Missing statement after label

[ignatirabo]

Hello, while decompiling a binary, I found a label that has no statement aftewards. Instead, it is followed by a closing curly bracket }.

The structure is something like:

for ... {
  if ... {
  }
  ...
  LAB:
}

For the task I am performing, it is important that the generated pseudo-C is correct C syntax (I don't really care about the semantics at this stage).

I was trying to fix this through a Ghidra script but I have not been able to find a way.
Instead, I modified ghidra/Ghidra/Features/Decompiler/src/decompile/cpp/printc.cc to add a semicolon after the colon.

Is it expected from Ghidra to generate 'incorrect' C code? Is this a bug?
Lastly, should I fork Ghidra and use this modified version, or is it possible to patch Ghidra or do this at the Abstract Analyzer level?

Thanks in advance.

[DualTachyon]

If there is an associated "goto LAB", it is likely to represent a "continue" statement. Ghidra isn't always able to recognise it.

[mumbel]

you haven't explained what part about this is invalid/incorrect C?

[dgutson]

you haven't explained what part about this is invalid/incorrect C?

the invalid C is that the label doesn't have an associated statement, but just closes the block.

According to the C standard (https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3220.pdf section 6.8.2)

Notice that is is always "label statement" so there has to be at least one statement.

Indeed, gcc in strict mode rejects the snippet that @ignatirabo posted, except when he added the semicolon.