Unexported names are a bit tricky, since they are not listed in the
export data file. Perhaps unsurprisingly, it's only meant to expose
exported objects.
One option would be to go back to adding an extra header to the export
data file, containing the unexported methods in a map[string]T or
[]string. However, we have an easier route: just parse the Go files and
look up the names directly.
This does mean that we parse the Go files every time "reverse" runs,
even if the build cache is warm, but that should not be an issue.
Parsing Go files without any typechecking is very cheap compared to
everything else we do. Plus, we save having to load go/types information
from the build cache, or having to load extra headers from export files.
It should be noted that the obfuscation process does need type
information, mainly to be careful about which names can be obfuscated
and how they should be obfuscated. Neither is a worry here; all names
belong to a single package, and it doesn't matter if some aren't
actually obfuscated, since the string replacements would simply never
trigger in practice.
The test includes an unexported func, to test the new feature. We also
start reversing the obfuscation of import paths. Now, the test's reverse
output is as follows:
goroutine 1 [running]:
runtime/debug.Stack(0x??, 0x??, 0x??)
runtime/debug/stack.go:24 +0x??
test/main/lib.ExportedLibFunc(0x??, 0x??, 0x??, 0x??)
p.go:6 +0x??
main.unexportedMainFunc(...)
C.go:2
main.main()
z.go:3 +0x??
The only major missing feature is positions and filenames. A follow-up
PR will take care of those.
Updates #5.
For now, this only implements reversing of exported names which are
hashed with action IDs. Many other kinds of obfuscation, like positions
and private names, are not yet implemented.
Note that we don't document this new command yet on purpose, since it's
not finished.
Some other minor cleanups were done for future changes, such as making
transformLineInfo into a method that also receives the original
filename, and making header names more self-describing.
Updates #5.
Daniel Martí