PR [19271](https://github.com/ziglang/zig/pull/19271) added some static function implementations from kernel32, but some parts of the library still used the dynamically loaded versions.
* 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.
PR https://github.com/ziglang/zig/pull/20679 ("std.c reorganization")
switched feature-detection code to use "T != void" checks in place of
"@hasDecl". However, the std.posix.system struct is empty, so
compile-time feature detection against symbols in there (specifically
`std.posix.system.ucontext_t` in this case), fail at compile time on
freestanding targets.
This PR adds a void ucontext_t into the std.posix.system default.
This PR also adds pseudo-"freestanding" variation of the StackIterator
"unwind" test. It is sort of hacky (its freestanding, but assumes it can
invoke a Linux exit syscall), but it does detect this problem.
Fixes#20710
This prevents it from trying to access thread local storage before it
has set up thread local storage, particularly when code coverage
instrumentation is enabled.
* 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
In the case that the allocator is unavailable (OOM, etc.), we can
possibly still output the panic message - so now we stack allocate the
message and copy it to the exit data for passing to boot services.
The previous version of this function referenced the argc_argv_ptr global
variable as an inline asm operand. This caused LLVM to generate prologue code to
initialize the ToC so that the global variable can actually be accessed.
Ordinarily, there's nothing wrong with that. But _start() is a naked function!
This makes it actually super surprising that LLVM did this. It also means that
the old version only really worked by accident.
Once the reference to the global variable was removed, no ToC was set up, thus
violating the calling convention once we got to posixCallMainAndExit(). This
then caused any attempt to access global variables here to crash - namely when
setting std.os.linux.elf_aux_maybe.
The fix is to just initialize the ToC manually in _start().