Ada 2012 Reference Manual
5.8 Goto Statements
A goto_statement specifies an explicit transfer of control from this statement to a target statement with a given label.
Syntax
Name Resolution Rules
The label_name shall resolve to denote a label; the statement with that label is the target statement.
Legality Rules
The innermost sequence_of_statements that encloses the target statement shall also enclose the goto_statement. Furthermore, if a goto_statement is enclosed by an accept_statement or a body, then the target statement shall not be outside this enclosing construct.
Dynamic Semantics
The execution of a goto_statement transfers control to the target statement, completing the execution of any compound_statement that encloses the goto_statement but does not enclose the target.
NOTES
9 The above rules allow transfer of control to a statement of an enclosing sequence_of_statements but not the reverse. Similarly, they prohibit transfers of control such as between alternatives of a case_statement, if_statement, or select_statement; between exception_handlers; or from an exception_handler of a handled_sequence_of_statements back to its sequence_of_statements.
Examples
Example of a loop containing a goto statement:
<<Sort>>
for I in 1 .. N-1 loop
if A(I) > A(I+1) then
Exchange(A(I), A(I+1));
goto Sort;
end if;
end loop;
for I in 1 .. N-1 loop
if A(I) > A(I+1) then
Exchange(A(I), A(I+1));
goto Sort;
end if;
end loop;
