From d727696830260ca64f5e8d54f38c94b9bcba33a1 Mon Sep 17 00:00:00 2001
From: Christoffer Lerno <christoffer@aegik.com>
Date: Sat, 21 Sep 2024 00:57:36 +0200
Subject: [PATCH] Segfault using ternary with no assignment #1468.

---
 releasenotes.md                              |  1 +
 src/compiler/llvm_codegen_expr.c             |  5 ++++
 test/test_suite/expressions/ternary_void.c3t | 31 ++++++++++++++++++++
 3 files changed, 37 insertions(+)
 create mode 100644 test/test_suite/expressions/ternary_void.c3t

diff --git a/releasenotes.md b/releasenotes.md
index ea2669429..420c218a9 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -46,6 +46,7 @@
 - Folding a constant array of structs at compile time would cause an assert.
 - Enum attributes would be overwritten by enum value attributes.
 - LLVM issue with try when bool is combined #1467
+- Segfault using ternary with no assignment #1468
 
 ### Stdlib changes
 - Additional init functions for hashmap.
diff --git a/src/compiler/llvm_codegen_expr.c b/src/compiler/llvm_codegen_expr.c
index d590fbffa..22dbe9b98 100644
--- a/src/compiler/llvm_codegen_expr.c
+++ b/src/compiler/llvm_codegen_expr.c
@@ -4969,6 +4969,11 @@ void gencontext_emit_ternary_expr(GenContext *c, BEValue *value, Expr *expr)
 		return;
 	}
 
+	if (expr->type == type_void)
+	{
+		llvm_value_set(value, NULL, expr->type);
+		return;
+	}
 	llvm_new_phi(c, value, "val", expr->type, lhs_value, lhs_exit, rhs_value, rhs_exit);
 }
 static LLVMValueRef llvm_emit_real(LLVMTypeRef type, Float f)
diff --git a/test/test_suite/expressions/ternary_void.c3t b/test/test_suite/expressions/ternary_void.c3t
new file mode 100644
index 000000000..91f1d60f8
--- /dev/null
+++ b/test/test_suite/expressions/ternary_void.c3t
@@ -0,0 +1,31 @@
+// #target: macos-x64
+module test;
+
+fn void foo() {  }
+fn void bar() {}
+
+fn void main()
+{
+    bool b = true;
+    true ? foo() : bar(); // ok
+    b ? foo() : bar(); // segfault
+}
+
+/* #expect: test.ll
+
+entry:
+  %b = alloca i8, align 1
+  store i8 1, ptr %b, align 1
+  call void @test.foo()
+  %0 = load i8, ptr %b, align 1
+  %1 = trunc i8 %0 to i1
+  br i1 %1, label %cond.lhs, label %cond.rhs
+cond.lhs:                                         ; preds = %entry
+  call void @test.foo()
+  br label %cond.phi
+cond.rhs:                                         ; preds = %entry
+  call void @test.bar()
+  br label %cond.phi
+cond.phi:                                         ; preds = %cond.rhs, %cond.lhs
+  ret void
+}