&self argument not implicitly null checked. #1556.

releasenotes.md

@@ -41,6 +41,7 @@
 - Improve infer conversions on constants, e.g. `ZString a = foo ? "a" : "b";` #1561
 - Show error when declarations do not start with `fn` in interfaces. #1565
 - `if (try foo)` was handled incorrectly inside a defer.
+- `&self` argument not implicitly null checked. #1556.
 
 ### Stdlib changes
 - Remove unintended print of `char[]` as String

src/compiler/sema_decls.c

@@ -1147,6 +1147,7 @@ static inline bool sema_analyse_signature(SemaContext *context, Signature *sig,
 		{
 			case VARDECL_PARAM_REF:
 				inferred_type = type_get_ptr(method_parent->type);
+				param->var.not_null = true;
 				if (!is_macro) param->var.kind = VARDECL_PARAM;
 				break;
 			case VARDECL_PARAM:

test/test_suite/methods/self_methods_null.c3t

@@ -0,0 +1,27 @@
+// #target: macos-x64
+// #safe: yes
+module test;
+distinct Foo = int;
+fn void Foo.test(&self) {}
+fn int main()
+{
+	Foo* a = null;
+	a.test();
+    return 0;
+}
+/* #expect: test.ll
+
+define void @test.Foo.test(ptr %0) #0 {
+entry:
+  %1 = icmp eq ptr %0, null
+  %2 = call i1 @llvm.expect.i1(i1 %1, i1 false)
+  br i1 %2, label %panic, label %checkok
+
+checkok:                                          ; preds = %entry
+  ret void
+
+panic:                                            ; preds = %entry
+  %3 = load ptr, ptr @std.core.builtin.panic, align 8
+  call void %3(ptr @.panic_msg, i64 62, ptr @.file, i64 20, ptr @.func, i64 4, i32 3)
+  unreachable
+}