pxb1988/dex2jar · error · RecognitionException

RecognitionException on invalid annotation element keyword…

Error message

RecognitionException on invalid annotation element keyword (expected 'c')

What it means

Same sAnnotationElement rule as error 130: this alternative expects the keyword 'c' (a class-descriptor annotation element, parsed as sClassDesc and converted via Type.getType). When the ID token matched by xid is not 'c', the guard if(!"c".contains($xid.text)){ throw new RecognitionException(input); } throws at Jasmin.g:1042, signaling the parser to backtrack. If no other alternative matches the element either, the whole .annotation block fails to assemble.

Solutions

Write the class-type annotation element exactly as 'c = <classDesc>' e.g. 'c = Ljava/lang/Class;.class' in the .j file
Verify letter case: the guard compares against lowercase 'c', so 'C' will not match
If the element is really an enum/string/primitive, use the corresponding keyword ('e', 's', or the token B/Z/S/C/I/J) instead
Regenerate the Jasmin file from the original dex/jar with a d2j-compatible dumper rather than editing by hand

Example fix

// before
classvalue = Ljava/lang/Class;.TYPE

// after
c = Ljava/lang/Class;.TYPE

Defensive patterns

Strategy: validation

Validate before calling

// validate class-descriptor annotation elements use keyword 'c'
for (String line : jasminLines) {
    if (line.matches("\\s*[A-Za-z_][\\w$]*\\s*=\\s*L[^ ]*\\.[^ ]+\\s*$") && !line.trim().startsWith("e ") && !line.matches("\\s*c\\s*=.*")) {
        throw new IllegalArgumentException("class annotation element must start with 'c = ': " + line.trim());
    }
}

Try / catch

try {
    Jasmin asm = new Jasmin(new FileReader(jasminFile));
    asm.parse();
} catch (RecognitionException | RuntimeException e) {
    LOG.error("annotation element in {} rejected (expect keyword 'c' before class desc)", jasminFile, e);
    throw new JasminSyntaxException("Invalid class annotation element", e);
}

Prevention

Always prefix class-type annotation values with 'c = ' in .j files
Do not use 'C' or full words like 'class' — the grammar compares against lowercase "c"
Diff generated Jasmin against a known-good d2j dump when porting from Soot syntax
Parse files in CI with the assembler to catch syntax drift early

When it happens

Trigger: An annotation element in a Jasmin file that supplies a class descriptor after 'name = ' but whose keyword ID is not exactly 'c', e.g. 'value = Ljava/lang/Class;.TYPE' written as 'classvalue = Ljava/lang/Class;.TYPE' or with the keyword omitted, inside '.annotation' ... '.end annotation' passed to the d2j-jasmin assembler.

Common situations: Migrating Jasmin output from Soot or older assemblers whose annotation-element syntax used full words ('class', 'enum', 'string') instead of the single letters this grammar hard-codes; typos like 'C' vs 'c' (grammar is case-sensitive); copy-pasted annotation lines edited by hand.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

AI-assisted analysis of pxb1988/dex2jar@b5bda4fb49 (2026-09-08). Data as JSON: /api/errors/e7c1ecc15990b1d8. Report an issue: GitHub.

Appendix: source

Thrown at d2j-jasmin/src/main/antlr3/com/googlecode/d2j/jasmin/Jasmin.g:1042

              	    | '.float_kind' a=STRING b=INT        {$nn=unEscapeString($a.text); $v=parseFloat($b.text);}
              	    | '.doub_kind' a=STRING b=(INT|LONG)  {$nn=unEscapeString($a.text); $v=parseDouble($b.text);}
              	    | '.str_kind' a=STRING b=STRING       {$nn=unEscapeString($a.text); $v=unEscapeString($b.text);}
              	    | '.enum_kind' a=STRING b=STRING      {$nn=unEscapeString($a.text); String on[]=parseOwnerAndName($b.text);$v=new String[]{on[0],on[1]};}
              	    | '.cls_kind' a=STRING b=STRING       {$nn=unEscapeString($a.text); $v=Type.getType(unEscapeString($b.text));}
              	    | '.arr_kind' a=STRING {List<Object> array=new ArrayList<>();} (t=sAnnotationElementSoot{array.add($t.v);})* '.end'  '.arr_elem'   {$nn=unEscapeString($a.text); $v=array;}
              	    | '.ann_kind' a=STRING q=sSubannotationSoot '.end' '.annot_elem'     {$nn=unEscapeString($a.text); $v=$q.v;})
	;

