Deprecation warnings incompletely controlled by compiler preferences

[iloveeclipse]

In the light of #4553 I've tried to construct a simple exmaple to understand which differences we have before / after the fix 545483d / #4293 with previous ecj version and with latest javac from Java 25.

Consider following code (in 3 different files, this is important for ecj):

package c;
@Deprecated
public class OldClass {
//  @Deprecated
    public void foo() {
    }
//  @Deprecated
    public void bar() {
    }
}

package c;
public class ExtendsOldClass extends OldClass {
	@Override
	public void foo() {
		super.foo();
	}
	public void callingFoo() {
		super.foo();
	}
	public void callingBar() {
		bar();
	}
}

package c;
public class UseOldClass {
	public void callingFoo() {
		new ExtendsOldClass().foo();
		new OldClass().foo();
	}
	public void callingBar() {
		new ExtendsOldClass().bar();
		new OldClass().bar();
	}
}

javac reports 3 warnings

javac -d /tmp/testcompile --release 17 -Xlint:deprecation  /data/workspaces/aloskuto-bf/Deprecation/src/c/*.java 
/data/workspaces/aloskuto-bf/Deprecation/src/c/ExtendsOldClass.java:2: warning: [deprecation] OldClass in c has been deprecated
public class ExtendsOldClass extends OldClass {
                                     ^
/data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java:5: warning: [deprecation] OldClass in c has been deprecated
                new OldClass().foo();
                    ^
/data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java:9: warning: [deprecation] OldClass in c has been deprecated
                new OldClass().bar();
                    ^
3 warnings

ecj latest (9 ! warnings with/without explicit -warn:+deprecation )

java -jar ~/Downloads/ecj-I20251026-1800.jar -d /tmp/testcompile --release 17 -warn:+deprecation /data/workspaces/aloskuto-bf/Deprecation/src/c/*.java
----------
1. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/ExtendsOldClass.java (at line 2)
        public class ExtendsOldClass extends OldClass {
                                             ^^^^^^^^
The type OldClass is deprecated
----------
2. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/ExtendsOldClass.java (at line 5)
        super.foo();
              ^^^
The method foo() from the type OldClass is deprecated
----------
3. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/ExtendsOldClass.java (at line 8)
        super.foo();
              ^^^
The method foo() from the type OldClass is deprecated
----------
----------
4. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 5)
        new OldClass().foo();
            ^^^^^^^^
The type OldClass is deprecated
----------
5. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 5)
        new OldClass().foo();
            ^^^^^^^^
The constructor OldClass() is deprecated
----------
6. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 5)
        new OldClass().foo();
                       ^^^
The method foo() from the type OldClass is deprecated
----------
7. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 9)
        new OldClass().bar();
            ^^^^^^^^
The type OldClass is deprecated
----------
8. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 9)
        new OldClass().bar();
            ^^^^^^^^
The constructor OldClass() is deprecated
----------
9. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 9)
        new OldClass().bar();
                       ^^^
The method bar() from the type OldClass is deprecated
----------
9 problems (9 warnings)

ecj latest (10 ! warnings with project settings)

org.eclipse.jdt.core.compiler.problem.deprecation=warning
org.eclipse.jdt.core.compiler.problem.deprecationInDeprecatedCode=disabled
org.eclipse.jdt.core.compiler.problem.deprecationWhenOverridingDeprecatedMethod=enabled

