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Merged
dlunch merged 1 commit into from
Jun 27, 2026
Merged

Implement the wide opcode #167

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90 changes: 64 additions & 26 deletions classfile/src/opcode.rs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -15,11 +15,11 @@ pub enum Opcode {
Aaload,
Aastore,
AconstNull,
Aload(u8),
Aload(u16),
Anewarray(ConstantPoolReference),
Areturn,
Arraylength,
Astore(u8),
Astore(u16),
Athrow,
Baload,
Bastore,
Expand All@@ -37,12 +37,12 @@ pub enum Opcode {
Dcmpl,
Dconst(u8),
Ddiv,
Dload(u8),
Dload(u16),
Dmul,
Dneg,
Drem,
Dreturn,
Dstore(u8),
Dstore(u16),
Dsub,
Dup,
DupX1,
Expand All@@ -60,12 +60,12 @@ pub enum Opcode {
Fcmpl,
Fconst(u8),
Fdiv,
Fload(u8),
Fload(u16),
Fmul,
Fneg,
Frem,
Freturn,
Fstore(u8),
Fstore(u16),
Fsub,
Getfield(ConstantPoolReference),
Getstatic(ConstantPoolReference),
Expand DownExpand Up@@ -99,8 +99,8 @@ pub enum Opcode {
Ifle(i16),
Ifnonnull(i16),
Ifnull(i16),
Iinc(u8, i8),
Iload(u8),
Iinc(u16, i16),
Iload(u16),
Imul,
Ineg,
Instanceof(ConstantPoolReference),
Expand All@@ -114,7 +114,7 @@ pub enum Opcode {
Ireturn,
Ishl,
Ishr,
Istore(u8),
Istore(u16),
Isub,
Iushr,
Ixor,
Expand All@@ -133,7 +133,7 @@ pub enum Opcode {
LdcW(ConstantPoolReference),
Ldc2W(ConstantPoolReference),
Ldiv,
Lload(u8),
Lload(u16),
Lmul,
Lneg,
Lookupswitch(i32, Vec<(i32, i32)>),
Expand All@@ -142,7 +142,7 @@ pub enum Opcode {
Lreturn,
Lshl,
Lshr,
Lstore(u8),
Lstore(u16),
Lsub,
Lushr,
Lxor,
Expand All@@ -156,14 +156,13 @@ pub enum Opcode {
Pop2,
Putfield(ConstantPoolReference),
Putstatic(ConstantPoolReference),
Ret(u8),
Ret(u16),
Return,
Saload,
Sastore,
Sipush(i16),
Swap,
Tableswitch(i32, Vec<(i32, i32)>),
Wide,
}