sSubannotationSoot  returns[AnnotationNode v]
	:	'.annotation' a=STRING   { $v=new AnnotationNode(unEscapeString($a.text)); }
	     (t=sAnnotationElementSoot {$v.visit($t.nn,$t.v);} )*
	    '.end' '.annotation'
	;
sAnnotationElement @init{List<Object> array = new ArrayList<Object>(); AnnotationNode _t= currentAnnotationVisitor;}
    :   a=sId (
             xid=ID { if(!"e".contains($xid.text)){ throw new RecognitionException(input);} }  c=OBJECT_TYPE '=' b=sWord {  _t.visit($a.text,new String[]{$c.text,$b.text}); }
           | AT b2=OBJECT_TYPE '=' {  currentAnnotationVisitor=new AnnotationNode($b2.text);} sSubannotation  { _t.visit($a.text,currentAnnotationVisitor); }
           | xid=ID { if(!"c".contains($xid.text)){ throw new RecognitionException(input);} } '=' b1=sClassDesc { currentAnnotationVisitor.visit($a.text,Type.getType($b1.text)); }
           | xid=ID { if(!"s".contains($xid.text)){ throw new RecognitionException(input);} } '=' b3=STRING      { currentAnnotationVisitor.visit($a.text,unEscapeString($b3.text)); }
           | UP_B  '=' b4=INT  { currentAnnotationVisitor.visit($a.text,(byte)parseInt($b4.text)); }
           | UP_Z  '=' b5=INT  { currentAnnotationVisitor.visit($a.text,0!=parseInt($b5.text)); }
           | UP_S  '=' b6=INT   { currentAnnotationVisitor.visit($a.text,(short)parseInt($b6.text)); }
           | UP_C  '=' b7=INT   { currentAnnotationVisitor.visit($a.text,(char)parseInt($b7.text)); }
           | UP_I  '=' b8=INT   { currentAnnotationVisitor.visit($a.text,parseInt($b8.text)); }
           | UP_J  '=' b9=(INT|LONG)  { currentAnnotationVisitor.visit($a.text,parseLong($b9.text)); }
           | UP_F  '=' b10=(INT|FLOAT|DOUBLE)  { currentAnnotationVisitor.visit($a.text,parseFloat($b10.text)); }
           | UP_D  '=' b11=(INT|FLOAT|DOUBLE)   { currentAnnotationVisitor.visit($a.text,parseDouble($b11.text)); }
           | ARRAY_B '='  (b12=INT {array.add((byte)parseInt($b12.text));} )+    { currentAnnotationVisitor.visit($a.text,array); }
           | ARRAY_Z '='  (b13=INT {array.add(0!=parseInt($b13.text));} )+       { currentAnnotationVisitor.visit($a.text,array); }
           | ARRAY_S '='  (b14=INT {array.add((short)parseInt($b14.text));} )+   { currentAnnotationVisitor.visit($a.text,array); }
           | ARRAY_C '='  (b15=INT {array.add((char)parseInt($b15.text));} )+    { currentAnnotationVisitor.visit($a.text,array); }
           | ARRAY_I '='  (b16=INT {array.add(parseInt($b16.text));} )+          { currentAnnotationVisitor.visit($a.text,array); }
           | ARRAY_J '='  (b17=(INT|LONG) {array.add(parseLong($b17.text));} )+  { currentAnnotationVisitor.visit($a.text,array); }
           | ARRAY_F '='  (b18=(INT|FLOAT|DOUBLE) {array.add(parseFloat($b18.text));} )+  { currentAnnotationVisitor.visit($a.text,array); }
           | ARRAY_D '='  (b19=(INT|DOUBLE) {array.add(parseDouble($b19.text));} )+       { currentAnnotationVisitor.visit($a.text,array); }
           | ARRAY_LOW_E c=OBJECT_TYPE '='  ((b1=sWord{  array.add(new String[]{$c.text,unEscape($b1.text)}); }|b2=STRING{  array.add(new String[]{$c.text,unEscapeString($b2.text)}); }|b3=DSTRING{  array.add(new String[]{$c.text,unEscapeString($b3.text)}); })  )+  { currentAnnotationVisitor.visit($a.text,array); }

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