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@foone@digipres.clubhas anyone written a C struct to python struct-module compiler yet?
like I'd love to do "structcompile.py windows.h BITMAPV5HEADER" and have it output "<LLLHHLLLLLLLLLLLLLLLLLLLLLLLLLL"
@foone Not that I’ve seen but that would be amazing. I think the hard part is C is a pain to parse.
@jscarsbrook @foone No, Not really. This ain't C++.
@jscarsbrook @foone sorry for sounding a bit grandiose there, but OK, let's do this in N toots; what I meant with "easy" is that the moment we read the header, all types are actually there, or the header is malformed. This is different than C++!
1. /tmp/test.h:
struct foo {
int a;
float b;
};
struct bar {
char foo[4];
struct foo baz;
};
2. our python script:
import clang.cindex
index = clang.cindex.Index.create()
#translation unit:
tu = index.parse("/tmp/test.h")
#… continued:
Cool approach.
This kinda nerd-sniped me. I ended up using pycparser to implement it.
https://gist.github.com/Vbitz/ed7488166d4df28f666cd836c5976ee6
I tried it on my native macos headers but it barfed on the clang extensions.
This should do what @foone wanted but the code probably needs some fixes.
# … continued from prev toot
children = { child.displayname: child for child in tu.cursor.get_children() }
my_struct = children["bar"]
fields = list(my_struct.get_fields())
for field in fields:
print(f"field {field.displayname} offset {my_struct.get_field_offsetof()} size {field.get_size()}")
Of course, at this point, you might (or might not!) want to recursively check for fields, whether something is a bitfield and so on.
@foone Would Kaitai help? Structures are still represented in Kaitai's structure format, but you do get Python accessibility: https://doc.kaitai.io/lang_python.html
@foone pretty simple, just:
def main(*args, **kwargs):
print("<LLLHHLLLLLLLLLLLLLLLLLLLLLLLLLL")
Need more test cases 
@foone it depends what you are doing but I think cffi might be what you want?
@glyph @foone +1, you can definitely get close this way, although I don't know if there's any affordance for translation to the `struct` module's format language, the `native_table` that maps those doesn't seem to be exposed on the Python side (not that you couldn't just write the equivalent in Python, though)