this is a bad commit that contains work in progress
changes to make fuzzing on macos work.
more specifically it contains macho-specific code
for loading debug information in the webserver.
it's messy because I'm still trying to understand
how this stuff works. with these changes the web
server loads but the wasm code panics.
it's unclear if the wasm panic is due to my dwarf
loading code being wrong or if we're encountering
some other latent issue.
heap.zig: define new default page sizes
heap.zig: add min/max_page_size and their options
lib/std/c: add miscellaneous declarations
heap.zig: add pageSize() and its options
switch to new page sizes, especially in GPA/stdlib
mem.zig: remove page_size
The implementation assumed that compilation units did not overlap, which
is not the case. The new implementation uses .debug_ranges to iterate
over the requested PCs.
This partially resolves#20990. The dump-cov tool is fixed but the same
fix needs to be applied to `std.Build.Fuzz.WebServer` (sorting the PC
list before passing it to be resolved by debug info).
I am observing LLVM emit multiple 8-bit counters for the same PC
addresses when enabling `-fsanitize-coverage=inline-8bit-counters`. This
seems like a bug in LLVM. I can't fathom why that would be desireable.
* libfuzzer: close file after mmap
* fuzzer/main.js: connect with EventSource and debug dump the messages.
currently this prints how many fuzzer runs have been attempted to
console.log.
* extract some `std.debug.Info` logic into `std.debug.Coverage`.
Prepares for consolidation across multiple different executables which
share source files, and makes it possible to send all the
PC/SourceLocation mapping data with 4 memcpy'd arrays.
* std.Build.Fuzz:
- spawn a thread to watch the message queue and signal event
subscribers.
- track coverage map data
- respond to /events URL with EventSource messages on a timer
* std.debug.Dwarf: add `sortCompileUnits` along with a field to track
the state for the purpose of assertions and correct API usage.
This makes batch lookups faster.
- in the future, findCompileUnit should be enhanced to rely on sorted
compile units as well.
* implement `std.debug.Dwarf.resolveSourceLocations` as well as
`std.debug.Info.resolveSourceLocations`. It's still pretty slow, since
it calls getLineNumberInfo for each array element, repeating a lot of
work unnecessarily.
* integrate these APIs with `std.Progress` to understand what is taking
so long.
The output I'm seeing from this tool shows a lot of missing source
locations. In particular, the main area of interest is missing for my
tokenizer fuzzing example.
with debug info resolved.
begin efforts of providing `std.debug.Info`, a cross-platform
abstraction for loading debug information into an in-memory format that
supports queries such as "what is the source location of this virtual
memory address?"
Unlike `std.debug.SelfInfo`, this API does not assume the debug
information in question happens to match the host CPU architecture, OS,
or other target properties.