impl Opcode {
Expand All@@ -176,7 +175,7 @@ impl Opcode {
0x32 => success(Opcode::Aaload).parse(data),
0x53 => success(Opcode::Aastore).parse(data),
0x01 => success(Opcode::AconstNull).parse(data),
0x19 => map(u8, Opcode::Aload).parse(data),
0x19 => map(u8, |x| Opcode::Aload(x as u16)).parse(data),
0x2a => success(Opcode::Aload(0)).parse(data),
0x2b => success(Opcode::Aload(1)).parse(data),
0x2c => success(Opcode::Aload(2)).parse(data),
Expand All@@ -187,7 +186,7 @@ impl Opcode {
.parse(data),
0xb0 => success(Opcode::Areturn).parse(data),
0xbe => success(Opcode::Arraylength).parse(data),
0x3a => map(u8, Opcode::Astore).parse(data),
0x3a => map(u8, |x| Opcode::Astore(x as u16)).parse(data),
0x4b => success(Opcode::Astore(0)).parse(data),
0x4c => success(Opcode::Astore(1)).parse(data),
0x4d => success(Opcode::Astore(2)).parse(data),
Expand All@@ -213,7 +212,7 @@ impl Opcode {
0x0e => success(Opcode::Dconst(0)).parse(data),
0x0f => success(Opcode::Dconst(1)).parse(data),
0x6f => success(Opcode::Ddiv).parse(data),
0x18 => map(u8, Opcode::Dload).parse(data),
0x18 => map(u8, |x| Opcode::Dload(x as u16)).parse(data),
0x26 => success(Opcode::Dload(0)).parse(data),
0x27 => success(Opcode::Dload(1)).parse(data),
0x28 => success(Opcode::Dload(2)).parse(data),
Expand All@@ -222,7 +221,7 @@ impl Opcode {
0x77 => success(Opcode::Dneg).parse(data),
0x73 => success(Opcode::Drem).parse(data),
0xaf => success(Opcode::Dreturn).parse(data),
0x39 => map(u8, Opcode::Dstore).parse(data),
0x39 => map(u8, |x| Opcode::Dstore(x as u16)).parse(data),
0x47 => success(Opcode::Dstore(0)).parse(data),
0x48 => success(Opcode::Dstore(1)).parse(data),
0x49 => success(Opcode::Dstore(2)).parse(data),
Expand All@@ -246,7 +245,7 @@ impl Opcode {
0x0c => success(Opcode::Fconst(1)).parse(data),
0x0d => success(Opcode::Fconst(2)).parse(data),
0x6e => success(Opcode::Fdiv).parse(data),
0x17 => map(u8, Opcode::Fload).parse(data),
0x17 => map(u8, |x| Opcode::Fload(x as u16)).parse(data),
0x22 => success(Opcode::Fload(0)).parse(data),
0x23 => success(Opcode::Fload(1)).parse(data),
0x24 => success(Opcode::Fload(2)).parse(data),
Expand All@@ -255,7 +254,7 @@ impl Opcode {
0x76 => success(Opcode::Fneg).parse(data),
0x72 => success(Opcode::Frem).parse(data),
0xae => success(Opcode::Freturn).parse(data),
0x38 => map(u8, Opcode::Fstore).parse(data),
0x38 => map(u8, |x| Opcode::Fstore(x as u16)).parse(data),
0x43 => success(Opcode::Fstore(0)).parse(data),
0x44 => success(Opcode::Fstore(1)).parse(data),
0x45 => success(Opcode::Fstore(2)).parse(data),
Expand DownExpand Up@@ -305,8 +304,8 @@ impl Opcode {
0x9e => map(be_i16, Opcode::Ifle).parse(data),
0xc7 => map(be_i16, Opcode::Ifnonnull).parse(data),
0xc6 => map(be_i16, Opcode::Ifnull).parse(data),
0x84 => map((u8, i8), |(index, constant)| Opcode::Iinc(index, constant)).parse(data),
0x15 => map(u8, Opcode::Iload).parse(data),
0x84 => map((u8, i8), |(index, constant)| Opcode::Iinc(index as u16, constant as i16)).parse(data),
0x15 => map(u8, |x| Opcode::Iload(x as u16)).parse(data),
0x1a => success(Opcode::Iload(0)).parse(data),
0x1b => success(Opcode::Iload(1)).parse(data),
0x1c => success(Opcode::Iload(2)).parse(data),
Expand DownExpand Up@@ -342,7 +341,7 @@ impl Opcode {
0xac => success(Opcode::Ireturn).parse(data),
0x78 => success(Opcode::Ishl).parse(data),
0x7a => success(Opcode::Ishr).parse(data),
0x36 => map(u8, Opcode::Istore).parse(data),
0x36 => map(u8, |x| Opcode::Istore(x as u16)).parse(data),
0x3b => success(Opcode::Istore(0)).parse(data),
0x3c => success(Opcode::Istore(1)).parse(data),
0x3d => success(Opcode::Istore(2)).parse(data),
Expand All@@ -369,7 +368,7 @@ impl Opcode {
})
.parse(data),
0x6d => success(Opcode::Ldiv).parse(data),
0x16 => map(u8, Opcode::Lload).parse(data),
0x16 => map(u8, |x| Opcode::Lload(x as u16)).parse(data),
0x1e => success(Opcode::Lload(0)).parse(data),
0x1f => success(Opcode::Lload(1)).parse(data),
0x20 => success(Opcode::Lload(2)).parse(data),
Expand All@@ -385,7 +384,7 @@ impl Opcode {
0xad => success(Opcode::Lreturn).parse(data),
0x79 => success(Opcode::Lshl).parse(data),
0x7b => success(Opcode::Lshr).parse(data),
0x37 => map(u8, Opcode::Lstore).parse(data),
0x37 => map(u8, |x| Opcode::Lstore(x as u16)).parse(data),
0x3f => success(Opcode::Lstore(0)).parse(data),
0x40 => success(Opcode::Lstore(1)).parse(data),
0x41 => success(Opcode::Lstore(2)).parse(data),
Expand All@@ -412,7 +411,7 @@ impl Opcode {
Opcode::Putstatic(ConstantPoolReference::from_constant_pool(constant_pool, x as _))
})
.parse(data),
0xa9 => map(u8, Opcode::Ret).parse(data),
0xa9 => map(u8, |x| Opcode::Ret(x as u16)).parse(data),
0xb1 => success(Opcode::Return).parse(data),
0x35 => success(Opcode::Saload).parse(data),
0x56 => success(Opcode::Sastore).parse(data),
Expand All@@ -427,10 +426,31 @@ impl Opcode {
}
})
.parse(data),
0xc4 => success(Opcode::Wide).parse(data),
0xc4 => Self::parse_wide(data),
_ => panic!("Unknown opcode: {:02x}", opcode),
}
}

