getContext
Capture the current context. The register values in the context will reflect the
state after the platform getcontext function returns.
It is valid to call this if the platform doesn't have context capturing support, in that case false will be returned.
Function parameters
Parameters
- context:*ThreadContext
Type definitions in this namespace
Types
- SourceLocation
- Unresolved source locations can be represented with a single `usize` that
A fully-featured panic handler namespace which lowers all panics to calls to `panicFn`.
Functions
- FullPanic
- A fully-featured panic handler namespace which lowers all panics to calls to `panicFn`.
- lockStdErr
- Allows the caller to freely write to stderr until `unlockStdErr` is called.
- lockStderrWriter
- Allows the caller to freely write to stderr until `unlockStdErr` is called.
- Print to stderr, silently returning on failure.
- dumpHex
- Tries to print a hexadecimal view of the bytes, unbuffered, and ignores any error returned.
- dumpHexFallible
- Prints a hexadecimal view of the bytes, returning any error that occurs.
- dumpCurrentStackTrace
- Tries to print the current stack trace to stderr, unbuffered, and ignores any error returned.
- dumpCurrentStackTraceToWriter
- Prints the current stack trace to the provided writer.
- copyContext
- Copies one context to another, updating any internal pointers
- relocateContext
- Updates any internal pointers in the context to reflect its current location
- getContext
- Capture the current context.
- dumpStackTraceFromBase
- Tries to print the stack trace starting from the supplied base pointer to stderr,
- captureStackTrace
- Returns a slice with the same pointer as addresses, with a potentially smaller len.
- dumpStackTrace
- Tries to print a stack trace to stderr, unbuffered, and ignores any error returned.
- assert
- Invokes detectable illegal behavior when `ok` is `false`.
- assertReadable
- Invokes detectable illegal behavior when the provided slice is not mapped
- assertAligned
- Invokes detectable illegal behavior when the provided array is not aligned
- panic
- Equivalent to `@panic` but with a formatted message.
- panicExtra
- Equivalent to `@panic` but with a formatted message, and with an explicitly
- defaultPanic
- Dumps a stack trace to standard error, then aborts.
- attachSegfaultHandler
- Attaches a global SIGSEGV handler which calls `@panic("segmentation fault");`
- inValgrind
- Detect whether the program is being executed in the Valgrind virtual machine.
Deprecated because it returns the optimization mode of the standard
Values
- runtime_safety
- Deprecated because it returns the optimization mode of the standard
- sys_can_stack_trace
- = switch (builtin.cpu.arch) { // Observed to go into an infinite loop. // TODO: Make this work. .mips, .mipsel, .mips64, .mips64el, .s390x, => false, // `@returnAddress()` in LLVM 10 gives // "Non-Emscripten WebAssembly hasn't implemented __builtin_return_address". // On Emscripten, Zig only supports `@returnAddress()` in debug builds // because Emscripten's implementation is very slow. .wasm32, .wasm64, => native_os == .emscripten and builtin.mode == .Debug, // `@returnAddress()` is unsupported in LLVM 13. .bpfel, .bpfeb, => false, else => true, }
- have_ucontext
- = posix.ucontext_t != void
- ThreadContext
- Platform-specific thread state.
- have_getcontext
- = @TypeOf(posix.system.getcontext) != void
- have_segfault_handling_support
- Whether or not the current target can print useful debug information when a segfault occurs.
- default_enable_segfault_handler
- = runtime_safety and have_segfault_handling_support
Source
Implementation
pub inline fn getContext(context: *ThreadContext) bool {
if (native_os == .windows) {
context.* = std.mem.zeroes(windows.CONTEXT);
windows.ntdll.RtlCaptureContext(context);
return true;
}
const result = have_getcontext and posix.system.getcontext(context) == 0;
if (native_os == .macos) {
assert(context.mcsize == @sizeOf(std.c.mcontext_t));
// On aarch64-macos, the system getcontext doesn't write anything into the pc
// register slot, it only writes lr. This makes the context consistent with
// other aarch64 getcontext implementations which write the current lr
// (where getcontext will return to) into both the lr and pc slot of the context.
if (native_arch == .aarch64) context.mcontext.ss.pc = context.mcontext.ss.lr;
}
return result;
}