This code has the hard-coded goal of supporting the executable's own
debug information and makes design choices along that goal, such as
memory-mapping the inputs, using dl_iterate_phdr, and doing conditional
compilation on the host target.
A more general-purpose implementation of debug information may be able
to share code with this, but there are some fundamental
incompatibilities. For example, the "SelfInfo" implementation wants to
avoid bloating the binary with PDB on POSIX systems, and likewise DWARF
on Windows systems, while a general-purpose implementation needs to
support both PDB and DWARF from the same binary. It might, for example,
inspect the debug information from a cross-compiled binary.
`SourceLocation` now lives at `std.debug.SourceLocation` and is
documented.
Deprecate `std.debug.runtime_safety` because it returns the optimization
mode of the standard library, when the caller probably wants to use the
optimization mode of their own module.
`std.pdb.Pdb` is moved to `std.debug.Pdb`, mirroring the recent
extraction of `std.debug.Dwarf` from `std.dwarf`.
I have no idea why we have both Module (with a Windows-specific
definition) and WindowsModule. I left some passive aggressive doc
comments to express my frustration.
std.debug.Dwarf is the parsing/decoding logic. std.dwarf remains the
unopinionated types and bits alone.
If you look at this diff you can see a lot less redundancy in
namespaces.
I pointed a fuzzer at the tokenizer and it crashed immediately. Upon
inspection, I was dissatisfied with the implementation. This commit
removes several mechanisms:
* Removes the "invalid byte" compile error note.
* Dramatically simplifies tokenizer recovery by making recovery always
occur at newlines, and never otherwise.
* Removes UTF-8 validation.
* Moves some character validation logic to `std.zig.parseCharLiteral`.
Removing UTF-8 validation is a regression of #663, however, the existing
implementation was already buggy. When adding this functionality back,
it must be fuzz-tested while checking the property that it matches an
independent Unicode validation implementation on the same file. While
we're at it, fuzzing should check the other properties of that proposal,
such as no ASCII control characters existing inside the source code.
Other changes included in this commit:
* Deprecate `std.unicode.utf8Decode` and its WTF-8 counterpart. This
function has an awkward API that is too easy to misuse.
* Make `utf8Decode2` and friends use arrays as parameters, eliminating a
runtime assertion in favor of using the type system.
After this commit, the crash found by fuzzing, which was
"\x07\xd5\x80\xc3=o\xda|a\xfc{\x9a\xec\x91\xdf\x0f\\\x1a^\xbe;\x8c\xbf\xee\xea"
no longer causes a crash. However, I did not feel the need to add this
test case because the simplified logic eradicates most crashes of this
nature.
