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java/non-final-call-in-constructor: a call made inside a lambda in the constructor is not reported #22970
Description
Description of the issue
The query reports toString() in the constructor of CtorSeed.Senior: Junior overrides it, the override reads name, and name is only assigned after super() returns, so new Junior() throws. Move the call into a lambda that the constructor runs right away (CtorVariant) and nothing is reported, though the call still happens during construction with the same effect.
Probably unqualifiedCallToNonAbstractMethod, which requires the call's enclosing callable to be the constructor (result.getEnclosingCallable() = c). Inside the lambda the enclosing callable is the lambda's own method.
Query: java/non-final-call-in-constructor (codeql/java-queries 1.1.10)
CodeQL CLI: 2.27.2
Code samples
seed/CtorSeed.java:
public class CtorSeed {
public static class Senior {
public Senior() {
toString(); // overridden in Junior, reads a field not yet set
}
public String toString() {
return "Senior";
}
}
public static class Junior extends Senior {
private String name;
public Junior() {
super();
name = "Junior";
}
public String toString() {
return name.toUpperCase(); // NullPointerException when called from Senior()
}
}
}variant/CtorVariant.java:
public class CtorVariant {
public static class Senior {
public Senior() {
Runnable r = () -> {
toString(); // the same call, inside a lambda run at once; not reported
};
r.run();
}
public String toString() {
return "Senior";
}
}
public static class Junior extends Senior {
private String name;
public Junior() {
super();
name = "Junior";
}
public String toString() {
return name.toUpperCase();
}
}
}How to reproduce
codeql database create db --language=java --build-mode=none \
--source-root=<one directory> --overwrite
codeql database analyze db \
codeql/java-queries:codeql-suites/java-security-and-quality.qls \
--format=csv --output=out.csv
# one database per directory
Expected result
"Non-final method invocation in constructor" on the toString() call inside the lambda in CtorVariant.java (line 6), as on CtorSeed.java (line 5).
Output of the commands above:
### CodeQL 2.27.2 query: java/non-final-call-in-constructor
### suite: java-security-and-quality.qls, --build-mode=none, per-file isolated databases
### extraction JDK: openjdk version "21.0.11" 2026-04-21 LTS
--- SEED -- expected: query fires (seed/)
"Non-final method invocation in constructor","If a constructor calls a method that is overridden in a subclass
--- VARIANT -- expected: query fires, actual: not reported (the bug) (variant/)
(query reported nothing)
Activity
sam-robson commentedon Nov 3, 2026
Hi @MarkLee131, thanks for the detailed report. We'll take a look into this and follow up.
sam-robson commentedon Nov 4, 2026
The
java/non-final-call-in-constructorquery is a syntactic check for direct calls made inside the constructor body itself, rather than tracking whether lambdas or callbacks created in a constructor are invoked synchronously before construction finishes (since callbacks defined in a constructor are typically invoked later, after initialization).