with this rewrite we can call functions inside of
inline assembly, enabling us to use the default start.zig logic
all that's left is to implement lr/sc loops for atomically manipulating
1 and 2 byte values, after which we can use the segfault handler logic.
I was doing duplicate work with `elemOffset` multiplying by the abi size and then the `ptr_add` `genBinOp` also multiplying.
This led to having writes happening in the wrong place.
the csrs `avl` and `vtype` are considered caller-saved so it could have changed while inside of the function.
the easiest way to handle this is to just set the cached `vtype` and `avl` to null, so that the next time something
needs to set it, it'll emit an instruction instead of relying on a potentially invalid setting.
The flag makes compiler_rt and libfuzzer be in debug mode.
Also:
* fuzzer: override debug logs and disable debug logs for frequently
called functions
* std.Build.Fuzz: fix bug of rerunning the old unit test binary
* report errors from rebuilding the unit tests better
* link.Elf: additionally add tsan lib and fuzzer lib to the hash
Before, this code:
@setRuntimeSafety(false);
var arr: [38]elf.Addr = undefined;
would emit a call to memset() in the output code in Debug mode, while in all the
release modes, LLVM optimized the memset() out as expected. Emitting the call in
Debug mode is problematic in some contexts, e.g. in std.os.linux.start_pie where
we are not yet ready to correctly perform calls because relocations haven't been
applied yet, or in the early stages of a dynamic linker, etc.
The `TargetOptions` default constructor initializes all `bool`s to
`false`, yet clang defaults to setting this option to `true`. Since
recent glibc versions on linux do not appear to support this being set
to `false`, just changing the default for now unless a use case for
making it configurable is found.
* Add -f(no-)sanitize-coverage-trace-pc-guard CLI flag which defaults to
off. This value lowers to TracePCGuard = true (LLVM backend) and -Xclang
-fsanitize-coverage-trace-pc-guard. These settings are not
automatically included with -ffuzz.
* Add `Build.Step.Compile` flag for sanitize_coverage_trace_pc_guard
with appropriate documentation.
* Add `zig cc` integration for the respective flags.
* Avoid crashing in ELF linker code when -ffuzz -femit-llvm-ir used
together.
Exposes sanitizer coverage flags to the target machine emit function.
Makes it easier to change sancov options without rebuilding the C++
files.
This also enables PCTable = true for sancov which is needed by AFL, and
adds the corresponding Clang flag.
* Add the `-ffuzz` and `-fno-fuzz` CLI arguments.
* Detect fuzz testing flags from zig cc.
* Set the correct clang flags when fuzz testing is requested. It can be
combined with TSAN and UBSAN.
* Compilation: build fuzzer library when needed which is currently an
empty zig file.
* Add optforfuzzing to every function in the llvm backend for modules
that have requested fuzzing.
* In ZigLLVMTargetMachineEmitToFile, add the optimization passes for
sanitizer coverage.
* std.mem.eql uses a naive implementation optimized for fuzzing when
builtin.fuzz is true.
Tracked by #20702