java -jar ~/Downloads/ecj-I20251026-1800.jar -d /tmp/testcompile --release 17 -properties /data/workspaces/aloskuto-bf/Deprecation/.settings/org.eclipse.jdt.core.prefs /data/workspaces/aloskuto-bf/Deprecation/src/c/*.java
----------
1. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/ExtendsOldClass.java (at line 2)
        public class ExtendsOldClass extends OldClass {
                                             ^^^^^^^^
The type OldClass is deprecated
----------
2. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/ExtendsOldClass.java (at line 4)
        public void foo() {
                    ^^^^^
The method ExtendsOldClass.foo() overrides a deprecated method from OldClass
----------
3. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/ExtendsOldClass.java (at line 5)
        super.foo();
              ^^^
The method foo() from the type OldClass is deprecated
----------
4. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/ExtendsOldClass.java (at line 8)
        super.foo();
              ^^^
The method foo() from the type OldClass is deprecated
----------
----------
5. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 5)
        new OldClass().foo();
            ^^^^^^^^
The type OldClass is deprecated
----------
6. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 5)
        new OldClass().foo();
            ^^^^^^^^
The constructor OldClass() is deprecated
----------
7. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 5)
        new OldClass().foo();
                       ^^^
The method foo() from the type OldClass is deprecated
----------
8. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 9)
        new OldClass().bar();
            ^^^^^^^^
The type OldClass is deprecated
----------
9. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 9)
        new OldClass().bar();
            ^^^^^^^^
The constructor OldClass() is deprecated
----------
10. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 9)
        new OldClass().bar();
                       ^^^
The method bar() from the type OldClass is deprecated
----------
10 problems (10 warnings)

Note, switching deprecation warnings in project settings off via

org.eclipse.jdt.core.compiler.problem.deprecation=disabled
org.eclipse.jdt.core.compiler.problem.deprecationInDeprecatedCode=disabled
org.eclipse.jdt.core.compiler.problem.deprecationWhenOverridingDeprecatedMethod=disabled

doesn't produce expected effect except one warning less is reported :-(

Before the 545483d / #4293 ecj reported 12 warnings (so the fix only changed 2 from 12 warnings)

java -jar ~/Downloads/ecj-I20251024-0020.jar -d /tmp/testcompile --release 17 -properties /data/workspaces/aloskuto-bf/Deprecation/.settings/org.eclipse.jdt.core.prefs /data/workspaces/aloskuto-bf/Deprecation/src/c/*.java
----------
1. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/ExtendsOldClass.java (at line 2)
        public class ExtendsOldClass extends OldClass {
                                             ^^^^^^^^
The type OldClass is deprecated
----------
2. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/ExtendsOldClass.java (at line 4)
        public void foo() {
                    ^^^^^
The method ExtendsOldClass.foo() overrides a deprecated method from OldClass
----------
3. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/ExtendsOldClass.java (at line 5)
        super.foo();
              ^^^
The method foo() from the type OldClass is deprecated
----------
4. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/ExtendsOldClass.java (at line 8)
        super.foo();
              ^^^
The method foo() from the type OldClass is deprecated
----------
5. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/ExtendsOldClass.java (at line 11)
        bar();
        ^^^
The method bar() from the type OldClass is deprecated
----------
----------
6. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 5)
        new OldClass().foo();
            ^^^^^^^^
The type OldClass is deprecated
----------
7. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 5)
        new OldClass().foo();
            ^^^^^^^^
The constructor OldClass() is deprecated
----------
8. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 5)
        new OldClass().foo();
                       ^^^
The method foo() from the type OldClass is deprecated
----------
9. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 8)
        new ExtendsOldClass().bar();
                              ^^^
The method bar() from the type OldClass is deprecated
----------
10. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 9)
        new OldClass().bar();
            ^^^^^^^^
The type OldClass is deprecated
----------
11. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 9)
        new OldClass().bar();
            ^^^^^^^^
The constructor OldClass() is deprecated
----------
12. WARNING in /data/workspaces/aloskuto-bf/Deprecation/src/c/UseOldClass.java (at line 9)
        new OldClass().bar();
                       ^^^
The method bar() from the type OldClass is deprecated
----------
12 problems (12 warnings)

Funny enough, if switching deprecation warnings seem to be inconsistent (command line vs preferences), disabling them seem to work via command line argument, even if enabled in preferences:

java -jar ~/Downloads/ecj-I20251026-1800.jar -d /tmp/testcompile --release 17 -properties /data/workspaces/aloskuto-bf/Deprecation/.settings/org.eclipse.jdt.core.prefs -warn:-deprecation  /data/workspaces/aloskuto-bf/Deprecation/src/d/*.java

... nothing reported ...

Observed

ecj seem to be inconsistent with itself and with javac regarding deprecation warnings handling.

