/**

* @name Dead code due to goto or break statement

* @description A goto or break statement is followed by unreachable code.

* @kind problem

* @problem.severity warning

* @precision high

* @id cpp/dead-code-goto

* @tags maintainability

* external/cwe/cwe-561

*/

import cpp

import semmle.code.cpp.commons.Exclusions

Stmt getNextRealStmt(BlockStmt b, int i) {

result = b.getStmt(i + 1) and

not result instanceof EmptyStmt

or

b.getStmt(i + 1) instanceof EmptyStmt and

result = getNextRealStmt(b, i + 1)

}

from JumpStmt js, BlockStmt b, int i, Stmt s

where

b.getStmt(i) = js and

s = getNextRealStmt(b, i) and

// the next statement isn't jumped to

not s instanceof LabelStmt and

not s instanceof SwitchCase and

// the next statement isn't breaking out of a switch

not s.(BreakStmt).getBreakable() instanceof SwitchStmt and

// the next statement isn't a loop that can be jumped into

not s.(Loop).getStmt().getAChild*() instanceof LabelStmt and

not s.(Loop).getStmt().getAChild*() instanceof SwitchCase and

// no preprocessor logic applies

not functionContainsPreprocCode(js.getEnclosingFunction())

select js, "This statement makes $@ unreachable.", s, s.toString()