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Merged
jarthana merged 2 commits into from
Jan 27, 2026
Merged

javac and ECJ handle Unicode ignorable character in method names differently during reflection #4770

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c65b485
javac and ECJ handle Unicode ignorable character in method names
jarthana Jan 20, 2026
d1203cf
Adding more test scenario
jarthana Jan 20, 2026
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44 changes: 34 additions & 10 deletions ...eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/parser/Scanner.java
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Original file line number Diff line number Diff line change
Expand Up @@ -460,19 +460,43 @@ public void checkTaskTag(int commentStart, int commentEnd) throws InvalidInputEx
public char[] getCurrentIdentifierSource() {
//return the token REAL source (aka unicodes are precomputed)
if (this.withoutUnicodePtr != 0) {
//0 is used as a fast test flag so the real first char is in position 1
char[] result = new char[this.withoutUnicodePtr];
System.arraycopy(
this.withoutUnicodeBuffer,
1,
result,
0,
this.withoutUnicodePtr);
return result;
// //0 is used as a fast test flag so the real first char is in position 1
return getIdentifierIgnoringIgnorable(this.withoutUnicodeBuffer, 1, this.withoutUnicodePtr);
}
int length = this.currentPosition - this.startPosition;
if (length == this.eofPosition) return this.source;
return this.deduplication.sharedCopyOfRange(this.source, this.startPosition, this.currentPosition);
return getIdentifierIgnoringIgnorable(this.source, this.startPosition, this.currentPosition - this.startPosition);
}
public char[] getIdentifierIgnoringIgnorable(char[] originalSource, int start, int length) {

if (length <= 0) return CharOperation.NO_CHAR;

int ignorableCount = 0;
int end = start + length;
for (int i = start; i < end; i++) {
if (Character.isIdentifierIgnorable(originalSource[i])) {
ignorableCount++;
}
}

// If nothing to remove, return a shared copy of the original
if (ignorableCount == 0) {
return this.deduplication.sharedCopyOfRange(originalSource, start, end);
}

int newLength = length - ignorableCount;
if (newLength <= 0) return CharOperation.NO_CHAR;

char[] compacted = new char[newLength];
int newEnd = 0;
for (int i = start; i < end; i++) {
char c = originalSource[i];
if (!Character.isIdentifierIgnorable(c)) {
compacted[newEnd++] = c;
}
}
// Return a deduplicated/shared copy of the compacted result
return this.deduplication.sharedCopyOfRange(compacted, 0, newEnd);
}

public int getCurrentTokenEndPosition(){
Expand Down
228 changes: 225 additions & 3 deletions ...t.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/ScannerTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -959,7 +959,7 @@ public void test045() {
* }
* }
*/
this.runConformTest(
this.runNegativeTest(
new String[] {
"_X.java",
"import java.lang.reflect.Field;\n" +
Expand Down Expand Up @@ -993,7 +993,122 @@ public void test045() {
" }\n" +
"}"
},
"SUCCESS");
"----------\n" +
"1. ERROR in _X.java (at line 5)\n" +
" String i\\u0001;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"2. ERROR in _X.java (at line 6)\n" +
" String i\\u0002;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"3. ERROR in _X.java (at line 7)\n" +
" String i\\u0003;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"4. ERROR in _X.java (at line 8)\n" +
" String i\\u0004;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"5. ERROR in _X.java (at line 9)\n" +
" String i\\u0005;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"6. ERROR in _X.java (at line 10)\n" +
" String i\\u0006;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"7. ERROR in _X.java (at line 11)\n" +
" String i\\u0007;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"8. ERROR in _X.java (at line 12)\n" +
" String i\\u0008;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"9. ERROR in _X.java (at line 13)\n" +
" String i\\u000e;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"10. ERROR in _X.java (at line 14)\n" +
" String i\\u000f;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"11. ERROR in _X.java (at line 15)\n" +
" String i\\u0010;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"12. ERROR in _X.java (at line 16)\n" +
" String i\\u0011;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"13. ERROR in _X.java (at line 17)\n" +
" String i\\u0012;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"14. ERROR in _X.java (at line 18)\n" +
" String i\\u0013;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"15. ERROR in _X.java (at line 19)\n" +
" String i\\u0014;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"16. ERROR in _X.java (at line 20)\n" +
" String i\\u0015;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"17. ERROR in _X.java (at line 21)\n" +
" String i\\u0016;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"18. ERROR in _X.java (at line 22)\n" +
" String i\\u0017;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"19. ERROR in _X.java (at line 23)\n" +
" String i\\u0018;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"20. ERROR in _X.java (at line 24)\n" +
" String i\\u0019;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"21. ERROR in _X.java (at line 25)\n" +
" String i\\u001a;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"22. ERROR in _X.java (at line 26)\n" +
" String i\\u001b;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n" +
"23. ERROR in _X.java (at line 27)\n" +
" String i\\u007f;\n" +
" ^^^^^^^\n" +
"Duplicate local variable i\n" +
"----------\n");
}
// https://bugs.eclipse.org/bugs/show_bug.cgi?id=264950
public void test046() {
Expand Down Expand Up @@ -1881,5 +1996,112 @@ public void testIssue4674() {
assertTrue("Should not have InvalidInputException", false);
}
}

