File: constexpr-array-unknown-bound.cpp

package info (click to toggle)
swiftlang 6.0.3-2
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 2,519,992 kB
  • sloc: cpp: 9,107,863; ansic: 2,040,022; asm: 1,135,751; python: 296,500; objc: 82,456; f90: 60,502; lisp: 34,951; pascal: 19,946; sh: 18,133; perl: 7,482; ml: 4,937; javascript: 4,117; makefile: 3,840; awk: 3,535; xml: 914; fortran: 619; cs: 573; ruby: 573
file content (26 lines) | stat: -rw-r--r-- 1,108 bytes parent folder | download | duplicates (20) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
 
// RUN: %clang_cc1 %s -Wno-uninitialized -std=c++1z -fsyntax-only -verify

const extern int arr[];
constexpr auto p = arr; // ok
constexpr int f(int i) {return p[i];} // expected-note {{read of dereferenced one-past-the-end pointer}}

constexpr int arr[] {1, 2, 3};
constexpr auto p2 = arr + 2; // ok
constexpr int x = f(2); // ok
constexpr int y = f(3); // expected-error {{constant expression}}
// expected-note-re@-1 {{in call to 'f({{.*}})'}}

// FIXME: consider permitting this case
struct A {int m[];} a;
constexpr auto p3 = a.m; // expected-error {{constant expression}} expected-note {{without known bound}}
constexpr auto p4 = a.m + 1; // expected-error {{constant expression}} expected-note {{without known bound}}

void g(int i) {
  int arr[i];
  constexpr auto *p = arr + 2; // expected-error {{constant expression}} expected-note {{without known bound}}

  // FIXME: Give a better diagnostic here. The issue is that computing
  // sizeof(*arr2) within the array indexing fails due to the VLA.
  int arr2[2][i];
  constexpr int m = ((void)arr2[2], 0); // expected-error {{constant expression}}
}