From f0bd93d1f01f0bf56c1c78fa8a9096b65f9ede11 Mon Sep 17 00:00:00 2001
From: Christoffer Lerno <christoffer@aegik.com>
Date: Mon, 16 Jun 2025 22:56:34 +0200
Subject: [PATCH] Additional #2210 fixes.

---
 src/compiler/llvm_codegen_expr.c              |  9 +--
 .../test_suite/assert/unreachable_macro_3.c3t | 45 ++++++++++++
 .../test_suite/assert/unreachable_macro_4.c3t | 24 +++++++
 .../assert/unreachable_macro_fn.c3t           | 69 +++++++++++++++++++
 4 files changed, 143 insertions(+), 4 deletions(-)
 create mode 100644 test/test_suite/assert/unreachable_macro_3.c3t
 create mode 100644 test/test_suite/assert/unreachable_macro_4.c3t
 create mode 100644 test/test_suite/assert/unreachable_macro_fn.c3t

diff --git a/src/compiler/llvm_codegen_expr.c b/src/compiler/llvm_codegen_expr.c
index 983a0ed2b..bf01a5f7e 100644
--- a/src/compiler/llvm_codegen_expr.c
+++ b/src/compiler/llvm_codegen_expr.c
@@ -6129,15 +6129,16 @@ static inline void llvm_emit_macro_block(GenContext *c, BEValue *be_value, Expr
 
 	c->debug.block_stack = &updated;
 	llvm_emit_return_block(c, be_value, expr->type, expr->macro_block.first_stmt, expr->macro_block.block_exit);
-	if (!c->current_block && !expr->macro_block.is_noreturn)
-	{
-		llvm_emit_block(c, llvm_basic_block_new(c, "after_macro"));
-	}
 	bool is_unreachable = expr->macro_block.is_noreturn && c->current_block;
 	if (is_unreachable)
 	{
 		llvm_emit_unreachable(c);
 	}
+	if (!c->current_block)
+	{
+		llvm_emit_block(c, llvm_basic_block_new(c, "after_macro"));
+		llvm_value_set(be_value, LLVMGetPoison(llvm_get_type(c, expr->type)), expr->type);
+	}
 	c->debug.block_stack = old_inline_location;
 }
 
diff --git a/test/test_suite/assert/unreachable_macro_3.c3t b/test/test_suite/assert/unreachable_macro_3.c3t
new file mode 100644
index 000000000..ec5365dd2
--- /dev/null
+++ b/test/test_suite/assert/unreachable_macro_3.c3t
@@ -0,0 +1,45 @@
+// #target: windows-x64
+module test;
+
+struct Window
+{
+	char* content;
+}
+
+macro Window @content($content = {},)
+{
+	$switch:
+		$case $defined((char*) $content):
+			return { .content = $content, };
+		$default:
+			unreachable();
+	$endswitch
+}
+
+fn void main()
+{
+	Window[] windows = {
+		@content($content: { "foo" },
+		),
+	};
+}
+
+/* #expect: test.ll
+
+define void @test.main() #0 {
+entry:
+  %windows = alloca %"Window[]", align 8
+  %literal = alloca [1 x %Window], align 8
+  %blockret = alloca %Window, align 8
+  unreachable
+
+after_macro:                                      ; No predecessors!
+  unreachable
+
+after_macro1:                                     ; No predecessors!
+  store %Window poison, ptr %literal, align 8
+  %0 = insertvalue %"Window[]" undef, ptr %literal, 0
+  %1 = insertvalue %"Window[]" %0, i64 1, 1
+  store %"Window[]" %1, ptr %windows, align 8
+  ret void
+}
diff --git a/test/test_suite/assert/unreachable_macro_4.c3t b/test/test_suite/assert/unreachable_macro_4.c3t
new file mode 100644
index 000000000..7b2e71fcc
--- /dev/null
+++ b/test/test_suite/assert/unreachable_macro_4.c3t
@@ -0,0 +1,24 @@
+// #target: windows-x64
+module test;
+
+fn void main()
+{
+	int[] kaput = { unreachable() };
+}
+
+/* #expect: test.ll
+
+define void @test.main() #0 {
+entry:
+  %kaput = alloca %"int[]", align 8
+  %literal = alloca [1 x i32], align 4
+  %blockret = alloca i32, align 4
+  unreachable
+
+after_macro:                                      ; No predecessors!
+  store i32 poison, ptr %literal, align 4
+  %0 = insertvalue %"int[]" undef, ptr %literal, 0
+  %1 = insertvalue %"int[]" %0, i64 1, 1
+  store %"int[]" %1, ptr %kaput, align 8
+  ret void
+}
diff --git a/test/test_suite/assert/unreachable_macro_fn.c3t b/test/test_suite/assert/unreachable_macro_fn.c3t
new file mode 100644
index 000000000..113d36c3e
--- /dev/null
+++ b/test/test_suite/assert/unreachable_macro_fn.c3t
@@ -0,0 +1,69 @@
+// #target: windows-x64
+module test;
+
+macro int create_int2() {
+	$$unreachable();
+	return 2;
+}
+
+fn void test()
+{
+	int x = create_int2();
+}
+macro int? create_int()
+{
+	$$unreachable();
+	return 2;
+}
+
+fn void tester(int x)
+{
+}
+
+fn void tester_test()
+{
+	(void)tester(create_int());
+}
+
+fn void tester_test2()
+{
+	(void)tester(create_int2());
+}
+
+/* #expect: test.ll
+
+; Function Attrs: nounwind uwtable
+define void @test.test() #0 {
+entry:
+  %x = alloca i32, align 4
+  %blockret = alloca i32, align 4
+  unreachable
+
+after_macro:                                      ; No predecessors!
+  store i32 poison, ptr %x, align 4
+  ret void
+}
+
+; Function Attrs: nounwind uwtable
+define void @test.tester(i32 %0) #0 {
+entry:
+  ret void
+}
+
+; Function Attrs: nounwind uwtable
+define void @test.tester_test() #0 {
+entry:
+  %blockret = alloca i32, align 4
+  unreachable
+}
+
+; Function Attrs: nounwind uwtable
+define void @test.tester_test2() #0 {
+entry:
+  %blockret = alloca i32, align 4
+  unreachable
+
+after_macro:                                      ; No predecessors!
+  call void @test.tester(i32 poison)
+  ret void
+}
\ No newline at end of file