This tool detects likely dead code in Logtalk entities and in Prolog modules compiled as objects. Predicates (and non-terminals) are classified as dead code when:
There is no scope directive for them.
They are not called, directly or indirectly, by any predicate with a (local or inherited) scope directive.
Predicates (and non-terminals) listed in
directives but that are not used are also classified as dead code.
Besides dead code, this tool can also help detect other problems in the
code that often result in reporting false positives. For example, typos
alias/2 directives, missing scope directives, and missing
Given the possibility of false positives, care must be taken before deleting reported dead code to ensure that it’s, in fact, code that is not used. A common cause of false positives is the use of conditional compilation directives to provide implementations for predicates missing in some systems.
dead_code_scanner.lgt source file implements the scanning
predicates for finding dead code in entities, libraries, and
directories. The source file
the default translations for the messages printed when scanning for dead
code. These messages can be intercepted to customize output, e.g. to
make it less verbose, or for integration with e.g. GUI IDEs and
continuous integration servers.
To consult this tool API documentation, open in a web browser the link:
For sample queries, please see the SCRIPT.txt file in the tool directory.
This tool can be loaded using the query:
| ?- logtalk_load(dead_code_scanner(loader)).
Use of local meta-calls with goal arguments only known at runtime can
result in false positives. When using library or user-defined
meta-predicates, it can be helpful to compile the source files with the
optimize flag turned on so that the meta-calls may be resolved at
compile time and thus allow calling information for the meta-arguments
to be recorded, avoiding false positives for predicates that are only
All source files are indented using tabs (a common setting is a tab width equivalent to 4 spaces).