sentinel slicing improvements

* add runtime safety for slicing pointers, arrays, and slices.
 * slicing without a sentinel value results in non-sentineled slice
 * improved `std.debug.panic` handling of panic-during-panic
This commit is contained in:
Andrew Kelley
2019-12-20 17:48:45 -05:00
parent 26f3c2d061
commit 8918cb06fc
6 changed files with 118 additions and 26 deletions

View File

@@ -219,7 +219,7 @@ pub fn panic(comptime format: []const u8, args: var) noreturn {
}
/// TODO multithreaded awareness
var panicking: u8 = 0; // TODO make this a bool
var panicking: u8 = 0;
pub fn panicExtra(trace: ?*const builtin.StackTrace, first_trace_addr: ?usize, comptime format: []const u8, args: var) noreturn {
@setCold(true);
@@ -230,21 +230,25 @@ pub fn panicExtra(trace: ?*const builtin.StackTrace, first_trace_addr: ?usize, c
resetSegfaultHandler();
}
if (@atomicRmw(u8, &panicking, builtin.AtomicRmwOp.Xchg, 1, builtin.AtomicOrder.SeqCst) == 1) {
// Panicked during a panic.
// TODO detect if a different thread caused the panic, because in that case
// we would want to return here instead of calling abort, so that the thread
// which first called panic can finish printing a stack trace.
os.abort();
switch (@atomicRmw(u8, &panicking, .Add, 1, .SeqCst)) {
0 => {
const stderr = getStderrStream();
stderr.print(format ++ "\n", args) catch os.abort();
if (trace) |t| {
dumpStackTrace(t.*);
}
dumpCurrentStackTrace(first_trace_addr);
},
1 => {
// TODO detect if a different thread caused the panic, because in that case
// we would want to return here instead of calling abort, so that the thread
// which first called panic can finish printing a stack trace.
warn("Panicked during a panic. Aborting.\n", .{});
},
else => {
// Panicked while printing "Panicked during a panic."
},
}
const stderr = getStderrStream();
stderr.print(format ++ "\n", args) catch os.abort();
if (trace) |t| {
dumpStackTrace(t.*);
}
dumpCurrentStackTrace(first_trace_addr);
os.abort();
}