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.
Switches from using r1 as a temporary to r2. That way, we don't have to set the
`noat` assembler option. (r1 is the scratch register used by the assembler's
pseudoinstructions; the assembler warns when code uses that register explicitly
without `noat` set.)
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.
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.
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.
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
