1.. title:: clang-tidy - cppcoreguidelines-avoid-goto 2 3cppcoreguidelines-avoid-goto 4============================ 5 6The usage of ``goto`` for control flow is error prone and should be replaced 7with looping constructs. Only forward jumps in nested loops are accepted. 8 9This check implements `ES.76 <https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#es76-avoid-goto>`_ 10from the CppCoreGuidelines and 11`6.3.1 from High Integrity C++ <http://www.codingstandard.com/rule/6-3-1-ensure-that-the-labels-for-a-jump-statement-or-a-switch-condition-appear-later-in-the-same-or-an-enclosing-block/>`_. 12 13For more information on why to avoid programming 14with ``goto`` you can read the famous paper `A Case against the GO TO Statement. <https://www.cs.utexas.edu/users/EWD/ewd02xx/EWD215.PDF>`_. 15 16The check diagnoses ``goto`` for backward jumps in every language mode. These 17should be replaced with `C/C++` looping constructs. 18 19.. code-block:: c++ 20 21 // Bad, handwritten for loop. 22 int i = 0; 23 // Jump label for the loop 24 loop_start: 25 do_some_operation(); 26 27 if (i < 100) { 28 ++i; 29 goto loop_start; 30 } 31 32 // Better 33 for(int i = 0; i < 100; ++i) 34 do_some_operation(); 35 36Modern C++ needs ``goto`` only to jump out of nested loops. 37 38.. code-block:: c++ 39 40 for(int i = 0; i < 100; ++i) { 41 for(int j = 0; j < 100; ++j) { 42 if (i * j > 500) 43 goto early_exit; 44 } 45 } 46 47 early_exit: 48 some_operation(); 49 50All other uses of ``goto`` are diagnosed in `C++`. 51