File: constexpr-steps.cpp

package info (click to toggle)
llvm-toolchain-21 1%3A21.1.6-3
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 2,245,028 kB
  • sloc: cpp: 7,619,726; ansic: 1,434,018; asm: 1,058,748; python: 252,740; f90: 94,671; objc: 70,685; lisp: 42,813; pascal: 18,401; sh: 8,601; ml: 5,111; perl: 4,720; makefile: 3,675; awk: 3,523; javascript: 2,409; xml: 892; fortran: 770
file content (17 lines) | stat: -rw-r--r-- 845 bytes parent folder | download | duplicates (14) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
 
// RUN: %clang_cc1 -std=c++1y -fsyntax-only -verify %s -DMAX=1234 -fconstexpr-steps=1234
// RUN: %clang_cc1 -std=c++1y -fsyntax-only -verify %s -DMAX=10 -fconstexpr-steps=10
// RUN: %clang -std=c++1y -fsyntax-only -Xclang -verify %s -DMAX=12345 -fconstexpr-steps=12345

// This takes a total of n + 4 steps according to our current rules:
//  - One for the compound-statement that is the function body
//  - One for the 'for' statement
//  - One for the 'int k = 0;' statement
//  - One for each of the n evaluations of the compound-statement in the 'for' body
//  - One for the 'return' statemnet
constexpr bool steps(int n) {
  for (int k = 0; k != n; ++k) {}
  return true; // expected-note {{step limit}}
}

static_assert(steps((MAX - 4)), ""); // ok
static_assert(steps((MAX - 3)), ""); // expected-error {{constant}} expected-note{{call}}