[LLVMdev] Questions about llvm/Object/COFF.h

[Marshall Clow]

So, I'm trying to use this file to look inside COFF files.
Got the header. OK.

Now I want to look at the sections.
Look, there's a section iterator. I can use that!

So, I write:
	for (llvm::object::section_iterator iter = Obj.begin_sections (); iter != Obj.end_sections(); ++iter ) 

and it doesn't compile. There's no ++ for section iterators.
Apparently, you're supposed to write.
	for (llvm::object::section_iterator iter = Obj.begin_sections (); iter != Obj.end_sections(); iter.increment(ec)) 
Srsly?
[ And - how do I go from a section_iterator to a coff_section ? ]

While I'm puzzling over that, I look some more, and I see:
	error_code getSection(int32_t index, const coff_section *&Res) const;

Cool. (A bit weird; why a signed index?, but whatever)
So I write:
	const llvm::object::coff_section *sect; 
	for (std::size_t i = 0; i < NumSections; ++i) 
		Obj.getSection(i, sect); 

And my program dies with a segmentation fault.
Turns out that sect == NULL.
More looking, I see that the sections are numbered 1 … N, not 0 ... N-1

Now I'm really really confused.  Why?

BTW - patch attached to add pre-increment to llvm::content_iterator (which is the template base for section_iterator, etc)

-- Marshall


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-- Marshall

Marshall Clow     Idio Software   <mailto:mclow.lists at gmail.com>

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