerated_array(Type *elem, Type *index, ExactValu
 	gb_memmove(t->EnumeratedArray.max_value, max_value, gb_size_of(ExactValue));
 	t->EnumeratedArray.op = op;
 
-	t->EnumeratedArray.count = 1 + exact_value_to_i64(exact_value_sub(*max_value, *min_value));
+	if (count == 0) {
+		t->EnumeratedArray.count = 0;
+	} else {
+		t->EnumeratedArray.count = 1 + exact_value_to_i64(exact_value_sub(*max_value, *min_value));
+	}
 	return t;
 }
 

From 394c12f68dc380aea93ad447f5f348383811d09f Mon Sep 17 00:00:00 2001
From: jakubtomsu <66876057+jakubtomsu@users.noreply.github.com>
Date: Sun, 1 Oct 2023 13:13:09 +0200
Subject: [PATCH 3/3] Remove unnecessary check zero fields check

---
 src/check_type.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/check_type.cpp b/src/check_type.cpp
index ee12b90ca39..d66b196bc64 100644
--- a/src/check_type.cpp
+++ b/src/check_type.cpp
@@ -2810,7 +2810,7 @@ gb_internal bool check_type_internal(CheckerContext *ctx, Ast *e, Type **type, T
 					}
 				}
 
-				if (!is_sparse && t->EnumeratedArray.count > bt->Enum.fields.count && bt->Enum.fields.count > 0) {
+				if (!is_sparse && t->EnumeratedArray.count > bt->Enum.fields.count) {
 					error(e, "Non-contiguous enumeration used as an index in an enumerated array");
 					long long ea_count   = cast(long long)t->EnumeratedArray.count;
 					long long enum_count = cast(long long)bt->Enum.fields.count;