public void testIssue4001_1() {
this.runConformTest(
new String[] {
"X.java",
"""
public class X {
String fieldWithUnicode\u0001Char = "";
public static void main(String[] args) {
try {
Class<?> clazz = Class.forName("X");
java.lang.reflect.Method method = clazz.getDeclaredMethod("methodWithUnicode\u0001Char");
System.out.println("Method found: " + method.getName());
} catch (ClassNotFoundException e) {
System.out.println("Class not found.");
} catch (NoSuchMethodException e) {
System.out.println("Method not found.");
}
try {
Class<?> clazz = Class.forName("X");
java.lang.reflect.Field field = clazz.getDeclaredField("fieldWithUnicode\u0001Char");
System.out.println("Field found: " + field.getName());
} catch (ClassNotFoundException e) {
System.out.println("Class not found.");
} catch (NoSuchFieldException e) {
System.out.println("Field not found.");
}
}
public static void methodWithUnicode\u0001Char() {
}
}""",
},
"Method not found.\n" +
"Field not found.");
}
public void testIssue4001_2() {
this.runConformTest(
new String[] {
"X.java",
"""
public class X {
String fieldWithUnicode\u0001Char = "";
public static void main(String[] args) {
try {
Class<?> clazz = Class.forName("X");
java.lang.reflect.Method method = clazz.getDeclaredMethod("methodWithUnicodeChar");
System.out.println("Method found: " + method.getName());
method.invoke(null);
} catch (ClassNotFoundException e) {
System.out.println("Class not found.");
} catch (NoSuchMethodException e) {
System.out.println("Method not found.");
} catch (Exception e) {
e.printStackTrace();
}
try {
Class<?> clazz = Class.forName("X");
java.lang.reflect.Field field = clazz.getDeclaredField("fieldWithUnicodeChar");
System.out.println("Field found: " + field.getName());
} catch (ClassNotFoundException e) {
System.out.println("Class not found.");
} catch (NoSuchFieldException e) {
System.out.println("Field not found.");
}
}
public static void methodWithUnicode\u0001Char() {
String fieldWithUnicode\u0001Char = "Hello";
System.out.println(fieldWithUnicodeChar);
}
}""",
},
"Method found: methodWithUnicodeChar\n" +
"Hello\n" +
"Field found: fieldWithUnicodeChar");
}
public void testIssue4001_3() {
this.runConformTest(
new String[] {
"X.java",
"""
public class X {
String fieldWithUnicode\u0001Char = "";
public static void main(String[] args) {
try {
Class<?> clazz = Class.forName("X");
java.lang.reflect.Method method = clazz.getDeclaredMethod("methodWithUnicodeChar");
System.out.println("Method found: " + method.getName());
} catch (ClassNotFoundException e) {
System.out.println("Class not found.");
} catch (NoSuchMethodException e) {
System.out.println("Method not found.");
}
try {
Class<?> clazz = Class.forName("X");
java.lang.reflect.Field method = clazz.getDeclaredField("fieldWithUnicodeChar");
System.out.println("Field found: " + method.getName());
} catch (ClassNotFoundException e) {
System.out.println("Class not found.");
} catch (NoSuchFieldException e) {
System.out.println("Field not found.");
}
}
public static void methodWithUnicode\u0001Char() {
}
}""",
},
"Method found: methodWithUnicodeChar\n" +
"Field found: fieldWithUnicodeChar");
}
}
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