/* * Copyright (c) 2017 - present Facebook, Inc. * All rights reserved. * * This source code is licensed under the BSD style license found in the * LICENSE file in the root directory of this source tree. An additional grant * of patent rights can be found in the PATENTS file in the same directory. */ namespace dead_stores { void easy_bad() { int x = 5; } void reassign_param_bad(int x) { x = 5; } int dead_then_live_bad() { int x = 5; x = 3; return x; } int use_then_dead_bad() { int x = 5; int y = x; x = 7; return y; } void dead_pointer_bad() { int num = 2; int* x = # } void plus_plus1_bad() { int i = 0; ++i; } void plus_plus2_bad() { int i = 0; i++; } int plus_plus3_bad() { int i = 0; return i++; } void FN_capture_no_read_bad() { int x = 0; [x]() { return; }(); } void init_capture_reassign_bad() { int i = 0; // this is a dead store return [i = 0]() { return i; } (); } void init_capture_no_call_bad() { [i = 0]() { return i; }; } int FN_init_capture_no_read_bad() { return [i = 0]() { return 0; } (); } int return_ok() { int x = 5; return x; } int branch_ok(bool b) { int x = 5; int y = 3; if (b) { y = x; } return y; } int loop_ok(bool b) { int x = 5; int y = 3; while (b) { y = x; b = false; } return y; } int loop_break_ok(bool b) { int x = 5; while (b) { x = 3; break; } return x; } int loop_continue_ok(bool b) { int x = 5; int y = 2; while (b) { y = x; x = 3; continue; } return y; } void assign_pointer1_ok(int* ptr) { *ptr = 7; } int* assign_pointer2_ok() { int num = 2; int* ptr = # return ptr; } void by_ref1_ok(int& ref) { ref = 7; } void by_ref2_ok(int& ref) { ref++; } int plus_plus_ok() { int x = 0; return ++x; } int plus_plus_loop_ok(int n) { int i; for (i = 0; i < n; i++) { i++; } return i; } void lambda_bad() { int x = []() { int y = 1; y = 2; return y; }(); return x; } void capture1_ok() { int x = 1; [x]() { return x; }(); } void capture2_ok(int x) { [x]() { return x; }(); } int capture_by_ref1_ok() { int x = 0; [&x]() { x++; }(); return x; } int capture_by_ref2_ok() { int x = 0; int y = 0; [&]() { x = x + y; y = x; }(); return x + y; } int FN_capture_by_ref_reuseBad() { int x = 0; [&x]() { x = 1; // dead, but we won't report x = 2; }(); return x; } int init_capture1_ok() { return [i = 0]() { return i; } (); } int init_capture2_ok() { int i = 0; return [j = i]() { return j; } (); } int init_capture3_ok() { int i = 0; return [i = i]() { return i; } (); } int init_capture4_ok() { int i = 0; int j = 0; return [ a = 0, b = i, c = j ]() { return a + b + c; } (); } int init_capture5_ok() { int i = 0; int k = [j = i]() { return j; } (); i = 5; // should not be flagged return i + k; } int init_capture6_ok() { int i = 0; int k = [i = i + 1]() { return i; } (); i = 5; // should not be flagged; return i + k; } char* global; void FP_assign_array_tricky_ok() { char arr[1]; global = arr; *(int*)arr = 123; // think this is a bug in the frontend... this instruction // looks like &arr:int = 123 } }