import definitions

/**

* An element that is the source of a jump-to-definition link.

*/

class Link extends Top {

Link() { exists(definitionOf(this, _)) }

}

/**

* Gets the length of the longest line in file `f`.

*/

pragma[nomagic]

private int maxCols(File f) {

result = max(Location l | l.getFile() = f | l.getStartColumn().maximum(l.getEndColumn()))

}

/**

* Gets the location of an element that has a link-to-definition (in a similar manner to

* `Location.charLoc`)

*/

predicate linkLocationInfo(Link e, string filepath, int begin, int end) {

exists(File f, int maxCols, int startline, int startcolumn, int endline, int endcolumn |

e.hasLocationInfo(filepath, startline, startcolumn, endline, endcolumn) and

f.getAbsolutePath() = filepath and

maxCols = maxCols(f) and

begin = (startline * maxCols) + startcolumn and

end = (endline * maxCols) + endcolumn

)

}

/**

* Gets a string describing a problem with a `Link`.

*/

string issues(Link e) {

strictcount(Top def | def = definitionOf(e, _)) > 1 and

result = "has more than one definition"

or

exists(string filepath1, int begin1, int end1, Link e2, string filepath2, int begin2, int end2 |

linkLocationInfo(e, filepath1, begin1, end1) and

linkLocationInfo(e2, filepath2, begin2, end2) and

filepath1 = filepath2 and

not end1 < begin2 and

not begin1 > end2 and

e != e2 and

not e.isFromTemplateInstantiation(_) and

not e2.isFromTemplateInstantiation(_)

) and

result = "overlaps another link"

}

from Link e

select e, issues(e)