foo.x was not always handled correctly when foo was optional.

releasenotes.md

@@ -41,6 +41,7 @@
 - Assert when struct size would exceed 4 GB.
 - Assert when encountering a malformed module alias.
 - Assert when encountering a test function with raw vaarg parameters.
+- `foo.x` was not always handled correctly when `foo` was optional.
 
 ### Stdlib changes
 - Add `ThreadPool` join function to wait for all threads to finish in the pool without destroying the threads.

src/compiler/sema_expr.c

@@ -6592,7 +6592,7 @@ CHECK_DEEPER:
 			if (missing_ref) goto MISSING_REF;
 			RETURN_SEMA_ERROR(expr, "The method '%s' has private visibility.", kw);
 		}
-		Type *parent_type = parent->type->canonical;
+		Type *parent_type = type_no_optional(parent->type)->canonical;
 		ASSERT(type_is_user_defined(parent_type));
 		if (missing_ref && parent_type->decl->unit->module->stage < ANALYSIS_POST_REGISTER)
 		{

test/test_suite/any/interface_fault.c3

@@ -0,0 +1,7 @@
+interface Foo { }
+fn int main()
+{
+	Foo? v;
+	v.nope(); // #error: The 'Foo' interface has no method 'nope', did you spell it correctly
+	return 0;
+}

test/test_suite/any/interface_through_fault.c3t

@@ -0,0 +1,89 @@
+// #target: macos-x64
+module test;
+interface Foo { fn int test(); }
+
+fn int int.test(&self) @dynamic => *self + 1;
+
+fn int main()
+{
+	Foo? v = (Foo)&&2;
+	int x = v.test()!!;
+	return x;
+}
+
+/* #expect: test.ll
+
+define i32 @main() #0 {
+entry:
+  %v = alloca %any, align 8
+  %v.f = alloca i64, align 8
+  %taddr = alloca i32, align 4
+  %x = alloca i32, align 4
+  %error_var = alloca i64, align 8
+  %.inlinecache = alloca ptr, align 8
+  %.cachedtype = alloca ptr, align 8
+  %varargslots = alloca [1 x %any], align 16
+  %indirectarg = alloca %"any[]", align 8
+  store ptr null, ptr %.cachedtype, align 8
+  store i32 2, ptr %taddr, align 4
+  %0 = insertvalue %any undef, ptr %taddr, 0
+  %1 = insertvalue %any %0, i64 ptrtoint (ptr @"$ct.int" to i64), 1
+  store %any %1, ptr %v, align 8
+  store i64 0, ptr %v.f, align 8
+  %optval = load i64, ptr %v.f, align 8
+  %not_err = icmp eq i64 %optval, 0
+  %2 = call i1 @llvm.expect.i1(i1 %not_err, i1 true)
+  br i1 %2, label %after_check, label %assign_optional
+
+assign_optional:                                  ; preds = %entry
+  store i64 %optval, ptr %error_var, align 8
+  br label %panic_block
+
+after_check:                                      ; preds = %entry
+  %ptradd = getelementptr inbounds i8, ptr %v, i64 8
+  %3 = load i64, ptr %ptradd, align 8
+  %4 = inttoptr i64 %3 to ptr
+  %5 = load ptr, ptr %.cachedtype, align 8
+  %6 = icmp eq ptr %4, %5
+  br i1 %6, label %cache_hit, label %cache_miss
+
+cache_miss:                                       ; preds = %after_check
+  %7 = call ptr @.dyn_search(ptr %4, ptr @"$sel.test")
+  store ptr %7, ptr %.inlinecache, align 8
+  store ptr %4, ptr %.cachedtype, align 8
+  br label %9
+
+cache_hit:                                        ; preds = %after_check
+  %8 = load ptr, ptr %.inlinecache, align 8
+  br label %9
+
+9:                                                ; preds = %cache_hit, %cache_miss
+  %fn_phi = phi ptr [ %8, %cache_hit ], [ %7, %cache_miss ]
+  %10 = icmp eq ptr %fn_phi, null
+  br i1 %10, label %missing_function, label %match
+
+missing_function:                                 ; preds = %9
+  %11 = load ptr, ptr @std.core.builtin.panic, align 8
+  call void %11(ptr @.panic_msg, i64 41, ptr @.file, i64 26, ptr @.func, i64 4, i32 9) #2
+  unreachable
+
+match:                                            ; preds = %9
+  %12 = load ptr, ptr %v, align 8
+  %13 = call i32 %fn_phi(ptr %12)
+  br label %noerr_block
+
+panic_block:                                      ; preds = %assign_optional
+  %14 = insertvalue %any undef, ptr %error_var, 0
+  %15 = insertvalue %any %14, i64 ptrtoint (ptr @"$ct.fault" to i64), 1
+  store %any %15, ptr %varargslots, align 16
+  %16 = insertvalue %"any[]" undef, ptr %varargslots, 0
+  %"$$temp" = insertvalue %"any[]" %16, i64 1, 1
+  store %"any[]" %"$$temp", ptr %indirectarg, align 8
+  call void @std.core.builtin.panicf
+  unreachable
+
+noerr_block:                                      ; preds = %match
+  store i32 %13, ptr %x, align 4
+  %17 = load i32, ptr %x, align 4
+  ret i32 %17
+}