From d2f046780da9c41b3ca41a7e5e06ee4994a2340a Mon Sep 17 00:00:00 2001
From: Christoffer Lerno <christoffer@aegik.com>
Date: Mon, 23 Feb 2026 23:28:32 +0100
Subject: [PATCH] - Compiler crash using `??` with a `void?` macro #2973

---
 releasenotes.md                            |  1 +
 src/compiler/llvm_codegen_expr.c           |  2 +-
 test/test_suite/errors/else_check_void.c3t | 17 +++++++++++++++++
 3 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 test/test_suite/errors/else_check_void.c3t

diff --git a/releasenotes.md b/releasenotes.md
index b60a0532f..d19d91ca2 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -58,6 +58,7 @@
 - Member access on a struct returned by the assignment expression, cause crash #2947
 - Trying to slice an indexable type leads to misleading error message #2958
 - Warn on use of visibility modifiers on methods. #2962
+- Compiler crash using `??` with a `void?` macro #2973
 
 ## 0.7.9 Change list
 
diff --git a/src/compiler/llvm_codegen_expr.c b/src/compiler/llvm_codegen_expr.c
index ed9cf0629..e3ff8326e 100644
--- a/src/compiler/llvm_codegen_expr.c
+++ b/src/compiler/llvm_codegen_expr.c
@@ -3921,7 +3921,7 @@ static void llvm_emit_else(GenContext *c, BEValue *be_value, Expr *expr)
 	assert(success_end_block && else_block_exit);
 
 	// We might have a void here
-	if (!real_value.value)
+	if (!real_value.value || LLVMIsUndef(real_value.value))
 	{
 		assert(type_flatten(expr->type) == type_void);
 		assert(!else_value.value);
diff --git a/test/test_suite/errors/else_check_void.c3t b/test/test_suite/errors/else_check_void.c3t
new file mode 100644
index 000000000..98a33a17d
--- /dev/null
+++ b/test/test_suite/errors/else_check_void.c3t
@@ -0,0 +1,17 @@
+module test;
+
+faultdef MALFORMED_RESPONSE;
+macro void? set_field(String[] tokens)
+{
+	if (tokens.len < 2) return MALFORMED_RESPONSE~;
+}
+
+fn void main()
+{
+	String[] tokens = { "a", "b" };
+	set_field(tokens) ?? (void)1;
+}
+
+/* #expect: test.ll
+
+fefe