Expected

1. After the fix 545483d / Do not emit restriction warning on inherited method #4293 I would not expect that deprecation warnings are reported on code that uses not explicitly deprecated methods, but obviously this is still the case.
   => to be addressed by members of a deprecated type are not implicitly deprecated #4564

For this ticket:

2. -warn:+deprecation should enable all deprecation warnings that should be reported (similar to -warn:-deprecation which disables all deprecation warnings).
3. org.eclipse.jdt.core.compiler.problem.deprecation* options seem not have same scope as -warn:+deprecation option on command line.
4. There is even worse discreptancies if specifying all classes in a single java file => Not all deprecation warnings reported for types defined in one java file #4563

[stephan-herrmann]

With #4564 I get

----------
1. WARNING in /tmp/c/ExtendsOldClass.java (at line 2)
        public class ExtendsOldClass extends OldClass {
                                             ^^^^^^^^
The type OldClass is deprecated
----------
----------
2. WARNING in /tmp/c/UseOldClass.java (at line 5)
        new OldClass().foo();
            ^^^^^^^^
The type OldClass is deprecated
----------
3. WARNING in /tmp/c/UseOldClass.java (at line 9)
        new OldClass().bar();
            ^^^^^^^^
The type OldClass is deprecated
----------
3 problems (3 warnings)

Still disabling these warnings via preferences doesn't work for me either:

$ cat prefs 
org.eclipse.jdt.core.compiler.problem.deprecation=disabled
org.eclipse.jdt.core.compiler.problem.deprecationInDeprecatedCode=disabled
org.eclipse.jdt.core.compiler.problem.deprecationWhenOverridingDeprecatedMethod=disabled
$ ecj -properties prefs  c/*.java
----------
1. WARNING in /tmp/c/ExtendsOldClass.java (at line 2)
        public class ExtendsOldClass extends OldClass {
                                             ^^^^^^^^
The type OldClass is deprecated
----------
----------
2. WARNING in /tmp/c/UseOldClass.java (at line 5)
        new OldClass().foo();
            ^^^^^^^^
The type OldClass is deprecated
----------
3. WARNING in /tmp/c/UseOldClass.java (at line 9)
        new OldClass().bar();
            ^^^^^^^^
The type OldClass is deprecated
----------
3 problems (3 warnings)

This part has been broken for more than 10 years.

Funny enough, if switching deprecation warnings seem to be inconsistent (command line vs preferences), disabling them seem to work via command line argument, even if enabled in preferences:

Right -warn:-deprecation works.

[stephan-herrmann]

@iloveeclipse do you want me to include this test in #4564 or do we consider the large number of tests that reacted to the fix as sufficient?

Where do you want the preferences thing to be addressed? Here, or new ticket?

[iloveeclipse]

do you want me to include this test in #4564

I would prefer to have more or less "complete" picture of what is expected for deprecation warnings in one test case or test class.

Where do you want the preferences thing to be addressed? Here, or new ticket?

My first concern was the inconsistency in reporting, which seem to be point of #4553, which was misunderstood by me.
So let use this ticket for inconsistency in preferences vs command line (point 2 and 3 from the list).
Point 4 has its own ticket already.

[stephan-herrmann]

do you want me to include this test in #4564

I would prefer to have more or less "complete" picture of what is expected for deprecation warnings in one test case or test class.

Too late for that 😄, we already have 4 test classes (50+ test cases) capturing the various expectations:

• DeprecatedTest -- uses the javadoc tag
• Deprecated15Test -- start with @Deprecated annotation
• Deprecated18Test -- just 2 lambda scenarios
• Deprecated9Test -- adds since and forRemoval testing, as well as warnings in module-info.java

Nevermind, it doesn't hurt to add one more test. Just not today...

[stephan-herrmann]

So let use this ticket for inconsistency in preferences vs command line (point 2 and 3 from the list).

Once more I renamed an issue to reflect our improved understanding.

@iloveeclipse I hope this reflects your intention without causing further confusion! ::

[iloveeclipse]

I hope this reflects your intention without causing further confusion!

I've updated description, we should be fine now with goals.