// wide (0xc4): widens the local variable index of the following instruction to 16 bits
fn parse_wide(data: &[u8]) -> IResult<&[u8], Self> {
let (data, opcode) = u8(data)?;

match opcode {
0x84 => map((be_u16, be_i16), |(index, constant)| Opcode::Iinc(index, constant)).parse(data),
0x15 => map(be_u16, Opcode::Iload).parse(data),
0x16 => map(be_u16, Opcode::Lload).parse(data),
0x17 => map(be_u16, Opcode::Fload).parse(data),
0x18 => map(be_u16, Opcode::Dload).parse(data),
0x19 => map(be_u16, Opcode::Aload).parse(data),
0x36 => map(be_u16, Opcode::Istore).parse(data),
0x37 => map(be_u16, Opcode::Lstore).parse(data),
0x38 => map(be_u16, Opcode::Fstore).parse(data),
0x39 => map(be_u16, Opcode::Dstore).parse(data),
0x3a => map(be_u16, Opcode::Astore).parse(data),
0xa9 => map(be_u16, Opcode::Ret).parse(data),
_ => panic!("Invalid wide opcode: {:02x}", opcode),
}
}
}

#[cfg(test)]
Expand DownExpand Up@@ -487,4 +507,22 @@ mod test {
assert!(remaining.is_empty());
assert!(matches!(opcode, Opcode::Invokedynamic(_)));
}

#[test]
fn test_wide_iload_reads_u16_index() {
// wide iload 0x0100, then nop — the trailing nop must not be misparsed
let (remaining, opcode) = Opcode::parse(&[0xc4, 0x15, 0x01, 0x00, 0x00], 0, &constant_pool()).unwrap();

assert!(matches!(opcode, Opcode::Iload(0x0100)));
assert_eq!(remaining, &[0x00]);
}

#[test]
fn test_wide_iinc_reads_u16_index_and_i16_const() {
// wide iinc 0x012c, 1000
let (remaining, opcode) = Opcode::parse(&[0xc4, 0x84, 0x01, 0x2c, 0x03, 0xe8], 0, &constant_pool()).unwrap();

assert!(matches!(opcode, Opcode::Iinc(0x012c, 1000)));
assert!(remaining.is_empty());
}
}
3 changes: 0 additions & 3 deletions jvm_rust/src/interpreter.rs
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Original file line numberDiff line numberDiff line change
Expand Up@@ -933,9 +933,6 @@ impl Interpreter {
stack_frame.operand_stack.push(value1);
stack_frame.operand_stack.push(value2);
}
Opcode::Wide => {
todo!()
}
}

Ok(ExecuteNext::Continue)
Expand Down
Binary file addedtest_data/WideLocals.class
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1 change: 1 addition & 0 deletions test_data/WideLocals.txt
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Original file line numberDiff line numberDiff line change
@@ -0,0 +1 @@
2097
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