From 9f4da339c36ac4bf31b442fe1bc09f539869dce8 Mon Sep 17 00:00:00 2001
From: Christoffer Lerno <christoffer@aegik.com>
Date: Thu, 12 Sep 2024 00:11:09 +0200
Subject: [PATCH] Support `int[*] { 1, 2, 3 }` expressions.

---
 releasenotes.md                               |  1 +
 src/compiler/sema_expr.c                      | 11 ++++------
 src/utils/lib.h                               | 17 ++++++++++++++++
 .../initializer_lists/infer_with_init.c3t     | 20 +++++++++++++++++++
 4 files changed, 42 insertions(+), 7 deletions(-)
 create mode 100644 test/test_suite/initializer_lists/infer_with_init.c3t

diff --git a/releasenotes.md b/releasenotes.md
index b4b9f7ca6..57c729658 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -6,6 +6,7 @@
 - Introduce `arg: x` named arguments instead of `.arg = x`, deprecate old style.
 - Support splat for varargs #1352.
 - Allow `var` in lambdas in macros.
+- Support `int[*] { 1, 2, 3 }` expressions.
 
 ### Fixes
 - Issue where a lambda wasn't correctly registered as external. #1408
diff --git a/src/compiler/sema_expr.c b/src/compiler/sema_expr.c
index 005dd6426..5a5c581f3 100644
--- a/src/compiler/sema_expr.c
+++ b/src/compiler/sema_expr.c
@@ -8913,17 +8913,15 @@ static inline bool sema_expr_analyse_builtin(SemaContext *context, Expr *expr, b
 	return true;
 }
 
-
 static inline bool sema_expr_analyse_compound_literal(SemaContext *context, Expr *expr)
 {
 	TypeInfo *type_info = expr->expr_compound_literal.type_info;
-	if (!sema_resolve_type_info(context, type_info, RESOLVE_TYPE_DEFAULT)) return false;
+	// We allow infering the size of arrays.
+	if (!sema_resolve_type_info(context, type_info, RESOLVE_TYPE_ALLOW_INFER)) return false;
 	Type *type = type_info->type;
 	if (type_is_optional(type))
 	{
-		SEMA_ERROR(type_info,
-				   "The type here should always be written as a plain type and not an optional, please remove the '!'.");
-		return false;
+		RETURN_SEMA_ERROR(type_info, "The type here should always be written as a plain type and not an optional, please remove the '!'.");
 	}
 	if (!sema_resolve_type_structure(context, type, type_info->span)) return false;
 	if (!sema_expr_analyse_initializer_list(context, type, expr->expr_compound_literal.initializer)) return false;
@@ -8970,8 +8968,7 @@ static inline bool sema_analyse_expr_dispatch(SemaContext *context, Expr *expr,
 		case EXPR_EMBED:
 			return sema_expr_analyse_embed(context, expr, false);
 		case EXPR_VASPLAT:
-			SEMA_ERROR(expr, "'$vasplat' can only be used inside of macros.");
-			return false;
+			RETURN_SEMA_ERROR(expr, "'$vasplat' can only be used inside of macros.");
 		case EXPR_GENERIC_IDENT:
 			return sema_expr_analyse_generic_ident(context, expr);
 		case EXPR_LAMBDA:
diff --git a/src/utils/lib.h b/src/utils/lib.h
index 7bfb7bf84..10ed52007 100644
--- a/src/utils/lib.h
+++ b/src/utils/lib.h
@@ -9,6 +9,7 @@
 
 #if PLATFORM_WINDOWS
 #include "direct.h"
+#include "intrin.h"
 #endif
 
 #if FETCH_AVAILABLE
@@ -412,6 +413,22 @@ static inline bool is_power_of_two(uint64_t x)
 	return x != 0 && (x & (x - 1)) == 0;
 }
 
+static int clz(uint64_t num)
+{
+#if IS_CLANG || IS_GCC
+	return (int)__builtin_ctzll(num);
+#else
+	unsigned long index;
+	_BitScanReverse64(&index, (__int64)num);
+	return (int)index;
+#endif
+}
+
+static inline unsigned char power_of_2(uint64_t pot_value)
+{
+	return 64 - clz(pot_value);
+}
+
 static inline uint32_t next_highest_power_of_2(uint32_t v)
 {
 	v--;
diff --git a/test/test_suite/initializer_lists/infer_with_init.c3t b/test/test_suite/initializer_lists/infer_with_init.c3t
new file mode 100644
index 000000000..4e7c62983
--- /dev/null
+++ b/test/test_suite/initializer_lists/infer_with_init.c3t
@@ -0,0 +1,20 @@
+// #target: windows-x64
+module test;
+const int[*] X = int[*] { 1, 2, 3 };
+int[*] y = int[*] { 1, 2, 3 };
+
+fn void main()
+{
+	int x = $typeof(int[*] { 1, 2, 3}).len;
+	int z = X.len;
+	int w = y.len;
+}
+
+/* #expect: test.ll
+
+@test.X = local_unnamed_addr constant [3 x i32] [i32 1, i32 2, i32 3], align 4
+@test.y = local_unnamed_addr global [3 x i32] [i32 1, i32 2, i32 3], align 4
+
+  store i32 3, ptr %x, align 4
+  store i32 3, ptr %z, align 4
+  store i32 3, ptr %w, align 4
\ No newline at end of file